CN106759463A - A kind of hypogee and its construction method - Google Patents

Abstract

What the present invention proposes is a kind of underground building and its construction method, and the bottom of its peripheral load-bearing wall 1 is provided with track, and during construction, the chain cutter for excavating rock and soil is installed on the track, and the chain cutter consists of a chain and a cutter fixed on the chain Composition, the chain cutter and the transmission device constitute the chain excavation device, the transmission device is located above the ground and consists of a sprocket and a driving device, etc., the driving device drives the chain cutter, and the chain cutter runs along the track, and the cutter at the bottom of the wall 1 excavates rock and soil, The chain cutter running upwards from the bottom brings the excavated rock and soil to the top, and the chain cutter at the bottom of the wall 1 and the wall 1 descend together. Advantages: It overcomes the defects of the existing technology. It can be prefabricated in blocks in the factory, or it can be poured and lowered in the fixed formwork on site. The construction is simple; the wall and the roof are used to form a water-retaining cofferdam. The rock and soil inside the building are removed, and the floor or bottom slab is poured; in addition, the construction period of the wall itself is short and the cost is low.

Description

A kind of underground building and its construction method

technical field

The invention relates to an underground building and its construction method, belonging to the technical field of civil engineering foundation construction.

Background technique

Existing underground building construction generally adopts the method of integral excavation, and foundation pit support generally adopts slope setting, slope reinforcement, pile row and underground diaphragm wall technology. The construction method of slope grading and slope reinforcement has the problems of large excavation area, high requirements on the surrounding environment, and difficulty in drainage of the foundation pit; the excavation of the foundation pit using row pile support requires prefabricated row piles, which will affect the bottom soil The requirements are high, the amount of supporting work is huge, and the safety factor is low; the excavation after the underground diaphragm wall is used, the underwater construction quality in the tank is difficult to control and detect, the construction period is long, and the interface between the tank sections is difficult to construct and easy to seepage .

Contents of the invention

What the present invention proposes is an underground building and its construction method, and its purpose aims at overcoming the defect existing in the prior art. Its main advantages: use the wall and roof to form a water retaining cofferdam, and form a dry construction environment after drainage, and then remove the rock and soil inside the building in the dry environment, and pour the floor or bottom slab; in addition, the construction period of the wall itself is short , low cost and simple construction.

Technical solution of the present invention: The bottom of the load-bearing wall 1 around the underground building is equipped with a track. During construction, a chain cutter for excavating rock and soil is installed on the track. The chain cutter is composed of a chain and a cutter fixed on the chain. The chain cutter and transmission The device constitutes a chain excavation device. The transmission device is located above the ground and consists of a sprocket and a driving device. The driving device drives the chain cutter, and the chain cutter runs along the track. The cutter at the bottom of the wall 1 digs rock and soil, and the chain running from the bottom upward The knife brings the excavated rock and soil to the top, and the chain knife at the bottom of the wall 1 and the wall 1 descend together.

The prefabrication method is divided into the following steps:

1) Block or integral prefabricated wall 1 in the workshop;

2) Transport to the on-site assembled wall 1 and squat down, and install the chain knife on the track at the bottom;

3) Install chain drives and other devices, and connect the chains with excavating knives;

4) Drive the chain, and the chain knife excavates the rock and soil at the bottom, and sends it to the top through the rock and soil conveying device, and the wall 1 descends accordingly;

5) Wall 1 is lowered to the design depth and grouted after the chain knife is removed.

