CN112285332B - Simulation test method for antifriction grouting of large-section rectangular jacking pipe - Google Patents

Abstract

The invention relates to a simulation test method for anti-friction grouting of large-section rectangular pipe jacking, comprising the following steps: configuring model soil and model slurry; placing the front pipe joint in a test soil box, and filling the model soil into the test soil The model soil is used to embed the front pipe joint in the box; the rear pipe joint is provided with a muddy water filling ring inside, and the muddy water filling ring forms a continuous grouting groove along the outer periphery of the rear pipe joint; The end of the upper pipe joint is docked with the end of the front pipe joint in the test soil box. When the rear pipe joint is jacked into the test soil box, inject muddy water to the outside of the rear pipe joint through the filling ring. Model grout, so as to realize the simulation test of anti-friction grouting for pipe jacking. The invention simulates the actual pipe jacking construction by jacking the rear pipe joints into the test soil box, and improves the accuracy of the friction resistance between the model slurry and the pipe joints measured by the simulation test by using the muddy water filling ring, which provides a good foundation for the pipe jacking construction. Provide practical guidance.

Description

Simulation test method of anti-friction grouting for large-section rectangular pipe jacking

technical field

The invention relates to the technical field of pipe jacking test methods, in particular to a simulation test method for anti-friction grouting of large-section rectangular pipe jacking.

Background technique

Pipe jacking construction is a non-excavation construction method that is increasingly developed and applied. It can cross existing roads, railways, rivers, underground pipelines, underground structures and cultural relics without excavating the surface layer. The pipe jacking construction method avoids the excavation of urban roads, reduces a large number of earthworks, reduces demolition and resettlement, saves construction land, reduces surrounding environmental interference, and does not interrupt ground traffic and logistics transportation activities. In recent years, urban underground space development, It is widely used in underground railway rail transit construction and municipal tunnel engineering.

During pipe jacking construction, the jacking force of the rear cylinder is a crucial parameter for pipe jacking construction, and the jacking force is related to the resistance of the cutter head during the jacking process of the pipe jacking machine and the frictional resistance on the outer surface of the pipe jacking. In order to reduce the friction resistance between the outer surface of the pipe jacking and the soil, the model slurry will be injected into the outer surface of the pipe jacking, and the friction resistance will be reduced by using the model slurry. The proportion of the model slurry is usually determined through the pipe jacking simulation test. Yes, but in the existing simulation test, the model grout is injected to the outer surface of the pipe joint through the grouting holes evenly arranged on the pipe joint. When the model grout is injected outward from the grouting hole, it will directly impact the soil , and it is not easy to spread uniformly to the outer surface of the pipe joint to form a mud sleeve, which makes the test results have large errors and has low reference value for actual construction.

Contents of the invention

The purpose of the present invention is to overcome the defects of the prior art, to provide a simulation test method for friction-reducing grouting of large-section rectangular pipe jacking, and to solve the problem that the grouting hole injected into the model grout in the existing pipe jacking simulation test will impact the soil and It is not easy to form uniformly distributed mud sleeves, which leads to large errors in test results and low reference value for actual construction.

The technical scheme for realizing the above-mentioned purpose is:

The invention provides a simulation test method for anti-friction grouting of rectangular pipe jacking with large cross-section, comprising the following steps:

Configure model soil and model slurry;

Provide a test soil box and a front pipe joint, place the front pipe joint in the test soil box, fill the model soil into the test soil box, and use the model soil to embed the front pipe section;

A rear pipe joint is provided, and a muddy water filling ring is provided in the provided rear pipe joint, and the muddy water filling ring is formed with grouting grooves connected in a circle along the outer periphery of the rear pipe joint;

The end of the rear pipe joint is docked with the end of the front pipe joint in the test soil box, and a pushing mechanism is set on the side of the rear pipe joint away from the test soil box, using The pushing mechanism pushes the rear pipe joint to push the rear pipe joint into the test soil box; and

During the jacking process of the rear pipe joint into the test soil box, inject the model grout to the outside of the rear pipe joint through the mud water injection ring, so as to realize anti-friction grouting for pipe jacking simulation test.

