Strengthening methods for buildings adjacent to tunnels

Abstract

The present invention discloses a method for reinforcing a tunnel adjacent to a building, which includes: laying at least one layer of pipe shed in the soil between each tunnel and the building for reinforcement; and grouting reinforcement and protection of the building. The present invention adopts a combined reinforcement method of pipe shed support and grouting reinforcement, which can effectively control the settlement of the building, better improve the reinforcement effect of the building, and ensure the safety of the structure; when grouting reinforcement is performed on the base of the building, the second grouting pipe used is designed to be tree-like, and the second grouting pipe is arranged at a large inclined angle, so that the diffusion range of the slurry in the soil is larger, so as to expand the grouting reinforcement range and improve the grouting reinforcement effect; at the same time, a mechanism for monitoring the settlement is designed, which can monitor the settlement at all times and accurately, respond in time according to the monitored settlement, and effectively control the settlement of the building.

Description

Technical Field

[0001] The present invention relates to the technical field of tunnel construction, and more particularly to a method for reinforcing a building adjacent to a tunnel. Background Art

[0002] With the rapid development of cities, it has become an inevitable trend to build underground buildings such as tunnels in prosperous cities. In limited urban space, tunnels often pass through the strata near or even directly below existing buildings. The excavation of tunnels will inevitably disturb the soil of surrounding buildings, destroy the original stratum balance, and redistribute the original stratum stress, affecting the stability of the building foundation, causing the building to sink or even collapse. Especially for areas with complex geological conditions, the construction is difficult and the safety risk is high, which puts forward more stringent requirements on construction technology and construction technology solutions. Therefore, reinforcement measures or restoration measures must be taken to prevent and control the settlement of buildings, and the settlement must be monitored at all times, and timely responses must be made to building settlement to ensure structural safety.

[0003] "A reinforcement method for the ground of a shield tunneling under a building" (application number: 202010462617.0) discloses a reinforcement structure for a shield tunneling under a building, comprising a pre-grouting reinforcement area and a pipe-roof reinforcement area. The pre-grouting reinforcement area is used to reinforce the shallow soil under the foundation, and the pipe-roof reinforcement area is used to reinforce the surrounding rock area under the shallow soil. By combining the two reinforcement methods, the physical and mechanical properties of the soil are effectively improved, which plays a role in reinforcing the foundation, preventing seepage, blocking water, reducing surface subsidence, and improving the bearing capacity of the foundation, thereby providing dual protection for buildings and tunnels. In this invention, only one layer of pipe shed is used for reinforcement. For soft and complex strata, the supporting effect of one layer of pipe shed is poor. At the same time, when grouting in the pre-grouting reinforcement area, sleeve valve pipes are generally used, which are vertical and have limited slurry diffusion area, so that the effect of grouting reinforcement is subject to certain restrictions. In addition, this invention performs supplementary grouting for soil disturbance at the arch caused by shield tunneling, and sets tracking supplementary grouting holes. Grouting is performed in time near the place where the soil disturbance occurs to reduce losses, and further reduce the effect of soil disturbance caused by stratum loss. Generally, settlement observation points need to be set up to observe the settlement of easily disturbed areas and building foundations at all times, but this invention does not mention the observation of settlement. In the prior art, the method of observing settlement is generally to use a total station or a level to observe, set an observation point mark that is easy to identify at the place to be measured, and use a total station or a level to perform intermittent measurements at fixed (permanent leveling point) measuring points manually. This conventional method of monitoring settlement is time-consuming and labor-intensive, and because it is intermittent measurement, the discovery of building settlement becomes a probabilistic event, and the settlement of the building cannot be reflected in time. The above prior art cannot effectively prevent and control building settlement, resulting in poor building reinforcement effect. Summary of the invention

[0004] An object of the present invention is to solve at least the above problems and to provide at least the advantages which will be described hereinafter.

[0005] Another object of the present invention is to provide a method for reinforcing a tunnel adjacent to a building. The present invention adopts a combined reinforcement method of multi-layer pipe shed support and grouting reinforcement to achieve double protection, effectively prevent and control the settlement of the building, and can better improve the reinforcement effect of the building to ensure structural safety. The present invention designs the grouting pipe to be tree-like, which can make the slurry spread over a larger range, improve the grouting reinforcement effect, and avoid the problem of limited slurry diffusion area when using conventional sleeve valve pipes for grouting. The present invention also designs a mechanism for monitoring the settlement, which can monitor the settlement at all times and accurately, avoiding the existing technology that the settlement can only be monitored intermittently and manually.

