CN114577679B - In-situ stratum grouting test device and method based on tunnel settlement efficient treatment - Google Patents

Abstract

The invention provides an in-situ stratum grouting test device and method based on efficient tunnel settlement treatment, wherein the device comprises a model barrel, a confining pressure pore pressure loading system, a grouting system, a sensor and a data acquisition system; the confining pressure pore pressure loading system comprises a confining pressure loading device, a pore pressure maintaining device and a reaction frame, wherein the confining pressure loading device is arranged around the soil body in the model barrel, and the pore pressure maintaining device is used for maintaining the pore water pressure of the soil body; the grouting system comprises a grouting pipe, a penetration device positioned above the grouting pipe, a mixer connected with the grouting pipe through a guide pipe and a standard pressure/volume controller for controlling grouting parameters; the sensor and data acquisition system comprises a sensor positioned in the soil body and a data acquisition and processing system connected with the sensor. The method can test the disturbance condition of the surrounding soil layer and the lifting effect of the tunnel under different grouting modes and different grouting parameters, and selects the optimal grouting mode and the optimal grouting parameters by comparing test results.

Description

In-situ stratum grouting test device and method based on tunnel settlement efficient treatment

Technical Field

The invention relates to the technical field of tunnels and underground engineering, in particular to an in-situ stratum grouting test device based on efficient tunnel settlement treatment. In addition, the invention also relates to a using method of the grouting test device.

Background

The shield tunnel is a main structural form of urban rail transit and municipal tunnel, is a prefabricated assembly structure and has the characteristics of long distance, more joints and weak longitudinal rigidity. In the long-term operation in-process in tunnel, receive factors such as train dynamic load, underground water exploitation, worker's postero-concretion and proximity construction, tunnel structure takes place too big horizontal convergence deformation and vertical difference easily and subsides, and then leads to diseases such as section of jurisdiction fracture, joint percolating water, track irregularity, threatens tunnel structure safety and normal use. At present, the problem of long-term settlement of an operation tunnel is generally solved in a grouting and lifting mode in engineering. However, the current grouting lifting technology still faces two technical problems: firstly, different grouting modes have different applicability to different working conditions, grouting parameters need to be determined according to engineering experience or a similarity method, and the final grouting effect cannot be ensured; secondly, secondary disturbance is easily caused to the shield tunnel and the underground stratum in the grouting process, the safety of the tunnel structure is affected, and the consolidation settlement of the foundation is caused.

The model test is an effective means for exploring grouting modes and parameters, predicting the tunnel deformation control effect and researching grouting stratum disturbance. However, the existing grouting test device cannot simultaneously consider the factors, and meanwhile, the existing grouting simulation device can only realize the simulation of a single grouting mode.

Disclosure of Invention

Therefore, the invention aims to overcome the defect that the existing grouting device can only realize grouting simulation in a single mode, and provides the in-situ stratum grouting test device based on tunnel settlement high-efficiency treatment.

The invention also aims to provide a using method of the grouting test device.

The in-situ stratum grouting test device based on the tunnel settlement efficient treatment comprises a model barrel, a confining pressure pore pressure loading system, a grouting system, a sensor and a data acquisition system;

the confining pressure and pore pressure loading system comprises a confining pressure loading device, a pore pressure maintaining device and a reaction frame, wherein the reaction frame is erected above the model barrel through frame legs arranged on two sides of the model barrel, the confining pressure loading device is arranged around a soil body in the model barrel to apply confining pressure, and the pore pressure maintaining device is used for maintaining the pore water pressure of the soil body in the model barrel;

the grouting system comprises a grouting pipe inserted into a soil body, a penetration device positioned above the grouting pipe, a mixer connected with the grouting pipe through a guide pipe and a standard pressure/volume controller used for controlling grouting parameters;

the sensor and data acquisition system comprises a sensor positioned in the soil body in the model barrel and a data acquisition and processing system connected with the sensor through a data line;

the model barrel comprises a main barrel for a grouting test and an extension barrel positioned above the main barrel, the extension barrel is detachably connected with the main barrel, and the extension barrel and the main barrel are circular barrels with the same diameter;

the confining pressure loading device comprises a confining pressure air bag which is positioned in the main barrel and arranged around the soil body; an air bag supporting framework arranged between the confining pressure air bag and the side wall of the main barrel, and an air compressor for inflating the confining pressure air bag; the device also comprises a pressurizing plate which is positioned between the soil body and the injection device and covers the upper part of the soil body and a servo control system for regulating and controlling the pressurizing plate through a hydraulic servo oil cylinder, wherein the pressurizing plate is lifted after the soil body is grouted to simulate the upward movement of the tunnel after the grouting is carried out below the tunnel; the air bag supporting framework is externally connected with a power supply.

