Model test device and method for pipe jacking resistance reduction

Abstract

The invention provides a model test device and method for pipe jacking resistance reduction, and relates to the technical field of pipe jacking construction of tunnel engineering. The test device drives the U-shaped plate to move in the radial direction of the top pipe through the first jack, the second jack and the third jack so as to adjust the position of the top pipe in the mud sleeve. The jacking assembly drives the jacking pipe to jack in the axial direction, the jacking pressure sensor monitors the resistance borne by the jacking pipe in the jacking process, the slurry pressure sensor monitors the grouting pressure, the influence of the slurry proportion and the grouting pressure on the resistance reduction effect of the jacking pipe under the condition that the jacking pipe and the slurry sleeve are at various relative positions is obtained, and a basis is provided for resistance reduction optimization.

Description

Technical Field

[0001] The invention relates to the technical field of tunnel engineering pipe jacking construction, and in particular to a model test device and method for pipe jacking drag reduction. Background Art

[0002] In the field of tunnel construction, pipe jacking is usually used to advance underground in order to build underground passages, pipelines or other underground structures. However, due to factors such as geological conditions, pipeline materials, and construction environment, pipe jacking construction often encounters problems such as large resistance and slow progress. The use of drag-reducing mud is a key way to solve these problems.

[0003] During the jacking process, the most ideal position for the jacking pipe in the mud casing is at the center. At this time, the jacking pipe has no contact with the surrounding soil and is subject to less frictional resistance. However, the jacking pipe often deviates from the optimal position, leaves the center of the mud casing, and even contacts the soil. The mud drag reduction effect under these non-ideal conditions also needs to be considered.

[0004] However, there is currently a lack of test equipment and methods to simulate the jacking of pipes at different positions in the mud casing and to accurately measure data such as friction resistance and soil pressure around the pipe, so as to analyze the factors affecting the drag reduction of pipe jacking and provide test equipment and theoretical basis for optimizing the drag reduction of pipe jacking by adjusting mud ratio, grouting pressure and other factors. Summary of the invention

[0005] In view of the deficiencies in the prior art, the present invention provides a model test device and method for pipe jacking drag reduction, which solves the problem of lack of test devices and methods for simulating and analyzing pipe jacking drag reduction.

[0006] To achieve the above objectives, the present invention is implemented through the following technical solutions:

[0007] A model test device and method for pipe jacking drag reduction, the test device comprising: a test box assembly and a jacking assembly;

[0008] The test box assembly includes: a rear plate, a front plate, a U-shaped plate and a base;

[0009] The rear plate and the front plate are both fixed on the base, and both are provided with through holes for the top pipe to pass through;

[0010] The front and rear ends of the U-shaped plate are both provided with rubber pads; the U-shaped plate is sealed and fitted with the rear plate and the front plate respectively through the corresponding rubber pads;

[0011] The first jack, the second jack and the third jack are respectively arranged below and on both sides of the U-shaped plate; the first jack is installed on the base, and the second jack and the third jack are both installed on the base through the support plate;

[0012] The jacking assembly includes: a servo jack and a jacking pressure sensor;

[0013] The servo jack is used to drive the jacking pipe to jack along the axial direction of the through hole, and the jacking pressure sensor monitors the jacking pressure of the servo jack in real time.

[0014] Preferably, a first waterproof rubber ring is arranged in the through hole of the rear plate, and a second waterproof rubber ring is arranged in the through hole of the front plate.

[0015] Preferably, the U-shaped plate comprises: a side plate and a bottom plate;

[0016] Side plates are welded to both ends of the bottom plate, and angle steels are welded to the connection between the side plates and the bottom plate.

[0017] Preferably, support frames are provided on both sides of the first jack;

[0018] The free ends of the first jack, the second jack and the third jack are all provided with pads.

[0019] Preferably, a gantry is installed on the base, a fourth jack is arranged at the bottom of the crossbeam of the gantry, and the fourth jack is located above the U-shaped plate.

