Indoor experimental device and experimental method of micro-disturbance grouting technology for operating subway

Abstract

The present invention relates to a simulation detection device for tunnels and shield equipment, and specifically to an indoor experimental device and experimental method for micro-disturbance grouting technology of an operating subway. The invention aims to solve the problem in the prior art that there is a lack of simulation equipment in the laboratory for micro-disturbance conditions during operation. The present invention includes a soil box for accommodating scaled segments, and a press-fitted cover is provided on the upper surface of the soil box. The cover is installed on a gantry-shaped reaction frame, and a hydraulic telescopic rod is provided between the cover and the reaction frame. The scaled segments form a scaled tunnel, and a grouting hole is reserved at the bottom of each scaled tunnel to connect the grouting circuit. A non-contact measuring mechanism is installed on the grouting circuit, and the grouting circuit also includes a bypass branch connected to a bypass grouting pipe. The bypass grouting pipe passes through the cover, and its end is located outside the scaled tunnel. The advantage is that the roundness of the scaled tunnel can be trimmed by superimposing grouting in small amounts and multiple times in stages around the scaled tunnel.

Description

Technical Field

[0001] The invention relates to the field of indoor experimental devices for micro-disturbance grouting technology for operating subways, in particular to an indoor experimental device and an experimental method for micro-disturbance grouting technology for operating subways. Background Art

[0002] In the field of tunnel construction, during the process of tunnel construction, the periphery is fixed with pipe segments, which is a conventional fixing method. However, after long-term use, the applicant found that the current pipe segments are prone to deformation after long-term use, and the deformation is very difficult to repair.

[0003] In actual work, the deformation of the segments can be divided into various forms, including being widened on both sides, deforming the entire segment into an elliptical shape, and also the front and rear deformations causing the entire longitudinal surface of the tunnel to sink. In the published patent application document, the application number is CN202210386268.8, entitled A method for grouting behind the wall of a shield tunnel segment. A technical method is disclosed. The method is specifically as follows: S1: When the shield equipment is digging the tunnel, the tunnel segments are laid closely following the shield equipment, and then the retractable transmission pipe is inserted deep between the tunnel segments and the tunnel soil wall, and the supply equipment is used to inject concrete through the transmission pipe. S2: As the transmission pipe is poured, the wrapping bag at the end of the transmission pipe will expand, allowing the concrete to be shaped and solidified inside the wrapping bag 2; through this setting, the expanded concrete will first enter the wrapping bag, allowing all the wrapping bags to expand first to determine the basic shape. When the wrapping bag is expanded as a whole, the remaining concrete will expand and penetrate outward to fill the small gaps, which not only reduces the pressure of concrete on the pipe segment and the soil wall, but also reduces the problem of tunnel leakage caused by excessive pressure. At the same time, even if leakage occurs, the concrete will be blocked by the wrapping bag and will not leak on a large scale. However, in this method, only the leakage problem is solved, and the deformation cannot be repaired.

[0004] Furthermore, the application number is CN202210387965.5, named a simulation device and simulation method for shield tunnel segment deformation and surface settlement, which realizes effective prevention and control of the horizontal displacement of the shield tunnel segment through the telescopic structure limiter, uses the multi-layer stratum spring that can be freely disassembled at the bottom, and the upper part uses a high-precision displacement sensor to monitor the settlement deformation of multiple positions in the tunnel. After the shield tunnel segment is assembled, the position of the shield tunnel segment is fixed through the cooperation of the telescopic structure limiter and the shell assembly. However, since it is impossible to predict where the deformation will occur, the large-scale reserved equipment has increased the construction cost to a certain extent.

[0005] However, when the pipeline undergoes overall arc-shaped settlement and deformation, the settlement manifests itself as a large-area and long-length settlement. However, at present, there is a lack of corresponding equipment to batch-repair the settled pipe segments and solve the problem of large-area deformation and settlement. This is something that cannot be solved in the existing technology and comparative documents, especially the lack of laboratory simulation equipment for this problem. This is a problem that urgently needs to be solved in the current technology. Summary of the invention

[0006] The purpose of the present invention is to solve the problem in the prior art that there is a lack of simulation equipment in the laboratory regarding micro-disturbance conditions during operation.