[0006] In order to achieve these purposes and other advantages according to the present invention, a method for reinforcing a tunnel adjacent to a building is provided. In order to achieve these purposes and other advantages according to the present invention, a method for reinforcing a tunnel adjacent to a building is provided, comprising:

[0007] Pipe shed support: at least one layer of pipe shed is laid in the soil between each tunnel and the building for reinforcement;

[0008] Grouting reinforcement, grouting reinforcement and protection of buildings, specifically:

[0009] Step i, arranging a plurality of first grouting holes on the periphery of the building, arranging a first grouting pipe in each first grouting hole, and injecting grout into the first grouting pipe;

[0010] Step ii, arranging a plurality of second grouting holes between the plurality of first grouting holes and the building, arranging a second grouting pipe in each second grouting hole, each second grouting pipe being in the shape of a tree branch, and comprising a main pipe and a plurality of branch pipes; grouting into the second grouting pipe;

[0011] Step iii, arrange multiple compensating grouting holes on the periphery of the building, arrange a compensating grouting pipe in each compensating grouting hole, and set a settlement monitoring device corresponding to each compensating grouting hole. Each settlement monitoring device includes a first container arranged at the settlement observation point, a second container arranged at the permanent leveling point, a water pipe connecting the first container and the second container, and a water level detection mechanism for monitoring the liquid level of the second container. When the change value of the liquid level of the second container is greater than the warning value, grouting is injected into the compensating grouting pipe.

[0012] Preferably, the pipe shed of a tunnel closest to the building is designed to be two layers, the upper pipe shed is laid on the lower pipe shed at an elevation angle of 1°, the horizontal centerline spacing between the two layers of pipe sheds is 35 cm, the length of the two layers of pipe sheds is 50 m, the circumferential spacing between any adjacent steel pipes in each layer of pipe shed is 40 cm, and each steel pipe is a Φ108 hot-rolled seamless steel pipe.

[0013] Preferably, three steel bars are arranged in each steel pipe, and a plurality of fixed steel pipes are arranged at intervals of 30 cm along the length direction of the steel bars, and each fixed steel pipe fixedly connects the three steel bars.

[0014] Preferably, two first grouting hole groups are arranged in parallel from the inside to the outside on the periphery of the building, each first grouting hole group includes a plurality of first grouting holes arranged at intervals along the circumference of the building, the inner first grouting hole group is spaced 2m from the building, the distance between the two first grouting hole groups is 0.6m, the distance between any two adjacent first grouting holes is 0.6m, and a first grouting pipe with a length of 6m is inserted into each first grouting hole; a double-tube backward segmented grouting process is adopted to inject grout into the first grouting pipe, the final grouting pressure is 0.6-1.0MPa, the grouting volume is 200-300L / m, the grouting material used is a double-liquid slurry of cement and water glass, the volume ratio of cement to water glass is 1:1, wherein the water-cement ratio of cement is 0.6:1-1.1, and the concentration of water glass is 35 degrees Baume.

[0015] Preferably, two second grouting hole groups are symmetrically arranged on both sides of the building, each second grouting hole group is 1.5m away from the building, each second grouting hole group includes three second grouting holes arranged at intervals, each second grouting hole extends downwardly in a direction close to the building, the inclination angles of the three second grouting holes on the same side are 30°, 40°, and 50°, respectively, and the hole depths are 8m, 9m, and 10m, respectively; a second grouting pipe is inserted into each second grouting hole, and grouting is injected into the second grouting pipe by a double-tube backward segmented grouting process, the final grouting pressure is 0.6-1.0MPa, the grouting volume is 200-300L / m, the grouting material used is a double liquid slurry of cement and water glass, the volume ratio of cement to water glass is 1:1, wherein the water-cement ratio of cement is 0.6:1-1.1, and the concentration of water glass is 35 degrees Baume.

[0016] Preferably, a plurality of through holes are arranged at intervals on each main pipe, one through hole corresponds to one branch pipe, and the outer side of each through hole is covered by a water-soluble tape;

[0017] Each branch pipeline is arranged perpendicularly to the main pipeline, and each branch pipeline includes a plurality of coaxial pipe bodies that are slidably sleeved in sequence. One end of each pipe body that is away from the through hole is connected to the inner wall of the main pipeline through a water-soluble adhesive. A plurality of elastic members are arranged inside the innermost pipe body, and one end of each elastic member is connected to the inner wall of the main pipeline, and the other end is connected to the other end of the innermost pipe body that is close to the through hole. Each elastic member is arranged so that when the outer side of the through hole is covered with a water-soluble adhesive tape, the elastic member is in a compressed state, and the plurality of pipe bodies of the branch pipeline are stored inside the main pipeline. When the water-soluble adhesive tape fails when it encounters water, the through hole is opened, and the plurality of pipe bodies extend through the through hole to the outside of the main pipeline under the elastic force of the elastic member.

[0018] A plurality of slurry outlet holes are arranged at intervals on each main pipeline and each pipe body.