Except for the prefabricated bottom, wall 1 is poured in the fixed formwork on site. The fixed formwork does not move during construction. With the excavation of the bottom rock and soil, wall 1 sinks while being poured; The bottom rail is fixedly connected with the bottom of the wall 1; the bottom of the middle frame is connected with the prefabricated bottom of the wall 1, the top of the middle frame is connected with the upper device, and the chain running is installed in the middle frame. The track and the middle frame are also part of the reinforcement cage of wall 1; the chain vertical conveyor of rock and soil is formed by the chain running upwards from the bottom and the closed cavity of the middle frame. With the sinking of the bottom of wall 1, the middle frame It also sinks synchronously; the upper device is fixed on the working platform or on the top of the middle frame, the upper device is equipped with a chain drive device and a tensioning device, and the chain on the bottom track passes through the middle frame and the drive device in the upper device, tensioning device The devices are connected; the specific construction is divided into the following steps:

1) Clean up the site and build a working platform;

2) Squat at the bottom of wall 1, and install a chain knife on the track at the bottom;

3) Assemble the middle frame, upper device and pouring formwork;

4) Install the chain driving device and the tensioning device, and connect the bottom track, the middle frame, and the chain knife of the upper device into one body to form a chain excavating device;

5) Make reinforcement cages and pour concrete in formwork;

6) Drive the chain, the chain knife excavates the rock and soil at the bottom of the wall 1, and transports the excavated rock and soil to the top through the middle frame, and the wall 1 descends accordingly;

7) As the bottom of wall 1 descends, wall 1 in the formwork descends while pouring;

8) The wall 1 is lowered to the design depth, the chain knife is removed, grouted, and the pouring formwork is removed.

The present invention has the advantages of overcoming the defects of the prior art, because the wall itself has an excavating device, so it can be prefabricated in blocks in the factory, or it can be lowered while pouring in the fixed formwork on site, and the construction is simple; using the wall and The top cover constitutes a water-retaining cofferdam, and after drainage, a dry construction environment is formed, and then the rock and soil inside the building are removed in the dry environment, and the floor or bottom slab is poured; in addition, the construction period of the wall itself is short and the cost is low.

Description of drawings

Fig. 1 is a schematic diagram of the structure of the wall 1, and also a schematic diagram of the structure of the chain excavation device 2 when excavating the rock and soil at the bottom of the foundation. Schematic diagram of the structure of the driving device 2-1-1, the sprocket 2-1-2 and the tensioning device 2-1-3 of 2-1;

Fig. 2 is the A direction view of Fig. 1;

Fig. 3 is a B-B sectional view of Fig. 1, and it is also a structural schematic diagram of the chain knife 3 excavating rock and soil at the bottom of the foundation and horizontally transporting the rock and soil, and also a mud pipeline 6 is provided in the wall 1, and the end of the pipeline 6 is a nozzle 6 Schematic diagram of the structure of -1;

Fig. 4 is the C-C sectional view of Fig. 1, also is the structural representation of the vertical rock and earth conveying device 7 that is made up of chain knife 3 and side cover 1-3;

Fig. 5 is a schematic diagram of the structure of the chain knife 3, (a) is a schematic diagram of the structure of the chain 3-1 and the knife 3-2, which is also composed of A ten-byte 3-1-1 and B ten-byte 3-1-2 The schematic diagram of the ten-byte structure of the chain 3-1; it is also the schematic diagram of the space bending realized by the chain 3-1. (b) is a schematic structural diagram of a chain knife composed of a rope 3-1B and a cutter 3-2B; it is also a schematic structural diagram of a rope 3-1B and a cutter 3-2B;

Fig. 6 is the A method construction schematic diagram of wall 1;

Fig. 7 is a schematic diagram of the B-method construction of the wall 1, which is also a schematic structural diagram of the bottom rail B-1 and the pouring formwork B-4, and is a structural schematic diagram of the upper device B-3 fixed on the working platform without lifting;

Fig. 8 is a view from direction A of Fig. 7, and is also a structural schematic diagram of the middle frame B-2 and the upper device B-3;

A in Fig. 9 is a schematic diagram of the initial state during method B construction, and it is also a schematic diagram of the structure of the upper device B-3 fixed on the top of the middle frame B-2, and b is a schematic diagram of the excavation at the bottom and the pouring of the upper part;

c in Figure 10 is a schematic diagram of method B construction when the foundation 1 sinks to a certain depth, and d is a schematic diagram of the construction equipment removed after the foundation 1 reaches the design depth;