[0007] The specific scheme of the present invention is: it includes a soil box for accommodating scaled pipe segments, the upper surface of the soil box is provided with a press-fitted cover body, the cover body is installed on a gantry-shaped reaction frame, a telescopic hydraulic rod is arranged between the cover body and the reaction frame, the scaled pipe segments form a scaled tunnel, a grouting hole is reserved at the bottom of each scaled tunnel section to connect the grouting circuit, the grouting circuit includes a grouting main pipe as a trunk line, and also includes a grouting branch pipe connected to the grouting main pipe and the same number of pipe section circles, the grouting branch pipe is flexibly connected to the corresponding grouting hole, a measuring mechanism is installed on the grouting circuit, and the grouting circuit also includes a bypass branch connected to a bypass grouting pipe, the bypass grouting pipe passes through the cover body, and its end is located outside the scaled tunnel.

[0008] In a specific implementation, at least two transverse connecting rods are provided on the cover body, the upper part of the transverse connecting rods is connected to the longitudinal connecting rods, the upper surface of the longitudinal connecting rods is connected to the piston end of the telescopic hydraulic rod, and a plurality of reserved side connection holes are evenly distributed in rows on the cover body and between the transverse connecting rods.

[0009] In a specific implementation, the grouting main pipe is installed on a pipe support, and the installation position of the end thereof coincides with the designed axis of the scaled tunnel.

[0010] In a specific implementation, the measuring mechanism includes a sliding block slidably mounted on the grouting trunk road, and a non-contact distance meter is installed on the sliding block.

[0011] In a specific implementation, a transition block is clamped on the top of the grouting trunk line, an open stepped hole corresponding to the outer contour of the grouting trunk line is arranged at the bottom of the transition block, a moving pair is arranged between the top of the transition block and the slider, and the non-contact distance meter is arranged on the top surface and both side surfaces of the slider.

[0012] In a specific implementation, the end of the grouting branch pipe is also provided with an extension pipe extending toward the bottom of the scaled tunnel.

[0013] In a specific implementation, a timed opening and closing valve is provided on the grouting branch pipe, and evenly distributed hydraulic cylinder groups are provided on both sides of the soil box.

[0014] In a specific implementation, a pressure detection mechanism for detecting the internal pipeline pressure is provided on the grouting branch pipe.

[0015] The present invention also relates to an experimental method for simulating the micro-disturbance of a subway casing, comprising the following steps:

[0016] (1) Installation equipment: a set of soil boxes with compression and tension equipment on the sides and top are formed, and through holes are provided on the front surface of the soil box to install scaled segments to form a scaled tunnel;

[0017] (2) Installing detection equipment: installing a grouting branch pipe in the scaled-down tunnel, with the outlet of the grouting branch pipe facing downward of the scaled-down tunnel, and installing a measuring mechanism on the grouting branch pipe to monitor the deformation of the pipe segment in real time;

[0018] (3) Grouting repair at the appropriate time: The compression and tension equipment applies force to the soil box to simulate the pressure settlement deformation around the scaled-down tunnel. When the measuring mechanism detects uneven settlement of the central axis of the scaled-down tunnel after deformation, the reinforcement slurry is injected layer by layer at the point where the uneven settlement is the largest.

[0019] Wherein, in step (3), the time interval between injection of each layer of the reinforcement slurry is greater than 15 minutes, and the secondary injection slurry is above the solidified upper injection slurry.

[0020] The invention also comprises bypass branches on two outer sides of the scaled-down segment to round off the side edges of the scaled-down tunnel.

[0021] The beneficial effects of the present invention are:

[0022] A set of simulated detection devices is provided, which can detect the deformation on the simulation platform in real time, provide simulation for actual work, and the detection process is fast and accurate;

[0023] The detection device in the present invention adopts the commonly used non-contact measurement. A single or small amount of sliding can realize the measurement of the distance in three directions and compare it with the basic data. When the distance changes, it means that the shape of the pipe segment and the tunnel has been disturbed and deformed. After that, reverse rounding can be achieved by superimposed grouting.