[0019] Preferably, a plurality of compensating grouting holes are arranged at intervals along the circumferential direction at 1.5 m from the periphery of the building, the spacing between any two adjacent compensating grouting holes is 2 m, the hole depth of the compensating grouting holes is 6 m, the two compensating grouting holes adjacent to the second grouting hole are 1 m apart from the second grouting hole, the hole depth of the compensating grouting holes is 6 m, and they are inclined toward the building with an inclination angle of 60°. The compensating grouting pipe adopts a PVC sleeve valve pipe, and the backward segmented grouting process is adopted to grout the compensating grouting pipe. The final grouting pressure is 0.5-2.0 MPa, and the grouting material used is a double liquid slurry of cement and water glass, and the volume ratio of cement to water glass is 1:1, wherein the water-cement ratio of cement is 0.8:1-1.1, and the concentration of water glass is 35 degrees Baume.

[0020] Preferably, the settlement observation point is arranged near the compensation grouting hole, and the first container and the second container are both containers of equal cross-section with equal cross-sectional areas;

[0021] The water level detection mechanism includes a floating plate arranged on the liquid surface of the second container and a laser displacement sensor arranged directly above the floating plate. The laser displacement sensor is fixed with a fixed bracket. The laser displacement sensor obtains the change value of the vertical height of the first container by measuring the change value of the liquid level height in the second container, and the value is the settlement amount of the settlement observation point.

[0022] Preferably, the warning value is a settlement amount of 8 to 10 mm, or a settlement rate exceeding 2 to 3 mm / d; when the change in the liquid level in the second container is greater than the warning value, grouting is injected into the compensating grouting pipe, and grouting is stopped when the elevation of the settlement observation point is within the range of ±3 to 4 mm of the starting elevation.

[0023] The present invention has at least the following beneficial effects:

[0024] The present invention provides a method for reinforcing a building adjacent to a tunnel, which can effectively prevent and efficiently control the settlement of the building, can better improve the reinforcement effect of the building, and ensure the safety of the structure.

[0025] 1. The present invention adopts a combined reinforcement method of pipe-roof support and grouting reinforcement. By setting up multi-layer pipe-roof support to improve the bearing capacity of the surrounding rock itself, the elastic resistance of the rock mass to the structure is improved, the stress conditions of the structure are improved, and the settlement of the building is effectively controlled; grouting reinforcement can increase the strength of the bedrock of the building, reduce the water permeability of the bedrock, and prevent the building from settling or tilting, thereby achieving double protection and effectively preventing and controlling the settlement of the building.

[0026] 2. When the present invention performs grouting reinforcement on the base of a building, the second grouting pipe used is designed to be tree-like, so that the slurry can diffuse over a larger range in the soil, consolidate with more soft soil, and better improve the bearing capacity of the stratum; and the second grouting pipe is arranged at a large inclined angle to further expand the grouting reinforcement range and improve the grouting reinforcement effect.

[0027] 3. The present invention designs a mechanism for monitoring settlement, which can monitor settlement at all times and accurately, respond in time according to the monitored settlement value, and effectively control the settlement of the building.

[0028] Other advantages, objectives and features of the present invention will be embodied in part through the following description, and in part will be understood by those skilled in the art through study and practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a schematic diagram of the cross-sectional structure of the present invention;

[0030] Figure 2 It is a schematic diagram of the longitudinal section structure of the present invention;

[0031] Figure 3 is a cross-sectional view of the second grouting pipe of the present invention;

[0032] Figure 4 It is a schematic diagram of the equipment for monitoring the amount of settlement according to the present invention;

[0033] Description of reference numerals:

[0034] 1-lower pipe shed; 2-upper pipe shed; 3-main pipe of the second grouting pipe; 4-branch pipe of the second grouting pipe; 5-water-soluble tape; 6-elastic member; 7-first container; 8-second container; 9-floating plate; 10-laser displacement sensor. DETAILED DESCRIPTION

[0035] The present invention is further described in detail below in conjunction with the accompanying drawings and embodiments so that those skilled in the art can implement the invention with reference to the description.

[0036] It should be understood that the terms such as “having”, “including” and “comprising” used herein do not exclude the existence or addition of one or more other elements or combinations thereof.

[0037] It should be noted that the experimental methods described in the following embodiments are conventional methods unless otherwise specified, and the reagents and materials can be obtained from commercial channels unless otherwise specified.

[0038] In the description of the present invention, the terms "lateral", "longitudinal", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" etc. to indicate directions or positional relationships are based on the directions or positional relationships shown in the accompanying drawings and are only for the convenience of describing the present invention and simplifying the description. They do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore should not be understood as a limitation on the present invention.