[0020] Preferably, the jacking assembly further comprises: a reaction frame, a cushion block and a lifting frame;

[0021] The reaction frame is fixed on the ground, the end of the servo jack is connected to the reaction frame, the head end of the servo jack is in contact with the jacking pipe through a cushion block, and the induction element of the jacking pressure sensor is arranged between the servo jack and the cushion block;

[0022] A roller is arranged on the top of the lifting frame, and the lifting frame supports the jacking pipe through the roller.

[0023] Preferably, the top tube comprises: a front tube and a rear tube;

[0024] The front tube and the rear tube are coaxially welded, and the outer diameter of the front tube is larger than the outer diameter of the rear tube;

[0025] The first water-stop rubber ring is used for the rear pipe to pass through and maintains water-stopping properties; the second water-stop rubber ring is used for the front pipe to pass through and maintains water-stopping properties.

[0026] Preferably, the test device further comprises: a grouting assembly;

[0027] The grouting assembly comprises: a grouting pipe, a grout storage tank and an air compressor;

[0028] The wall of the rear pipe is provided with a plurality of grouting holes, which are connected to the grouting pipes through a plurality of six-way pipes connected in series. The head ends of the grouting pipes extend into the slurry storage tank. The air compressor is used to press the slurry in the slurry storage tank along the grouting pipes, six-way pipes and grouting holes to the outside of the wall of the rear pipe.

[0029] Preferably, a solenoid valve is provided at the head end of each section of the six-way pipe; and a mud pressure sensor is provided on the grouting pipe.

[0030] A model test method for pipe jacking drag reduction, the test method comprising the following steps:

[0031] S1. Apply vaseline on the inner wall of the back plate and the front plate, fill the test soil into the test box assembly in layers and compact it, gradually adding until it reaches below the through hole;

[0032] S2. Apply vaseline to the first and second waterproof rubber rings, insert the top pipe into the through hole, keep the rear pipe and the first waterproof rubber ring waterproof, and keep the front pipe and the second waterproof rubber ring waterproof. Adjust the height of the lifting frame to keep the top pipe in shape and position, adjust the axial position of the top pipe until the front pipe completely enters the test box assembly, and continue to fill and compact until it is full.

[0033] S3, start the servo jack, observe the position of the grouting hole, and control the grouting hole entering the test box assembly to grout the rear pipe outside through the solenoid valve at the six-way pipe head end;

[0034] S4. When the front pipe is completely pushed out of the test box assembly, the jacking is stopped. A mud sleeve has been formed between the rear pipe and the soil. The first jack, the second jack and the third jack are operated to move the soil in the box as a whole while keeping the position of the jacking pipe unchanged, so as to change the relative position of the jacking pipe in the mud sleeve.

[0035] S5. After the jacking pipe and the mud sleeve are adjusted to the relative position to be tested, start the servo jack and continue jacking until the end of the test. Record the monitoring data of the jacking pressure sensor and the mud pressure sensor during the jacking process. Repeat S1 to S5 to obtain the relationship between the resistance encountered by the jacking pipe during the jacking process and the mud ratio and grouting pressure under various relative positions of the jacking pipe and the mud sleeve.

[0036] The present invention provides a model test device and method for pipe jacking drag reduction. Compared with the prior art, it has the following beneficial effects:

[0037] In the present invention, the test device drives the U-shaped plate to move radially along the jacking pipe through the first jack, the second jack and the third jack, so as to adjust the position of the jacking pipe in the mud sleeve; the jacking assembly drives the jacking pipe to jack in the axial direction, the jacking pressure sensor monitors the resistance encountered by the jacking pipe during the jacking process, and the mud pressure sensor monitors the grouting pressure, so as to obtain the influence of the mud ratio and the grouting pressure on the drag reduction effect of the jacking pipe under various relative positions of the jacking pipe and the mud sleeve, thereby providing a basis for drag reduction optimization. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0039] Figure 1 It is a schematic diagram of the structure of the test device in the embodiment of the present invention;

[0040] Figure 2 It is a structural schematic diagram of a test box assembly in an embodiment of the present invention;

[0041] Figure 3 An exploded view of a test box assembly in an embodiment of the present invention;

[0042] Figure 4 An exploded view of the rear plate, the front plate and the U-shaped plate in an embodiment of the present invention;