As one preferred choice of the grouting test device, 4 CPTU probing holes are reserved on the pressurizing plate, the central angle between two adjacent CPTU probing holes is 90 degrees, the distance from the CPTU probing hole to the center of the pressurizing plate from near to far is a CPTU hole three, a CPTU hole four, a CPTU hole one and a CPTU hole two which are the same in distance, a sealing ring is arranged along the side surface of the pressurizing plate, and at least two vibration exciters are arranged around the center of the pressurizing plate.

As a preferable preference of the grouting test device, the pore pressure maintaining device comprises a hydraulic pump, and the upper part of the hydraulic pump is provided with a pressure gauge for measuring the pore water pressure.

As a preferable example of the grouting test device of the present invention, the grouting pipes include four different types, which are an electrokinetic chemical grouting pipe, a sleeve valve grouting pipe, a film bag type grouting pipe, and a micro-disturbance grouting pipe.

As a preferable preference of the grouting test device, the sensor and data acquisition system further comprises a sensor fixing rod which is arranged in the soil body and used for fixing the sensor.

Preferably, the bottom of the leg of the reaction frame is provided with a fixable pulley.

As a preferable example of the grouting test device of the present invention, the guide pipe is provided with two valves, and a pressure gauge and a flow gauge are provided between the two valves.

The invention provides a using method of a grouting test device, which comprises the following steps:

s1: preparation: preparing sandy soil and clay; calibrating a sensor; preparing a grouting material according to test requirements;

s2: and (3) a test stage: the device is installed from bottom to top: assembling a reaction frame, placing a main barrel and an extension barrel on a supporting base, fixing a sensor fixing rod embedded with a sensor on the base of the main barrel, leading out a sensor data line from a wire outlet, and externally connecting a data acquisition and processing system;

s2 a: sample loading and fixing: pouring the remolded soil prepared by the test to the position away from the middle part of the main barrel according to the calculated amount, placing the grouting pipe at the right center of the main barrel, pouring the residual soil into the main barrel and the extension barrel, and additionally installing a pressurizing plate. And controlling the pressurizing plate to apply stable consolidation pressure through the hydraulic servo oil cylinder until the pressurizing plate is settled stably and the drainage groove is drained without water. Removing the pressurizing plate, the hydraulic servo oil cylinder and the extension barrel in sequence, scraping soil bodies exceeding the height range of the main barrel and leveling the top surfaces of the soil bodies;

s2 b: simulating the in-situ stress state of the soil body: and applying stable confining pressure on the soil body in the main barrel through the confining pressure air bag and the hydraulic servo oil cylinder, and simulating the in-situ stress of the soil body in the tunnel buried depth. The pore water pressure in the soil body is maintained through the hydraulic pump 5;

s2 c: and (3) CPTU detection: and opening the first CPTU hole of the pressurizing plate, and inserting the three-bridge probe into the first CPTU hole through the penetration device for detection. After the detection is finished, the three-bridge probe is pulled out, and the first CPTU hole is blocked;

s2 d: grouting and experimental data acquisition: and adjusting the pressurization mode of the servo control system, and switching to a force-displacement related mode. The mixer and the grouting pipe are connected through a conduit, the mixed slurry is poured into the mixer, and the standard pressure/volume controller and the valve are opened to start grouting. The injection device is started during grouting, so that the grouting pipe moves upwards at a preset speed, the pipe can be pulled out while grouting, and the data of the sensor is acquired through the data acquisition and processing system in the grouting process;

s2 e: and (3) CPTU detection: and opening a CPTU hole two CPTU hole three and a CPTU hole four of the pressurizing plate, and inserting the three-bridge probe into the CPTU hole positions through the penetration device for detection. After the detection is finished, the three-bridge probe is pulled out, and a CPTU hole II, a CPTU hole III and a CPTU hole IV are blocked;

s2 f: standing and solidifying: closing the standard pressure/volume controller and the valve, standing the soil body in the main barrel, continuously recording the data of the differential displacement sensor and the change of other sensors, observing the drainage consolidation and sedimentation rule of the soil body after grouting is finished, and finishing the test after the differential displacement sensor is stabilized;

s2 g: and removing the pressurizing plate and the hydraulic servo oil cylinder, separating the side wall of the main barrel from the base, and testing the properties of the soil body in the barrel.

