CN205576990U - Cross section and wear bridge pier tunnel slip casting supporting construction - Google Patents

Abstract

The utility model discloses a grouting support structure for a bridge-crossing pile tunnel at a river crossing section, which comprises: an underpinning beam connecting each pile foundation structure above the geological layer of the shallow-buried underground excavation tunnel to be constructed, which is used to carry the The load carried by the pile foundation structure; several underpinning columns connected and supporting the underpinning beam, which are used to bear the load carried by the underpinning beam; Hole grouting reinforcement layer. The utility model transfers the load of the underpinned pile foundation structure to the underpinning beam through the underpinning beam, and then transfers it to the underpinning column through the underpinning beam, so as not to reduce the bearing capacity and overall rigidity of the upper structure of the original pile foundation structure Construction is carried out under the premise; at the same time, a deep hole grouting reinforcement layer is added to further improve the bearing capacity of the pile foundation; the utility model has the advantages of saving space, low cost, short construction period, not affecting the upper traffic, safe and reliable, and reducing environmental pollution. .

Description

A grouting support structure for crossing bridge pile tunnels

technical field

The utility model relates to tunnel design and construction technology, in particular to a support structure for shallow buried tunnels, in particular to a grouting support structure for tunnels crossing bridge piles.

Background technique

When cities in our country are developing towards large-scale and modernization, a large number of high-rise buildings and underground tunnels are built in cities with a high concentration of population, so higher requirements are put forward for the construction of transportation, commerce and people's living facilities. In the construction of underground railways, shopping malls and many other underground facilities, it is often necessary to pass through some high-rise buildings, bridge structures or important historical buildings, which requires underpinning or reinforcement of the foundations of the original buildings (structures); The number of underpinnings required for construction (structure) is large, and when the original buildings (structures) need to be rebuilt, added floors or increased loads, underpinning technology also needs to be used; for example, in a complex urban environment, if Direct micro-explosion excavation of shallow subway tunnels will directly disturb the bridge piles above the tunnel, which will damage the bridge structure and have a great impact on the daily traffic of urban traffic vehicles.

Therefore, how to effectively solve the problems of stratum movement and surface subsidence caused by the excavation construction of shallow tunnels without changing the tunnel line, without demolishing the upper bridge structure, and without major safety accidents, so as to prevent the existing buildings on the surface and surrounding Excessive deformation and destruction of objects is an important research topic in current tunnel design and construction technology.

Contents of the invention

In view of the defects existing in the prior art, the purpose of this utility model is to provide a kind of grouting support structure for crossing the bridge pile tunnel, which is especially suitable for the crossing pile tunnel of the river crossing section of the tunnel. The overall force of the original pile foundation reduces the load of the pile foundation on the upper part of the tunnel, thereby reducing the local stress concentration, so that the shallow buried tunnel can safely pass through the bridge section, and can improve the strength of the foundation soil, eliminate collapsibility and Anti-seepage and plugging, etc.

In order to achieve the above object, the technical scheme of the utility model:

A grouting support structure for crossing bridge pile tunnels, characterized in that:

include

An underpinning beam connecting the various pile foundation structures of the geological layer above the shallow buried tunnel to be constructed, the underpinning beam is used to bear the load carried by each of the pile foundation structures;

a plurality of underpinning columns connected to and supporting the underpinning beam, the underpinning columns are used to carry the load carried by the underpinning beam;

And the deep hole grouting reinforcement layer arranged on the vault layer of the shallow buried tunnel to be constructed.

Further, the underpinning beam and each of the pile foundation structures are connected through a beam-embracing column structure, and the beam-embracing column structure means that each of the pile foundation structures passes through the inside of the underpinning beam respectively, and each passes through several planting bars and The underpinning beam is fixed as a whole.

Preferably, the planting bars are evenly arranged from the circumferential direction of the edge of the pile foundation structure, and are evenly arranged in multiple layers along the radial direction of the pile foundation structure.

