Pipe jacking construction simulation test device and test method

Abstract

A pipe jacking construction simulation test device and test method, including test box, pipe jacking, pipe jacking drive assembly, infiltration flow assembly, leakage monitoring assembly and sand body flow monitoring assembly, the middle part of test box is provided with a partition, which divides the test box into filling side and well side, the pipe jacking enters through the pipe jacking entrance hole and is driven by the pipe jacking drive assembly, and advances in the filling side through the cooperation of horizontal slide rail and chute until passing through the partition;Infiltration flow assembly and leakage monitoring assembly are used to monitor the seepage condition of filling side and well side, and sand body flow monitoring assembly is used to monitor the flow condition of sand body in the pipe jacking process;The pipe jacking is cylindrical pipe body or / and non-cylindrical pipe body, and its position in the test box is adjusted by slide rail moving adjusting member.The present application can simulate the leakage water condition of construction filling side and receiving well side in the pipe jacking construction process, study the flow condition and soil layer pressure of filling soil at different positions around the pipe jacking, and the influence of vertical load.

Description

Technical Field

[0001] This invention relates to the field of construction simulation testing technology, and in particular to a pipe jacking construction simulation testing device and testing method. Background Technology

[0002] Pipe jacking is a pipeline laying technology that involves little or no excavation. Although it does not require excavation, the construction process inevitably disturbs the soil around the pipe, causing soil deformation or displacement. When the deformation or displacement exceeds a certain range, it will affect or damage the corresponding buildings, structures, roads, landscapes, and underground pipelines, thus causing a series of safety problems. In fact, accidents caused by ground collapse and tilting of surrounding buildings occur frequently during construction. Therefore, during construction, it is necessary to make certain predictions and estimates of the soil conditions around the pipe during the construction project and take corresponding measures based on the prediction results.

[0003] Simulation tests can predict soil deformation and displacement during construction to a certain extent, understand the impact of water leakage during construction, and assess the pressure of the surrounding soil layers, providing theoretical and practical support for actual construction and production, and providing basic data for related theories. Existing simulation tests of pipe jacking construction mainly focus on the study of ground settlement, drag-reducing grouting effect, and sewage leakage. However, during pipe jacking construction, the soil around the pipe does not simply settle; it moves with the pipe's advancement. This movement causes settlement in the vertical direction and tilting of the soil layer in the horizontal direction. This is one of the reasons for the tilting of ground buildings, structures, and roads, and the rupture of underground pipelines. Therefore, it is necessary to study the flow of backfill at different locations around the pipe during construction. In addition to flowing towards the launching shaft and the pipe, underground seepage water will also flow towards the receiving shaft when the pipe reaches it, inducing the loss of foundation soil and sand, and thus triggering ground subsidence accidents. Existing pipe jacking simulation tests mostly limit the observation of soil layers to a section perpendicular to the pipe's direction of advancement, making it difficult to directly observe the entire pipe jacking process, including observation and research from sections parallel to the pipe's direction of advancement, as well as dynamic simulation. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the prior art and provide a simulation test device and method for pipe jacking construction. It can comprehensively simulate the flow of backfill and soil pressure at different locations around the pipe during the pipe jacking process, study the water leakage on the backfill side and the receiving well side during the pipe jacking process, simulate the vertical loading force of the soil layer, and study the influence of different loading forces on the flow of backfill and soil pressure at different locations around the pipe.

[0005] This invention is achieved through the following technical solution:

[0006] A simulation test device for pipe jacking construction includes a test chamber, a pipe, a pipe jacking drive assembly, an infiltration flow assembly, a leakage monitoring assembly, and a sand flow monitoring assembly. The top of the test chamber is open, and one side is made of transparent material for easy observation and photography; this side is the first side. A partition is provided in the middle of the test chamber to simulate the well wall of a receiving well. The partition is perpendicular to the first side and divides the test chamber into a backfill side and a well side. The backfill side is filled with test backfill, and the well side is empty (without any material) to simulate the receiving well to which the pipe jacking will reach. The side of the test chamber opposite the partition is the second side. A pipe jacking entry hole is provided on the second side. The pipe jacking enters the backfill side of the test chamber through the pipe jacking entry hole and is driven by the pipe jacking drive assembly to advance in the backfill side until it passes through the partition. Because the soil layer in actual construction is not dry sand, but sand with a certain moisture content, seepage water will accumulate during construction, affecting the pipe jacking construction and the flow of sand around the pipe. To simulate the impact of seepage water, an infiltration flow rate component is set up. The outlet of the infiltration flow rate component is located above the backfill side of the test chamber, used to spray water to humidify the backfill to simulate water seepage in the soil during pipe jacking. The seepage monitoring component is used to monitor the seepage on the backfill side and the well side. The sand flow monitoring component is used to monitor the flow of sand during pipe jacking through the first side.

[0007] Furthermore, a horizontal slide rail is provided inside the test chamber along the direction of the jacking pipe excavation, and a groove adapted to the horizontal slide rail is provided on the jacking pipe. The jacking pipe moves and advances along the direction of the horizontal slide rail through the cooperation of the horizontal slide rail and the groove.

[0008] The jacking pipe is a cylindrical pipe or / and a non-cylindrical pipe. The chute is set at the top and bottom of the jacking pipe. The non-cylindrical pipe is obtained by cutting off a portion of the cylindrical pipe with a plane parallel to the axis, and its cross-section perpendicular to the axis is an arc with a central angle of ≥180°. The opening of the non-cylindrical pipe is close to the first side of the test chamber to observe the flow of the backfill around the jacking pipe during the jacking process. The non-cylindrical pipes with different central angles correspond to the backfill at different positions around the jacking pipe during the jacking process. When the jacking pipe is a cylindrical pipe, the jacking pipe is parallel to the first side, close to the first side or separated from the first side by a certain distance. The different intervals between the cylindrical pipe and the first side correspond to the backfill at different positions around the jacking pipe during the jacking process.

[0009] Furthermore, the test chamber is also equipped with a slide rail moving adjustment component for adjusting the installation position of the slide rail. The side where the upper partition of the test chamber is located is the third side. The slide rail moving adjustment component includes transverse support bars respectively set on the second side and the third side and positioned opposite each other. The transverse support bars are parallel to the bottom surface of the test chamber and are provided with transverse elongated slots. The two ends of the slide rail are provided with fixing holes. The two ends of the slide rail are fixed to the transverse support bars on the second side and the third side through the cooperation of the fixing holes and the transverse elongated slots. The installation position of the slide rail on the transverse support bars is adjusted through the transverse elongated slots, thereby adjusting the position of the jacking pipe in the test chamber.

[0010] Furthermore, the area between the upper and lower horizontal support bars on the second side is the insertion area, and the area between the upper and lower horizontal support bars on the third side is the exit area. The insertion and exit areas are left empty. During the test, a jacking material that can be jacked through by the jacking pipe is pasted on the insertion and exit areas, and the edges are sealed.

[0011] Furthermore, the jacking pipe is a straight-through pipe body with open front and rear ends, and the jacking pipe driving assembly is a hydraulic jack, an electric telescopic rod, or a cylinder.

[0012] Furthermore, the pipe jacking includes a pipe body and a drill bit. The pipe jacking drive assembly includes a lead screw, a nut, a drive motor, a fixed base, a motor mounting base, and a motor slide rail. The drill bit is rotatably mounted on the front end face of the pipe body, and a soil inlet hole is provided on the front end face of the pipe body. The front end of the lead screw passes through the pipe body and is connected to the drill bit for transmission. The nut is fixed on the fixed base, and the middle part of the lead screw is screwed onto the nut. The rear end of the lead screw is connected to the drive motor for driving. The drive motor is mounted on the motor mounting base, and a slider is provided at the bottom of the motor mounting base. The motor slide rail is set parallel to the lead screw, and the slider is set on the motor slide rail. The motor mounting base can move back and forth along the motor slide rail. The lead screw rotates under the drive of the drive motor, driving the drill bit to rotate, and simultaneously driving the pipe body to move horizontally to excavate forward in the backfill, realizing that one drive motor simultaneously drives the pipe body to advance and the drill bit to rotate.