[0043] Figure 5 A schematic diagram of the structure of the rear plate and the front plate in an embodiment of the present invention;

[0044] Figure 6 A schematic diagram of the structure of a U-shaped plate in an embodiment of the present invention;

[0045] Figure 7 It is a partial structural schematic diagram of a test box assembly in an embodiment of the present invention;

[0046] Figure 8 Schematic diagram of the position change of the U-shaped plate in an embodiment of the present invention;

[0047] Fig. 9 It is a schematic diagram of the structure of the lifting frame in an embodiment of the present invention;

[0048] Fig.10 It is a schematic diagram of the structure of the jacking pipe in an embodiment of the present invention;

[0049] Fig.11 This is a schematic diagram of the structure of a six-way pipe in an embodiment of the present invention;

[0050] Fig.12 It is a schematic diagram of the local structure of the test device after the mud jacket is generated in the embodiment of the present invention;

[0051] Fig.13 It is a schematic diagram of the structure of the test device in the initial state of the test in an embodiment of the present invention;

[0052] Fig.14 It is a schematic diagram of the structure of the test device after the mud sleeve is generated in the embodiment of the present invention;

[0053] Fig.15 This is a schematic diagram of the structure of the test device in the test end state in an embodiment of the present invention;

[0054] Fig.16 Schematic diagram of the relative positions of the jacking pipe and the mud jacket in an embodiment of the present invention;

[0055] The reference numerals in the figure are set as: rear plate 1, front plate 2, side plate 3, bottom plate 4, first water-stop rubber ring 5, second water-stop rubber ring 6, rubber pad 7, oblique support 8, first jack 9, second jack 10, third jack 11, fourth jack 12, pad 13, support plate 14, support frame 15, gantry 16, mud sleeve 17, six-way pipe 18, base 19, front pipe 20, rear pipe 21, lifting frame 22, servo jack 23, pad 24, jacking pressure sensor 25, reaction frame 26, grouting pipe 27, mud pressure sensor 28, slurry storage tank 29, air compressor 30. DETAILED DESCRIPTION

[0056] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention are clearly and completely described. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0057] The embodiments of the present application provide a model test device and method for pipe jacking drag reduction, thereby solving the problem of lack of test devices and methods for simulating and analyzing pipe jacking drag reduction.

[0058] In order to better understand the above technical solution, the above technical solution will be described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0059] Example:

[0060] like Figures 1 to 16 As shown, the present invention provides a model test device for pipe jacking drag reduction, the test device comprising: a test box assembly and a jacking assembly;

[0061] The test box assembly includes: a rear plate 1, a front plate 2, a U-shaped plate and a base 19;

[0062] The rear plate 1 and the front plate 2 are both fixed on the base 19, and both the rear plate 1 and the front plate 2 are provided with through holes for the top pipe to pass through;

[0063] The front and rear ends of the U-shaped plate are both provided with rubber pads 7; the U-shaped plate is sealed and fitted with the rear plate 1 and the front plate 2 respectively through the corresponding rubber pads 7;

[0064] A first jack 9, a second jack 10 and a third jack 11 are respectively arranged below and on both sides of the U-shaped plate; the first jack 9 is mounted on a base 19, and the second jack 10 and the third jack 11 are both mounted on the base 19 through a support plate 14; the first jack 9 is used to drive the U-shaped plate to move up and down, and the second jack 10 and the third jack 11 are used to drive the U-shaped plate to move left and right;

[0065] The jacking assembly includes: a servo jack 23 and a jacking pressure sensor 25;

[0066] The servo jack 23 is used to drive the jacking pipe to jack along the axial direction of the through hole, and the jacking pressure sensor 25 monitors the jacking pressure of the servo jack 23 in real time.

[0067] like Figure 5 As shown, the outer sides of the rear plate 1 , the front plate 2 and the support plate 14 are reinforced by the oblique supports 8 .

[0068] like Figure 5 As shown, a first waterproof rubber ring 5 is arranged in the through hole of the rear plate 1 , and a second waterproof rubber ring 6 is arranged in the through hole of the front plate 2 .