Further, the underpinning column is connected to the underpinning beam through a number of longitudinal ribs evenly arranged on the contact surface between the underpinning column and the underpinning beam.

Further, the deep hole grouting reinforcement layer takes the excavation baseline of the vault layer of the shallow buried tunnel to be constructed as the reference line, and extends to both ends of the reference line respectively.

Further, the reinforcement depth of the deep hole grouting reinforcement layer is based on the distance detected to the pebble layer in the vault layer of the shallow buried tunnel to be constructed.

Further, several advanced probe holes are set on the deep hole grouting reinforcement layer, so that the reinforcement depth of the deep hole grouting reinforcement layer can pass through the excavation face of the vault layer of the shallow buried tunnel to be constructed. Calibrate and adjust the detection results of several advanced probe holes.

Compared with the prior art, the utility model has the beneficial effects:

On the basis of not removing the original pile foundation structure, the utility model transfers the load of the underpinned pile foundation structure to the underpinning beam through the underpinning beam, and then transfers it to the underpinning column through the underpinning beam to replace the original pile. The foundation bears the load on its upper part, so as to realize the construction without reducing the bearing capacity and overall rigidity of the upper part of the original pile foundation structure; at the same time, a deep hole grouting reinforcement layer is added to further improve the strength of the foundation soil and eliminate collapsibility. Therefore, the bearing capacity of the pile foundation is improved; therefore, the utility model has the advantages of space saving, low cost, short construction period, no influence on upper traffic, safety and reliability, and reduction of environmental pollution.

Description of drawings

Fig. 1 is the schematic diagram of the connection structure of pile foundation structure, underpinning beam and underpinning column described in the utility model;

Fig. 2 is a schematic diagram of the connection structure between the underpinning beam and the pile foundation structure described in the utility model;

Fig. 3 is a schematic diagram of the cross-sectional structure of Fig. 2;

Fig. 4 is a schematic diagram of the connection structure of the underpinning beam and the underpinning column described in the present invention;

Fig. 5 is a schematic diagram of the connection section structure of the pile foundation structure, the underpinning beam and the underpinning column described in the present invention;

Fig. 6 is a schematic diagram of the section structure of the deep hole grouting reinforcement layer described in the present invention;

Figure 7a is a schematic diagram of the original structure before the construction of the construction embodiment described in the utility model;

Fig. 7b is a schematic diagram of excavating foundation trenches for the pile foundation underpinning structure according to the construction embodiment of the present invention;

Fig. 7c is a schematic diagram of the construction of the pile foundation underpinning structure perfusion underpinning pile construction according to the construction embodiment of the present invention;

Fig. 7d is a schematic diagram of the construction of the pile foundation underpinning structure poured underpinning beam according to the construction embodiment of the present invention;

Fig. 7e is a schematic diagram of the completion of the backfilling construction of the pile foundation underpinning structure according to the construction embodiment of the present invention.

In the figure: 1. The geological stratum above the original shallow buried tunnel to be constructed, 2. Pile foundation structure, 3. Underpinning beam, 4. Underpinning column, 5. Planting reinforcement, 6. Longitudinal reinforcement, 7. Grout reinforcement layer, 8, grouting hole, 9, excavation baseline.

detailed description

In order to make the purpose, technical solution and advantages of the utility model clearer, the utility model will be further described in detail below in conjunction with the accompanying drawings.

The support structure described in the utility model is suitable for adjacent buildings (structures) in shallow buried tunnels, where ground conditions are limited, excavation affects the bearing capacity of pile bottoms, end-bearing pile foundations invade tunnel vaults, and stratum structures are complex. , The surrounding environment is complex, the construction of underground excavation under the condition of rich water or similar engineering construction and other construction occasions.

The main design points of the utility model include:

1. Design from the auxiliary structure of pile foundation stability:

When the shallow-buried tunnel crosses the bridge, as shown in Figure 1 and Figure 5, the pile foundation underpinning structure is designed to realize the load transfer without demolishing the original pile foundation structure, without reducing the bearing capacity and overall stiffness of the superstructure. And realize the transformation of the superstructure. At the same time, the pile foundation underpinning structure bears most of the load of the bridge, thereby reducing the load at the bottom of the bridge pile, and reducing the disturbance to the upper bridge when the tunnel passes through the pile foundation.

