CN114810098A - Multi-cabin pipe gallery underground excavation construction method - Google Patents

Abstract

The invention discloses a multi-cabin pipe gallery underground excavation construction method which is characterized in that vertical two lining structures which are independently arranged between adjacent cabins are combined into a common vertical two lining structure to serve as a common intermediate wall between the adjacent cabins of an underground excavation pipe gallery. Among the preliminary bracing structure, the vertical preliminary bracing structure of sharing that plays supporting role between adjacent cabins is replaced by two vertical lining structures of sharing, makes two lining structures of undercut piping lane form a continuous outsourcing preliminary bracing structure outward. On the premise of meeting the underground excavation supporting conditions, the shared intermediate wall between the adjacent cabins of the underground excavation pipe gallery and the shared intermediate wall between the adjacent cabins of the open excavation pipe gallery can be kept consistent, so that the multi-cabin pipe gallery constructed by the open excavation method is directly connected with the multi-cabin pipe gallery constructed by the underground excavation method, and an intermediate wall thickness transition section is not required to be arranged.

Description

A construction method for underground excavation of multi-chamber pipe gallery

technical field

The invention relates to a construction method for underground excavation of a pipe gallery, in particular to a construction method for undercover excavation applied to a multi-cabin pipe gallery to reduce the thickness of a partition wall between adjacent cabins.

Background technique

In the construction of the pipe gallery, the construction scheme combining the open-cut method and the under-cut method is generally adopted. When the construction conditions are met, the open-cut method is generally used, that is, the foundation pit is excavated, and the pipe gallery construction is carried out in the foundation pit. After the construction of the pipe gallery in the foundation pit is completed, the foundation pit is backfilled as required; When the buildings, structures or pipelines intersect, the undercut method is generally used to penetrate the existing buildings, structures or pipelines.

Please refer to the cross-sectional view of the multi-cabin pipe gallery constructed by the open-cut method using the three-cabin pipe gallery as an example shown in Figure 2. Among the multi-cabin pipe gallery constructed by the open-cut method, the open-cut pipe gallery set between adjacent cabins The thickness of the common partition wall between adjacent cabins is generally 0.2m~0.5m. In the multi-chamber pipe gallery constructed by the underground excavation method, in order to ensure the stability of the pipe gallery structure, the pipe gallery structure mainly includes the initial support structure and the secondary lining structure. Please refer to the cross-sectional view of the multi-compartment pipe gallery with the three-chamber pipe gallery as an example shown in Figure 3. In the general underground excavation method, each cabin has an independent secondary lining structure, and the adjacent cabins Between the two vertical lining structures, the general underground excavation pipe gallery is set to share the vertical initial support structure, and the general underground excavation pipe gallery between the adjacent cabins The common partition wall between the adjacent cabins is set independently by the adjacent cabins The vertical secondary lining structure and the general underground pipe gallery share the vertical initial support structure, and the thickness is generally 0.8m~1.2m.

Since the thickness of the common partition wall between the adjacent cabins of the cut-and-cover pipe gallery is inconsistent with the thickness of the common partition wall between the adjacent cabins of the general open-cut pipe gallery, when the multi-compartment pipe gallery constructed by the cut-and-cover method is different from that of the multi-compartment constructed by the general open-cut method When the pipe galleries are connected, it is necessary to set up the thickness transition section of the partition wall in the multi-chamber pipe galleries constructed by the cut-and-cover method, so that the thickness of the common partition wall between the adjacent cabins of the open-cut pipe galleries gradually transitions to that adjacent to the general open-cut pipe galleries. The common partition wall between the cabins is consistent to ensure that the multi-compartment pipe gallery constructed by the open-cut method is in one-to-one correspondence with the multi-compartment pipe gallery of the general open-cut method, which is convenient for the open-cut method. The multi-chamber pipe gallery constructed by the excavation method is connected.

The construction process of the thickness transition section of the common partition wall set in the multi-chamber pipe gallery constructed by the open-cut method is relatively complicated, the quality control is difficult, and the construction is difficult.

SUMMARY OF THE INVENTION

The purpose of the present invention is to solve the above problems and provide a multi-chamber pipe gallery underground excavation construction method. The vertical secondary lining structure is used as the common partition wall between the adjacent cabins of the underground tunnel. The second lining structure of the bottom plate forms a closed second lining structure of the pipe gallery cabin; in the initial support structure, the common vertical initial supporting structure that plays a supporting role between adjacent cabins is replaced by the common vertical second lining structure, so that the underground excavation pipe gallery A continuous outsourcing initial support structure is formed outside the secondary lining structure. On the premise of satisfying the conditions of undercut support, the invention can make the adjacent cabins of the undercut pipe gallery share the partition wall and the adjacent cabins of the open cut pipe gallery. The shared middle partition wall is kept the same, so that the multi-chamber pipe gallery constructed by the cut-and-cover method and the multi-chamber tube gallery constructed by the undercut method are directly connected, and there is no need to set the transition section of the thickness of the middle partition wall.

The present invention mainly realizes above-mentioned purpose through following technical scheme:

A construction method for underground excavation of a multi-chamber pipe gallery, which is mainly characterized in that:

Step 1: Processing of the initial support structure of the underground tunnel and the processing of the secondary lining structural steel bar.

The material and structural form of the initial support structure are determined according to the actual geology and design requirements, which can be I-beam or steel grating. The initial support structure and secondary lining structural steel bars are pre-processed according to the design drawings.

During the conversion of the initial support structure system, the initial support structure of the rear-excavated cabin dome and the initial support structure of the rear-excavated cabin floor need to be adjacent to the first-excavated cabin vault initial support structure and the first-excavated cabin. The initial support structure of the base plate is connected.

Further, when processing the initial support structure of the dome of the first excavation cabin, the pre-buried steel plate of the initial support structure of the dome is set near the arch foot of the first excavation cabin vault near the side of the back excavation cabin. The initial support structure of the vault of the cabin excavated after the excavation is connected with the initial support structure of the vault of the adjacent first excavated cabin.

Further, when processing the initial support structure of the first excavation cabin bottom plate, the pre-embedded steel plate of the bottom plate initial support structure is arranged on the side of the first excavated cabin bottom plate close to the rear excavation cabin, which is used for the initial support of the rear excavation cabin bottom plate. The protective structure is connected with the initial supporting structure of the adjacent first excavated cabin floor.

Further, when processing the structural steel bars for the second lining of the cabin dome excavation first, the pre-buried steel plates for the second lining structural steel bar of the dome roof shall be set near the arch foot of the second excavated cabin side near the side of the second lining of the cabin excavated first. The second lining structural steel bar of the cabin dome of the rear excavated cabin is connected with the second lining structural steel bar of the adjacent first excavated cabin roof.

Further, when processing the structural steel bars for the second lining of the cabin floor excavated first, the pre-embedded steel plates for the structural steel bars of the second lining of the second lining of the cabin floor of the first excavated cabin are set near the side of the rear excavated cabin, which are used for the second lining of the second lining of the bottom excavated cabin. The structural steel bars are connected with the second lining structural steel bars of the adjacent first excavated cabin floor.

Further, it is necessary to process the initial support structure of the dome of the rear excavation cabin, the initial support structure of the bottom plate of the rear excavation cabin, the second lining of the dome of the rear excavated cabin, and the second lining of the bottom plate of the rear excavated cabin. Supporting steel bars, vertical secondary lining structural steel bars and secondary lining structural longitudinal steel bars and stirrups, and vertical initial support structures.