[0039] like Figure 1 As shown, the present invention provides a method for reinforcing a tunnel adjacent to a building, characterized in that it includes:

[0040] Pipe shed support: at least one layer of pipe shed is laid in the soil between each tunnel and the building for reinforcement;

[0041] Grouting reinforcement, grouting reinforcement and protection of buildings, specifically:

[0042] Step i, arranging a plurality of first grouting holes on the periphery of the building, arranging a first grouting pipe in each first grouting hole, and injecting grout into the first grouting pipe;

[0043] Step ii, arranging a plurality of second grouting holes between the plurality of first grouting holes and the building, arranging a second grouting pipe in each second grouting hole, each second grouting pipe having a tree-like shape, and comprising a main pipe 3 and a plurality of branch pipes 4; grouting into the second grouting pipes;

[0044] Step iii, arrange multiple compensating grouting holes on the periphery of the building, arrange a compensating grouting pipe in each compensating grouting hole, and set a settlement monitoring device corresponding to each compensating grouting hole. Each settlement monitoring device includes a first container 7 arranged at the settlement observation point, a second container 8 arranged at the permanent leveling point, a water pipe connecting the first container 7 and the second container 8, and a water level detection mechanism for monitoring the liquid level of the second container 8. When the change value of the liquid level of the second container 8 is greater than the warning value, grouting is injected into the compensating grouting pipe.

[0045] The double reinforcement method of pipe shed support and grouting reinforcement is used to control the settlement of the building. At least one layer of pipe shed is laid in the soil between each tunnel and the building for reinforcement: Step i, installation of the sleeve arch and guide pipe: first, excavation of the sleeve arch foundation trench and pouring of concrete into the sleeve arch foundation; then erecting a double-layer four-frame steel arch frame, the inner steel arch frame is equipped with four I20a I-beams with a spacing of 50cm, the outer steel arch frame is made of I16 I-beams, and the steel arch frame is connected as a whole with a Φ133mm longitudinal orifice pipe, and the steel arch frame is fixed with locking anchor rods and steel pipes; after the steel arch frame is installed, multiple guides are installed. The pipes are fixed on the steel arch frame in turn and welded; after the guide pipe is welded, concrete is poured to further fix the sleeve arch and the guide pipe; step ii, drilling: drilling along the length direction of the guide pipe with a pipe shed drilling machine; step iii, jacking the steel pipe: then multiple steel pipes are jacked into the hole in turn by a machine, and the multiple steel pipes are fixed on the sleeve arch with an orifice pipe; step iv, pipe shed grouting: 20cm thick concrete is sprayed on the face, and the orifice pipe and the end of the steel pipe are tightly sealed with plain cement slurry, and grouting is performed after it solidifies and hardens;

[0046] Grouting reinforcement and protection of buildings: step i, first apply a grouting-stopping curtain: arrange a plurality of first grouting holes on the periphery of the building, arrange a first grouting pipe in each first grouting hole, and inject grout into the first grouting pipe to form a grouting-stopping curtain; step ii, reinforce the base of the building: arrange a plurality of second grouting holes between the plurality of first grouting holes and the building, arrange a second grouting pipe in each second grouting hole, and inject grout into the second grouting pipe; step iii, perform compensating grouting: arrange a plurality of compensating grouting holes on the periphery of the building, arrange a compensating grouting pipe in each compensating grouting hole, and each compensating grouting hole is provided with a device for monitoring the amount of settlement. When the settlement value is greater than the warning value, grouting is injected into the compensating grouting pipe to lift the building, wherein each device for monitoring the amount of settlement includes a first container 7 arranged at the settlement observation point, a second container 8 arranged at the permanent leveling point, a water pipe connecting the first container 7 and the second container 8, and a water level detection mechanism for monitoring the liquid level of the second container 8.

[0047] In the above technical scheme, in order to effectively control the settlement of the building, at least one layer of pipe shed is laid between the tunnel and the soil of the building as support. In step i, the sleeve arch and the guide pipe are first installed: the earthwork of the sleeve arch foundation trench is excavated by manual labor and excavators; the sleeve arch foundation is cast with C25 concrete; then a double-layer four-frame steel arch frame is erected (with a longitudinal spacing of 0.5m). The inner layer of the steel arch frame uses four I20a I-beams with a spacing of 50cm. A 15mm thick steel sheet is welded to the end of each I-beam. The outer steel arch frame uses I16 I-beams. All I-beams are first assembled on a flat site. After the plane position and elevation are ensured to be correct, all I-beams are installed. After the steel arch frame is installed, the steel arch frame is connected as a whole with a Φ133mm longitudinal orifice pipe, and the steel arch frame is fixed with a locking anchor rod and a steel pipe support method; then multiple guide pipes are fixed to the steel arch frame in turn with Φ22mm fixing bars and welded; after the guide pipes are welded, 100cm thick C25 concrete is poured. Wrap the sleeve arch and guide pipe; step ii, drilling: set up a drilling platform and a pipe-roof drilling rig, and then use the pipe-roof drilling rig to drill holes along the length direction of the guide pipe, and the drilling sequence is from high hole position to low hole position; step iii, jacking steel pipes: multiple steel pipes are pushed into the hole in sequence by a machine, and the section lengths of the two steel pipes used are 3m and 6m respectively. The steel pipe inserted in each hole is a combination of the two steel pipes. Any two connected steel pipes are connected with threads, the thread length is 15cm, and the rock-entering end of the steel pipe is provided with a long A cone head with a diameter of 15 cm is used. A slurry outlet hole with a diameter of 12 mm is drilled around the side wall of each steel pipe. The slurry outlet holes are arranged in a staggered manner with a spacing of 50 cm. A 10 mm thick reinforcement hoop is welded at the tail of the steel pipe to prevent leakage during grouting. The pipe-roof steel pipe is fixed on the sleeve arch through a Φ127 orifice pipe; Step iv, pipe-roof grouting: to prevent slurry from leaking during grouting, 20 cm thick concrete is sprayed on the face of the tunnel. The orifice pipe and the end of the steel pipe are tightly sealed with relatively sticky plain cement slurry, and grouting is performed after it solidifies and hardens;