The pile foundation underpinning structure includes each pile foundation structure 2 connected to the geological layer 1 above the shallow buried tunnel to be constructed, and an underpinning beam 3 for carrying the load carried by the pile foundation structure 2;

And connecting and supporting the underpinning beam 3, the underpinning column 4 for carrying the load carried by the underpinning beam 3;

The underpinning beam 3 is respectively connected to the pile foundation structure 2 through a beam-embracing column structure, as shown in Figure 2, the beam-embracing column structure means that the pile foundation structure 2 passes through the underpinning beam 3 and passes Several planting bars 5 are fixed together with the underpinning beam 3 . Preferably, as shown in Figure 3, the planting bars 5 are evenly arranged from the circumferential direction of the edge of the pile foundation structure 2, and multi-layer planting bars are evenly arranged along the radial direction of the pile foundation structure, so that the support The changing beam 3 is fastened to the pile foundation structure 2 as an integral structure.

Among them, the specific structural distribution feature of the underpinning beam 3 is that a horizontal beam frame is established between the original bridge piles (that is, the pile foundation structure) in the geological layer above the shallow buried excavation tunnel to be constructed, and is connected with the underpinning beam. The pile forms a whole to bear the upper load. At the same time, the pile foundation structure is combined with the implanted steel bars of the pile foundation structure to surround the pile foundation structure in the underpinning beam. When the upper load When it is transferred to the pile foundation structure, the pile foundation structure transfers the load to the underpinning beam, thus forming a beam-embracing-column process.

Further, as shown in Figure 4, the underpinning column 4 is connected to the underpinning beam 3 through several longitudinal ribs 6, and the longitudinal ribs 6 are evenly arranged on the underpinning column 4 in contact with the underpinning beam 3 That is, some through holes are set on the underpinning beam, and some longitudinal ribs are set in the through holes; at the same time, holes are opened on the contact surface (the position of the underpinning column corresponding to the underpinning beam), and the longitudinal ribs of the underpinning beam are penetrated. Pass through the underpinning column and seal the holes with chemical planting glue.

The underpinning column adopts pouring concrete, and the points are fixed, holes are drilled, steel cages are lowered, and concrete is poured in advance according to the design.

The formation of the underpinning beam connects the underpinning column and the underpinning column as a whole, so that the overall force of the pile foundation is reduced, the load of the pile foundation on the upper part of the tunnel is reduced, and the local stress concentration is reduced, so that the shallow buried tunnel can pass through safely bridge section.

The specific implementation technology is as follows: first, according to the exploration and design requirements, drill holes at fixed points on site. Since the construction process of bored piles has a weakening effect on the bearing capacity of the original piles, it is necessary to use the empirical formula: To check and calculate its bearing capacity, where d and D are the pile diameters of each pile foundation structure and the pile diameter of the underpinning pile in the shallow buried tunnel to be constructed, respectively.

It should be noted that: in the construction process of this utility model, the construction of the underpinning pile needs to be completed before the construction of the underpinning beam. The various pile foundation structures above the excavated tunnel are connected as a whole, that is, the connection form between the underpinning beam and each of the pile foundation structures adopts the form of a beam holding a column. In order to ensure that the column will not be damaged during construction, the principle of drilling and anchoring should be followed when drilling. After the drilling is completed, the debris in the hole should be blown out, and the reinforcement should be anchored immediately and glue should be injected until the strength of the glue reaches 100%. Only then can the next hole be drilled. After all the steel bars are anchored, the steel bars of the underpinning beam are bound and concrete is poured to complete the underpinning beam; as shown in Figure 7a-7e (the tunnel marks appear in the figure to show the relative position of the bridge, not the actual tunnel structure) as shown in the construction example The construction process of the pile foundation underpinning structure is: excavation of the foundation pit → construction of underpinning piles (manual excavation piles) and pre-jack caps → planting reinforcement on each pile foundation structure and performing interface treatment → binding underpinning beam reinforcement → Pouring the underpinning beam → pre-topping → pouring the micro-expansion concrete between the underpinning pile and the underpinning beam → backfilling.