[0024] In response to micro-disturbance situations, laboratory simulation is implemented, and quantitative control is exercised each time grouting is carried out. Grouting is carried out in small amounts and multiple times in stages from the bottom of the tunnel to the bottom in layers. At the same time, uneven settlement is detected and with the help of a test bench, a reasonable rounding plan is determined. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a schematic diagram of the axial uneven settlement in the tunnel under actual conditions;

[0026] Figure 2 It is a three-dimensional diagram of the experimental apparatus;

[0027] Figure 3 It is a stereogram of the test device from another angle;

[0028] Figure 4 yes Figure 2 a front view of the device shown;

[0029] Figure 5 yes Figure 2 a top view of the device shown;

[0030] Figure 6 is a top view corresponding to another embodiment;

[0031] Figure 7 This is the installation diagram of the grouting main pipe and grouting branch pipe;

[0032] The names of the components in the figure are: 1. Hydraulic cylinder; 2. Self-reaction frame; 3. Cover body; 4. Soil box; 5. Scaled pipe segment; 6. Grouting main pipe; 7. Grouting branch pipe; 8. Sliding block; 9. Non-contact distance meter; 10. Reserved bypass hole; 12. Bypass grouting pipe; 13. Hydraulic cylinder group; 14. Hydraulic top plate. DETAILED DESCRIPTION

[0033] The preferred embodiments of the present invention are described below in conjunction with the accompanying drawings. It should be understood that the preferred embodiments described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention.

[0034] Example 1

[0035] An indoor experimental device for micro-disturbance grouting technology in an operating subway, see Figures 1 to 7 , an indoor experimental device for micro-disturbance grouting technology of operating subway is designed, including a soil box 4 for accommodating scaled pipe segments 5, a press-fit cover body is arranged on the upper surface of the soil box 4, the cover body is installed on a gantry-shaped reaction frame, a telescopic hydraulic rod is arranged between the cover body and the reaction frame, the scaled pipe segments 5 form a scaled tunnel, and a grouting hole is reserved at the bottom of each scaled tunnel to connect the grouting circuit, the grouting circuit includes a grouting main pipe 6 as a trunk, and also includes a grouting branch pipe 7 connected to the grouting main pipe 6 and consistent with the number of pipe sections, the grouting branch pipe 7 is flexibly connected to the corresponding grouting hole, a measuring mechanism is installed on the grouting circuit, and the grouting circuit also includes a bypass branch connected to the bypass grouting pipe 12, the bypass grouting pipe 12 passes through the cover body, and its end is outside the scaled tunnel. The grouting main pipe 6 is installed on the pipeline bracket, and the installation position of its end coincides with the design axis of the scaled tunnel.

[0036] The measuring mechanism includes a slider 8 which is slidably mounted on the grouting trunk line, and a non-contact distance meter 9 is installed on the slider 8. During operation, one set of sliding measurements can be used, or multiple sets can be installed. When the measurement data on one set is different from the normal data, it can be determined that the roundness has deviated. When the data at different positions before and after show an arithmetic difference, it can be determined that uneven settlement has occurred. When uneven settlement occurs, grouting is mainly performed layer by layer at the bottom of the settlement. When deformation occurs on the side, grouting is performed using a bypass to achieve extrusion repair after the grouting solidifies.

[0037] A transition block is clamped on the top of the grouting trunk line, and an open stepped hole corresponding to the outer contour of the grouting trunk line is arranged at the bottom of the transition block. A moving pair is arranged between the top of the transition block and the slider 8, and the non-contact distance meter 9 is respectively arranged on the top surface and both side surfaces of the slider 8.

[0038] The end of the grouting branch pipe 7 is also provided with an extension pipe extending and installed toward the bottom of the scaled tunnel, so as to be used when the distance to be repaired is relatively long.

[0039] The grouting branch pipe 7 is provided with a timed opening and closing valve, and both sides of the soil box 4 are also provided with evenly distributed hydraulic cylinder groups 13. In specific working conditions, the side pressure can be simulated by pressurizing the hydraulic cylinder group 13. The hydraulic cylinders in the hydraulic cylinder group control each hydraulic top plate in the corresponding box body to achieve force transmission.

[0040] The grouting branch pipe 7 is provided with a pressure detection mechanism for detecting the internal pipeline pressure.