In the simulation test method of the present invention, the actual pipe jacking construction is simulated by jacking the rear pipe joints into the test soil box, and the grouting grooves formed in a circle by the muddy water filling ring can be used to evenly inject the model grout into the rear The outer side of the pipe joint, compared with the grouting hole in the prior art, the grouting groove allows the model grout to be injected synchronously to the outer side of the pipe joint at the same pressure, avoiding single-point injection that is easy to impact the soil and make the For the problem of uneven grout, the model grout forms a uniform mud sleeve on the outside of the pipe joint, which improves the accuracy of the friction resistance between the model grout and the pipe joint measured by the simulation test, and provides practical guidance for pipe jacking construction.

The further improvement of the simulation test method of anti-friction grouting for large-section rectangular pipe jacking of the present invention lies in that the provided rear pipe joint is also provided with an annular cavity arranged along the ring direction of the rear pipe joint and arranged in the rear pipe joint. A slurry inlet channel inside the pipe joint and communicated with the annular cavity;

One end of the annular cavity communicates with the grouting groove;

When injecting the model slurry, the grouting pipe is communicated with the slurry inlet channel, and the model slurry is injected into the annular cavity through the slurry inlet channel, and the injected model slurry is filled with the annular cavity and then released from the annular cavity. The grouting groove is injected to the outside of the rear pipe joint.

The further improvement of the simulated test method of anti-friction grouting for large-section rectangular pipe jacking of the present invention lies in that muddy water filling rings are arranged at intervals on the provided rear pipe joint;

Connect a grouting pipe separately for each muddy water filling ring;

When using each grouting pipe to inject the model slurry into the corresponding muddy water injection ring, add pigments to the model slurry so that the model grout injected by each grouting pipe has different colors, thereby according to the model slurry of different colors Obtain the slurry diffusion situation at the corresponding muddy water filling ring.

The further improvement of the simulation test method of anti-friction grouting for large-section rectangular pipe jacking of the present invention lies in that the provided rear pipe joint is a transparent structure;

When the model slurry is injected, the image information of the model slurry injected into the outside of the rear pipe joint is collected inside the rear pipe joint, so as to obtain the diffusion path of the model slurry.

The further improvement of the simulation test method of the large-section rectangular pipe jacking anti-friction grouting of the present invention is that when the model soil is filled into the test soil box, the filled model soil is layered and compacted, and Place a horizontal displacement sensor and a vertical displacement sensor on the surface of each model soil layer;

Using the horizontal displacement sensor to detect the horizontal displacement information of the corresponding model soil layer;

Using the vertical displacement sensor to detect the vertical displacement information of the corresponding model soil layer;

Multiple rows of settlement monitoring points are set on the upper surface of the model soil, and surface displacement sensors are set on the top of the test soil box corresponding to each settlement monitoring point;

Using the surface displacement sensor to detect the settlement displacement information of each settlement monitoring point;

Using the horizontal displacement information and vertical displacement information of each model soil layer and the settlement displacement information of the upper surface of the model soil to obtain the three-dimensional change status information of the model soil.

The further improvement of the simulation test method of anti-friction grouting for large-section rectangular pipe jacking of the present invention is to install a first earth pressure sensor on the side of the front pipe joint close to the rear pipe joint;

During the jacking process of the rear pipe section, the soil pressure of the model soil is detected by the first earth pressure sensor.

The further improvement of the simulated test method of anti-friction grouting for large-section rectangular pipe jacking of the present invention lies in that a second earth pressure sensor is installed on the outer periphery of the rear pipe joint;

During the jacking process of the rear pipe joint, the soil mass pressure of the model soil is detected by the second earth pressure sensor.

The further improvement of the simulation test method of anti-friction grouting for large-section rectangular pipe jacking of the present invention is to provide a load cell, and use the load cell to connect the rear pipe joint and the front pipe joint;

During the jacking process of the rear pipe joint, the force sensor is used to detect the frictional resistance of the rear pipe joint.

The further improvement of the simulated test method of the anti-friction grouting for large-section rectangular pipe jacking of the present invention lies in that when configuring the model soil, the similarity ratio between the model soil and the prototype soil of the actual construction of pipe jacking is set;

Using the set similarity ratio and the parameter information of the prototype soil to calculate and obtain the parameter information of the model soil to be configured;

According to the obtained parameter information of the model soil, the model soil is configured.