2. The pile foundation underpinning structure combined with the directional deep hole grouting reinforcement layer is used to control seepage and water gushing to treat the soil and structure stability around the tunnel.

That is, the deep hole grouting reinforcement layer 7 is set on the vault layer of the shallow-buried tunnel to be constructed using the pile foundation underpinning structure.

specific:

Setting the deep hole grouting reinforcement layer means adopting directional deep hole grouting technology, that is, injecting various organic or inorganic chemical grouts into the soil by air pressure or hydraulic pressure, which can solidify the foundation, improve the strength of the foundation soil, eliminate collapsibility and prevent Therefore, for shallow-buried underground tunnels to be constructed using pile foundation underpinning technology, the hole grouting reinforcement layer can be combined with the pile foundation underpinning structure to greatly improve the performance of shallow buried underground excavation. The bearing capacity of the original pile foundation bearing layer on the tunnel vault and the upper part greatly reduces the deformation and settlement of the structure, which can further increase the stability of the pile foundation and improve the bearing capacity of the pile foundation.

The deep hole grouting reinforcement layer is based on the excavation baseline 9 on the vault layer of the shallow buried tunnel to be constructed as the reference line, and is extended to the two ends of the reference line respectively. If the excavation baseline can be used as the reference line, respectively 0.4m inward and 2m outward, the grouting reinforcement length is set within 12m, and the permeability coefficient after reinforcement is required to reach: 10-6-10-7cm/sec, the bearing capacity of the foundation is ≥300KPa, and the uniaxial unconfined resistance Compressive strength ≥ 0.5MPa, overall unconfined compressive strength ≥ 2.8MPa.

Its grouting hole 8 can carry out punching according to becoming certain angle of inclination with the vault top layer such as forming 150 ° from bottom to top along the vault top layer to punch and set.

The reinforcement depth of the deep hole grouting reinforcement layer is based on the distance detected to the pebble layer in the vault layer of the shallow buried tunnel to be constructed. That is to say, the scope of pebble layer intrusion into the vault is used as the reference reinforcement length value. The specific implementation principle is to drill holes to faults and water gushing zones, rock-soil caves, pores of rock particles, rock-soil interface or rock-soil cracks and fine-grained holes. The grout material with filling and cementing properties is injected into the granular rock body, and the rock mass in the fault and water gushing zone is filled, compacted, infiltrated, split, consolidated, etc., to make the rock mass strength, stability and isolation The water-proof performance can be improved to ensure the normal construction of tunnels and underground works.

The technical characteristics of the deep hole grouting reinforcement layer:

(1) Grouting scope:

The scope of grouting is comprehensively determined according to factors such as geological conditions, groundwater pressure, and tunnel construction methods. Generally speaking, the construction radius of the grouting reinforcement layer should be 2 to 3 times the tunnel excavation radius, and it should be 4 to 6 times the tunnel excavation radius when the groundwater pressure is too high or the construction is under water.

(2) Layout of grouting holes

The grouting holes are arranged evenly in combination with the grouting diffusion radius of a single grouting hole and the overall excavation parameters of the shallow buried tunnel to be constructed, as shown in Figure 6, along the shallow buried tunnel to be constructed layer by layer. Arrange a number of grouting holes until the grouting diffusion radius of each grouting hole can completely cover the scope of the shallow buried tunnel to be constructed; for example, the grouting diffusion radius can be determined to be 1.0m according to the grouting test, and the grouting pressure can be controlled by the site. , injection capacity and grouting time to determine the layout of the holes. When grouting, first drill the grouting hole, then put the steel pipe in the grouting hole, and finally grout the surrounding rock through the steel pipe.