Fig. 11 is a structural schematic diagram of a load-bearing wall 1 around a subway station or a multi-storey building, and is also a structural schematic diagram in which the surrounding walls are embedded in each other;

Fig. 12 is the A-A view of Fig. 11, which is also a schematic diagram of the load-bearing walls 1 on both sides of the subway station and the tunnel after reaching the design depth, and also the position of the interface between the retaining walls 1-4 on the wall 1 and the corresponding floor slabs on the wall 1 Schematic diagram of the structure of prefabricated grooves 1-7;

Fig. 13 is the schematic diagram of cleaning the upper rock and soil and installing the prefabricated top cover 4 or the cast-in-place top cover 4;

Fig. 14 is after backfilling the rock and soil on the top cover 4, constructing the upper road surface, excavating the rock and soil of the negative layer, and removing the groove cover plate 1-7 after the schematic diagram of the cast-in-place floor slab 5;

Fig. 15 is after the rock and soil in the subway station or the multi-storey building is removed, the structural schematic diagram of floor slab 5 being all cast in place;

Figure 16 is a top view of the underwater tunnel, which is also the structure of the closed area surrounded by the water retaining walls 1-4 on both sides (including the tunnel wall 1 at the bottom) and the transverse water retaining walls 1-5, which becomes the work area of the construction tunnel after drainage schematic diagram;

Figure 17 is a schematic structural view of the operation area formed by the retaining walls 1-4 on both sides (including the tunnel wall 1 at the bottom) and the transverse retaining walls 1-5;

Fig. 18 is a schematic structural view of the supports 1-6 of the longitudinal retaining walls or water retaining walls 1-5 on both sides, and it is also a structural schematic view of clearing part of the rock and soil in the upper part of the tunnel wall 1 after the water retaining wall is used to form an operation area;

Fig. 19 is a schematic diagram of the rock-soil backfill after the construction of the roof 4 of the tunnel is completed, and the water retaining wall 1-4 is separated from the tunnel wall 1;

Fig. 20 is a structural schematic diagram of the bottom floor 5 of the construction tunnel after cleaning the rock and soil in the tunnel wall 1 and the roof 4 of the tunnel;

Figure 21 is a structural schematic diagram of the bottom chain knife track and the side chain knife track of wall 1. There are five types of track including A1, A2, B, C and D, where A1 and A2 are concave, B is flat, and C is Convex;

Fig. 22 is a structural schematic diagram of D being a tapered structure in which vertical rows of tracks are staggered;

Fig. 23 is a schematic structural view of the D-shaped track of the wall 1 and multiple rows of chain knives.

1 in the figure is the load-bearing walls on both sides of the tunnel and the surrounding walls of the subway station; 1-1 is the track on which the chain knife 3 runs at the bottom of wall 1; 1-2 is the track on which the chain knife 3 runs on the side of wall 1; 1-3 is the bottom The side cover of wall 1 with bevels; 1-4 is the longitudinal retaining wall or water retaining wall on the upper part of wall 1; 1-5 is the transverse water retaining wall perpendicular to the length direction of the tunnel; 1-6 is the longitudinal retaining wall on both sides The support of the wall or water retaining wall 1-4; 1-7 is the prefabricated groove of the wall 1 at the interface position corresponding to each floor; 2 is the chain excavation device; 2-1 is the transmission device of the chain excavation device 2 ; 2-1-1 is the driving device of the transmission device 2-1; 2-1-2 is the sprocket wheel of the transmission device 2-1; 2-1-3 is the tensioning device of the transmission device 2-1; 3 is the composition The chain cutter of the chain excavation device 2; 3-1 is the chain forming the chain cutter 3, including crawler belts, ropes and flexible belts; 3-1-1 is the A ten-byte forming the chain ten-byte; 3-1-2 3-1B is the steel cable that forms the chain knife 3; 3-2 is the tool for excavating rock and soil fixed on the chain 3-1; 3-2B is fixed on the steel cable 3-1B is the tool for excavating rock and soil; 4 is the roof of the tunnel or subway station; 5 is the floor of the tunnel or subway station; 6 is the mud pipeline in the wall 1; 6-1 is the end of the pipeline mud 6 7 is the vertical rock and soil conveying device; B-1 is the bottom track in B method; B-2 is the middle frame in B method; B-3 is the upper device in B method; B-4 is Pour formwork in Method B.