Further, since the vertical initial support structure between successively excavated cabins will be dismantled during the construction of the post-excavation cabin, the vertical initial support structure between successively excavated cabins needs to be set up separately to facilitate later dismantling.

It should be noted that all the cabins included in the tunnel tunnel are numbered sequentially from either end to the other end: No. 01 cabin, No. 02 cabin, No. 03 cabin... No. N cabin; among them, the odd-numbered cabins are The cabins are excavated first, and the cabins with even numbers are excavated later. For the last numbered cabins, when the number of cabins contained in the tunnel tunnel is odd, the last numbered cabin is the first excavation cabin; when the number of cabins contained in the tunnel tunnel is even, the last numbered cabin is the rear excavation cabin, which is also named as Excavate the cabin after the end. The first excavation cabin is the first excavation cabin in the construction of the underground excavation pipe gallery; the post excavation cabin is the first excavation cabin after completion of a certain depth excavation, initial support structure and secondary lining structure construction, Re-excavated cabin. The adjacent cabins of the first excavation cabin are the latter excavation cabins. When the number of cabins contained in the underground excavation pipe gallery is even, the last numbered cabin is the last excavated cabin.

Step 2: Reinforce the excavated soil before excavating the cabin of the underground tunnel.

Further, when the excavated soil is reinforced, the reinforcement measures of the excavated soil can be based on the stability of the excavated soil, and can adopt advanced pipe shed, advanced small pipe grouting, deep hole grouting or no excavation soil reinforcement.

Preferably, the excavated soil in all cabins of the tunnel tunnel should be reinforced to ensure the stability of the soil during excavation.

Step 3: First excavate the soil at the cabin and install the initial support structure.

Further, when excavating the cabin first for soil excavation, the method of excavating the cabin soil first is determined according to the stability of the excavated soil, and can adopt the full-section excavation, the step method, and the reserved core soil method.

Further, with the excavation of the first excavation cabin, according to the requirements of the initial support structure spacing in the design, the initial support structure of the first excavation cabin dome, the vertical initial support structure and the vertical initial support structure between the cabins were excavated in time. The vertical initial support structure and the vertical initial support structure between the cabins are excavated successively, and the vertical initial support structure of the adjacent longitudinally excavated cabin vaults is excavated successively. Install reinforced mesh between the vertical primary supporting structures and between the vertical primary supporting structures and excavate the primary supporting structures of the cabin vaults by spraying first, excavate successively the vertical primary supporting structures and vertical primary supporting structures between the chambers Structural concrete.

Further, after excavating the initial support structure of the cabin dome, excavating the vertical initial support structure between the cabins successively and the concrete of the vertical initial support structure to meet the design requirements, install the preliminary support structure of the cabin floor by excavating first. Install reinforced mesh between the longitudinally adjacent initial support structures of the first-excavated cabin floor and spray concrete for the initial support structure of the first-excavated cabin floor.

Preferably, in the first excavation of the cabin, first excavate the initial support structure of the cabin dome, successively excavate the vertical initial support structure between the cabins, the vertical initial support structure and the first excavation between the initial support structure of the cabin bottom plate Bolted connection.

Step 4: Level the concrete surface of the vertical initial support structure between the successive excavated cabins close to the side of the later excavated cabin.

It should be noted that the purpose of leveling the concrete surface of the vertical initial support structure between the successive excavation cabins close to the side of the rear excavation cabin is to excavate the vertical initial support structure between the cabins successively, and then excavate the cabin and the rear. The common secondary lining structure of the excavated cabins (that is, the common partition wall between the adjacent cabins of the underground excavation pipe gallery) faces the concrete surface of the rear excavated cabin to be flat, so as to ensure that the appearance quality of the secondary lining structure of the rear excavated cabin meets the requirements.

Step 5: Lay and install the pre-excavated cabin waterproof layer and the reserved overlap waterproof layer reserved for overlapping with the adjacent post-excavated cabin waterproof layer.

Further, it is necessary to reserve an overlap waterproof layer on the vault of the first excavated cabin on the side close to the rear excavated cabin for overlapping with the adjacent rear excavated cabin dome roof waterproof layer.

Further, it is necessary to reserve an overlapping waterproof layer on the bottom plate for overlapping with the waterproof layer of the bottom plate of the adjacent rear excavation cabin on the side close to the rear excavation cabin before the waterproof layer of the bottom plate of the first excavated cabin.

Preferably, the length of the reserved overlapping waterproof layer for the vault and the reserved overlapping waterproof layer for the bottom plate is 0.4m~0.8m.

Preferably, in order to save waterproof materials, the waterproof layer at the vertical initial support structure between the successively excavated cabins that needs to be removed in the subsequent construction is not laid.

Step 6: Apply mold release agent evenly on the concrete surface of the vertical initial support structure between successive excavation cabins close to the side of the rear excavated cabin.

It should be noted that the purpose of evenly applying mold release agent to the concrete surface of the vertical initial support structure between the successive excavation cabins near the rear excavation cabin is to facilitate the removal and separation of the vertical initial support structure between the successive excavation cabins.

Step 7: First excavate the secondary lining structure of the cabin to install the reinforcement and pour the concrete of the secondary lining structure.

Further, install the first excavation cabin dome second lining structural steel bar, vertical second lining structural steel bar, successively excavate the cabin common vertical second lining structural steel bar, first excavate the cabin bottom second lining structural steel bar and the second lining structure longitudinal steel bar and stirrups.

Erection of the first excavation cabin with dome double lining structure, vertical double lining structure and the common vertical double lining structure formwork for successive excavation cabins, pouring first excavation cabin with vault double lining structure, vertical double lining structure and successive excavation cabins. The excavated cabins share the vertical secondary lining structural concrete; after the first excavated cabins are installed with the vaulted secondary lining structure, the vertical secondary lining structure, and the successively excavated cabins share the vertical secondary lining structural concrete to meet the design requirements, the first excavated cabins will be removed. Install the dome-top two-lining structure, the vertical two-lining structure, and excavate the cabins to share the vertical two-lining structure formwork, and then pour the first-excavated cabin floor second-lining structure concrete, and level the first-excavated cabin bottom second-lining structure concrete surface .

Preferably, in the first excavation of the cabin, first excavate the cabin dome second lining structural steel bar, the vertical second lining structural steel bar, excavate the cabin shared vertical second lining structural steel bar first, and first excavate the cabin floor between the second lining structural steel bar Use welded connections.

Step 8: Soil excavation at the rear excavation cabin and installation of the initial support structure.

Further, the rear excavation cabin is constructed by the upper and lower steps method, and the staggered distance between the upper and lower steps is 3.0m~6.0m.

When the number of cabins in the underground tunnel is odd:

Further, when the excavation depth of the upper step is 3.0m~6.0m, the concrete protective layer at the pre-embedded steel plate of the initial support structure of the dome of the first excavation cabin adjacent to the rear excavation cabin is removed, so that the initial support of the dome can be eliminated. All the embedded steel plates of the structure leak out, and ensure that the surface of the embedded steel plates of the initial supporting structure of the vault is clean and free of debris;

Then, connect the initial support structure of the rear-excavated cabin vault with the pre-embedded steel plate of the adjacent first-excavated cabin vault support structure, and install steel mesh between the longitudinally adjacent rear-excavated cabin vault initial support structures and After spraying, excavate the concrete for the initial support structure of the cabin vault.