[0013] Furthermore, the jacking drive assembly, including the lead screw and nut, also includes a gear set mounted on the front end face of the pipe body. The gear set includes a driving gear and several driven gears. The several driven gears mesh with the driving gear respectively. Each driven gear is coaxially connected to a drill bit. After the front end of the lead screw passes through the pipe body, it drives several drill bits to rotate through the gear set.

[0014] Furthermore, a vertical loading component is also required at the top of the test chamber to pressurize the soil layer in the test chamber. The vertical loading component includes a pressure plate and a pressure plate driving component. The pressure plate covers the top of the soil layer in the test chamber, and the pressure plate driving component is connected to the pressure plate drive to drive the pressure plate to move downward to apply pressure to the soil. Soil pressure cells are pre-embedded at different locations in the test fill to control the pressure applied to the soil by the vertical loading component and to monitor the pressure changes at each location during the pipe jacking process.

[0015] Furthermore, the infiltration flow component includes a water tank, a water pump, a control valve, and a water outlet module. The water tank, water pump, control valve, and water outlet module are connected in sequence via water pipes. The water outlet module is located directly above the test chamber, and several water outlet holes are evenly distributed at the bottom of the water outlet module for uniformly spraying water into the test chamber.

[0016] The leakage monitoring component includes a first measuring cup and a second measuring cup. The bottom of the test chamber on the backfill side and the well side are respectively provided with a first water outlet and a second water outlet. The first water outlet and the second water outlet are respectively connected to the first measuring cup and the second measuring cup through pipes to receive leakage water from the backfill side and the well side. Water entering through the first measuring cup can simulate the underground water leakage of the soil layer during the pipe jacking process. Water entering through the second measuring cup can simulate the situation of underground water leakage into the receiving well when the pipe jacking penetrates the receiving well.

[0017] Furthermore, the sand flow monitoring component includes tracer particles, an image acquisition device, and a data processing system. The tracer particles can be distinguished from the test fill soil by color, and the image acquisition device can directly acquire images of the tracer particles. Alternatively, the soil flow monitoring component includes tracer particles, a light source, an image acquisition device, and a data processing system. The tracer particles are illuminated by the light source and then their images are acquired by the image acquisition device. Several of the tracer particles are distributed in the fill soil close to the first side or the first and second sides. The light source illuminates the tracer particles, and the image acquisition device is positioned directly in front of the tracer particles to capture images of the soil flow during the pipe jacking process. The data processing system is connected to the image acquisition device and is used to extract the displacement field and velocity field of the tracer particle images by analyzing the image displacement of the tracer particles, and then determine the sand flow based on the time interval between the images.

[0018] A method for simulating pipe jacking construction, using the aforementioned pipe jacking construction simulation test device, includes the following steps:

[0019] S1. Install a jacking material in the penetration area between the upper and lower transverse support bars on the second side and the exit area between the upper and lower transverse support bars on the third side, and seal it. Adjust the position of the slide rail on the transverse support bar according to the position of the jacking pipe in the test chamber and fix it.

[0020] S2. Fill the test soil layer by layer in the test chamber. During the filling process, place tracer particles at the corresponding positions on the first side or the first and second sides, and pre-embed earth pressure cells at the corresponding positions in the soil. After filling the soil to the set position, compact it. Install the infiltration flow component, leakage monitoring component and sand flow monitoring component. Turn on the infiltration flow component and observe and record the data of the leakage monitoring component.

[0021] S3. After the leakage rate stabilizes, open the jacking pipe entry hole at the corresponding position in the penetration area, insert the jacking pipe into the jacking pipe entry hole, and use the cooperation of the chute and the slide rail to make the jacking pipe enter the test chamber slightly, and connect the jacking pipe to the jacking pipe drive assembly.

[0022] S4. According to the test procedure, turn on the pipe jacking drive assembly and the sand flow monitoring assembly, and record the data of water leakage on the backfill side, displacement data of tracer particles, and pressure data of each earth pressure cell in the backfill during the pipe jacking process; when the pipe jacking penetrates the partition, record the water leakage data on the well side.