detailed description

A track is provided at the bottom of the load-bearing wall 1 around an underground building. During construction, a chain knife for excavating rock and soil is installed on the track. The chain knife is composed of a chain and a knife fixed on the chain. The chain knife and the transmission device form a chain The excavating device, the transmission device is located above the ground and consists of a sprocket and a driving device. The driving device drives the chain cutter, and the chain cutter runs along the track. The rock soil is brought to the top, and the chain knife at the bottom of the wall 1 and the wall 1 descend together.

The construction method of described wall 1 is prefabrication method, divides following steps:

1) Block or integral prefabricated wall 1 in the workshop;

2) Transport to the on-site assembled wall 1 and squat down, and install the chain knife on the track at the bottom;

3) Install chain drives and other devices, and connect the chains with excavating knives;

4) Drive the chain, and the chain knife excavates the rock and soil at the bottom, and sends it to the top through the rock and soil conveying device, and the wall 1 descends accordingly;

5) Wall 1 is lowered to the design depth and grouted after the chain knife is removed.

Except for the prefabricated bottom, the wall 1 is poured in the fixed formwork on site, and the fixed formwork does not move during construction. With the excavation of the rock and soil at the bottom, the wall 1 sinks while being poured; , the middle frame and the upper device, the bottom track is fixedly connected with the bottom of the wall 1; the bottom of the middle frame is connected with the prefabricated bottom of the wall 1, the top of the middle frame is connected with the upper device, and the middle frame is installed with The track on which the chain runs, the middle frame is also an integral part of the reinforcement cage of wall 1; the chain-type rock-soil vertical conveyor is composed of the chain running upwards from the bottom and the closed cavity of the middle frame. With the sinking of the bottom of wall 1, The middle frame also sinks synchronously; the upper device is fixed on the working platform or on the top of the middle frame, the upper device is equipped with a chain drive device and a tensioning device, and the chain on the bottom track passes through the middle frame and the drive device in the upper device , and the tensioning device are connected; the specific construction is divided into the following steps:

1) Clean up the site and build a working platform;

2) Squat at the bottom of wall 1, and install a chain knife on the track at the bottom;

3) Assemble the middle frame, upper device and pouring formwork;

4) Install the chain driving device and the tensioning device, and connect the bottom track, the middle frame, and the chain knife of the upper device into one body to form a chain excavating device;

5) Make reinforcement cages and pour concrete in formwork;

6) Drive the chain, the chain knife excavates the rock and soil at the bottom of the wall 1, and transports the excavated rock and soil to the top through the middle frame, and the wall 1 descends accordingly;

7) As the bottom of wall 1 descends, wall 1 in the formwork descends while pouring;

8) The wall 1 is lowered to the design depth, the chain knife is removed, grouted, and the pouring formwork is removed.

During the construction of the wall 1, when the top is lower than the ground (or water surface), a temporary retaining wall (or water retaining wall) higher than the ground (or water surface) is installed on the top.

The water retaining wall (or earth retaining wall) exceeds the wall 1 in the width direction and is lower than the water bottom (or ground), and a chain knife is installed at the bottom of this part.

During the construction of the wall 1, a temporary lane for vehicles is provided in the wall 1 or on the top of the wall 1.

The wall 1 has a prefabricated groove at the interface position corresponding to each floor slab, and steel bars or welded steel plates or connectors for connecting the wall 1 and the floor slab are reserved in the groove.

After the wall 1 sinks to the design depth, the top cover is constructed first, and then the part below the top cover is constructed after the construction of the top cover is completed.