Further, after the concrete construction of the initial support structure of the rear excavation cabin vault is completed, the lower steps are excavated, and the concrete protection layer at the pre-embedded steel plate of the initial support structure of the first excavation cabin bottom adjacent to the rear excavation cabin is removed. , so that all the embedded steel plates of the initial supporting structure of the bottom plate leak out, and ensure that the surface of the embedded steel plates of the initial supporting structure of the bottom plate is clean and free of debris;

Then, connect the initial support structure of the back excavation cabin floor with the pre-embedded steel plate of the adjacent first excavated cabin floor support structure, install steel mesh between the initial support structures of the longitudinal adjacent back excavation cabin floor and spray the back excavation. Excavate the concrete for the initial support structure of the cabin floor.

When the number of tunnel tunnels is an even number:

Except for the rear excavation cabins at the end, the other rear excavation cabins shall be constructed according to the construction method mentioned above when the number of underground excavation pipe gallery cabins is odd.

Further, when excavating the cabin after the end for soil excavation, the soil excavation method for the cabin after the end is determined according to the stability of the excavated soil, and can adopt the full-section excavation, step method, reserved core soil method, etc. .

With the excavation of the post-excavation cabin, the initial support structure and vertical initial support structure of the dome of the post-excavation cabin should be installed in time according to the requirements of the initial support structure spacing in the design.

Further, one side of the initial support structure of the dome of the cabin excavated after the end is connected with the embedded steel plate of the initial support structure of the adjacent dome of the first excavated cabin, and the other side is connected with the upper part of the vertical initial support structure. The vertical primary support structure is temporarily reinforced by locking foot anchors. Install reinforced mesh between the initial support structure of the cabin vault and the vertical initial support structure after the longitudinal adjacent end, and spray the concrete for the initial support structure of the cabin vault and the concrete for the initial vertical support structure after the end .

Further, after the initial support structure of the cabin vault and the initial vertical support structure concrete meet the design requirements after the end of the excavation, install the initial support structure of the cabin bottom excavated after the end, and excavate the initial support structure of the cabin bottom after the end. One side is connected to the pre-embedded steel plate of the initial support structure of the adjacent first excavated cabin floor, the other side is connected to the lower part of the vertical initial support structure, and the steel bars are installed between the initial support structures of the cabin floor after excavation at the end of the longitudinal adjacent end. Excavate the initial supporting structure concrete of the cabin floor after the mesh and spray the end.

Preferably, the connection between the initial support structure of the rear excavation cabin vault and the initial support structure of the rear excavation cabin vault and the embedded steel plate of the initial support structure of the vault may be welding connection or bolt connection.

Preferably, the connection between the initial support structure of the rear excavation cabin floor and the initial support structure of the rear excavation cabin floor and the embedded steel plate of the initial support structure of the floor can be welding connection or bolt connection.

Preferably, after the excavation depth of the adjacent first-excavated cabin reaches 10.0m~15.0m, the excavation of the post-excavation cabin is started and the excavation of the post-excavation cabin is completed.

Step 9: Remove the vertical initial support structure between the successively excavated cabins.

It should be noted that the purpose of removing the vertical initial support structure between successively excavated cabins is to form a continuous overall initial support structure for the initial support structure of the underground excavation pipe gallery.

During the process of dismantling the vertical initial support structure between the successively excavated cabins, care should be taken not to damage the completed initial support structure of the dome roof of the first excavated cabin, the initial support structure of the first excavated cabin bottom plate, and the common vertical two The lining structure (that is, the common partition wall between the adjacent cabins of the underground tunnel), the lapped waterproof layer reserved for the vault and the lapped waterproof layer reserved for the bottom plate.

Step 10: Lay and excavate the waterproof layer of the cabin after installation.

Further, when laying and installing the waterproof layer of the excavated cabin after installation, the waterproof layer of the dome roof of the rear excavation cabin must be effectively overlapped with the reserved overlapping waterproof layer of the vault to ensure the waterproof effect.

Further, when laying and installing the waterproof layer of the excavated cabin after installation, the waterproof layer of the bottom plate of the rear excavated cabin must be effectively overlapped with the reserved lap waterproof layer of the bottom plate to ensure the waterproof effect.

Step 11: Reinforcement installation of the secondary lining structure of the rear excavation cabin and concrete pouring of the secondary lining structure.

When the number of cabins in the underground tunnel is odd:

Further, the concrete protective layer at the pre-embedded steel steel plate of the second lining structure of the dome of the first excavation cabin adjacent to the rear excavation cabin is removed, so that all the steel embedded steel plates of the second lining structure of the dome roof leak out, and ensure the second lining of the dome roof. The surface of the structural steel embedded steel plate is clean and free of debris;

Then, connect the second lining structural steel bar of the rear excavation cabin with the pre-embedded steel plate of the second lining structural steel bar of the adjacent first excavated cabin dome, install the longitudinal steel bars and stirrups of the second lining structure, and erect and install the rear excavation cabin vault The secondary lining structural formwork, excavate the secondary lining structural concrete of the cabin vault after pouring; after the secondary lining structural concrete of the secondary lining of the secondary lining of the post excavation cabin roof meets the design requirements, remove the secondary lining structural formwork of the secondary lining of the post excavation cabin vault.

Further, the concrete protective layer at the pre-embedded steel plate of the second lining structural steel bar on the bottom plate of the first excavation cabin adjacent to the rear excavation cabin is removed, so that all the embedded steel steel plate of the second lining structural steel bar on the bottom floor is leaked, and the pre-embedded steel steel plate of the second lining structure on the bottom floor is ensured. The surface of the buried steel plate is clean and free of debris;

Then, connect the secondary lining structural steel bars of the rear excavated cabin floor with the pre-embedded steel plates adjacent to the secondary lining structural steel bars of the first excavated cabin floor, install the longitudinal steel bars and stirrups of the secondary lining structure, and excavate the secondary lining structural concrete of the cabin floor after pouring. , and excavate the second-lined structural concrete surface of the cabin floor after leveling.

When the number of tunnel tunnels is an even number:

Except for the rear excavation cabins at the end, the other rear excavation cabins shall be constructed according to the construction method mentioned above when the number of underground excavation pipe gallery cabins is odd.

Further, install the secondary lining structural steel bar and vertical secondary lining structural steel bar of the rear excavation cabin at the end, the secondary lining structural steel bar and the secondary lining structural longitudinal steel bar and stirrup of the rear excavation cabin bottom plate.

At the end of the excavation, one side of the second lining structural steel bar of the cabin vault is connected with the pre-buried steel plate of the adjacent second lining structural steel bar of the first excavation cabin, and the other side is connected with the vertical second lining structural steel bar; One side of the lining structural steel bar is connected with the pre-embedded steel plate for the second lining structural steel bar on the bottom of the adjacent first excavated cabin, and the other side is connected with the vertical second lining structural steel bar.

After erection and installation, excavate the cabin dome secondary lining structural formwork and vertical secondary lining structural formwork, excavate the cabin dome secondary lining structural concrete and vertical secondary lining structural concrete after the end of pouring; After the lining structural concrete and the vertical secondary lining structural concrete meet the design requirements, the secondary lining structural formwork and the vertical secondary lining structural formwork of the cabin vault shall be excavated at the end of the excavation.

Then, excavate the secondary lining structural concrete of the cabin floor after the end of pouring, and level the surface of the secondary lining structural concrete of the cabin floor after the end of the excavation.