[0023] S5. Repeat steps S1 to S4, replacing non-cylindrical pipes with different central angles, and adjusting the distance between the cylindrical pipe and the first side surface. Keep the pipe diameters of the non-cylindrical pipe and the cylindrical pipe consistent, and ensure that the opening of the non-cylindrical pipe is close to the first side surface. Obtain the flow and pressure data of the backfill at different locations during the pipe jacking process to guide the assessment of the occurrence of displacement, settlement, and other conditions of the soil layer near the pipe jacking in actual production.

[0024] Furthermore, in step S2, after filling the backfill to the set position, a vertical loading component for applying vertical load to the backfill is installed and activated on top of the backfill. When the vertical load reaches the set value, the load is kept constant, and steps S3 to S5 are continued for testing. The value of the vertical load is changed according to a certain pattern, and steps S1 to S5 are repeated to study the influence of the vertical load on the flow of backfill and soil pressure (deformation mechanism) around the pipe jacking.

[0025] Furthermore, in step S2, when the infiltration flow component is activated, the water flow rate is changed according to a certain pattern. Steps S1 to S5 are repeated to study the relationship between the moisture content of the fill and the seepage rate, as well as the influence of the moisture content of the fill on the flow (flow mechanism) and soil pressure of the fill around the pipe jacking.

[0026] This invention, by setting a partition in the middle of the test chamber, can simultaneously simulate the construction backfill side and the receiving well side during pipe jacking construction. By setting up infiltration flow rate components and leakage monitoring components, the seepage conditions on both the backfill and well sides can be observed and studied. Furthermore, by changing the infiltration flow rate and water level, the effects of backfill with different moisture contents on leakage, backfill flow, and soil pressure can be investigated. The sand flow monitoring component allows for the observation of backfill flow on a cross-section parallel to the pipe's forward direction during pipe jacking. This is further demonstrated by the use of horizontal slide rails within the test chamber, the jacking pipe's upper chute, and cylindrical and non-cylindrical pipe bodies. The system can be configured to conduct a series of tests by replacing non-cylindrical pipes with different central angles and adjusting the distance between the cylindrical pipe and the first side. This allows for the observation of soil flow around the pipe at different locations, as well as soil pressure at different locations. The data can be corroborated and supplemented by the monitoring data from the second side, providing more accurate and comprehensive basic data on soil flow and soil pressure around the pipe to guide actual construction. The vertical loading component can more accurately simulate the actual geological conditions during construction and also study the impact of vertical loads on soil flow and soil pressure around the pipe. Attached Figure Description

[0027] Figure 1 This is a front structural diagram of an embodiment of the present invention.

[0028] Figure 2 This is a side view of an embodiment of the present invention.

[0029] Figure 3 This is a schematic diagram of the test chamber in an embodiment of the present invention.

[0030] Figure 4 This is a schematic diagram of the jacking pipe structure in an embodiment of the present invention.

[0031] Figure 5 This is a schematic diagram of the assembly of the test chamber and the jacking pipe in an embodiment of the present invention.

[0032] Figure 6 This is a top view schematic diagram of the partial structure of the test chamber and the jacking pipe in an embodiment of the present invention.

[0033] Figure 7 The diagram shows the exploded cross-section (a) and assembled cross-section (b) of the test chamber in an embodiment of the present invention, which is fitted with a non-cylindrical jacking pipe with a central angle.

[0034] Figure 8 The diagram shows the exploded cross-section (a) and assembled cross-section (b) of the test chamber in an embodiment of the present invention, which is fitted with another non-cylindrical jacking pipe with a central angle.

[0035] Figure 9 This is a cross-sectional schematic diagram of a non-cylindrical jacking pipe with different central angles (a)-(g) in an embodiment of the present invention.

[0036] Figure 10 This is a cross-sectional schematic diagram of the cylindrical top pipe and the first side of the test chamber at different test distances in an embodiment of the present invention.

[0037] Figure 11 This is a cross-sectional schematic diagram of the combination of cylindrical jacking pipes of different diameters with the test chamber in an embodiment of the present invention.