Described underground building is subway station or multi-storey underground building, and concrete construction method is divided into following steps:

1) Construction of surrounding load-bearing walls 1;

2) Install prefabricated roof or cast-in-place roof;

3) Construction of the road above the roof, and excavation of the rock and soil of the negative layer;

4) Remove the groove cover plate, and cast in-situ negative floor slab;

5) Excavate the rock and soil of the negative second floor;

6) Remove the groove cover and cast-in-place negative second-floor slab;

Repeat steps 3) and 4) to work from top to bottom until all underground floors are completed.

The underground building is an underwater tunnel, and several connecting supports are provided between the water retaining walls on both sides of the tunnel. The closed area surrounded by the water retaining walls on both sides (including the tunnel wall at the bottom) and the transverse water retaining wall becomes the operation area of the construction tunnel after drainage.

The bottom of the horizontal water retaining wall and the bottom of the support whose lower plane is lower than the water bottom before construction are provided with a track on which a chain cutter for excavating rock and soil is installed. The chain cutter is composed of a chain and a cutter fixed on the chain. The chain The knife and the transmission device form a chain excavation device. The transmission device is located above the water surface and consists of a sprocket and a drive device. During construction, the drive device drives the chain, and the chain drives the cutter to run along the track. The cutter at the bottom excavates the rock and runs vertically upwards. The chain knife will bring the excavated rock and soil to the top, the tunnel wall (including the side water retaining wall) and the horizontal water retaining wall will drop to the design depth together, and the water retaining walls on both sides (including the tunnel wall at the bottom) and the horizontal water retaining wall will The wall forms a closed area, in which drainage, excavation, and tunnel construction are carried out; the specific construction is divided into the following steps:

1) Form one or several work areas with water retaining walls on both sides (including the tunnel wall at the bottom) and transverse water retaining walls;

2) Divide the operation area into tunnel wall (including side retaining wall), support and transverse retaining wall construction section, drainage section, excavation section, tunnel construction section and retaining wall demolition section, and carry out corresponding work in each functional section functional work;

3) The water retaining wall removal section is located at the tunnel roof and after the construction is completed, the water retaining wall will be separated from the tunnel wall;

4) Move the removed retaining wall to the front to form a new work area;

5) Repeat the above 1) ~ 4) cycle construction until complete;

For the segmentation in 2) above, when there is only one area, it is segmented by time; when there are several areas, it is segmented by space.

The said underground building is a land tunnel, and the area between the retaining walls on both sides (including the tunnel wall at the bottom) is the operation area for constructing the tunnel. It is characterized by the following steps:

1) The tunnel walls and retaining walls on both sides of the construction form several work areas;

2) Divide the operation area into two side walls and retaining wall construction section, excavation section, tunnel construction section and retaining wall demolition section, and carry out corresponding functional operations in each functional section;

3) The removal section of the retaining wall is located after the construction of the tunnel roof is completed, and the retaining wall is separated from the tunnel wall;

4) Move the removed retaining wall to the front to form a new work area;

5) Repeat the above 1) ~ 4) cycle construction until complete;

For the segmentation in 2) above, when there is only one area, it is segmented by time; when there are several areas, it is segmented by space.

Further describe the present invention below in conjunction with accompanying drawing:

As shown in Figures 1 to 5, the load-bearing walls on both sides of the tunnel and the bottom of the load-bearing walls 1 around the subway station are provided with a track 1-1. During construction, a chain cutter 3 for excavating rock and soil is installed on the track. 3-1 and the cutter 3-2 fixed on the chain, the chain cutter 3 and the transmission device 2-1 form the chain excavation device 2, and the transmission device 2-1 is located above the ground by the drive device 2-1-1 and the chain Wheel 2-1-2 etc., drive device 2-1-1 drives chain 3-1, chain 3-1 drives cutter 3-2 to run along the track, cutter 3-2 at the bottom of wall 1 excavates rock and soil, vertically upward The chain cutter 3 of operation brings the excavated rock and soil to the top, and the chain cutter 3 at the bottom of the wall 1 and the wall 1 descend together.