As a preferred method of use in the present invention,

in S1, the preparation method of the sandy soil is a rain falling method, and the clay preparation adopts a remolded soil preparation device; the calibration mode of the sensor is calibration through a calibration tank and a data acquisition and processing system;

in S2, uniformly smearing silicone grease on the inner walls of the main barrel and the extension barrel;

in S2d, the air bag supporting framework and the electric chemical grouting pipe need to be connected with a power supply in advance during electric chemical grouting, and the standard pressure/volume controller is connected to inject grout after water is accumulated in the drainage tank.

As a preference of the method used in the present invention, the method further comprises:

s3: a finishing stage: and (4) disassembling from top to bottom during disassembling, correspondingly cleaning, and preparing for the next round of test.

The technical scheme of the invention has the following advantages:

1. the invention can realize the grouting in various modes such as electric chemical grouting, sleeve valve pipe grouting, micro-disturbance grouting, film bag grouting and the like, the grouting parameters are simple and controllable, and the construction process of the shield tunnel under different working conditions on site is effectively reduced;

2. after grouting is finished, the grouting simulation device can realize distribution excavation verification, track and record the diffusion range of grout, count grout vein distribution, and sample and analyze the reinforcing effect of grouting on foundation soil;

3. the invention can simulate the synergistic effect of a prototype tunnel-foundation soil-grouting system. The pressurizing plate can be lifted in the grouting process, the differential displacement sensor on the loading device system can measure the displacement variation and feed back the displacement variation to the servo control system, the loading system adopts a displacement-force related mode to adjust the load of the pressure plate, the load variation is determined according to the foundation bed coefficient of the soil body, the tunnel lifting-re-landing process under different grouting working conditions can be reduced, meanwhile, the loading system can also realize the servo power loading function through the control system, and the power response and the long-term settlement rule of the stratum in the grouting process under the action of the train cyclic load are researched;

4. according to the confining pressure pore pressure loading system, remolded soil can reach an in-situ stress state, and the tunnel grouting working condition is reduced to a great extent.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and other drawings can be obtained by those skilled in the art without creative efforts.

FIG. 1 is a schematic structural view of a grouting test apparatus in example 1 of the present invention.

Fig. 2 is a schematic structural view of a pressure increasing plate in embodiment 1 of the present invention.

Fig. 3 is a schematic structural view of an electro-chemical grouting pipe in embodiment 2 of the present invention.

FIG. 4 is a schematic view of a sleeve valve tube structure;

wherein, (a) is the outer tube structure schematic diagram of the half-sleeve valve tube in embodiment 2 of the invention;

(b) an enlarged view of the structure in dotted line in (a);

(c) is a schematic structural diagram of the inner tube of the sleeve valve tube in the embodiment 2 of the invention.

FIG. 5 is a schematic structural view of a membrane bag type grouting pipe;

wherein, (a) is a schematic structural diagram of an outer pipe of the membrane bag type grouting pipe in embodiment 2 of the invention;

(b) an enlarged view of the structure in dotted line in (a);

(c) a schematic diagram of the connection between the outer tube of the membrane bag type grouting pipe and a rubber membrane in embodiment 2 of the invention;

(d) is a schematic view of the inner pipe structure of the membrane bag type grouting pipe in embodiment 2 of the invention;

(e) is a schematic diagram of the grouting of the film bag type grouting pipe in the embodiment 2 of the invention.

FIG. 6 is a schematic view of a perturbation grouting tube structure;

wherein, (a) is a schematic structural diagram of a perturbation grouting pipe in embodiment 2 of the present invention;

(b) is a schematic diagram of the micro-disturbance grouting pipe protection sleeve and pipe drawing in embodiment 2 of the present invention.

FIG. 7 is a flow chart of an apparatus according to embodiment 3 of the present invention.

FIG. 8 is a schematic diagram showing the variation of the overburden stress P/platen displacement S-time t in example 3 of the present invention.