[0038] Figure 12 This is a schematic diagram of the structure of the jacking pipe driving assembly and the jacking pipe in an embodiment of the present invention.

[0039] Figure 13 This is a schematic diagram of the installation structure of the jacking pipe drive assembly and different jacking pipes in an embodiment of the present invention.

[0040] Figure 14 This is a schematic diagram of the installation structure of the vertical loading component and the earth pressure box in an embodiment of the present invention.

[0041] Figure 15 This is a schematic diagram of the soil cross-sections at different locations around the jacking pipe during the jacking process in an embodiment of the present invention.

[0042] Figure reference numerals: 1-Test chamber; 2-Jack pipe; 3-Jack pipe drive assembly; 4-Infiltration flow assembly; 5-Leakage monitoring assembly; 6-Sand flow monitoring assembly; 7-Earth pressure cell; 8-Vertical loading assembly; 11-Baffle plate; 12-Backfill side; 13-Well side; 14-First side; 15-Second side; 151-Penetration area; 16-Horizontal slide rail; 17-Jack pipe entry hole; 18-Third side; 181-Penetration area; 19-Horizontal support bar; 191-Horizontal long slot; 192-Vertical support bar; 193-Vertical long... 21-Slot; 22-Pipe body; 23-Drill bit; 24-Driving gear; 25-Driven gear; 26-Inlet hole; 31-Drive motor; 32-Lead screw; 33-Nut; 34-Fixed seat; 35-Motor mounting seat; 36-Slider; 37-Motor slide rail; 41-Water tank; 42-Water pump; 43-Control valve; 44-Water outlet module; 51-First measuring cup; 52-Second measuring cup; 61-Tracer particle; 62-Light source; 63-Image acquisition device; 81-Reaction frame; 82-Pressure plate drive assembly; 83-Pressure plate. Detailed Implementation

[0043] A simulation test device for pipe jacking construction, such as Figures 1 to 3As shown, the system includes a test chamber 1, a jacking pipe 2, a jacking pipe drive assembly 3, an infiltration flow assembly 4, a leakage monitoring assembly 5, and a sand flow monitoring assembly 6. The test chamber 1 has an open top, with one side made of a transparent material, such as plexiglass, for easy observation and photography. This side is the first side 14. The remaining sides can also be made of transparent or non-transparent materials, such as steel plates or plastic sheets. A partition 11 is installed in the middle of the test chamber 1 to simulate the well wall of the receiving well. The partition 11 is perpendicular to the first side 14, dividing the test chamber 1 into a backfill side 12 and a well side 13. The backfill side 12 is filled with test backfill soil, which should be taken from the soil layer of the actual jacking construction site or similar backfill soil, with a similar filling density, which is closer to the actual construction than general backfill soil and transparent soil. The well side 13 is empty and is used to simulate the receiving well that the jacking pipe 2 will reach, similar to the actual receiving well.

[0044] The side of the test chamber 1 opposite the backfill side 12 and the partition 11 is the second side 15. A pipe entry hole 17 is provided on the second side 15. The pipe 2 enters the backfill side 12 of the test chamber 1 through the pipe entry hole 17 and is driven forward in the backfill side 12 by the pipe drive assembly 3 until it passes through the partition 11. Because the soil layer in actual construction is not dry sand but sand with a certain moisture content, seepage water will accumulate during construction, affecting the pipe jacking construction and the flow of sand around the pipe. To simulate the impact of seepage water, an infiltration flow component 4 is set up. The outlet of the infiltration flow component 4 is located above the backfill side 12 of the test chamber 1, used to spray water onto the backfill side 12 to humidify it and simulate water seepage in the soil during the pipe jacking process. The seepage monitoring component 5 is used to monitor the seepage situation on the backfill side 12 and the well side 13. The sand flow monitoring component 6 is used to monitor the flow of sand during the tunneling process of the pipe jacking 2 via the first side 14.

[0045] As one implementation method, such as Figures 3 to 5 As shown, a horizontal slide rail 16 is provided inside the test chamber 1 along the excavation direction of the jacking pipe 2. A groove 21 adapted to the horizontal slide rail 16 is provided on the jacking pipe 2. The jacking pipe 2 moves and advances along the direction of the horizontal slide rail 16 through the cooperation of the horizontal slide rail 16 and the groove 21. Preferably, the grooves 21 on the jacking pipe 2 are respectively located at the top and bottom of the jacking pipe 2.