[0069] The first waterproof rubber ring 5 , the second waterproof rubber ring 6 and the rubber pad 7 are all coated with lubricant.

[0070] like Figure 6 As shown, the U-shaped plate includes: a side plate 3 and a bottom plate 4;

[0071] The two ends of the bottom plate 4 are respectively welded with side plates 3 , and angle steels are welded at the connection between the side plates 3 and the bottom plate 4 .

[0072] like Figure 7 , Figure 8 As shown, the free ends of the first jack 9 , the second jack 10 and the third jack 11 are all provided with pads 13 .

[0073] The backing plate 13, the rear plate 1 and the front plate 2 are all coated with drag-reducing coating.

[0074] like Figure 7 , Figure 8 As shown, support frames 15 are provided on both sides of the first jack 9, and the support frames 15 are used to support the U-shaped plate.

[0075] like Figure 7 , Figure 8 As shown, a gantry 16 is installed on the base 19, and a fourth jack 12 is arranged at the bottom of the crossbeam of the gantry 16. The fourth jack 12 is located above the U-shaped plate and cooperates with the cover plate to apply a vertical load to the soil in the test box assembly.

[0076] like Figure 1 , Fig. 9 As shown, the jacking assembly further includes: a reaction frame 26, a cushion block 24 and a lifting frame 22;

[0077] The reaction frame 26 is fixed on the ground and reinforced by diagonal braces. The end of the servo jack 23 is connected to the reaction frame 26. The head end of the servo jack 23 contacts the jacking pipe through the cushion block 24. The sensing element of the jacking pressure sensor 25 is arranged between the servo jack 23 and the cushion block 24.

[0078] A roller is disposed on the top of the lifting frame 22 , and the lifting frame 22 supports the jacking pipe through the roller, thereby reducing the friction resistance between the jacking pipe and the lifting frame 22 when the jacking pipe passes through.

[0079] like Fig.10 As shown, the top tube includes: a front tube 20 and a rear tube 21;

[0080] The front tube 20 and the rear tube 21 are coaxially welded, and the outer diameter of the front tube 20 is greater than the outer diameter of the rear tube 21 .

[0081] The first waterproof rubber ring 5 allows the rear pipe 21 to pass through and maintains waterproof performance; the second waterproof rubber ring 6 allows the front pipe 20 to pass through and maintains waterproof performance.

[0082] like Figure 1 , Fig.10 , Fig.11 As shown, the test device also includes: a grouting component;

[0083] The grouting assembly includes: a grouting pipe 27, a grout storage tank 29 and an air compressor 30;

[0084] The wall of the rear pipe 21 is provided with a plurality of grouting holes, which are connected to the grouting pipe 27 through a plurality of six-way pipes 18 connected in series. The head end of the grouting pipe 27 extends into the slurry storage tank 29. The air compressor 30 is used to press the slurry in the slurry storage tank 29 along the grouting pipe 27, the six-way pipe 18, and the grouting holes to the outside of the wall of the rear pipe 21.

[0085] A solenoid valve is provided at the head end of each six-way pipe 18 for controlling the pulp outlet position.

[0086] like Figure 1 As shown, a mud pressure sensor 28 is provided on the grouting pipe 27 for monitoring the grouting pressure.

[0087] like Figure 12 to Figure 16 As shown, the present invention provides a model test method for pipe jacking drag reduction, and the test method comprises the following steps:

[0088] S1. Apply vaseline on the inner walls of the rear plate 1 and the front plate 2 to facilitate the subsequent U-shaped plate to push the box soil to move under the drive of the first jack 9, the second jack 10 and the third jack 11, and fill the test soil into the test box assembly in layers and compact it, gradually adding it until it is below the through hole;

[0089] S2, apply vaseline to the first waterproof rubber ring 5 and the second waterproof rubber ring 6, insert the top pipe into the through hole, keep the rear pipe 21 and the first waterproof rubber ring 5 waterproof, keep the front pipe 20 and the second waterproof rubber ring 6 waterproof, adjust the height of the lifting frame 22 to keep the top pipe shape, adjust the axial position of the top pipe until the front pipe 20 completely enters the test box assembly, continue to fill and compact until it is filled, at this time the top pipe position is as follows Fig.13 As shown;