The further improvement of the simulation test method of anti-friction grouting for large-section rectangular pipe jacking of the present invention lies in that multiple groups of model grouts are configured when configuring the model grout;

Carry out simulation tests on multiple groups of model grouts, and obtain the construction parameters corresponding to multiple groups of model grouts;

The model grout with the best construction parameters is selected as the grout for anti-friction grouting for rectangular pipe jacking.

Description of drawings

Fig. 1 is a flow chart of the simulated test method of anti-friction grouting for large-section rectangular pipe jacking of the present invention.

Fig. 2 is a structural schematic diagram of the test device used in the simulation test method of anti-friction grouting for large-section rectangular pipe jacking according to the present invention.

Fig. 3 is a structural schematic diagram of the jacking state of the test device shown in Fig. 2 .

Fig. 4 is a schematic structural view of the front pipe section of the test device shown in Fig. 2 .

Fig. 5 is a structural schematic diagram of the rear pipe joint of the test device shown in Fig. 2 .

Fig. 6 is a cross-sectional view of the junction of the rear pipe joint and the front pipe joint of the test device shown in Fig. 2 .

Fig. 7 is a cross-sectional view of the muddy water filling ring of the rear pipe joint of the test device shown in Fig. 2 .

Detailed ways

The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

Referring to Fig. 1, the present invention provides a simulation test method for anti-friction grouting of large-section rectangular pipe jacking, which is used to simulate the pipe jacking process. The flow of the model slurry at the filling ring is obtained to obtain the diffusion path of the model slurry. The three-dimensional changes of the model soil during the pipe jacking process can be obtained by setting various sensors, and the delamination displacement and surface displacement of each layer of the model soil can be obtained. Utilizing the simulated test method of the present invention can provide effective guiding significance for actual construction. The simulation test method of the anti-friction grouting for large-section rectangular pipe jacking of the present invention will be described below in conjunction with the accompanying drawings.

Referring to Fig. 1, it shows a flow chart of the simulated test method of anti-friction grouting for large-section rectangular pipe jacking of the present invention. Next, with reference to FIG. 1 , the simulated test method for anti-friction grouting for large-section rectangular pipe jacking of the present invention will be described.

As shown in Figure 1, the simulated test method of the anti-friction grouting for large-section rectangular pipe jacking of the present invention comprises the following steps:

Execute step S11, configure model soil and model slurry; then execute step S12;

Execute step S12, provide the test soil box and the front pipe joint, as shown in Figure 2, place the front pipe joint 22 in the test soil box 21, fill the model soil into the test soil box and embed it with the model soil Front pipe joint 22; then execute step S13;

Execute step S13, provide the rear pipe joint, as shown in Figure 5 and Figure 7, the provided rear pipe joint 24 is provided with a muddy water filling ring 241, and the muddy water filling ring 241 is formed along the outer periphery of the rear pipe joint 24 There are grouting grooves 2411 connected in a circle; then step S14 is performed;

Execute step S14, dock the end of the rear pipe joint 24 with the end of the front pipe joint 22 in the test soil box 21, and set a push mechanism 26 on the side of the rear pipe joint 24 away from the test soil box 21 , using the pushing mechanism 26 to push the rear pipe joint 24 to push the rear pipe joint 24 into the test soil box 21; then perform step S15;

Execute step S15, in the process of jacking the rear pipe joint 24 into the test soil box 21, inject the model slurry to the outside of the rear pipe joint 24 through the mud water injection ring 241, so as to realize the simulation of pipe jacking anti-friction grouting test.

The simulated test method of the present invention utilizes the pushing mechanism 26 to push the rear pipe joint 24 from the outside of the test soil box 21 to the test soil box 21, thereby realizing the simulated actual pipe jacking construction. The muddy water filling ring 241 is arranged at intervals, and the muddy water filling ring 241 is provided with a grouting groove 2411 formed in a circle on the outer periphery of the rear pipe joint 24. The synchronous filling of the model slurry under the same pressure can make the model slurry evenly cover the outer circumference of the rear pipe joint 24, thereby achieving a better effect of reducing friction. Compared with the point-to-point grouting method of the grouting hole in the prior art, it can avoid impact on the soil body, avoid disturbance to the soil body, and avoid concentration of grout near the grouting hole.