[0046] The partition 11 is made of gypsum, foam, or waterproof cardboard at the point where the jacking pipe 2 exits, while the remaining portion is made of plastic, stainless steel, or gypsum. Plastic and stainless steel are materials that the jacking pipe 2 cannot penetrate and are waterproof, simulating the concrete pouring on the walls of some receiving wells to improve their load-bearing capacity. The pre-drilled hole at the exit point of the jacking pipe 2 allows the jacking pipe 2 to penetrate, simulating the untreated walls of some receiving wells.

[0047] As one implementation method, such as Figure 3 , Figure 5 The jacking pipe 2 can be a cylindrical or non-cylindrical tube. The non-cylindrical tube is obtained by cutting off a portion of a cylindrical tube with a plane parallel to the axis, and its cross-section perpendicular to the axis is an arc with a central angle ≥180°. The opening of the non-cylindrical tube is close to the first side 14 of the test chamber 1 to observe the flow of the backfill around the jacking pipe 2 during its advancement. In this case, the grooves 21 on the jacking pipe 2 can be located on the vertical diameter of the arc of the jacking pipe 2's cross-section. When the jacking pipe 2 is a cylindrical tube, it is parallel to the first side 14, close to the first side 14, or at a certain distance from the first side 14. In this case, the grooves 21 on the jacking pipe 2 are located on the vertical diameter of the arc of the jacking pipe 2's cross-section.

[0048] Multiple simulation devices can be fabricated according to the above simulation test plan, representing different distances between the cylindrical pipe and the first side surface 14. These different distances can be set into different gradient sequences according to the needs of the simulation test, such as arithmetic or geometric sequences. Taking a 1m diameter cylindrical jacking pipe 2 as an example, the jacking pipe 2 can be set at distances of 140m, 0.2m, 0.4m, 0.6m, 0.8m, and 1m from the first side surface, respectively. The diameter of the cylindrical pipe can be reduced proportionally according to the actual pipe section being constructed. For non-cylindrical pipes 22, arcs with corresponding central angles are set according to a certain rule based on the diameter of the pipe 22, such as... Figure 9 (a)-(f) allow for the setting of jacking pipe 2 with arcs having central angles of 180°, 210°, 240°, 270°, 300°, and 330°, such as... Figure 9 (g) 360° corresponds to a cylindrical tube. The position of the slide rail on the test chamber 1 corresponds to the position of the slide groove 21 on the top tube 2. The side where the partition plate 11 is located is the third side 18. The top tube inlet hole 17 on the second side 15 and the tube outlet hole on the third side 18 are fixedly set in the corresponding positions.

[0049] To improve the versatility of the test simulation device and reduce costs, a single test simulation device can be manufactured to conduct multiple simulated test schemes. This device, in addition to the aforementioned components, also includes a slide rail moving component mounted on the test chamber 1, specifically, as follows: Figures 5 to 8 , Figure 10 Transverse support bars 19 are respectively provided on the second side 15 and the third side 18, with opposite positions. The transverse support bars 19 are parallel to the bottom surface of the test chamber 1. The transverse support bars 19 are provided with transverse elongated slots 191. The two ends of the slide rail are provided with fixing holes. The two ends of the slide groove 21 are fixed to the transverse support bars 19 on the second side 15 and the third side 18 through the cooperation of the fixing holes and the transverse elongated slots 191. The installation position of the slide groove 2 on the transverse support bars 19 is adjusted by adjusting the transverse elongated slots 191, thereby adjusting the position of the jacking pipe 2 in the test chamber 1. The jacking pipe 2 includes both cylindrical and non-cylindrical pipes. Regardless of whether it is a cylindrical or non-cylindrical pipe, the slide groove 21 is preferably set at the top and bottom of the jacking pipe 2. This allows the position of the jacking pipe 2 to be adjusted according to the test requirements. When it is a non-cylindrical pipe, such as Figure 7 , Figure 8 Regardless of its central angle, the opening of the tube 22 must be tightly attached to the inner wall of the first side 14.