[0048] Grouting reinforcement technology is to inject one or more slurry materials with fluidity, filling properties, and gelling properties into the soft stratum in a certain ratio through the grouting pipe. The slurry squeezes out the moisture and air between the soil particles by penetration, splitting, and compaction, so that the slurry and the original loose soil particles are bonded into a whole, thereby improving the strength of the bedrock of the building, reducing the water permeability of the bedrock, and preventing the building from settling or tilting. Step i, constructing a grouting curtain: arranging a plurality of first grouting holes on the periphery of the building, arranging a first grouting pipe in each first grouting hole, and injecting grout into the first grouting pipe. The grouting curtain formed can control the flow direction of the slurry during the subsequent grouting reinforcement and compensation grouting of the building base, so that it will not dissipate around the stratum, and avoid the slurry from flowing out to cause the surface uplift; step ii, reinforce the building base, arrange a plurality of second grouting holes between the plurality of first grouting holes and the building, arrange a second grouting pipe in each second grouting hole, and inject grout into the second grouting pipe, so that The slurry is filled in the weak area of ​​the stratum to improve the density of the base and form a bearing layer to achieve the purpose of strengthening the stratum. Among them, each second grouting pipe (including a main pipe 3 and multiple branch pipes 4) is in the shape of a tree branch, which can make the slurry spread more effectively in the soil and consolidate with more weak soil, thereby improving the grouting reinforcement effect and avoiding the problem of limited slurry diffusion area when using conventional sleeve valve pipes for grouting; step iii, compensatory grouting is carried out. The purpose of compensatory grouting is to effectively control the settlement of the building. Therefore, it is necessary to observe the settlement observation point. When When a building undergoes a large settlement, grouting is carried out in time to lift the building and effectively control the settlement of the building: multiple compensation grouting holes are arranged on the periphery of the building, a compensation grouting pipe is arranged in each compensation grouting hole, and a settlement monitoring device is set up corresponding to each compensation grouting hole. When the settlement value is greater than the warning value, grouting is injected into the compensation grouting pipe, wherein each settlement monitoring device includes a first container 7 arranged at the settlement observation point, a second container 8 arranged at the permanent leveling point, a water pipe connecting the first container 7 and the second container 8, and a water pipe for monitoring the liquid level of the second container 8. The height water level detection mechanism, since the first container 7 and the second container 8 form a communicating vessel, when the settlement observation point where the first container 7 is located is displaced in the vertical direction (settled or lifted), the first container 7 will also settle or rise accordingly, and the height of the liquid surface of the first container 7 will change accordingly, causing the liquid surface height of the second container 8 to change. According to the principle of communicating vessels, there is a numerical relationship between the change value of the liquid surface height of the second container 8 and the change value of the height of the first container 7 (or the settlement observation point). Therefore, the change value of the liquid surface height of the second container 8 can reflect the settlement amount of the settlement observation point.

[0049] In another technical solution, the pipe shed of a tunnel closest to the building is designed to be two layers, which can provide better support effect and achieve better building reinforcement effect, such as Figure 2As shown, the upper pipe rack 2 is laid on the lower pipe rack 1 at an elevation angle of 1°, the horizontal centerline spacing between the two pipe racks is 35 cm, the length of the two pipe racks is 50 m, the circumferential spacing between any adjacent steel pipes in each pipe rack is 40 cm, and each steel pipe is a Φ108 hot-rolled seamless steel pipe.

[0050] In another technical solution, in order to increase the rigidity and strength of the pipe roof, three φ22 steel bars are set in the steel pipe, and multiple Φ42×3.5mm fixed steel pipes are arranged at intervals of 30cm along the length of the steel bars, and each fixed steel pipe fixes and connects the three steel bars.