Preferably, the second lining structural steel bar of the rear excavation cabin and the second rear lining structural steel bar of the rear excavation cabin are respectively connected with the pre-embedded steel plate of the second lining structural steel roof of the dome by welding connection.

Preferably, the second lining structural steel bars of the rear excavation cabin floor and the second lining structural steel bars of the rear excavation cabin floor at the end are respectively connected with the pre-embedded steel plates of the second floor lining structural steel bars by welding connection.

The above-mentioned construction method omits the pre-conventional pre-construction preparations, necessary safety measures, quality requirements, basic techniques and operating rules during construction, which are well known to those skilled in the art.

The present invention has at least the following advantages or beneficial effects:

The invention provides a multi-cabin pipe gallery underground excavation construction method, which effectively reduces the thickness of the common partition wall between adjacent cabins of the undercover pipe gallery. Under the premise of supporting conditions, the common partition wall between the adjacent cabins of the open-cut pipe gallery can be kept consistent with the common partition wall between the adjacent cabins of the open-cut pipe gallery, so that the multi-cabin pipe gallery constructed by the open-cut method can be compared with the open-cut pipe gallery. The multi-chamber pipe gallery constructed by the method is directly connected, and there is no need to set the thickness transition section of the middle partition wall.

Description of drawings

In order to illustrate the technical solution of the present invention more clearly, the following will briefly introduce the drawings required for the present invention. It should be understood that the following drawings should not be regarded as a limitation of the scope. In other words, on the premise of no creative work, other related drawings can also be obtained from these drawings.

Fig. 1 is described multi-chamber pipe gallery underground excavation construction method flow chart;

Figure 2 is a cross-sectional view of the multi-cabin pipe gallery constructed by the open-cut method, taking the three-cabin pipe gallery as an example;

Figure 3 is a cross-sectional view of a multi-chamber pipe gallery constructed by a general underground excavation method, taking the three-cabin pipe gallery as an example;

Fig. 4 is the sectional view of the initial support structure of the underground excavation pipe gallery in Example 1;

5 is a cross-sectional view of the secondary lining structure of the underground excavation pipe gallery and the arrangement of the reinforcement bars of the secondary lining structure in Embodiment 1;

6 is a schematic diagram of the initial support structure, secondary lining structure and waterproof layer of the first excavated cabin in Example 1;

7 is a schematic diagram of the initial support structure, secondary lining structure and waterproof layer of the excavated cabin after Example 1;

8 is a schematic diagram of the initial support structure, secondary lining structure and waterproof layer of the first excavated cabin in Example 2;

9 is a schematic diagram of the initial support structure, the secondary lining structure and the waterproof layer of the post-excavation cabin and the final post-excavation cabin in Example 2.

Icons: 1- Excavate the cabin first; 11- Excavate the initial support structure of the cabin vault first; 111- Pre-embedded steel plate for the initial support structure of the vault; 12- Excavate the initial support structure of the cabin bottom plate first; 121- The initial stage of the bottom plate Pre-embedded steel plate for supporting structure; 13- First excavation of the second lining structure of the cabin dome; 131- First excavation of the second lining structure of the cabin dome; 1311 - Pre-embedded steel plate of the second lining structure of the vault; 14- First excavation of the cabin Bottom two lining structure; 141- First excavation cabin bottom two lining structural steel bars; 1411- Bottom two bottom lining structural steel bars pre-embedded steel plate; 15- First excavating cabin waterproof layer; 151- First excavating cabin dome waterproof layer; 1511- 152- First-excavation cabin bottom waterproof layer; 1521- Bottom plate reserved lap waterproof layer; 2- Rear excavation cabin; 21- Rear excavation cabin vault initial support structure; 22 - Initial support structure of the rear excavation cabin floor; 23- The second lining structure of the rear excavation cabin vault; 231- The second lining structure of the rear excavation cabin dome; 24- The second lining structure of the rear excavation cabin floor; 241 - The rear 25- Rear excavation cabin waterproof layer; 251- Rear excavation cabin dome waterproof layer; 252- Rear excavation cabin floor waterproof layer; 26- Rear excavation cabin; 261- End 262-Initial support structure of the rear excavation cabin vault; 262-Initial support structure of the rear excavation cabin bottom plate; 263-The second lining structure of the rear excavation cabin dome; 264-The second lining structure of the rear excavation cabin bottom plate;31 -Initial support structure; 311- Vertical initial support structure shared by general underground tunnels; 312- Vertical initial support structure between successively excavated cabins; 313-Vertical initial support structure; 41- Secondary lining structure; 411- Secondary lining structural steel bar; 412-Vertical secondary lining structure; 4121-Vertical secondary lining structural steel bar; 413- Secondary lining structural longitudinal steel bar and stirrup; The cabins excavated successively share the vertical secondary lining structural steel bars; the adjacent cabins of the 51-cut and cut pipe gallery share the middle partition wall.

Detailed ways

In order to make the purpose, technical solutions and advantages of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are the present invention. Some examples, but not all examples.

Thus, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but is merely representative of selected embodiments of the invention. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without creative efforts shall fall within the scope of the present invention.

It should be noted that like numerals and letters refer to like items in the following figures, so once an item is defined in one figure, it does not require further definition and explanation in subsequent figures.

In the description of the embodiments of the present invention, it should be noted that if the terms "center", "upper", "lower", "left", "right", "inner", "outer", etc. indicate the orientation or position The relationship is based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship that is conventionally placed in the invention, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must be It has a specific orientation, is constructed and operates in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first", "second", "third", etc. are only used to differentiate the description and should not be construed as indicating or implying relative importance.

In the description of the embodiments of the present invention, it should also be noted that, unless otherwise expressly specified and limited, the terms "set", "installed", "connected" and "connected" should be understood in a broad sense. It can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or a welding connection; it can be directly connected or indirectly connected through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

Example 1

The basic situation of Example 1, a certain 3-cabin pipe gallery is a trunk line integrated pipe gallery, which is an important municipal passage connecting the urban area and the airport. The pipe gallery needs to pass through a certain level of road, and the length of the undercut section is 30.0m. The cabins on both sides of the pipe gallery are power cabins and thermal cabins, and the width of the cabins is 2.0m; the middle cabin is the water signal cabin, and the width of the cabin is 3.9m; the height of the pipe gallery is 5.0m. The initial support structure (31) of the pipe gallery is a steel grating, and the concrete thickness of the initial support structure (31) is 0.25m; the thickness of the secondary lining structure (41) is 0.4m, which is shared with the adjacent cabins of the cut-and-cover pipe gallery. The thickness of the partition wall (51) is the same.

Please refer to Figure 1 and Figure 4 to Figure 7. In Embodiment 1, the cabins on both sides are the first excavation cabin (1), the middle cabin is the rear excavation cabin (2), and the construction method of the multi-chamber pipe gallery underground excavation is as follows:

Step 1: Processing of the initial support structure (31) of the buried pipe gallery and the processing of the secondary lining structural steel bar (411).

In Embodiment 1, the initial support structure (31) is a steel grating. The primary support structure (31) and the secondary lining structural steel bar (411) are pre-processed according to the design drawings.

When processing the preliminary support structure (11) of the first excavation cabin dome, the preliminary support structure of the first excavation cabin (11) is set near the arch foot of the back excavation cabin (2) side. The structural pre-embedded steel plate (111) is used to connect the initial support structure (21) of the dome of the rear excavation cabin with the initial support structure (11) of the adjacent first excavated cabin dome.