As shown in Figure 6, the wall 1 adopts the A method prefabrication method and divides the following steps:

1) Block the prefabricated wall 1 in the workshop, transport it to the site to assemble the wall 1 and squat down, and install the chain knife 3 on the track 1-1 at the bottom, install the chain drive device 2-1-1 and other devices, connect and install the The chain 3-1 of digging knife 3, as shown in a among the figure;

2) Drive the chain 3-1, the chain knife excavates the rock and soil at the bottom, and sends it to the top through the chain knife 3, and the wall 1 descends accordingly, as shown in b in the figure;

3) After descending to a certain depth, the prefabricated parts of wall 1 assembled on the ground can also be assembled while sinking, as shown in c in the figure;

4) Grout after descending to the design depth, or remove the chain knife 3, as shown in figure d.

As shown in Figures 7 to 10, the wall 1 is divided into the following steps by adopting the method B cast-in-place method:

1) Clean up the site and build a working platform;

2) Assemble the bottom track B-1 and pouring formwork B-4, that is, the bottom squat position of the wall 1, and install the chain knife 3 on the bottom track;

3) Assemble the middle frame B-2 and the upper device B-3;

4) Install the chain driving device 2-1-1 and the tensioning device 2-1-3, and connect the bottom rail B-1, the middle frame B-2, the upper device B-3 and the chain 3-1 into one body to form a chain excavation device 2;

5) Make a reinforcement cage, weld the middle frame B-2 and the reinforcement cage into one, and the middle frame B-2 is also a component of the pouring formwork;

6) Pouring concrete in formwork B-4;

7) Drive the chain 3-1, the chain knife 3 excavates the rock and soil at the bottom, and transports the excavated rock and soil to the top through the middle frame B-2, and the wall 1 descends accordingly;

8) With the excavation of the bottom of wall 1, wall 1 in formwork B-4 descends while pouring;

9) Descend to the design depth and remove the chain knife 3 and then grout;

10) Remove the upper device and the part of the middle frame higher than wall 1, and remove the pouring formwork.

As shown in Figures 12 to 15, the construction method of a subway station or multi-storey underground building is divided into the following steps:

1) Construction of the bearing wall 1 of the subway station;

2) Install prefabricated roof 4 or cast-in-place roof 4;

3) Construct the road above the roof, and excavate the rock and soil of the negative layer;

4) Remove the groove cover plate and cast-in-place negative floor slab 5;

5) Excavate the rock and soil of the negative second floor;

6) Remove the groove cover and cast-in-place negative second floor slab 5;

Repeat steps 3) and 4) to work from top to bottom until all underground floors are completed.

As shown in Figure 16, a number of connecting supports 1-6 are provided between the water retaining walls 1-4 on both sides of the underwater tunnel. The water retaining walls 1-5, the closed area surrounded by the water retaining walls 1-4 on both sides (including the tunnel wall 1 at the bottom) and the transverse water retaining walls 1-5 become the operation area of the construction tunnel after drainage.

As shown in Figures 16 to 20, the bottom of the wall 1 and the bottom of the support whose lower plane is lower than the water bottom before construction are provided with rails, and chain cutters 3 for excavating rock and soil are installed on the rails, and the cutter 3-2 at the bottom excavates rock and soil , the chain knife 3 running vertically upwards brings the excavated rock and soil to the top, the tunnel wall 1 (including the side retaining walls 1-4) and the horizontal retaining walls 1-5 descend to the design depth together, and the retaining walls on both sides 1-4 (including the tunnel wall 1 at the bottom) and the horizontal retaining wall 1-5 form a closed area, in which drainage, excavation, and tunnel construction are carried out; the specific construction is divided into the following steps:

1) Use retaining walls 1-4 on both sides (including the tunnel wall 1 at the bottom) and transverse retaining walls 1-5 to form one or several work areas;

2) Divide the operation area into tunnel wall 1 (including side retaining wall 1-4), support 1-6 and transverse retaining wall 1-5 construction section, drainage section, excavation section, tunnel construction section and retaining wall Remove the section, and carry out corresponding functional operations in each functional section;

3) The removal section of the water retaining wall 1-4 is located at the tunnel roof 4. After the construction is completed, the water retaining wall will be separated from the tunnel wall;

4) Move the removed retaining wall 1-4 to the front end to form a new work area;

5) Repeat the above 1) ~ 4) cycle construction until complete;

For the segmentation in 2) above, when there is only one area, it is segmented by time; when there are several areas, it is segmented by space.