In a specific embodiment of the present invention, as shown in FIG. 7 , the provided rear pipe joint 24 is also provided with an annular cavity 2412 arranged circumferentially along the rear pipe joint 24 and an annular cavity 2412 arranged in the rear pipe joint 24 The grouting channel 2413 inside and communicated with the annular cavity 2412; one end of the annular cavity 2412 communicates with the grouting groove 2411; when injecting the model slurry, the grouting pipe 27 is communicated with the grouting channel 2413, and passes through the grouting channel 2413 The model slurry is injected into the annular cavity 2412 , and the injected model slurry fills the annular cavity 2412 and then injects from the grout groove 2411 to the outside of the rear pipe joint 24 .

Specifically, the slurry inlet channel 2413 communicates with the bottom of the annular chamber 2412, the slurry inlet channel 2413 extends from the bottom of the annular cavity 2412 to the inner surface of the rear pipe section 24, the slurry inlet channel 2413 is located at the bottom of the rear pipe section 24 A grout inlet is provided on the inner surface, through which the grout inlet is connected to the grouting pipe 27 , and the model grout is injected into the grouting channel 2413 by using the grouting pipe 27 . The grouting groove 2411 communicates with the end of the annular cavity 2412, the grouting groove 2411 extends from the end of the annular cavity 2412 to the outer surface of the rear pipe joint 24, and the grouting groove 2411 is located outside the rear pipe joint 24 An annular grouting notch 2414 is formed on the surface. In this way, when injecting the model slurry, the model slurry is injected into the slurry inlet channel 2413 through the grouting pipe 27, and the model slurry is injected from the slurry inlet channel 2413 into the annular cavity 2412. When the annular cavity 2412 is filled with the model slurry , the injected model slurry will be injected to the outside of the rear pipe joint 24 through the grouting groove 2411 and the grouting notch 2414 together, and the model slurry will diffuse in the rear pipe joint 24 through the annular cavity 2412 to form a mud sleeve, and then stabilize entering the outer side of the rear pipe joint 24 can make the mold slurry coat the outer periphery of the rear pipe joint 24 more uniformly.

Further, the installation direction of the grouting groove 2411 is parallel to the end surface of the rear pipe section 24; the installation direction of the annular cavity 2412 is perpendicular to the end surface of the rear pipe section 24, that is, the grouting groove 2411 and the annular groove 2412 are vertically connected , so that the muddy water filling ring 241 is L-shaped.

In a specific embodiment of the present invention, as shown in Fig. 5 and Fig. 7, muddy water filling ring 241 is provided at intervals on the provided rear pipe joint 24; Grouting pipe 27; when utilizing each grouting pipe 27 to inject model grout in corresponding muddy water injection ring 241, in model grout, add pigment so that the model grout injected by each grouting pipe 27 has different colors, thereby According to the model grout of different colors, the grout diffusion at the corresponding muddy water filling ring is obtained.

Injecting the mold slurry into the corresponding muddy water injection ring 241 through the separately connected grouting pipe 27 can realize the injection of the mold slurry at each muddy water injection ring 241 separately.

Further, the provided rear pipe joint 24 is a transparent structure; when the model slurry is injected, the image information of the model slurry injected into the outside of the rear pipe joint is collected inside the rear pipe joint 24 to obtain the diffusion path of the model slurry.

Preferably, a camera is arranged in the rear pipe joint 24, and the camera is used to take pictures of the diffusion of the injected anti-friction mud through the transparent structure.

Furthermore, the front pipe joint 22 and the rear pipe joint 24 are made of acrylic material, the front pipe joint 22 and the rear pipe joint 24 are transparent, have a perspective function, and can be observed inside the pipe joint The condition of the outside of the pipe joint. With the help of the camera installed inside the rear pipe joint 24, the situation of the anti-friction mud outside the rear pipe joint 24 can be photographed to obtain the situation of the whole process of the diffusion of the anti-friction mud, and further analysis can obtain the flow characteristics of the anti-friction mud.