[0050] To accommodate jacking pipes 2 of different diameters, mounting components can be installed at different heights corresponding to the second side 15 and the third side 18. For example, support brackets (with the two ends of the horizontal support strips 19 fixed to the support brackets) or vertical support strips 192 can be installed on the four columns of the test chamber 1 frame. Figure 11 The vertical support bar 192 is provided with a vertical long slot 193. When using jacking pipes 2 of different diameters, the horizontal support bar 19 can be installed on the support bracket at different heights or on the vertical support bar 192 as needed, and the installation height of the horizontal support bar 19 can be adjusted through the vertical long slot 193.

[0051] In this case, such as Figure 5A permeable material, such as gypsum board, foam plastic, or waterproof cardboard, can be installed in the area between the upper and lower horizontal support bars 19 on the second side 15 and the third side 18. The remaining areas of the second side 15 and the third side 18 can be filled with non-permeable materials, such as plastic or stainless steel. The area between the upper and lower horizontal support bars 19 on the second side 15 is the penetration area 151, and the area between the upper and lower horizontal support bars 19 on the third side 18 is the exit area 181. The penetration area 151 and the exit area 181 can be left unfilled. During testing, permeable materials, such as gypsum board, foam plastic, or waterproof cardboard, are installed on the penetration area 151 and the exit area 181 by adhesive or other means. The edges are sealed with sealant to prevent leakage. A jacking pipe inlet hole 17 is then opened at the corresponding position in the penetration area 151 on the second side 15, and the jacking pipe 2 exits at the corresponding position in the exit area 181 on the third side 18. Sufficient quantities of gypsum board, foam plastic, or waterproof cardboard can be prepared in advance and replaced when conducting another set of tests after one set is completed. Scale lines can be set on the second side 15 and the third side 18 to facilitate adjustment of the slide rail's installation position.

[0052] This allows for the replacement of non-cylindrical tubes with different central angles (such as...) within a simulation testing device. Figure 9 ) and adjust the distance between the cylindrical tube and the first side 14 (e.g. Figure 10 A series of experiments were conducted to achieve the functions that could only be achieved by the aforementioned multiple simulation test devices.

[0053] Conventional pipe jacking construction uses high-pressure hydraulic jacks to push cement or steel pipes and a tunneling machine from the working shaft to the receiving shaft. To simulate the jacking process, the pipe jacking drive component 3 in this invention can use common linear drive devices, such as hydraulic jacks, electric telescopic rods, and cylinders. The front end of the pipe is hollow, allowing the excavated soil to directly enter the pipe during jacking. A pressure ring is installed at the rear end of the pipe to increase the force-bearing area. The linear drive device propels the pipe forward through the pressure ring.

[0054] To simulate the tunnel jacking construction process in the form of a shield tunnel, as one implementation method, such as Figure 12 , Figure 13As shown, the jacking pipe 2 includes a pipe body 22 and a drill bit 23. The jacking pipe drive assembly 3 includes a lead screw 32, a nut 33, a drive motor 31, a fixed base 34, a motor mounting base 35, and a motor slide rail 37. The drill bit 23 is rotatably mounted on the front end face of the pipe body 22. A soil inlet hole 26 is provided on the front end face of the pipe body 22 to facilitate backfilling during excavation. The front end of the lead screw 32 passes through the pipe body 22 and is connected to the drill bit 23. The nut 33 is fixed on the fixed base 34, and the middle part of the lead screw 32 is screwed onto the nut 33. The rear end of the rod 32 is connected to the drive motor 31. The drive motor 31 is mounted on the motor mounting base 35. A slider 36 is provided at the bottom of the motor mounting base 35. The motor slide rail 37 is set parallel to the lead screw 32. The slider 36 is set on the motor slide rail 37. The motor mounting base 35 can move back and forth along the motor slide rail 37. The lead screw 32 rotates under the drive of the drive motor 31, which drives the drill bit 23 to rotate. At the same time, it drives the pipe body 22 to move horizontally to excavate forward in the backfill. This realizes that one drive motor 31 can simultaneously drive the pipe body 22 to move forward and the drill bit 23 to rotate.