Description of reference numerals:

1. a main barrel; 2. lengthening the barrel; 3. a confining pressure air bag; 4. an air bag support armature; 5. a hydraulic pump; 6. a reaction frame; 601. a pulley can be fixed; 7. a differential displacement sensor; 8. a pressure increasing plate; 801. a CPTU hole I; 802. a CPTU hole two; 803. CPTU hole three; 804. a CPTU hole four; 805. a seal ring; 9. a hydraulic servo cylinder; 10. a servo control system; 11. a vibration exciter; 12. a grouting pipe; 13. a penetration device; 14. a mixer; 15. a standard pressure/volume controller; 16. a valve; 17. a pressure gauge; 18. a flow meter; 19. a conduit; 20. a sensor fixing rod; 21. a sensor; 22. a data acquisition and processing system; 23. an air compressor; 24. a power source; 25. a water discharge groove.

Detailed Description

The technical solutions of the present invention will be described clearly and completely with reference to the accompanying drawings, and it should be understood that the described embodiments are some, but not all embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description and simplicity of description, but do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

In the description of the present invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly and may be, for example, fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in a specific case to those of ordinary skill in the art.

Furthermore, the technical features involved in the different embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.

Example 1

This embodiment provides an in situ stratum slip casting test device based on high-efficient improvement of tunnel subsides, as shown in fig. 1, include: the device comprises a model barrel, a confining pressure pore pressure loading system, a grouting system, a sensor and a data acquisition system;

the confining pressure and pore pressure loading system comprises a confining pressure loading device, a pore pressure maintaining device and a reaction frame 6, wherein the reaction frame 6 is erected above the model barrel through frame legs arranged on two sides of the model barrel, the confining pressure loading device is arranged around a soil body in the model barrel to apply confining pressure, and the pore pressure maintaining device is used for maintaining the pore water pressure of the soil body in the model barrel;

the grouting system comprises a grouting pipe 12 inserted into the soil body, a penetration device 13 positioned above the grouting pipe 12, a mixer 14 connected with the grouting pipe 12 through a conduit 19, and a standard pressure/volume controller 15 for controlling grouting parameters;

the sensor and data acquisition system comprises a sensor 21 located in the soil mass in the model barrel and a data acquisition and processing system 22 connected to the sensor 21 by a data line.

The model bucket is including the main bucket 1 that is used for the slip casting experiment and the extension bucket 2 that is located 1 top of main bucket, extension bucket 2 is connected with main bucket 1 detachable, extension bucket 2 and main bucket 1 are the same circular bucket of diameter.

Adopt above-mentioned structure, because the soil body is comparatively loose before not exerting pressure, can not place it completely in the main barrel 1, the fine solution this problem of setting up of extension bucket 2, after exerting pressure to the soil body and accomplishing, extension bucket 2 can take off, can not produce harmful effects to follow-up experiment.

The confining pressure loading device comprises a confining pressure air bag 3 which is positioned in the main barrel 1 and arranged around the soil body; an air bag supporting framework 4 arranged between the confining pressure air bag 3 and the side wall of the main barrel 1, and an air compressor 23 for inflating the confining pressure air bag 3; the device also comprises a pressurizing plate 8 which is positioned between the soil body and the penetration device 13 and covers the upper part of the soil body and a servo control system 10 which regulates and controls the pressurizing plate 8 through a hydraulic servo oil cylinder 9, and the pressurizing plate 8 is lifted after the soil body is grouted to simulate the tunnel to move upwards after grouting below the tunnel; the air bag supporting framework 4 is externally connected with a power supply 24.

By adopting the structure, the confining pressure loading device can enable the soil body to reach an in-situ stress state, the maximum reduction of the grouting working condition of the tunnel is realized, and meanwhile, the power supply 24 externally connected with the air bag supporting framework 4 can be used as an electric chemical grouting cathode.

As shown in fig. 2, 4 CPTU probing holes are reserved on the pressurizing plate 8, a central angle between two adjacent CPTU probing holes is 90 degrees, the distance from the CPTU probing hole to the center of the pressurizing plate 8 from near to far is a third CPTU hole 803, a fourth CPTU hole 804, a first CPTU hole 801 and a second CPTU hole 802, the distances from the first CPTU hole to the fourth CPTU hole are the same, a sealing ring 805 is arranged along the side surface of the pressurizing plate 8, and at least two vibration exciters 11 are arranged around the center of the pressurizing plate 8.