In a specific embodiment of the present invention, as shown in Figure 2 and Figure 3, when the model soil is filled in the test soil box 21, the filled model soil is layered and compacted, and each model soil A horizontal displacement sensor and a vertical displacement sensor are placed on the surface of the soil layer;

Using a horizontal displacement sensor to detect the horizontal displacement information of the corresponding model soil layer;

Using a vertical displacement sensor to detect the vertical displacement information of the corresponding model soil layer;

Set multiple rows of settlement monitoring points on the upper surface of the model soil, and set a surface displacement sensor 282 on the top of the test soil box 21 corresponding to each settlement monitoring point;

Utilize the surface displacement sensor 282 to detect the settlement displacement information of each settlement monitoring point;

Using the horizontal displacement information and vertical displacement information of each model soil layer and the settlement displacement information of the upper surface of the model soil to obtain the three-dimensional change status information of the model soil.

When the model soil is compacted in layers, the compaction quality is controlled by the percentage of compression, and the settlement of the model soil in the test soil box is controlled by the percentage of displacement settlement in the consolidation fast shear test.

Preferably, a measuring board 283 is set at the settlement monitoring point on the upper surface of the model soil, and an installation beam 214 is installed on the top of the test soil box 21, and the surface displacement sensor 282 is installed and fixed on the installation beam 214, and the corresponding measurement The plate 283 is arranged oppositely, and the distance information between it and the measuring plate 283 is detected by the ground surface displacement sensor 282, so that the surface displacement change of the model soil can be obtained.

Further, there are multiple horizontal displacement sensors, vertical displacement sensors and ground surface displacement sensors 282 arranged at uniform intervals. In this way, the overall three-dimensional change data of the model soil wrapped outside the pipe joint can be obtained. Based on the obtained three-dimensional change data, the overall dynamic change of the model soil can be drawn, so that the impact of pipe jacking construction on the soil can be intuitively obtained.

Preferably, the vertical displacement sensor is an LVDT linear displacement sensor, and the horizontal displacement sensor is a MEMS fixed inclinometer.

In a specific embodiment of the present invention, as shown in FIG. 4 , a first earth pressure sensor 284 is installed on the side of the front pipe joint 22 close to the rear pipe joint 24; , the soil mass pressure of the model soil is detected by the first earth pressure sensor 284 .

The first earth pressure sensor 284 is arranged on the outer surface of the front pipe joint 22, and is arranged at intervals along the outer circumference of the front pipe joint 22. The first earth pressure sensor 284 is in contact with the model soil. When moving forward, the first earth pressure sensor 284 can detect the soil pressure, so that during the jacking process of the rear pipe section 24, the first earth pressure sensor 284 is used to detect the soil pressure in real time, thereby obtaining the soil pressure The change.

In a specific embodiment of the present invention, as shown in FIG. 5 , a second earth pressure sensor 285 is installed on the periphery of the rear pipe joint 24; The sensor 285 detects the soil mass pressure of the model soil.

The second earth pressure sensor 285 is arranged at intervals along the outer circumference of the rear pipe joint 24, and the second earth pressure sensor 285 is arranged on the outer surface of the rear pipe joint 24. When the rear pipe joint 24 is pushed into the model soil, the The second earth pressure sensor 285 can detect the earth mass pressure at the rear pipe joint 24, so as to obtain the change of the earth mass pressure during the whole jacking process. When adding the anti-friction mud, the first earth pressure sensor and the second earth pressure sensor are used to detect the variation of the soil pressure during the slurry filling process.

In a specific embodiment of the present invention, as shown in Fig. 2 and Fig. 6, load cell 281 is provided, utilizes load cell 281 to connect rear pipe joint 24 and front pipe joint 22; During the jacking process, the force sensor 281 is used to detect the frictional resistance of the rear pipe section 24 .

During the uniform jacking process of the rear pipe joint 24 in the test soil box 21, the jacking force received by the rear pipe joint 24 is equal to the frictional resistance of the model soil on the rear pipe joint 24, that is, the force detected by the load cell 281 That is, the frictional resistance suffered by the rear pipe joint 24 . Furthermore, the model slurry is injected into the outside of the rear pipe joint 24, and the model slurry is coated on the outer periphery of the rear pipe joint 24. At this time, the force detected by the load cell 281 is the frictional resistance between the model slurry and the rear pipe joint 24. .