When processing the preliminary support structure (12) of the first excavation cabin floor, the pre-embedded steel plate (121) of the bottom preliminary support structure is arranged on the side of the first excavated cabin bottom preliminary support structure (12) close to the rear excavation cabin (2). It is used for connecting the initial support structure (22) of the bottom of the cabin after excavation with the preliminary support structure (12) of the bottom of the adjacent first excavated cabin.

When the structural steel bar (131) for the second lining of the cabin dome is excavated first, the second lining structure of the dome is set near the arch foot of the first excavated cabin dome second lining structural steel bar (131) near the side of the second excavated cabin (2). The steel pre-embedded steel plate (1311) is used for connecting the second lining structural steel bar (231) of the cabin dome of the rear excavation with the second lining structural steel bar (131) of the adjacent first excavated cabin dome.

When processing the second lining structural steel bar (141) of the first excavation cabin floor, the pre-embedded steel plate (1411) of the second floor second lining structural steel bar is set on the side of the first excavating cabin floor second lining structural steel bar (141) close to the rear excavation cabin (2). It is used for connecting the second lining structural steel bar (241) of the bottom excavated cabin floor with the second lining structural steel bar (141) of the adjacent first excavated cabin bottom floor.

It is also necessary to process the initial support structure (21) of the dome of the rear excavation cabin, the initial support structure of the bottom plate of the rear excavation cabin (22), the second lining supporting steel bar of the dome of the rear excavation cabin (231), and the rear excavation cabin. The bottom plate of the excavated cabin is lined with a second lining supporting steel bar (241), a vertical second lining structural steel bar (4121), a second lining structure longitudinal steel bar and stirrups (413), and a vertical initial support structure (313).

Since the vertical initial support structure (312) between the successively excavated cabins will be removed during the construction of the later excavated cabin (2), the vertical initial support structure (312) between the successively excavated cabins needs to be set separately. Easy to dismantle later.

Step 2: Reinforce the excavated soil before excavating the cabin of the underground tunnel.

When the excavated soil is reinforced, the reinforcement measures of the excavated soil are based on the stability of the excavated soil. In Example 1, deep-hole grouting is used for the reinforcement of the full-section excavated soil, and cement slurry is used for grouting in the deep-hole. , the water-cement ratio is 1:1, the depth of one grouting is 10.0m, and the grouting radius is not less than 1.5m, so as to ensure that the soil reinforcement of all cabins of the underground tunnel is completed before the soil is excavated.

Step 3: First excavate the cabin (1) for soil excavation and installation of the initial support structure (31).

In Example 1, the cabin (1) was excavated first by adopting the step method for soil excavation, and the upper and lower steps were staggered by 4.0m to 5.0m.

With the excavation of the first excavation cabin (1), according to the requirements of the initial design support structure (31) spacing, install the first excavation cabin dome preliminary support structure (11) in time, and successively excavate the vertical preliminary support between the cabins The structure (312) and the vertical initial support structure (313) are temporarily reinforced with locking anchor rods. Reinforcement mesh is installed and sprayed between the adjacent first-excavated cabin vault initial support structures (11), the successively excavated vertical initial support structures (312) and vertical initial support structures (313) First, excavate the initial support structure (11) of the cabin vault, and then excavate the concrete of the vertical initial support structure (312) and the vertical initial support structure (313) between the cabins successively.

After excavating the preliminary support structure (11) of the cabin vault, excavating the vertical preliminary support structure (312) and vertical preliminary support structure (313) between the cabins successively to meet the design requirements, the first excavation cabin is installed. As for the initial support structure (12) of the bottom plate, a steel mesh sheet is installed between the longitudinally adjacent preliminary support structures (12) of the cabin bottom plate which are excavated first, and concrete is sprayed for the preliminary support structure (12) of the first excavated cabin bottom plate.

In the first excavation of the cabin (1), the preliminary support structure (11) of the cabin dome is excavated first, the vertical preliminary support structure (312), the vertical preliminary support structure (313), and the Bolt connection is adopted between the initial support structures (12) of the bottom plate of the excavated cabin.

Step 4: Leveling the concrete surface of the vertical initial support structure (312) between the successive excavation cabins close to the side of the rear excavation cabin (2).

Step 5: Lay and install a pre-excavated cabin waterproof layer (15) and a reserved overlap waterproof layer reserved for overlapping with the adjacent rear-excavated cabin waterproof layer (25).

It is necessary to reserve the lap joint of the vault on the side close to the rear excavation cabin (2) for overlapping with the vault waterproof layer (251) of the adjacent rear excavation cabin. Waterproof layer (1511).

It is necessary to reserve the lap waterproof layer ( 1521).

The length of the reserved overlapping waterproof layer (1511) for the vault and the reserved overlapping waterproof layer (1521) for the bottom plate is 0.5m~0.6m.

In order to save waterproof materials, the waterproof layer at the vertical initial support structure (312) between the successive excavation cabins that needs to be removed in the subsequent construction is not laid.

Step 6: Evenly apply release agent on the concrete surface of the vertical initial support structure (312) between the successive excavation cabins near the side of the rear excavation cabin (2).

Step 7: First, excavate the reinforcement bars (411) of the cabin secondary lining structure and install the concrete for the secondary lining structure (41).

Install the double lining structural steel bar (131) for the first excavation of the cabin dome, the vertical second lining structural steel bar (4121), the common vertical second lining structural steel bar (4141) for excavating the cabin first, and the second lining structural steel bar for the second lining of the cabin floor ( 141) and the longitudinal reinforcement and stirrups (413) of the secondary lining structure.

Erection the first-excavated cabin with dome secondary lining structure (13), the vertical secondary lining structure (412), and the successively excavated cabins share the vertical secondary lining structure (414) formwork, and pour the first-excavated cabin with vaulted secondary lining Structure (13), vertical secondary lining structure (412) and successively excavated cabins share vertical secondary lining structure (414) concrete; 412) and successively excavated cabins sharing the vertical secondary lining structure (414) After the concrete meets the design requirements, dismantle the first excavated cabin to install the dome secondary lining structure (13), the vertical secondary lining structure (412) and the successively excavated cabins The vertical secondary lining structure (414) formwork is shared, and then the concrete of the secondary lining structure (14) of the cabin floor is excavated first, and the concrete surface of the secondary lining structure (14) of the cabin floor is leveled.

In the first excavation of the cabin (1), the second lining structural steel bar (131) and the vertical second lining structural steel bar (4121) of the cabin dome are excavated first. Welding connection is adopted between the second lining structural steel bars (141) of the bottom plate of the excavated cabin.

Step 8: The soil excavation at the rear excavation cabin (2) and the installation and construction of the initial support structure (31).

In Example 1, the rear excavation cabin (2) is constructed by the upper and lower steps method, and the staggered distance between the upper and lower steps is 4.0m~5.0m.

In Example 1, the number of cabins in the underground tunnel is 3, which is an odd number.