[0051] In another technical solution, two first grouting hole groups are arranged in parallel from the inside to the outside of the building, each first grouting hole group includes a plurality of first grouting holes arranged at intervals along the circumference of the building, the inner first grouting hole group is spaced 2m from the building, the two first grouting hole groups are spaced 0.6m apart, and the distance between any two adjacent first grouting holes is 0.6m apart. A first grouting pipe with a length of 6m is inserted into each first grouting hole; a double-tube backward segmented grouting process is adopted to inject grout into the first grouting pipe, the final grouting pressure is 0.6-1.0MPa, the grouting volume is 200-300L / m, the grouting material used is a double-liquid slurry of cement and water glass, and the volume ratio of cement to water glass is 1:1. The double-liquid slurry has the advantages of good controllability and high stone rate after solidification, wherein the water-cement ratio of cement is 0.6:1-1.1, and the concentration of water glass is 35 degrees Baume.

[0052] In another technical solution, two second grouting hole groups are symmetrically arranged on both sides of the building, each second grouting hole group is 1.5m away from the building, each second grouting hole group includes 3 second grouting holes arranged at intervals, each second grouting hole extends downwardly in a direction close to the building, and the inclination angles of the three second grouting holes on the same side are 30°, 40°, and 50°, respectively, and the hole depths are 8m, 9m, and 10m, respectively; a second grouting pipe is inserted into each second grouting hole, and a double-tube backward segmented grouting is adopted. The grouting process is to inject grout into the second grouting pipe, the final grouting pressure is 0.6-1.0MPa, the grouting volume is 200-300L / m, the grouting material is a double liquid slurry of cement and water glass, and the volume ratio of cement to water glass is 1:1. The double liquid slurry has the advantages of good controllability and high stone rate after solidification. Among them, the water-cement ratio of cement is 0.6:1-1.1, and the concentration of water glass is 35 degrees Baume; arranging the second grouting pipe in this inclined large-angle manner can effectively expand the grouting reinforcement range and improve the building reinforcement effect.

[0053] In another technical solution, Figure 3As shown, a plurality of through holes are arranged at intervals on each main pipe 3, one through hole corresponds to a branch pipe 4, and the outer side of each through hole is covered by a water-soluble adhesive tape 5; each branch pipe 4 is arranged vertically with the main pipe 3, and each branch pipe 4 includes a plurality of coaxial pipe bodies which are slidably sleeved in sequence, and one end of each pipe body away from the through hole is connected to the inner wall of the main pipe 3 by a water-soluble adhesive, and a plurality of elastic members 6 are arranged inside the innermost pipe body, and one end of each elastic member 6 is connected to the inner wall of the main pipe 3, and the other end is connected to the inner wall of the innermost pipe body. The other end of the through hole is connected; when the second grouting pipe is not inserted into the second grouting hole, the outside of the through hole is covered with a water-soluble tape 5. At this time, the elastic member 6 is in a compressed state, and multiple tube bodies of the branch pipeline 4 can be accommodated in the main pipeline 3. The second grouting pipe is inserted into the second grouting hole. The water-soluble tape 5 fails when encountering formation water, and the through hole is opened. Under the elastic force of the elastic member 6, multiple tube bodies pass through the through hole and extend to the outside of the main pipeline 3. At this time, the second grouting pipe forms a tree-like shape; at the same time, multiple slurry outlet holes are arranged at intervals on each main pipeline 3 and each tube body. Since the second grouting hole formed by drilling is generally vertical, in order to facilitate the insertion of the second grouting pipe into the second grouting hole, the branch pipe is designed to be compressible and retractable; under the action of the elastic member, the branch pipe extends into the soil, which can make the slurry during grouting diffuse over a larger range in the soil, and the slurry is consolidated with more weak soil, thereby better improving the bearing capacity of the formation, avoiding the problem of limited slurry diffusion surface of conventional sleeve valve pipes, and being able to improve the grouting reinforcement effect of buildings; at the same time, the branch pipe has a certain rigidity and strength, and can also play a certain anchoring role in the soil, further improving the bearing capacity of the formation.

[0054] In another technical solution, a plurality of compensating grouting holes are arranged at 1.5 m from the periphery of the building along the circumferential direction, the spacing between any two adjacent compensating grouting holes is 2 m, the two compensating grouting holes adjacent to the second grouting hole are 1 m apart from the second grouting hole, the depth of the compensating grouting holes is 6 m, and they are inclined toward the direction of the building with an inclination angle of 60°. The compensating grouting pipe adopts a PVC sleeve valve pipe, and the backward segmented grouting process is adopted to grout the compensating grouting pipe. The final grouting pressure is 0.5 to 2.0 MPa. The grouting material used is a double liquid slurry of cement and water glass, and the volume ratio of cement to water glass is 1:1. The double slurry has the advantages of good controllability and high stone rate after solidification. Among them, the water-cement ratio of cement is 0.8:1 to 1.1, and the concentration of water glass is 35 degrees Baume.