The frictional resistance between the rear pipe joint and the model soil or model slurry can be accurately obtained through the installed load cell 281, which provides a basis for selecting the proportion of the model slurry and also provides reference data for the jacking force of the pipe jacking construction.

Further, as shown in FIG. 4 and FIG. 5 , a first connecting plate 221 is provided on the inner side of the front pipe joint 22 , and the first connecting plate 221 is arranged close to the nozzle of the front pipe joint 22 ; A second connecting plate 242 is arranged on the inner side of the inner side, and the second connecting plate 242 is arranged near the end of the rear pipe section 24. The second connecting plate 242 is set corresponding to the first connecting plate 221. As shown in FIG. 6, the measurement The force sensor 281 is installed between the first connecting plate 221 and the second connecting plate 242 , and is fixedly connected with the first connecting plate and the second connecting plate 242 . Preferably, there are four first connecting plates 221 and four second connecting plates 242 , which are respectively arranged at the corners of the pipe joints. Correspondingly, four load cells 281 are also provided. The rear pipe joint 24 is connected to the front pipe joint 22 through the load cell 281, so that after the rear pipe joint 24 receives the jacking force, the jacking force is completely transmitted to the front pipe joint 22 through the load cell 281, so that the rear pipe joint 24 The pipe joint 24 and the front pipe joint 22 move forward together, so that the rear pipe joint 24 enters the test soil box 21, and the front end of the front pipe joint 22 protrudes from the hole 212 of the test soil box 21. The pipe joint 22 does not transmit the jacking force to other structures, so when the rear pipe joint 24 is jacking at a constant speed, the jacking force detected by the load cell 281 is all used to offset the frictional resistance of the pipe joint, that is, the frictional resistance and the jacking force The thrust is equal. Preferably, the force sensor 281 is a FC-TJ01 standard S-type measuring sensor from Shanghai Naichuang Testing Technology Co., Ltd.

As shown in Fig. 2 and Fig. 3, a starting bracket 231 is arranged on the rear side of the test soil box 21, and the starting bracket 231 is used to support the rear pipe joint 24, and at the rear of the starting bracket 231 A backrest frame 25 is provided, and a plurality of support beams 251 are supported and connected between the backrest frame 25 and the test soil box 21 . A push mechanism 26 is installed on the back rest frame 25, and the push mechanism 26 is preferably an electric cylinder, and the push mechanism 26 is used to apply a push force to the rear pipe joint 24. As shown in Figure 5, the rear end of the rear pipe joint 24 is provided with a force transmission frame 243, which is connected to the telescopic rod of the electric cylinder, and the electric cylinder stretches out the telescopic rod forward, and then passes through the force transmission frame 243. Push the rear joint 24 forward.

A receiving bracket 232 is provided on the front side of the test soil box 21 for supporting the test soil box 21 protruding from the front side of the test soil box 21 . In order not to affect the frictional resistance detected by the load cell, freely rotatable rollers are set on the top of the receiving bracket 232, and the front pipe joints 22 are supported by the rollers, so that when the front pipe joints 22 move forward, the rollers can rotate Reduce the frictional resistance between it and the front pipe joint 22. Similarly, a plurality of freely rotatable rollers are also set on the top of the starting bracket 231, and the rollers are used to support the rear pipe joint 24. When the rear pipe joint 24 moves forward, the rolling wheels on the starting bracket 231 Roll to reduce its frictional resistance with the rear pipe joint 24 pieces.

The test soil box 21 is a square box with an accommodating space 211 formed inside the square box. The square box also has a top opening 213 through which model soil is added. The opposite sides of the square box are provided with openings 212 , the openings 212 on one side are used for the ejection of the front pipe joint 22 , and the openings 212 on the other side are used for the jacking of the rear pipe joint 24 .

In a specific embodiment of the present invention, when configuring the model soil, the similarity ratio between the model soil and the actual prototype soil for pipe jacking is set;

Using the set similarity ratio and the parameter information of the prototype soil to calculate the parameter information of the model soil to be configured;

According to the obtained parameter information of the model soil, the model soil is configured.