Claims (12)

1. An underground building, characterized in that the bottom of the load-bearing wall (1) around the underground building is provided with a track, during construction, a chain knife for digging rock and soil is installed on the track, and the chain knife is composed of a chain and a knife fixed on the chain , the chain cutter and the transmission device constitute a chain excavation device, the transmission device is located above the ground and consists of a sprocket and a drive device, etc., the drive device drives the chain cutter, the chain cutter runs along the track, and the cutter at the bottom of the wall (1) excavates rock and soil , the chain cutter running upwards from the bottom brings the excavated rock and soil to the top, and the chain cutter at the bottom of the wall (1) descends together with the wall (1). 2. A kind of underground building according to claim 1, characterized in that the construction method of the wall (1) is a prefabrication method, which is divided into the following steps: 1) Block or integral prefabricated wall (1) in the workshop; 2) Transport to the on-site assembled wall (1) and squat, and install a chain knife on the track at the bottom; 3) Install chain drives and other devices, and connect the chains with excavating knives; 4) Drive the chain, and the chain knife excavates the rock and soil at the bottom, and sends it to the top through the rock and soil conveying device, and the wall (1) descends accordingly; 5) The wall (1) is lowered to the design depth and grouted after the chain knife is removed. 3. A kind of underground building according to claim 1, characterized in that the wall (1) is poured in the fixed formwork on site except for the prefabricated bottom, and the fixed formwork does not move during construction. excavation, the wall (1) sinks while pouring; the chain type excavation device is composed of a bottom track, a middle frame and an upper device, and the bottom track is fixedly connected with the bottom of the wall (1); the bottom of the middle frame is connected with the The prefabricated bottom of the wall (1) is connected, the top of the middle frame is connected with the upper device, and the track running by the chain is installed in the middle frame, and the middle frame is also a component of the steel cage of the wall (1); The chain and the closed chamber of the middle frame form a chain-type rock-soil vertical conveyor. With the sinking of the bottom of the wall (1), the middle frame also sinks synchronously; the upper device is fixed on the working platform or fixed on the middle frame The top of the upper device is equipped with a chain driving device and a tensioning device, and the chain on the bottom track is connected to the driving device and the tensioning device in the upper device through the middle frame; the specific construction is divided into the following steps: 1) Clean up the site and build a working platform; 2) Squat at the bottom of the wall (1), and install a chain knife on the track at the bottom; 3) Assemble the middle frame, upper device and pouring formwork; 4) Install the chain driving device and the tensioning device, and connect the bottom track, the middle frame, and the chain knife of the upper device into one body to form a chain excavating device; 5) Make reinforcement cages and pour concrete in formwork; 6) Drive the chain, the chain knife excavates the rock and soil at the bottom of the wall (1), and transports the excavated rock and soil to the top through the middle frame, and the wall (1) descends accordingly; 7) As the bottom of the wall (1) descends, the wall (1) in the formwork descends while pouring; 8) The wall (1) is lowered to the design depth, and the chain knife is removed, then the grouting is performed, and the pouring formwork is removed. 4. An underground building according to claim 1, characterized in that when the wall (1) is constructed, when the top is lower than the ground (or water surface), the top is installed with a temporary Retaining wall (or water retaining wall). 5. An underground building according to claim 4, characterized in that the water retaining wall (or retaining wall) is beyond the wall (1) in the width direction and is lower than the water bottom (or ground) , then the bottom of this part is equipped with a chain knife. 6. The underground building according to claim 1, characterized in that when the wall (1) is being constructed, a temporary lane for vehicles is provided inside the wall (1) or on the upper part of the wall (1). 7. An underground building according to claim 1, characterized in that the wall (1) has a prefabricated groove at the interface corresponding to each floor, and the wall (1) and the floor are reserved in the groove Reinforcing bars or welded steel plates or connectors for connection. 