When the excavation depth of the upper step is 4.0m~5.0m, the concrete protective layer at the pre-embedded steel plate (111) of the initial support structure of the vault shall be removed by chiseling and removing the adjacent first-excavated cabin (1) to the rear-excavated cabin (2). Make all the embedded steel plates (111) of the initial support structure of the vault leak out, and ensure that the surface of the embedded steel plates (111) of the initial support structure of the vault is clean and free of debris;

Then, connect (111) the initial support structure (21) of the vault of the rear-excavated cabin with the embedded steel plate of the adjacent first-excavated cabin (1) vault support structure, and at the initial stage of the vault of the adjacent rear-excavated cabin in the longitudinal direction Reinforcing steel mesh sheets are installed between the supporting structures (21) and the concrete for the initial supporting structure (21) of the cabin vault is excavated after spraying.

After the concrete construction of the initial support structure (21) of the vault of the rear excavation cabin is completed, the lower step excavation is carried out, and the first excavation cabin (1) adjacent to the rear excavation cabin (2) is removed and the initial support structure of the bottom plate is pre-buried The concrete protective layer at the steel plate (121) makes all the embedded steel plates (121) of the initial support structure of the base plate leak out, and ensures that the surface of the embedded steel plates (121) of the initial support structure of the base plate is clean and free of debris;

Then, connect the initial support structure (22) of the bottom plate of the rear excavation cabin to the pre-embedded steel plate (121) of the bottom support structure of the adjacent first excavated cabin (1). (22) Install reinforcement mesh and excavate the initial support structure (22) concrete of the cabin floor after spraying.

The connection method between the initial support structure (21) of the rear excavation cabin vault and the embedded steel plate (111) of the initial support structure of the vault is welding connection.

The connection between the initial support structure (22) of the bottom plate of the rear excavation cabin and the embedded steel plate (121) of the initial support structure of the bottom plate is a welding connection.

After the adjacent first excavation cabin (1) reaches a depth of 12.0m, the excavation of the rear excavation cabin (2) starts.

Step 9: Remove the vertical initial support structure (312) between the successively excavated cabins.

Step 10: Lay the waterproof layer (25) of the excavated cabin after installation.

When laying and installing the post-excavation cabin waterproof layer (25), the post-excavation cabin dome waterproof layer (251) must be effectively overlapped with the dome reserved lap waterproof layer (1511) to ensure the waterproof effect.

When laying the waterproof layer (25) of the excavated cabin after installation, the waterproof layer (252) of the bottom plate of the rear excavated cabin must be effectively overlapped with the reserved lap waterproof layer (1521) of the bottom plate to ensure the waterproof effect.

Step 11: Installation of the rebar (411) for the secondary lining structure of the rear excavation cabin and concrete pouring for the secondary lining structure (41).

In Example 1, the number of cabins in the underground tunnel is 3, which is an odd number.

Chisel off the concrete protective layer at the first excavated cabin (1) adjacent to the rear excavation cabin (2) at the pre-buried steel steel plate (1311) of the secondary lining structure of the vault, so that the pre-buried steel steel plate (1311) of the secondary lining structure of the vault will be removed. All leakage, and ensure that the surface of the embedded steel plate (1311) of the second lining structure of the vault is clean and free of debris;

Then, connect the rebar (231) of the second lining structure of the rear excavated cabin with the pre-embedded steel plate (1311) of the second lining structural steel of the adjacent first excavated cabin (1), and install the longitudinal steel bars and stirrups of the second lining structure (413), erect and install the template of the second lining structure (23) of the excavated cabin dome, pour the concrete of the second lining structure of the second lining of the cabin dome (23) after pouring; After the design requirements are met, the template for the second lining structure (23) of the cabin dome is removed and excavated.

Chisel off the concrete protective layer at the first excavation cabin (1) adjacent to the rear excavation cabin (2) at the pre-embedded steel plate (1411) of the second floor lining structure, so that all the pre-buried steel plates (1411) of the second floor lining structure are leaked , and ensure that the surface of the pre-embedded steel plate (1411) for the second lining structure of the bottom plate is clean and free of debris;

Then, connect the secondary lining structural steel bars (241) of the rear excavated cabin with the pre-embedded steel plates (1411) of the adjacent first excavated cabin (1) floor, and install the secondary lining structural longitudinal steel bars and stirrups (413). ), excavate the concrete of the secondary lining structure (24) of the cabin floor after pouring, and excavate the concrete surface of the secondary lining structure (24) of the cabin floor after leveling.

The connection mode of the second lining structural steel bar (231) of the rear excavation cabin and the pre-embedded steel plate (1311) of the second lining structural steel bar of the vault is the welding connection.

The connection mode of the second lining structural steel bar (241) of the rear excavation cabin and the pre-embedded steel plate (1411) of the second lining structural steel reinforcing bar of the floor is welding connection.

Example 2

The basic situation of Example 2, a 4-cabin pipe gallery passes through a certain river, and the width of the 4 cabins is 2.0m, including 2 power cabins, 1 water signal cabin and 1 spare cabin, and the height of the buried pipe gallery is 4.5m . The initial supporting structure of the pipe gallery is I-beam, the concrete thickness of the initial supporting structure (31) is 0.3m; the thickness of the secondary lining structure is 0.4m, and the thickness of the partition wall (51) is shared with the adjacent cabins of the cut-and-cut pipe gallery. Consistent. The total length of the underground tunnel is 50.0m. The excavation soil reinforcement measures adopt advanced pipe shed.

Please refer to Figure 1 and Figure 8 to Figure 9. In Example 2, all the cabins included in the underground excavation pipe gallery are sequentially numbered from the left end to the right end as No. 01 cabin, No. 02 cabin, No. 03 cabin and No. 04 cabin, wherein, No. 01 cabin and No. 03 cabin are opened first. The excavation cabin (1), the No. 02 cabin is the rear excavation cabin (2), and the 04 cabin is the rear excavation cabin (26). The construction method for underground excavation of the multi-cabin pipe gallery is as follows:

Please refer to the construction method described in Example 1 for the construction methods of No. 01 cabin, No. 02 cabin and No. 03 cabin. The different parameters in each step are:

Step 1: Processing of the initial support structure (31) of the buried pipe gallery and the processing of the secondary lining structural steel bar (411).

In Example 2, the initial support structure (31) is an I-beam.

Step 2: Reinforce the excavated soil before excavating the tunnel cabin.

In Example 2, the full-section excavated soil was reinforced with an advanced pipe shed.

Step 3: First excavate the soil at the cabin (1) and install the initial support structure (31).

In Example 2, the cabin (1) was excavated first by adopting the step method for soil excavation, and the upper and lower steps were staggered by 3.0m to 4.0m.

Step 5: Lay and install a pre-excavated cabin waterproof layer (15) and a reserved overlap waterproof layer reserved for overlapping with the adjacent rear-excavated cabin waterproof layer (25).

In Embodiment 2, the length of the reserved overlapping waterproof layer (1511) for the vault and the reserved overlapping waterproof layer (1521) for the bottom plate is 0.6 m to 0.7 m.

Step 8: The soil excavation at the rear excavation cabin (2) and the installation and construction of the initial support structure (31).

In Example 2, the rear excavation cabin (2) is constructed by using the upper and lower steps method, and the staggered distance between the upper and lower steps is 3.0m~4.0m.

In Embodiment 2, the connection method between the initial support structure (21) of the rear-excavated cabin dome and the embedded steel plate (111) of the initial support structure of the dome is bolt connection.

In Embodiment 2, the connection mode of the initial support structure (22) of the back excavation cabin floor and the embedded steel plate (121) of the initial support structure of the floor is bolt connection.

In Example 2, after the excavation depth of the adjacent first excavation cabin (1) reaches 10.0 m, the excavation of the rear excavation cabin (2) is started.