Preferably, the geometric similarity ratio of 1:20 is determined according to the actual situation and constraints. According to the second theorem of similarity theory and the dimensional analysis method, the specific parameter ratios of the model soil and the model slurry can be obtained. A specific example will be used below to illustrate. The cohesion of the prototype soil is 11kpa, based on the similarity ratio of 1:20, the cohesion of the model soil is calculated to be 0.55kpa. In the test, undisturbed soil, bentonite, barite powder, double fly powder, washing powder, fine sand, water and other materials were selected to configure the model soil. By repeatedly adjusting the ratio of the above materials, the model soil that meets the required parameter adjustment was obtained. .

When configuring the model soil, measure the moisture content of the undisturbed soil, use the moisture content to calculate and measure the amount of water contained in the undisturbed soil in the configured model soil, and correspondingly reduce the amount of water that needs to be added when configuring the model soil, thus saving The process of drying the undisturbed soil can speed up the configuration efficiency of the model soil.

In a specific embodiment of the present invention, when configuring the model slurry, configure multiple groups of model slurry;

Carry out simulation tests on multiple groups of model grouts, and obtain the construction parameters corresponding to multiple groups of model grouts;

The model grout with the best construction parameters is selected as the grout for anti-friction grouting for rectangular pipe jacking.

Specifically, three model slurries were prepared, the first model slurry comprising sodium bentonite, CMC (sodium carboxymethylcellulose, carboxymethylcellulose), soda ash and water. The second model slurry contained sodium bentonite, CMC (sodium carboxymethylcellulose), soda ash, water, and HS-3. The third model slurry contained sodium bentonite, CMC (sodium carboxymethylcellulose), soda ash, water, HS-3, and polyacrylamide. Among them, HS-3 uses the high-performance mud material for pipe jacking produced by Anji Lvsheng Building Materials Co., Ltd., model HS-3.

In the following, a specific simulation test example is taken as an example to illustrate the test method.

During the test, the depth of the model soil above the front pipe joint 22 is designed according to the soil embedding in actual construction. In this test, two buried depths are set, one is 7m-0.35m, and the other is 5m-0.25m. There are two kinds of propulsion speed settings, one is 0.5cm/min, and the other is 0.3cm/min. There are also two types of grouting quantity, one is 10L/ring, and the other is 15L/ring.

The three model grouts configured above were subjected to the following test under the conditions of the same burial depth, the same advancing speed and the same amount of grouting, and the rear pipe joint was pushed to complete 3/4 of the process at the set advancing speed, and the machine was shut down for one day. Wait until the third day to observe the thixotropic effect of the model slurry.

It is also possible to conduct comparative tests on a variety of model slurries with different proportions, such as the comparison of shallow burial and deep burial tests of different proportions of model slurries, and the comparison of high-speed propulsion and slow propulsion tests of model slurries with different proportions. Experimental comparisons of low and high grout volumes of model grouts with different ratios were carried out.

Through a large number of test data, the best construction parameters and the best ratio of model grout can be obtained.

The present invention has been described in detail above with reference to the embodiments of the accompanying drawings, and those skilled in the art can make various changes to the present invention according to the above description. Therefore, some details in the embodiments should not be construed as limiting the present invention, and the present invention will take the scope defined by the appended claims as the protection scope of the present invention.

Claims (9)