[0090] S3, start the servo jack 23, observe the position of the grouting hole, and control the grouting hole entering the test box assembly to grout the outside of the rear pipe 21 through the solenoid valve at the head end of the six-way pipe 18;

[0091] S4. When the front pipe 20 is completely pushed out of the test box assembly, the jacking is stopped. At this time, the position of the jacking pipe is as follows: Fig.14 As shown, the enlarged view of the box is as follows Fig.12 As shown, a mud sleeve 17 has been formed between the rear pipe 21 and the soil. The first jack 9, the second jack 10 and the third jack 11 are operated to move the soil in the box as a whole while keeping the position of the jacking pipe unchanged, so as to change the relative position of the jacking pipe in the mud sleeve 17. Fig.16 As shown, A is the jacking pipe, M is the outer wall of the mud sleeve, and B, C, D, and E are the relative positions of the jacking pipe in the mud sleeve 17 after the box soil is moved;

[0092] S5, after the jacking pipe and the mud sleeve 17 are adjusted to the relative position to be tested, the servo jack 23 is started to continue jacking until the test is completed. At this time, the jacking pipe position is as follows: Fig.15 As shown, the monitoring data of the jacking pressure sensor 25 and the mud pressure sensor 28 during the jacking process are recorded, and S1 to S5 are repeated to obtain the relationship between the resistance encountered by the jacking pipe during the jacking process and the mud ratio and grouting pressure under various relative positions of the jacking pipe and the mud sleeve 17; and to provide a test model for the subsequent optimization of test factors such as mud ratio and grouting pressure to reduce resistance.

[0093] In summary, compared with the prior art, the present invention has the following beneficial effects:

[0094] In the embodiment of the present invention, the test device drives the U-shaped plate to move radially along the jacking pipe through the first jack 9, the second jack 10 and the third jack 11, so as to adjust the position of the jacking pipe in the mud sleeve; the jacking assembly drives the jacking pipe to jack in the axial direction, the jacking pressure sensor 25 monitors the resistance encountered by the jacking pipe during the jacking process, and the mud pressure sensor 28 monitors the grouting pressure, so as to obtain the influence of the mud ratio and the grouting pressure on the drag reduction effect of the jacking pipe under various relative positions of the jacking pipe and the mud sleeve 17, thereby providing a basis for drag reduction optimization.

[0095] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0096] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A model test device for pipe jacking drag reduction, characterized in that: The test device comprises: a test box assembly and a jacking assembly; The test box assembly comprises: a rear plate (1), a front plate (2), a U-shaped plate and a base (19); The rear plate (1) and the front plate (2) are both fixed on the base (19), and both the rear plate (1) and the front plate (2) are provided with through holes for the top pipe to pass through; The front and rear ends of the U-shaped plate are both provided with rubber pads (7); the U-shaped plate is sealed and fitted with the rear plate (1) and the front plate (2) respectively through the corresponding rubber pads (7); A first jack (9), a second jack (10) and a third jack (11) are respectively arranged below and on both sides of the U-shaped plate; the first jack (9) is mounted on a base (19), and the second jack (10) and the third jack (11) are both mounted on the base (19) via a support plate (14); The jacking assembly comprises: a servo jack (23) and a jacking pressure sensor (25); The servo jack (23) is used to drive the jacking pipe to axially advance along the through hole, and the jacking pressure sensor (25) monitors the jacking pressure of the servo jack (23) in real time.

2. The model test device for pipe jacking drag reduction according to claim 1, characterized in that: A first water-stopping rubber ring (5) is arranged in the through hole of the rear plate (1), and a second water-stopping rubber ring (6) is arranged in the through hole of the front plate (2).

3. The model test device for pipe jacking drag reduction according to claim 1, characterized in that: The U-shaped plate comprises: a side plate (3) and a bottom plate (4); The two ends of the bottom plate (4) are respectively welded with side plates (3), and angle steel is welded at the connection between the side plates (3) and the bottom plate (4).