By adopting the structure, the dynamic loading mode can be realized through the vibration exciter 11, the dynamic response, the tunnel lifting and the long-term settlement rule of the stratum in the grouting process under the action of the circulating load of the train are researched, and the CPTU refers to the piezocone penetration test.

In this embodiment, the pore pressure maintaining device comprises a hydraulic pump 5, and a pressure gauge 17 for measuring the pore water pressure is arranged on the upper part of the hydraulic pump 5.

By adopting the structure, the pressure gauge 17 is used for measuring the pore water pressure in the soil body in real time, and when the pore water pressure fluctuates, the pore water pressure is adjusted through the hydraulic pump 5 connected with the pressure gauge 17.

In this embodiment, the grouting pipes 12 include four different types, which are an electro-chemical grouting pipe, a sleeve valve grouting pipe, a film bag grouting pipe, and a micro-disturbance grouting pipe.

By adopting the structure, the device can simulate the disturbance effect of different grouting modes on the soil body and the shield tunnel lifting effect, thereby selecting the most suitable and effective grouting mode.

In this embodiment, the sensor and data acquisition system further includes a sensor fixing rod 20 disposed in the soil body for fixing a sensor 21, where the sensor 21 includes various sensors 21 such as a pore pressure gauge, a soil pressure cell, and a bending element.

By adopting the structure, the situation that the position of the sensor 21 changes along with the settlement of the soil body in the soil body consolidation process is effectively avoided, so that the data recorded by the sensor 21 is inconsistent with the required data.

In this embodiment, a fixable pulley 601 is mounted at the bottom of the leg of the reaction frame 6.

By adopting the structure, the device has certain mobility, so that the tester can move the device conveniently, and the problem that the device can not be moved conveniently and quickly in the test process is avoided. Simultaneously gasbag braced skeleton 4 is printed by 3D and is made, has higher bulk rigidity, can make the confined pressure that confined pressure gasbag 3 applyed more even, prevents that confined pressure gasbag 3 from warping, and gasbag braced skeleton 4 is stainless steel material

In this embodiment, two valves 16 are arranged on the conduit 19, and a pressure gauge 17 and a flow gauge 18 are arranged between the two valves 16.

By adopting the structure, the valve 16 is used for adjusting and controlling the flow and the pressure of the mixed slurry in the conduit 19, and the pressure gauge 17 and the flow gauge 18 are used for monitoring the condition of the mixed slurry in the grouting process, so that the grouting process can be smoothly finished according to the preset grouting parameters.

The test device can test the disturbance condition of surrounding soil layers and the lifting effect of the shield tunnel under different grouting modes and different grouting parameters, and selects the optimal grouting mode and the optimal grouting parameters in the engineering by comparing test results so as to be applied to actual engineering and achieve the aim of efficiently treating tunnel settlement.

The hydraulic servo oil cylinder 9 regulates and controls the load of the pressure increasing plate 8 through the servo control system 10 to realize pressure stabilization and pressure servo change based on the equal rigidity principle, the differential displacement sensor 7 can record the displacement variation of the pressure increasing plate 8 and feed the displacement variation back to the servo control system 10 in the grouting and post-construction stages, the load of the pressure increasing plate 8 is adjusted in a displacement-force related mode, and the load change is determined according to the foundation bed coefficient of the soil body.

Example 2

This example is four different types of slip casting tubes 12 from example 1.

As shown in fig. 3, quincunx grouting holes are uniformly distributed on the outer wall of the electric chemical grouting pipe, and comprise an inner pipe and an outer pipe, wherein the outer pipe is made of steel, the inner pipe is made of corrosion-resistant PVC, one end of the electric chemical grouting pipe is conical, the other end of the electric chemical grouting pipe is provided with threads, the electric chemical grouting pipe is externally connected with a positive electrode of a power supply 24 through a lead, and the electric chemical grouting pipe can be used as an electric chemical grouting anode at the same time;

as shown in fig. 4, the sleeve valve grouting pipe has an outer pipe which is a sleeve valve pipe, 3 rows of quincunx grouting holes are reserved at the front end, 4 grouting holes are uniformly distributed in each row, an openable sealing ring is arranged between two adjacent quincunx grouting holes, 3 closed grouting areas are formed, and the sleeve valve grouting pipe also comprises an inner pipe which is used for grouting, discharging the grouting from the end part and filling different grouting areas;

as shown in fig. 5, the membrane bag type grouting pipe comprises an inner pipe and an outer pipe, and the outer pipe is different from the outer pipe of the sleeve valve grouting pipe in that a groove is formed in the position of an openable sealing ring on the outer wall of the front end of the outer pipe and used for clamping a hoop for fixing a rubber membrane. The rubber film wraps the slurry during grouting to prevent slurry from flowing and realize directional treatment.