(3) Grouting pressure

The grouting pressure is the energy given to the grout to penetrate, diffuse, split and compact in the soil layer, and its size determines the quality of the grouting effect and the cost. The grouting pressure can be controlled according to the hydrostatic pressure at the grouting place plus 1-1.5MPa. During actual construction, the construction technical parameters such as grouting pressure, grout ratio, and grouting speed should be determined through field tests according to the depth and geological conditions.

The directional grouting reinforcement layer can be set according to the grouting orientation, depth and grouting amount determined by the advanced geological exploration holes, that is, several advanced geological exploration holes are set on the deep hole grouting reinforcement layer, so as to make the deep hole grouting The reinforcement depth of the slurry reinforcement layer is calibrated and adjusted by setting the detection results of several advanced geological exploration holes on the excavation face of the vault layer of the shallow buried tunnel to be constructed. It should be noted that the setting of the directional grouting reinforcement layer also needs to consider the bearing capacity of the vault layer from the shallow buried tunnel to be constructed (including the finishing pressure of the original upper building and the pile foundation underpinning structure).

Accurate deep hole grouting to strengthen and stop water can effectively improve the formation properties, prevent river flooding, increase the bearing capacity of the arch ring, effectively control the water leakage of the tunnel face, and ensure the safety of tunnel construction. Therefore, the implementation of the structure described in the utility model not only enables the excavation of the tunnel to safely pass through the dangerous section, but also greatly improves the strata around the tunnel, and greatly improves the bearing capacity and stability of the Weitai Bridge.

It can be seen that the use of pile foundation underpinning and directional grouting reinforcement has formed a new and comprehensive professional technology for dealing with complex geological conditions, complex structures and construction in complex environments.

The above is only a preferred embodiment of the utility model, but the scope of protection of the utility model is not limited thereto. Any equivalent replacement or change of the new technical solution and the concept of the utility model shall be covered by the protection scope of the utility model.

Claims (7)

1. A bridge pile tunnel grouting support structure in the section of the river, characterized in that: An underpinning beam connecting the various pile foundation structures of the geological layer above the shallow buried tunnel to be constructed, the underpinning beam is used to bear the load carried by each of the pile foundation structures; a plurality of underpinning columns connected to and supporting the underpinning beam, the underpinning columns are used to carry the load carried by the underpinning beam; And the deep hole grouting reinforcement layer arranged on the vault layer of the shallow buried tunnel to be constructed. 2. The bridge pile tunnel grouting support structure in the river crossing section according to claim 1, characterized in that: The underpinning beam is connected to each of the pile foundation structures through a beam-embracing column structure, and the beam-embracing column structure means that each of the pile foundation structures passes through the inside of the underpinning beam respectively, and is connected to the underpinning beam through several planting bars. The changing beam is fixed as a whole. 3. The bridge pile tunnel grouting support structure in the river crossing section according to claim 2, characterized in that: The planting bars are evenly arranged from the peripheral direction of the pile foundation structure, and are evenly arranged in multiple layers along the radial direction of the pile foundation structure. 4. The bridge pile tunnel grouting support structure in the river crossing section according to claim 1, characterized in that: The underpinning column is connected to the underpinning beam through a number of longitudinal reinforcements evenly arranged on the contact surface between the underpinning column and the underpinning beam. 5. The bridge pile tunnel grouting support structure in the river crossing section according to claim 1, characterized in that: The deep hole grouting reinforcement layer is based on the excavation baseline of the vault layer of the shallow buried tunnel to be constructed, and is extended to both ends of the baseline. 6. The bridge pile tunnel grouting support structure in the river crossing section according to claim 1, characterized in that: The reinforcement depth of the deep hole grouting reinforcement layer is based on the distance detected to the pebble layer in the vault layer of the shallow buried tunnel to be constructed. 7. The bridge pile tunnel grouting support structure for crossing the river according to any one of claims 1-5, characterized in that: Several advanced probe holes are arranged on the deep hole grouting reinforcement layer.