Since the number of cabins in the underground excavation pipe gallery in Example 2 is 4, which is an even number, for the rear excavation cabin (26) at the end, steps 8 and 11 include the following contents:

Step 8: The soil excavation at the rear excavation cabin (2) and the installation and construction of the initial support structure (31).

In Example 2, the number of cabins in the underground tunnel is 4, which is an even number.

After the end of the excavation of the cabin (26), the soil excavation adopts the step method. Following the excavation of the post-excavation cabin (26), install the post-excavation cabin dome preliminary support structure (261) and vertical preliminary support structure (313) in time according to the requirements of the initial design support structure spacing.

One side of the preliminary support structure (261) of the dome of the cabin excavated after the end is connected with the embedded steel plate (111) of the preliminary support structure of the adjacent first excavated cabin (1), and the other side is connected with the vertical preliminary support structure (313) Upper connection. The vertical primary support structure (313) is temporarily reinforced with locking foot anchors. Install steel mesh between the initial support structure (261) and vertical initial support structure (313) of the cabin vault after the longitudinal adjacent end and excavate the initial support structure (261) of the cabin vault after spraying the end. Concrete and vertical primary support structure (313) Concrete.

After the end of the excavation, the initial support structure (261) and vertical initial support structure (313) of the cabin dome meet the design requirements, and then the initial support structure (262) of the cabin bottom plate will be excavated after the end of installation, and then excavated after the end of the installation. One side of the preliminary support structure (262) of the cabin floor is connected with the embedded steel plate (121) of the preliminary support structure of the adjacent first excavated cabin (1), and the other side is connected with the lower part of the vertical preliminary support structure (313). Install reinforced mesh between the longitudinally adjacent initial support structures (262) of the rear excavation cabin floor and spray concrete for the initial support structure (262) of the rear end excavation cabin floor.

The connection method of the initial support structure (261) of the cabin vault after the end of the excavation and the embedded steel plate (111) of the initial support structure of the vault is bolt connection.

The connection method between the initial support structure (262) of the cabin floor after the end excavation and the embedded steel plate (121) of the initial support structure of the floor is bolt connection.

Step 11: Reinforcement (411) of the secondary lining structure is installed in the rear excavation cabin (2) and concrete is poured for the secondary lining structure (41).

In Example 2, the number of cabins in the underground tunnel is 4, which is an even number.

Install the rear excavation cabin dome secondary lining structure (263) steel bar, vertical secondary lining structural steel bar (4121), the end rear excavation cabin bottom secondary lining structure (264) steel bar and the secondary lining structure longitudinal steel bar and stirrup (413) ).

At the end of the excavation cabin dome secondary lining structure (263), one side of the steel bar is connected with the pre-embedded steel plate (1311) of the adjacent first excavated cabin (1) dome secondary lining structural steel bar, and the other side is connected with the vertical secondary lining structural steel bar (4121) Connection; at the end, the second lining structure of the cabin bottom excavated at the end (264) One side of the steel bar is connected with the pre-embedded steel plate (1411) of the second lining structure of the adjacent first excavation cabin (1), and the other side is connected with the vertical two Lining structural steel bar (4121) connection.

After erection and installation, excavate the formwork of the secondary lining structure of the cabin dome (263) and the formwork of the vertical secondary lining structure (412), and excavate the secondary lining structure of the cabin dome after the pouring (263) Concrete and vertical secondary lining structure (412) ) concrete; after the final excavation of the secondary lining structure of the cabin dome (263) and the concrete of the vertical secondary lining structure (412) meet the design requirements, remove the formwork and vertical secondary lining structure (263) of the secondary lining structure of the dome excavated after the end of the excavation To the second liner structure (412) template.

Then, the concrete of the secondary lining structure ( 264 ) of the second lining structure of the cabin bottom excavated after the end is poured, and the concrete surface of the secondary lining structure ( 264 ) of the second lining structure of the second lining structure of the cabin floor after the final excavation is leveled.

The connection between the rebar of the second lining structure of the dome (263) and the pre-embedded steel plate (1311) of the second lining structure of the dome after the excavation at the end is by welding.

The connection between the steel bars of the second lining structure (264) of the cabin floor after the end excavation and the pre-embedded steel plates (1411) of the second lining structure of the floor is welded connection.

The above-mentioned embodiment 1 and embodiment 2 omit the pre-conventional pre-construction preparations, necessary safety measures, quality requirements, basic technology and operation rules in the construction process that are well known to those skilled in the art.

The above are only preferred embodiments of the present invention, and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims (5)

1. A multi-cabin pipe gallery underground excavation construction method is characterized by comprising the following main construction steps:

step 1: processing a preliminary bracing structure (31) of the underground excavated pipe gallery and processing a secondary lining structural steel bar (411);

step 2: before the underground pipe gallery cabin is excavated, reinforcing an excavated soil body;

and step 3: firstly, excavating soil at the excavation cabin (1) and installing and constructing a primary supporting structure (31);

and 4, step 4: leveling the concrete surface of the vertical primary supporting structure (312) between the successively excavated cabins, which is close to the side of the rear excavated cabin (2);

and 5: paving and installing a pre-excavated cabin waterproof layer (15) and reserving a reserved lapping waterproof layer for lapping with an adjacent post-excavated cabin waterproof layer (25);

step 6: uniformly smearing a release agent on the concrete surface of the vertical primary support structure (312) between the successively excavated cabins, which is close to the rear excavated cabin (2);

and 7: firstly, excavating a cabin second lining structural steel bar (411) for installation and pouring concrete of a second lining structure (41);

and 8: excavating soil at the rear excavation cabin (2) and installing and constructing a primary supporting structure (31);

and step 9: dismantling a vertical primary supporting structure (312) between successively excavated cabins;

step 10: a cabin waterproof layer (25) is excavated after the installation;

step 11: and (3) installing second lining structural steel bars (411) of the rear excavation cabin and pouring concrete of the second lining structure (41).

2. The multi-cabin pipe gallery underground excavation construction method according to claim 1, wherein in the step 1:

arranging a pre-buried steel plate (111) of the arch crown primary support structure near an arch foot of the side of the rear excavation cabin (2) of the first excavation cabin arch crown primary support structure (11), and connecting the rear excavation cabin arch crown primary support structure (21) with the adjacent first excavation cabin arch crown primary support structure (11);

arranging a bottom plate primary supporting structure embedded steel plate (121) on the side, close to the rear excavation cabin (2), of the front excavation cabin bottom plate primary supporting structure (12), and connecting the rear excavation cabin bottom plate primary supporting structure (22) with the adjacent front excavation cabin bottom plate primary supporting structure (12);

arranging a vault secondary lining structural steel bar embedded steel plate (1311) near an arch foot of the side of the back excavation cabin (2) close to the vault secondary lining structural steel bar (131) of the vault of the first excavation cabin, and connecting the vault secondary lining structural steel bar (231) of the back excavation cabin with the adjacent vault secondary lining structural steel bar (131) of the first excavation cabin;

arranging a bottom plate secondary lining structural steel bar embedded steel plate (1411) at the side of the primary excavation cabin bottom plate secondary lining structural steel bar (141) close to the secondary excavation cabin (2), wherein the bottom plate secondary lining structural steel bar (241) is used for connecting the secondary excavation cabin bottom plate secondary lining structural steel bar (141) with the adjacent primary excavation cabin bottom plate secondary lining structural steel bar (141);

vertical primary supporting structures (312) among the successively excavated cabins need to be arranged independently, and later-stage dismantling is facilitated.