As shown in fig. 6, 2 rows of quincunx grouting holes are arranged at the front end of the micro-disturbance grouting pipe, and a protective sleeve is arranged at the front end of the micro-disturbance grouting pipe to prevent the grouting holes from being blocked in the process of inserting the micro-disturbance grouting pipe into the soil body. During grouting, the front end of the micro-disturbance grouting pipe is separated from the protective sleeve through a mechanical device, and grouting can be started.

Example 3

This example is a method of using the grouting test apparatus of example 1, and as shown in fig. 7 to 8, includes the following steps:

s1: preparing sand by a rain falling method, and preparing clay by a remolded soil preparation device; calibrating the sensor 21 by a calibration tank and a data acquisition and processing system 22; preparing a grouting material according to test requirements;

s2: in the test stage, the device is installed from bottom to top: assembling a reaction frame 6, placing the main barrel 1 and the extension barrel 2 on a supporting base, fixing a sensor fixing rod 20 embedded with a sensor 21 on the base of the main barrel 1, leading out a sensor data wire from a wire outlet, and externally connecting a data acquisition and processing system 22;

s2 a: loading and fixedly connecting, uniformly smearing silicone grease on the inner walls of the main barrel 1 and the extension barrel 2, pouring remolded soil prepared by a test to the middle part of the main barrel 1 according to the calculated dosage, placing the grouting pipe 12 in the center of the main barrel 1, pouring the rest soil into the main barrel 1 and the extension barrel 2, additionally installing the pressure increasing plate 8, controlling the pressure increasing plate 8 to apply stable consolidation pressure through the hydraulic servo oil cylinder 9 until the pressure increasing plate 8 is settled stably and the water drainage groove 25 is drained, sequentially removing the pressure increasing plate 8, the hydraulic servo oil cylinder 9 and the extension barrel 2, scraping soil bodies exceeding the height range of the main barrel 1 and scraping the top surfaces of the soil bodies;

s2 b: simulating the in-situ stress state of the soil body, applying stable confining pressure to the soil body in the main barrel 1 through the confining pressure air bag 3 and the hydraulic servo oil cylinder 9, simulating the in-situ stress of the soil body in the buried depth of the tunnel, and maintaining the pore water pressure in the soil body through the hydraulic pump 5;

s2 c: the CPTU detection is carried out, opening a CPTU hole I801 of the pressurizing plate 8, inserting the three-bridge probe into the CPTU hole I801 through the penetration device 13, carrying out detection, and after the detection is finished, pulling out the three-bridge probe to block the CPTU hole I801;

s2 d: the method comprises the steps of acquiring grouting and experimental data, adjusting a pressurizing mode of a servo control system 10, switching to a force-displacement related mode, connecting a mixer 14 and a grouting pipe 12 through a guide pipe 19, pouring mixed grout into the mixer 14, opening a standard pressure/volume controller 15 and a valve 16 to start grouting, and starting a penetration device 13 at the same time of grouting to enable the grouting pipe 12 to move upwards according to a preset speed so as to realize the function of pulling out the pipe while grouting, particularly, during electrokinetic chemical grouting, an air bag supporting framework 4 and an electrokinetic chemical grouting pipe need to be communicated with a power supply 24 in advance, after water is accumulated in a drainage tank 25, the standard pressure/volume controller 15 is communicated to inject the grout, and data of a sensor 21 is acquired through a data acquisition and processing system 22 in the grouting process;

s2 e: detecting the CPTU, namely opening a CPTU hole two 802, a CPTU hole three 803 and a CPTU hole four 804 of the pressurizing plate 8, inserting the three-bridge probe into the CPTU hole position through the penetration device 13, detecting, and pulling out the three-bridge probe after the detection is finished to block the CPTU hole two 802, the CPTU hole three 803 and the CPTU hole four 804;