[0041] The present invention also relates to an experimental method for simulating the micro-disturbance of a subway casing, comprising the following steps:

[0042] (1) Installation equipment: a soil box 4 with compression and tension equipment on the sides and top is formed, and a through hole is provided on the front surface of the soil box 4 to install the scaled-down segments 5, so as to form a scaled-down tunnel;

[0043] (2) Installing detection equipment: installing a grouting branch pipe 7 in the scaled-down tunnel, with the outlet of the grouting branch pipe 7 facing downward of the scaled-down tunnel, and installing a measuring mechanism on the grouting branch pipe 7 to monitor the deformation of the pipe segment in real time;

[0044] (3) Grouting repair at the right time: The compression and tension equipment applies force to the soil box 4 to simulate the pressure settlement deformation around the scaled-down tunnel. When the measuring mechanism detects uneven settlement of the central axis of the scaled-down tunnel after deformation, the reinforcement slurry is injected layer by layer at the point where the uneven settlement is maximum.

[0045] Wherein, in step (3), the time interval between injection of each layer of the reinforcement slurry is greater than 15 minutes, and the secondary injection slurry is above the solidified upper injection slurry.

[0046] The invention also includes bypass branches on both outer sides of the scaled-down segment 5 to round off the side edges of the scaled-down tunnel.

[0047] During the working process of this embodiment, the geometric ratio is 1:10, and the size of the model box is 1.5m*2m*2.2m in length*width*height. The length is about 12 rings of model segments, and the width of both sides of the segment ring is slightly larger than one times the tunnel diameter. The thickness of the simulated overburden on the segment ring is about 10m, and the thickness of the underlying soil layer is one times the tunnel diameter.

[0048] In order to simulate the drilling and grouting conditions inside the pipeline and to measure the convergence deformation and settlement changes of the segment ring, the two ends of the segment ring are set to be open and fixedly connected to the soil box 4. Considering the boundary effect, the first and last ring segments are not taken as the experimental research objects.

[0049] Since the actual segment material itself has high rigidity and small deformation, the segment out of roundness is mainly due to the deformation of the joints. In order to facilitate processing and manufacturing, steel segments with the same high rigidity are used for simulation. The ring width is 1.2m and it is divided into 6 pieces according to the commonly used design of subway segments. The joints are assembled with scaled bolts and staggered joints according to the actual working conditions on site.

[0050] The grouting pressure is controlled within 0.5 MPa. The single-side soil box 4 can withstand a maximum force of 250 t. The soil box 4 is made of steel plates with ribs added on the outside.

[0051] The upper oil cylinder is used to provide the soil pressure and additional load on the ground. The soil thickness of 10m is about 0.2MPa. The upper steel plate of the soil box 4 can move freely in the height direction to evenly transfer the pressure of the jack to the upper surface of the stratum.

[0052] Example 2

[0053] The principle of this embodiment is the same as that of embodiment 1, except that Figure 7 , and also includes at least two transverse connecting rods provided on the cover body, the upper part of the transverse connecting rod is connected to the longitudinal connecting rod, the upper surface of the longitudinal connecting rod is connected to the piston end of the telescopic hydraulic rod, and a plurality of reserved bypass holes 10 are evenly arranged in rows on the cover body and between the transverse connecting rods. In the specific implementation process, when the left and right sides of the tunnel are deformed, grouting and pressurization can be achieved through bypass to help repair the pipe segment. In other words, removable grouting holes are reserved on the upper steel plate, and the grouting holes are arranged in a matrix, which is convenient for conducting micro-disturbance tests of grouting from the surface. Removable grouting holes are reserved at the bottom of the pipe segment ring, and the grouting holes are in a vertical direction.