4. The model test device for pipe jacking drag reduction according to claim 1, characterized in that: Support frames (15) are provided on both sides of the first jack (9); The free ends of the first jack (9), the second jack (10) and the third jack (11) are all provided with pads (13).

5. The model test device for pipe jacking drag reduction according to claim 1, characterized in that: A gantry (16) is installed on the base (19), and a fourth jack (12) is arranged at the bottom of the crossbeam of the gantry (16), and the fourth jack (12) is located above the U-shaped plate.

6. The model test device for pipe jacking drag reduction according to claim 1, characterized in that: The jacking assembly further comprises: a reaction frame (26), a cushion block (24) and a lifting frame (22); The reaction frame (26) is fixed on the ground, the end of the servo jack (23) is connected to the reaction frame (26), the head end of the servo jack (23) is in contact with the jacking pipe through the cushion block (24), and the sensing element of the jacking pressure sensor (25) is arranged between the servo jack (23) and the cushion block (24); A roller conveyor is provided on the top of the lifting frame (22), and the lifting frame (22) supports the jacking pipe via the roller conveyor.

7. The model test device for pipe jacking drag reduction according to claim 2, characterized in that: The top pipe comprises: a front pipe (20) and a rear pipe (21); The front tube (20) and the rear tube (21) are coaxially welded, and the outer diameter of the front tube (20) is greater than the outer diameter of the rear tube (21); The first waterproof rubber ring (5) allows the rear pipe (21) to pass through and maintains waterproof properties; the second waterproof rubber ring (6) allows the front pipe (20) to pass through and maintains waterproof properties.

8. The model test device for pipe jacking drag reduction according to claim 7, characterized in that: The test device also includes: a grouting assembly; The grouting assembly comprises: a grouting pipe (27), a grout storage tank (29) and an air compressor (30); The wall of the rear pipe (21) is provided with a plurality of grouting holes, the grouting holes are connected to the grouting pipe (27) through a plurality of six-way pipes (18) connected in series, the head end of the grouting pipe (27) extends into the slurry storage tank (29), and the air compressor (30) is used to press the slurry in the slurry storage tank (29) along the grouting pipe (27), the six-way pipe (18), and the grouting holes to the outside of the wall of the rear pipe (21).

9. The model test device for pipe jacking drag reduction according to claim 8, characterized in that: A solenoid valve is arranged at the head end of each six-way pipe (18); and a mud pressure sensor (28) is arranged on the grouting pipe (27).

10. A model test method for pipe jacking drag reduction, characterized in that: The test method comprises the following steps: S1. Apply vaseline on the inner wall of the rear plate (1) and the front plate (2), fill the test soil into the test box assembly in layers and compact it, gradually adding until it reaches below the through hole; S2. Apply vaseline to the first waterproof rubber ring (5) and the second waterproof rubber ring (6), insert the top pipe into the through hole, keep the rear pipe (21) and the first waterproof rubber ring (5) waterproof, and keep the front pipe (20) and the second waterproof rubber ring (6) waterproof, adjust the height of the lifting frame (22) to keep the top pipe in shape, adjust the axial position of the top pipe until the front pipe (20) completely enters the test box assembly, and continue to fill and compact until it is full; S3, start the servo jack (23), observe the position of the grouting hole, and control the grouting hole entering the test box assembly to the outside of the rear pipe (21) through the solenoid valve at the head end of the six-way pipe (18); S4, when the front pipe (20) is completely pushed out of the test box assembly, the jacking is stopped, and a mud sleeve (17) is formed between the rear pipe (21) and the soil. The first jack (9), the second jack (10) and the third jack (11) are operated to move the soil in the box as a whole while keeping the position of the jacking pipe unchanged, so as to change the relative position of the jacking pipe in the mud sleeve (17); S5, after the jacking pipe and the mud sleeve (17) are adjusted to the relative position to be tested, the servo jack (23) is started to continue jacking until the test is completed, and the monitoring data of the jacking pressure sensor (25) and the mud pressure sensor (28) during the jacking process are recorded, and S1 to S5 are repeated to obtain the relationship between the resistance encountered by the jacking pipe during the jacking process and the mud ratio and grouting pressure under various relative positions of the jacking pipe and the mud sleeve (17).

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