s2 f: standing and solidifying: closing the standard pressure/volume controller 15 and the valve 16, standing the soil body in the main barrel 1, continuously recording the data of the differential displacement sensor 7 and the change of the other sensors 21, observing the drainage consolidation and sedimentation rule of the soil body after the grouting is finished, and finishing the test of the round after the differential displacement sensor 7 is stabilized;

s2 g: removing the pressurizing plate 8 and the hydraulic servo oil cylinder 9, separating the side wall of the main barrel 1 from the base, and testing the properties of soil in the barrel;

s3: a finishing stage: and disassembling the device from top to bottom, cleaning the testing device and preparing for the next test.

It should be understood that the above examples are only for clarity of illustration and are not intended to limit the embodiments. Other variations and modifications will be apparent to persons skilled in the art in light of the above description. And are neither required nor exhaustive of all embodiments. And obvious variations or modifications derived therefrom are intended to be within the scope of the invention.

Claims (3)

1. The use method of the in-situ stratum grouting test device based on the tunnel settlement efficient treatment is characterized by comprising the following steps of: the grouting test device comprises a model barrel, a confining pressure hole pressure loading system, a grouting system, a sensor and a data acquisition system;

the confining pressure and pore pressure loading system comprises a confining pressure loading device, a pore pressure maintaining device and a reaction frame (6), wherein the reaction frame (6) is erected above the model barrel through frame legs arranged on two sides of the model barrel, the confining pressure loading device is arranged around a soil body in the model barrel to apply confining pressure, and the pore pressure maintaining device is used for maintaining the pore water pressure of the soil body in the model barrel;

the grouting system comprises a grouting pipe (12) inserted into the soil body, a penetration device (13) positioned above the grouting pipe (12), a mixer (14) connected with the grouting pipe (12) through a guide pipe (19) and a standard pressure/volume controller (15) for controlling grouting parameters;

the sensor and data acquisition system comprises a sensor (21) positioned in the soil body in the model barrel and a data acquisition and processing system (22) connected with the sensor (21) through a data line;

the model barrel comprises a main barrel (1) used for a grouting test and an extension barrel (2) positioned above the main barrel (1), the extension barrel (2) is detachably connected with the main barrel (1), and the extension barrel (2) and the main barrel (1) are circular barrels with the same diameter;

the confining pressure loading device comprises a confining pressure air bag (3) which is positioned in the main barrel (1) and arranged around the soil body; an air bag supporting framework (4) arranged between the confining pressure air bag (3) and the side wall of the main barrel (1), and an air compressor (23) for inflating the confining pressure air bag (3); the device also comprises a pressurizing plate (8) which is positioned between the soil body and the injection device (13) and covers the upper part of the soil body and a servo control system (10) which regulates and controls the pressurizing plate (8) through a hydraulic servo oil cylinder (9), and the pressurizing plate (8) is lifted after the soil body is grouted to simulate the tunnel to move upwards after grouting below the tunnel; the air bag supporting framework (4) is externally connected with a power supply (24);

the device comprises a pressurizing plate (8), wherein 4 CPTU probing holes are reserved on the pressurizing plate (8), the central angle between every two adjacent CPTU probing holes is 90 degrees, the distances from the CPTU probing holes to the circle center of the pressurizing plate (8) from near to far are a CPTU hole III (803), a CPTU hole IV (804), a CPTU hole I (801) and a CPTU hole II (802) which are the same in distance, a sealing ring (805) is arranged along the side surface of the pressurizing plate (8), and at least two vibration exciters (11) are arranged around the circle center of the pressurizing plate (8);

the pore pressure maintaining device comprises a hydraulic pump (5), and a pressure gauge (17) for measuring pore water pressure is arranged at the upper part of the hydraulic pump (5);

the grouting pipes (12) comprise four different types, namely an electric chemical grouting pipe, a sleeve valve grouting pipe, a film bag type grouting pipe and a micro-disturbance grouting pipe;

the sensor and data acquisition system also comprises a sensor fixing rod (20) which is arranged in the soil body and is used for fixing the sensor (21);

the bottom of the leg of the reaction frame (6) is provided with a fixable pulley (601);

the guide pipe (19) is provided with two valves (16), and a pressure gauge (17) and a flow meter (18) are arranged between the two valves (16);

the use method of the grouting test device comprises the following steps:

s1: preparation: preparing sandy soil and clay; calibrating the sensor (21); preparing a grouting material according to test requirements;

s2: and (3) a test stage: the device is installed from bottom to top: assembling a reaction frame (6), placing the main barrel (1) and the extension barrel (2) on a supporting base, fixing a sensor fixing rod (20) embedded with a sensor (21) on the base of the main barrel (1), leading out a sensor data line from a wire outlet, and externally connecting a data acquisition and processing system (22);

s2 a: sample loading and consolidation: pouring remolded soil prepared by a test to the middle part of a main barrel (1) according to the calculated using amount, placing a grouting pipe (12) in the center of the main barrel (1), pouring the residual soil into the main barrel (1) and an extension barrel (2), additionally installing a pressure increasing plate (8), controlling the pressure increasing plate (8) to apply stable consolidation pressure through a hydraulic servo oil cylinder (9) until the pressure increasing plate (8) is settled stably and a drainage groove (25) is drained without water, sequentially removing the pressure increasing plate (8), the hydraulic servo oil cylinder (9) and the extension barrel (2), scraping soil bodies exceeding the height range of the main barrel (1) and leveling the top surfaces of the soil bodies;

s2 b: and (3) simulating the in-situ stress state of the soil body: applying stable confining pressure on the soil body in the main barrel (1) through a confining pressure air bag (3) and a hydraulic servo oil cylinder (9), simulating the in-situ stress of the soil body in the tunnel buried depth, and maintaining the pore water pressure in the soil body through a hydraulic pump (5);

s2 c: and (3) CPTU detection: opening a CPTU hole I (801) of the pressurizing plate (8), inserting the three-bridge probe into the CPTU hole I (801) through the penetrating device (13), detecting, pulling out the three-bridge probe after detection is finished, and blocking the CPTU hole I (801);

s2 d: grouting and experimental data acquisition: adjusting a pressurization mode of a servo control system (10), switching to a force-displacement related mode, connecting a mixer (14) and a grouting pipe (12) through a guide pipe (19), pouring mixed grout into the mixer (14), opening a standard pressure/volume controller (15) and a valve (16) to start grouting, and starting a penetration device (13) while grouting to enable the grouting pipe (12) to move upwards according to a preset speed, so that the pipe can be pulled out while grouting is performed, and acquiring data of a sensor (21) through a data acquisition and processing system (22) in the grouting process;

s2 e: the CPTU detection is carried out, opening a CPTU hole II (802), a CPTU hole III (803) and a CPTU hole IV (804) of the pressurizing plate (8), inserting the three-bridge probe into the CPTU hole positions through the penetration device (13), carrying out detection, and after the detection is finished, pulling out the three-bridge probe to block the CPTU hole II (802), the CPTU hole III (803) and the CPTU hole IV (804);

s2 f: standing and solidifying: closing the standard pressure/volume controller (15) and the valve (16), standing the soil body in the main barrel (1), continuously recording the data of the differential displacement sensor (7) and the change of other sensors (21), observing the drainage consolidation and sedimentation rule of the soil body after the grouting is finished, and finishing the test after the differential displacement sensor (7) is stabilized;

s2 g: and (3) removing the pressurizing plate (8) and the hydraulic servo oil cylinder (9), separating the side wall of the main barrel (1) from the base, and testing the properties of the soil body in the barrel.

2. The use method of the in-situ stratum grouting test device based on tunnel settlement efficient treatment according to claim 1 is characterized by comprising the following steps:

in S1, the preparation method of the sandy soil is a rain falling method, and the clay preparation adopts a remolded soil preparation device; the calibration mode of the sensor (21) is that the sensor is calibrated by a calibration tank and a data acquisition and processing system (22);

in S2, uniformly smearing silicone grease on the inner walls of the main barrel (1) and the extension barrel (2);

in S2d, the air bag supporting framework (4) and the electric chemical grouting pipe need to be connected with the power supply (24) in advance during electric chemical grouting, and after water is accumulated in the drainage groove (25), the standard pressure/volume controller (15) is connected to inject grout.

3. The use method of the in-situ stratum grouting test device based on the tunnel settlement efficient treatment according to claim 2 is characterized by further comprising the following steps:

s3: a finishing stage: and (4) disassembling from top to bottom during disassembling, correspondingly cleaning, and preparing for the next round of test.

Images