[0055] In another technical solution, the settlement observation point is set near the compensation grouting hole, such as Figure 4As shown, the first container 7 and the second container 8 are both containers of equal cross-section with equal cross-sectional areas. The water level detection mechanism includes a float 9 arranged on the liquid surface of the second container 8 and a laser displacement sensor 10 arranged directly above the float 9. The laser emitter of the laser displacement sensor 10 is vertically aligned with the float 9, and the laser displacement sensor 10 is fixed with a fixed bracket; the laser displacement sensor 10 obtains the change value of the vertical height of the first container 7 by measuring the change value of the liquid level height in the second container 8, and its value is the settlement amount of the settlement observation point.

[0056] The specific mechanism for calculating the amount of sedimentation is as follows: the laser transmitter of the laser displacement sensor 10 emits laser light toward the floating plate 9 and measures the round trip time of the laser light. The round trip time is multiplied by the speed of light to obtain the round trip distance. Half of the round trip distance is the distance h between the liquid surface in the second container 8 and the laser transmitter of the laser displacement sensor 10. 0 (Unit: mm); When the height of the settlement observation point where the first container 7 is located changes (settlement or elevation), the first container 7 also produces a height displacement (settlement or elevation). Since the first container 7 and the second container 8 form a communicating vessel, the liquid level of the second container 8 will change (decrease or increase). The laser displacement sensor 10 can measure the distance h between the second container 8 and the laser emitter of the laser sensor at this time. t (unit: mm), the change value of the liquid level height of the second container 8 (h t -h 0 There is a numerical relationship between the height change value X (unit: mm) and the height change value of the first container: X = (h t -h 0 ) / 2, unit: mm, therefore, the sedimentation amount of the first container 7 (or the sedimentation observation point) is obtained by constantly monitoring the change in the liquid level height of the second container 8.

[0057] In another technical solution, the warning value is set to 8 to 10 mm of settlement, or the settlement rate exceeds 2 to 3 mm / d; when the change value of the liquid level in the second container 8 is greater than the warning value, grouting is injected into the compensating grouting pipe, and the grouting is stopped when the elevation of the settlement observation point is within the range of +3 to 4 mm or -3 to 4 mm of the starting elevation, that is, the liquid level in the second container 8 is 1.5 to 2 mm higher or lower than the initial liquid level. The numerical range of the laser displacement sensor 10 should be (h 0 -1.5)~(h 0 -2) or (h 0 +1.5)~(h 0 +2), unit: mm; the grouting material is a double liquid slurry of cement and water glass, the volume ratio of cement to water glass is 1:1, the double slurry has the advantages of good controllability and high stone rate after solidification, among which the water-cement ratio of cement is 0.8:1~1:1, and the concentration of water glass is 35 degrees Baume.

[0058] The number of devices and processing scales described here are used to simplify the description of the present invention. Applications, modifications and variations of the present invention will be obvious to those skilled in the art.

[0059] Although the embodiments of the present invention have been disclosed as above, they are not limited to the applications listed in the specification and the implementation modes, and they can be fully applied to various fields suitable for the present invention. For those familiar with the art, additional modifications can be easily implemented. Therefore, without departing from the general concept defined by the claims and the scope of equivalents, the present invention is not limited to the specific details and the illustrations shown and described herein.

Claims

1. Reinforcement methods for buildings adjacent to tunnels, It is characterized in that include: Pipe shed support: at least one layer of pipe shed is laid in the soil between each tunnel and the building for reinforcement; Grouting reinforcement, grouting reinforcement and protection of buildings, specifically: Step i, arranging a plurality of first grouting holes on the periphery of the building, arranging a first grouting pipe in each first grouting hole, and injecting grout into the first grouting pipe; Step ii, arranging a plurality of second grouting holes between the plurality of first grouting holes and the building, arranging a second grouting pipe in each second grouting hole, each second grouting pipe being in the shape of a tree branch, and comprising a main pipe and a plurality of branch pipes; grouting into the second grouting pipe; Step iii, arranging a plurality of compensating grouting holes on the periphery of the building, arranging a compensating grouting pipe in each compensating grouting hole, and correspondingly setting a settlement monitoring device for each compensating grouting hole, each settlement monitoring device comprising a first container arranged at a settlement observation point, a second container arranged at a permanent level point, a water pipe connecting the first container and the second container, and a water level detection mechanism for monitoring the liquid level of the second container, and when the change value of the liquid level of the second container is greater than the warning value, grouting is injected into the compensating grouting pipe; Multiple through holes are arranged at intervals on each main pipe, one through hole corresponds to one branch pipe, and the outside of each through hole is covered with a water-soluble tape; Each branch pipeline is arranged perpendicularly to the main pipeline, and each branch pipeline includes a plurality of coaxial pipe bodies that are slidably sleeved in sequence. One end of each pipe body that is away from the through hole is connected to the inner wall of the main pipeline through a water-soluble adhesive. A plurality of elastic members are arranged inside the innermost pipe body, and one end of each elastic member is connected to the inner wall of the main pipeline, and the other end is connected to the other end of the innermost pipe body that is close to the through hole. Each elastic member is arranged so that when the outer side of the through hole is covered with a water-soluble adhesive tape, the elastic member is in a compressed state, and the plurality of pipe bodies of the branch pipeline are stored inside the main pipeline. When the water-soluble adhesive tape fails when it encounters water, the through hole is opened, and the plurality of pipe bodies extend through the through hole to the outside of the main pipeline under the elastic force of the elastic member. A plurality of slurry outlet holes are arranged at intervals on each main pipeline and each pipe body.