8. An underground building according to claim 1, characterized in that the roof is constructed first after the wall (1) sinks to the design depth, and the part below the roof is constructed after the construction of the roof is completed. 9. A kind of underground building according to claim 2, 3, 8, characterized in that said underground building is a subway station or a multi-storey underground building, and the specific construction method is divided into the following steps: 1) Construction of surrounding load-bearing walls (1); 2) Install prefabricated roof or cast-in-place roof; 3) Construction of the road above the roof, and excavation of the rock and soil of the negative layer; 4) Remove the groove cover plate, and cast in-situ negative floor slab; 5) Excavate the rock and soil of the negative second floor; 6) Remove the groove cover and cast-in-place negative second-floor slab; Repeat steps 3) and 4) to work from top to bottom until all underground floors are completed. 10. A kind of underground building according to claim 1, characterized in that said underground building is an underwater tunnel, and several connecting supports are arranged between the water retaining walls on both sides of the tunnel, and the bottom plane of the support is higher than that of the tunnel roof. On the upper plane, one end is a transverse retaining wall perpendicular to the two side walls, and the closed area surrounded by the retaining walls on both sides (including the tunnel wall at the bottom) and the transverse retaining wall becomes the work area of the construction tunnel after drainage. 11. A kind of underground structure according to claim 10, it is characterized in that the bottom of the horizontal retaining wall and the support bottom of the lower plane before construction are lower than the bottom of the water are provided with rails, and excavation rock and soil are installed on the rails The chain knife is composed of a chain and a knife fixed on the chain. The chain knife and the transmission device form a chain excavation device. The transmission device is located above the water surface and consists of a sprocket and a driving device; during construction, the driving device drives the chain. The chain drives the cutter to run along the track, the cutter at the bottom excavates the rock and soil, the chain cutter running vertically upwards brings the excavated rock and soil to the top, and the tunnel wall (including the side retaining wall) and the horizontal retaining wall descend to the design depth together , the retaining walls on both sides (including the tunnel wall at the bottom) and the transverse retaining wall form a closed area, in which drainage, excavation, and tunnel construction are carried out; the specific construction is divided into the following steps: 1) Form one or several work areas with water retaining walls on both sides (including the tunnel wall at the bottom) and transverse water retaining walls; 2) Divide the operation area into tunnel wall (including side retaining wall), support and transverse retaining wall construction section, drainage section, excavation section, tunnel construction section and retaining wall demolition section, and carry out corresponding work in each functional section functional work; 3) The water retaining wall removal section is located at the tunnel roof and after the construction is completed, the water retaining wall will be separated from the tunnel wall; 4) Move the removed retaining wall to the front to form a new work area; 5) Repeat the above 1) ~ 4) cycle construction until complete; For the segmentation in 2) above, when there is only one area, it is segmented by time; when there are several areas, it is segmented by space. 12. An underground building according to claim 1, characterized in that the underground building is a land tunnel, and the area between the retaining walls on both sides (including the tunnel wall at the bottom) is the working area of the construction tunnel, It is characterized by the following steps: 1) The tunnel walls and retaining walls on both sides of the construction form several work areas; 2) Divide the operation area into two side walls and retaining wall construction section, excavation section, tunnel construction section and retaining wall demolition section, and carry out corresponding functional operations in each functional section; 3) The removal section of the retaining wall is located after the construction of the tunnel roof is completed, and the retaining wall is separated from the tunnel wall; 4) Move the removed retaining wall to the front to form a new work area; 5) Repeat the above 1) ~ 4) cycle construction until complete; For the segmentation in 2) above, when there is only one area, it is segmented by time; when there are several areas, it is segmented by space.