1. A simulation test method of anti-friction grouting for large-section rectangular pipe jacking, characterized in that, comprising the steps: Configure model soil and model slurry; Provide a test soil box and a front pipe joint, place the front pipe joint in the test soil box, fill the model soil into the test soil box, and use the model soil to embed the front pipe section; A rear pipe joint is provided, and a muddy water filling ring is provided in the provided rear pipe joint, and the muddy water filling ring is formed with grouting grooves connected in a circle along the outer periphery of the rear pipe joint; The provided rear pipe joint is also provided with an annular chamber arranged circumferentially along the rear pipe joint and a slurry inlet channel arranged inside the rear pipe joint and communicating with the annular chamber. The annular chamber One end of one end is communicated with the grouting groove, and when injecting the model grout, the grouting pipe is communicated with the grouting channel, and the model grout is injected into the annular cavity through the grouting channel, and the injected After filling the annular cavity, the model slurry is injected from the grouting groove to the outside of the rear pipe joint; The end of the rear pipe joint is docked with the end of the front pipe joint in the test soil box, and a pushing mechanism is set on the side of the rear pipe joint away from the test soil box, using The pushing mechanism pushes the rear pipe joint to push the rear pipe joint into the test soil box; and During the jacking process of the rear pipe joint into the test soil box, inject the model grout to the outside of the rear pipe joint through the mud water injection ring, so as to realize anti-friction grouting for pipe jacking simulation test. 2. the simulated test method of anti-friction grouting for large-section rectangular pipe jacking as claimed in claim 1, is characterized in that, the interval on the provided rear pipe joint is provided with a muddy water filling ring; Connect a grouting pipe separately for each muddy water filling ring; When using each grouting pipe to inject the model slurry into the corresponding muddy water injection ring, add pigments to the model slurry so that the model grout injected by each grouting pipe has different colors, thereby according to the model slurry of different colors Obtain the slurry diffusion situation at the corresponding muddy water filling ring. 3. the simulated test method of anti-friction grouting for large-section rectangular pipe jacking as claimed in claim 2, is characterized in that, the provided rear pipe joint is a transparent structure; When the model slurry is injected, the image information of the model slurry injected into the outside of the rear pipe joint is collected inside the rear pipe joint, so as to obtain the diffusion path of the model slurry. 4. the simulated test method of anti-friction grouting for large-section rectangular pipe jacking as claimed in claim 1, is characterized in that, when described model soil is filled in described test soil box, to the model soil filled in Carry out layered compaction, and place horizontal displacement sensors and vertical displacement sensors on the surface of each model soil layer; Using the horizontal displacement sensor to detect the horizontal displacement information of the corresponding model soil layer; Using the vertical displacement sensor to detect the vertical displacement information of the corresponding model soil layer; Multiple rows of settlement monitoring points are set on the upper surface of the model soil, and surface displacement sensors are set on the top of the test soil box corresponding to each settlement monitoring point; Using the surface displacement sensor to detect the settlement displacement information of each settlement monitoring point; Using the horizontal displacement information and vertical displacement information of each model soil layer and the settlement displacement information of the upper surface of the model soil to obtain the three-dimensional change status information of the model soil. 5. The simulation test method of anti-friction grouting for large-section rectangular pipe jacking as claimed in claim 1, wherein a first earth pressure sensor is installed on the side of the front pipe joint close to the rear pipe joint ; During the jacking process of the rear pipe section, the soil pressure of the model soil is detected by the first earth pressure sensor. 6. the simulated test method of anti-friction grouting for large-section rectangular pipe jacking as claimed in claim 1, is characterized in that, the second earth pressure sensor is installed on the outer periphery of described rear pipe joint; During the jacking process of the rear pipe joint, the soil mass pressure of the model soil is detected by the second earth pressure sensor. 7. The simulated test method of anti-friction grouting for large-section rectangular pipe jacking as claimed in claim 1, characterized in that a load cell is provided, and the rear pipe joint and the front part are connected by the load cell Pipe section; During the jacking process of the rear pipe joint, the force sensor is used to detect the frictional resistance of the rear pipe joint. 8. the simulated test method of anti-friction grouting for large-section rectangular pipe jacking as claimed in claim 1, is characterized in that, when configuring model soil, the similarity ratio of the prototype soil of setting model soil and pipe jacking actual construction; Using the set similarity ratio and the parameter information of the prototype soil to calculate and obtain the parameter information of the model soil to be configured; According to the obtained parameter information of the model soil, the model soil is configured. 9. the simulated test method of anti-friction grouting for large-section rectangular pipe jacking as claimed in claim 1, is characterized in that, when configuring the model grout, configure multiple groups of model grout; Carry out simulation tests on multiple groups of model grouts, and obtain the construction parameters corresponding to multiple groups of model grouts; The model grout with the best construction parameters is selected as the grout for anti-friction grouting for rectangular pipe jacking.

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