2. The method for reinforcing a building adjacent to a tunnel as claimed in claim 1, It is characterized in that The pipe shed of a tunnel closest to the building is designed to be two-layered. The upper pipe shed is laid on the lower pipe shed at an elevation angle of 1°. The horizontal centerline spacing between the two layers of pipe sheds is 35cm. The length of the two layers of pipe sheds is 50m. The circumferential spacing between any adjacent steel pipes in each layer of pipe shed is 40cm. Each steel pipe is Φ108 hot-rolled seamless steel pipe.

3. The method for reinforcing a building adjacent to a tunnel as claimed in claim 2, It is characterized in that Three steel bars are set in each steel pipe, and a plurality of fixed steel pipes are arranged at intervals of 30 cm along the length direction of the steel bars, and each fixed steel pipe fixes and connects the three steel bars.

4. The method for reinforcing a building adjacent to a tunnel as claimed in claim 1, It is characterized in that Two first grouting hole groups are arranged in parallel from the inside to the outside of the building, each first grouting hole group includes a plurality of first grouting holes arranged at intervals along the circumference of the building, the inner first grouting hole group is spaced 2m from the building, the two first grouting hole groups are spaced 0.6m, and the distance between any two adjacent first grouting holes is 0.6m. A first grouting pipe with a length of 6m is inserted into each first grouting hole; a double-tube backward segmented grouting process is adopted to inject grout into the first grouting pipe, the final grouting pressure is 0.6-1.0MPa, the grouting volume is 200-300L / m, the grouting material used is a double-liquid slurry of cement and water glass, the volume ratio of cement to water glass is 1:1, wherein the water-cement ratio of cement is 0.6:1-1.1, and the concentration of water glass is 35 degrees Baume.

5. The method for reinforcing a building adjacent to a tunnel as claimed in claim 1, It is characterized in that Two second grouting hole groups are symmetrically arranged on both sides of the building, with each second grouting hole group being 1.5m away from the building. Each second grouting hole group includes three second grouting holes arranged at intervals, and each second grouting hole extends downwardly in a direction close to the building. The inclination angles of the three second grouting holes on the same side are 30°, 40° and 50°, respectively, and the hole depths are 8m, 9m and 10m, respectively. A second grouting pipe is inserted into each second grouting hole, and grouting is injected into the second grouting pipe by a double-tube backward segmented grouting process. The final grouting pressure is 0.6-1.0MPa, and the grouting volume is 200-300L / m. The grouting material used is a double-liquid slurry of cement and water glass with a volume ratio of cement to water glass of 1:1, wherein the water-cement ratio of cement is 0.6:1-1.1, and the concentration of water glass is 35 degrees Baume.

6. The method for reinforcing a building adjacent to a tunnel as claimed in claim 1, It is characterized in that A plurality of compensating grouting holes are arranged at 1.5m from the periphery of the building along the circumferential interval, the spacing between any two adjacent compensating grouting holes is 2m, the two compensating grouting holes adjacent to the second grouting hole are 1m apart from the second grouting hole, the depth of the compensating grouting holes is 6m, and they are inclined toward the direction of the building with an inclination angle of 60°. The compensating grouting pipe adopts PVC sleeve valve pipe, and the backward segmented grouting process is adopted to inject grout into the compensating grouting pipe. The final grouting pressure is 0.5~2.0MPa, and the grouting material used is a double liquid slurry of cement and water glass. The volume ratio of cement to water glass is 1:1, wherein the water-cement ratio of cement is 0.8:1~1.1, and the concentration of water glass is 35 degrees Baume.

7. The method for reinforcing a building adjacent to a tunnel as claimed in claim 1 or 6, It is characterized in that The settlement observation point is set near the compensation grouting hole, and the first container and the second container are both equal-section containers with equal cross-sectional areas; The water level detection mechanism includes a floating plate arranged on the liquid surface of the second container and a laser displacement sensor arranged directly above the floating plate. The laser displacement sensor is fixed with a fixed bracket. The laser displacement sensor obtains the change value of the vertical height of the first container by measuring the change value of the liquid level height in the second container, and the value is the settlement amount of the settlement observation point.

8. The method for reinforcing a building adjacent to a tunnel as claimed in claim 1, It is characterized in that The warning value is a settlement amount of 8 to 10 mm; when the change in the liquid level height of the second container is greater than the warning value, grouting is injected into the compensating grouting pipe, and grouting is stopped when the elevation of the settlement observation point is within the range of ±3 to 4 mm of the starting elevation.

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