3. The multi-cabin pipe gallery underground excavation construction method according to claim 1, wherein in the step 5:

a vault reserved lapping waterproof layer (1511) for lapping with an adjacent back excavation cabin vault waterproof layer (251) is reserved on the side, close to the back excavation cabin (2), of the first excavation cabin vault waterproof layer (151);

a bottom plate reserved lapping waterproof layer (1521) for lapping with an adjacent rear excavation cabin bottom plate waterproof layer (252) is reserved on the side, close to the rear excavation cabin (2), of the first excavation cabin bottom plate waterproof layer (152);

waterproof layers which need to be dismantled in subsequent construction and are arranged at the vertical primary supporting structures (312) between the excavated cabins are not laid.

4. The method for multi-cabin pipe gallery underground excavation construction according to claim 1, wherein in the step 8:

the rear excavation cabin (2) is constructed by adopting an up-and-down step method;

when the secretly dig piping lane cabin number is the odd:

when the excavation depth of the upper step is 3.0-6.0 m, chiseling a concrete protective layer at the pre-buried steel plate (111) of the arch crown primary support structure of the pre-excavated cabin (1) adjacent to the post-excavated cabin (2), so that all the pre-buried steel plates (111) of the arch crown primary support structure are leaked out, and the surface of the pre-buried steel plates (111) of the arch crown primary support structure is clean and free of impurities;

then, connecting (111) the post-excavation cabin vault primary support structure (21) with the pre-buried steel plates of the vault support structures of the adjacent pre-excavation cabins (1), installing reinforcing steel meshes between the longitudinally adjacent post-excavation cabin vault primary support structures (21), and excavating the cabin vault primary support structure (21) concrete after spraying;

after the concrete construction of the post-excavation cabin vault primary support structure (21) is completed, performing lower bench excavation, chiseling a concrete protective layer at a position, adjacent to the post-excavation cabin (2), of a pre-embedded steel plate (121) of a bottom plate primary support structure of the pre-excavation cabin (1), so that the pre-embedded steel plate (121) of the bottom plate primary support structure is completely leaked out, and the surface of the pre-embedded steel plate (121) of the bottom plate primary support structure is ensured to be clean and free of impurities;

then, connecting the post-excavation cabin bottom plate primary supporting structures (22) with the embedded steel plates (121) of the bottom plate supporting structures of the adjacent pre-excavation cabins (1), installing reinforcing steel meshes between the longitudinally adjacent post-excavation cabin bottom plate primary supporting structures (22), and excavating the cabin bottom plate primary supporting structures (22) after spraying concrete;

when the secretly dig piping lane cabin number is the even number:

except the rear excavation cabins (26) at the end, constructing other rear excavation cabins (2) according to the construction method when the number of the underground excavation pipe gallery cabins is odd;

installing a final excavation cabin vault primary support structure (261) and a vertical primary support structure (313) in time according to the requirement of the designed primary support structure distance along with the final excavation cabin (26) excavation;

one side of the post-excavation cabin vault primary support structure (261) is connected with the embedded steel plate (111) of the vault primary support structure of the adjacent pre-excavation cabin (1), and the other side of the post-excavation cabin vault primary support structure is connected with the upper part of the vertical primary support structure (313); a vertical primary supporting structure (313) is temporarily reinforced by adopting a locking pin anchor rod; installing reinforcing mesh sheets between primary supporting structures (261) of the excavated cabin vault after the longitudinal adjacent tail and between primary vertical supporting structures (313), and spraying concrete of the primary supporting structures (261) of the excavated cabin vault after the tail and concrete of the primary vertical supporting structures (313);

after the tail excavation cabin vault primary support structure (261) and the vertical primary support structure (313) reach the design requirements, the cabin bottom plate primary support structure (262) is excavated after the installation tail, one side of the cabin bottom plate primary support structure (262) is connected with the embedded steel plate (121) of the primary support structure of the bottom plate of the adjacent first excavation cabin (1), the other side of the cabin bottom plate primary support structure is connected with the lower part of the vertical primary support structure (313), and reinforcing mesh sheets are installed between the longitudinally adjacent tail excavation cabin bottom plate primary support structures (262) and the cabin bottom plate primary support structure (262) is excavated after the spraying tail.

5. The method for multi-cabin pipe gallery underground excavation construction according to claim 1, wherein in the step 11:

when the secretly dig piping lane cabin number is the odd:

chiseling a concrete protective layer at a vault secondary-lining structure steel bar embedded steel plate (1311) of a vault of a first excavation cabin (1) adjacent to a later excavation cabin (2), so that the vault secondary-lining structure steel bar embedded steel plate (1311) is completely leaked out, and the surface of the vault secondary-lining structure steel bar embedded steel plate (1311) is ensured to be clean and free of impurities;

secondly, connecting the post-excavation cabin vault secondary lining structure steel bars (231) with the adjacent pre-embedded steel plates (1311) of the pre-excavation cabin (1) vault secondary lining structure steel bars, installing secondary lining structure longitudinal steel bars and stirrups (413), erecting a post-excavation cabin vault secondary lining structure (23) template, and excavating cabin vault secondary lining structure (23) concrete after pouring; after the concrete of the secondary lining structure (23) of the arch top of the excavated cabin reaches the design requirement, removing the template of the secondary lining structure (23) of the arch top of the excavated cabin;

chiseling a concrete protective layer at a position, adjacent to the rear excavation cabin (2), of a pre-excavation cabin (1) and a pre-buried steel plate (1411) of a second-lining structural steel bar of a bottom plate, so that the pre-buried steel plate (1411) of the second-lining structural steel bar of the bottom plate is completely leaked out, and the surface of the pre-buried steel plate (1411) of the second-lining structural steel bar of the bottom plate is clean and free of impurities;

secondly, connecting the post-excavation cabin bottom plate secondary lining structural steel bars (241) with the adjacent pre-embedded steel plates (1411) of the pre-excavation cabin (1) bottom plate secondary lining structural steel bars, installing the secondary lining structural longitudinal steel bars and the stirrups (413), excavating the cabin bottom plate secondary lining structure (24) concrete after pouring, and excavating the concrete surface of the cabin bottom plate secondary lining structure (24) after leveling;

when the secretly dig piping lane cabin number is the even number:

except the rear excavation cabins (26) at the end, constructing other rear excavation cabins (2) according to the construction method when the number of the underground excavation pipe gallery cabins is odd;

mounting reinforcing steel bars of a post-ending excavated cabin vault secondary lining structure (263), vertical secondary lining structural reinforcing steel bars (4121), post-ending excavated cabin base plate secondary lining structure (264) reinforcing steel bars, longitudinal reinforcing steel bars of the secondary lining structure and stirrups (413);

one side of a steel bar of a post-tail excavation cabin vault secondary lining structure (263) is connected with an adjacent pre-excavation cabin (1) vault secondary lining structure steel bar embedded steel plate (1311), and the other side of the steel bar is connected with a vertical secondary lining structure steel bar (4121); after the end, one side of the steel bar of the two-lining structure (264) of the bottom plate of the excavated cabin is connected with the embedded steel plate (1411) of the two-lining structure steel bar of the bottom plate of the adjacent excavated cabin (1) firstly, and the other side of the steel bar is connected with the two vertical-lining structure steel bar (4121).

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