[0054] Finally, it should be noted that the above are only preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or replace some of the technical features therein with equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. An indoor experimental device for micro-disturbance grouting technology for operating subways, characterized by: The invention comprises a soil box (4) for accommodating scaled pipe segments (5); a press-fitted cover is arranged on the upper surface of the soil box (4); the cover is mounted on a gantry-shaped reaction frame; a telescopic hydraulic rod is arranged between the cover and the reaction frame; the scaled pipe segments (5) form a scaled tunnel; a grouting hole is reserved at the bottom of each scaled tunnel section to connect a grouting circuit; the grouting circuit comprises a grouting main pipe (6) as a main line; and a grouting branch pipe (7) connected to the grouting main pipe (6) and having the same number of pipe segments; and the grouting branch pipe (7) is connected to the grouting main pipe (6) and has the same number of pipe segments. The pipe (7) is flexibly connected to the corresponding grouting hole, a measuring mechanism is mounted on the grouting circuit, the grouting circuit also includes a bypass branch connected to a bypass grouting pipe (12), the bypass grouting pipe (12) passes through the cover body, and its end is located outside the scaled tunnel. The two sides of the soil box (4) are also provided with evenly distributed hydraulic cylinder groups (13), and the simulation of side pressure is achieved by pressurizing the hydraulic cylinder group (13), and the hydraulic cylinders in the hydraulic cylinder group control each hydraulic top plate in the corresponding box body.

2. The indoor experimental device for micro-disturbance grouting technology for operating subway according to claim 1, characterized in that: At least two transverse connecting rods are provided on the cover body, the upper part of the transverse connecting rods is connected to the longitudinal connecting rods, the upper surface of the longitudinal connecting rods is connected to the piston end of the telescopic hydraulic rod, and a plurality of reserved side connection holes (10) are evenly arranged in a row on the cover body and between the transverse connecting rods.

3. The indoor experimental device for micro-disturbance grouting technology for operating subway according to claim 2, characterized in that: The grouting main pipe (6) is installed on a pipe support, and the installation position of the end thereof coincides with the designed axis of the scaled tunnel.

4. The indoor experimental device for micro-disturbance grouting technology for operating subway as claimed in claim 3, characterized in that: The measuring mechanism comprises a sliding block (8) slidably mounted on the grouting trunk road, and a non-contact distance meter (9) is mounted on the sliding block (8).

5. The indoor experimental device for micro-disturbance grouting technology for operating subway as claimed in claim 4, characterized in that: A transition block is clamped on the top of the grouting trunk line, an open stepped hole corresponding to the outer contour of the grouting trunk line is provided at the bottom of the transition block, a moving pair is provided between the top of the transition block and the slider (8), and the non-contact distance meter (9) is provided on the top surface and both side surfaces of the slider (8).

6. The indoor experimental device for micro-disturbance grouting technology for operating subways according to claim 1, characterized in that: The end of the grouting branch pipe (7) is also provided with an extension pipe extending and installed toward the bottom of the scaled tunnel, and the grouting branch pipe (7) is provided with a timed opening and closing valve.

7. The indoor experimental device for micro-disturbance grouting technology for operating subway as claimed in claim 5, characterized in that: The grouting branch pipe (7) is provided with a pressure detection mechanism for detecting the internal pipeline pressure.

8. An experimental method for simulating micro-disturbance of a subway casing, using the indoor experimental device for micro-disturbance grouting technology of an operating subway as claimed in claim 1, characterized in that: The following steps are involved: (1) Installation equipment: forming a set of soil boxes (4) with compression and tension equipment on the sides and top, and the front surface of the soil box (4) is provided with through holes for installing scaled-down segments (5) to form a scaled-down tunnel; (2) Installing detection equipment: installing a grouting branch pipe (7) in the scaled-down tunnel, the outlet of the grouting branch pipe (7) facing downward of the scaled-down tunnel, and installing a measuring mechanism on the grouting branch pipe (7) to monitor the deformation of the pipe segment in real time; (3) Grouting repair at an appropriate time: The compression and tension equipment applies force to the soil box (4) to simulate the pressure settlement deformation around the scaled-down tunnel. When the measuring mechanism detects uneven settlement of the central axis of the scaled-down tunnel after deformation, reinforcing slurry is injected layer by layer corresponding to the point where the uneven settlement is maximum. In step (3), the time interval between the injection of each layer of the reinforcing slurry is greater than 15 minutes, and the secondary injection slurry is above the solidified upper injection slurry.

9. The experimental method for simulating the micro-disturbance of a steel casing according to claim 8, characterized in that: It also includes bypass branches on both outer sides of the scaled-down segment (5) to round off the side edges of the scaled-down tunnel.

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