[0055] Specifically, such as Figure 13 The jacking pipe 2 is equipped with multiple drill bits 23. The jacking pipe drive assembly 3 also includes a gear set mounted on the front end face of the pipe body 22. The gear set includes a driving gear 24 and several driven gears 25. The driven gears 25 mesh with the driving gear 24 respectively. Each driven gear 25 is coaxially connected to one of the drill bits 23. The front end of the lead screw 32 passes through the pipe body 22 and drives the drill bits 23 to rotate through the gear set. For cylindrical pipe bodies, such as... Figure 13 (a) The shafts of the drive gear 24 and the lead screw 32 are located on the axis of the tube 22, and several drive gears 24 are evenly distributed around it. For non-cylindrical tubes, such as Figure 13 (b) and Figure 13 (c) The shafts of the drive gear 24 and the lead screw 32 are located in the middle of the tube 22. The gear set is enclosed by a housing to prevent the backfill from affecting the operation of the gear set.

[0056] Pipe jacking construction often needs to be carried out at considerable depths or under heavy loads. The jacking pipe 2 typically needs to withstand significant loads in the vertical direction. To simulate this situation, such as... Figure 14A vertical loading assembly 8 needs to be installed on the top of the test chamber 1 to pressurize the soil layer in the test chamber 1. Specifically, the vertical loading assembly 8 may include a pressure plate 83 and a pressure plate driving assembly 82. The pressure plate 83 covers the top of the soil layer in the test chamber 1, and the pressure plate driving assembly 82 drives the pressure plate 83 to move downward to apply pressure to the soil. The pressure plate driving assembly 82 is installed on the reaction frame 81 and may be a jack, an electric telescopic rod, or a cylinder. Soil pressure boxes 7 can be pre-embedded at different locations in the soil. The embedding positions of the soil pressure boxes 7 can be as follows: Figure 14 As shown, it can ensure that each characteristic position can be monitored to control the pressure of the vertical loading component 8 on the soil, and to monitor the pressure changes at each position during the jacking process of the pipe jacking 2.

[0057] As one implementation method, such as Figure 1 The infiltration flow component 4 includes a water tank 41, a water pump 42, a control valve 43, and a water outlet module 44. The water tank 41, water pump 42, control valve 43, and water outlet module 44 are connected sequentially via water pipes. The water outlet module 44 is positioned directly above the test chamber 1, with several water outlet holes evenly distributed at its bottom for uniformly spraying water into the test chamber 1. The water outlet module 44 can be a mesh water distribution pipe or a shower-style water outlet plate.

[0058] As one implementation method, such as Figure 1 The leakage monitoring component 5 includes a first measuring cup 51 and a second measuring cup 52. The bottom of the backfill side 12 and the well side 13 of the test chamber 1 are respectively provided with a first water outlet and a second water outlet. The first water outlet and the second water outlet are respectively connected to the first measuring cup 51 and the second measuring cup 52 through pipes to receive the leakage water from the backfill side 12 and the well side 13. The water intake of the first measuring cup 51 can simulate the underground water leakage of the soil layer during the tunneling of the pipe jacking 2. The water intake of the second measuring cup 52 can simulate the underground water leakage into the receiving well when the pipe jacking 2 penetrates the receiving well.

[0059] The sand flow monitoring component 6 can simulate the flow of sand around the jacking pipe 2 during the jacking construction process. The flow of sand on the first side 14 can be observed with the naked eye. Alternatively, several tracer particles 61, such as dyed sand grains, can be evenly placed in the sand on the first side 14. Coordinate scale lines can be set on the first side 14, and the coordinate changes of each tracer particle 61 can be observed and recorded with the naked eye, thereby studying the overall flow of sand.

[0060] To more accurately and automatically measure the flow of sand, as one embodiment, the sand flow monitoring component 6 includes tracer particles 61, an image acquisition device 63, and a data processing system. A plurality of the tracer particles 61 are distributed in the fill soil adjacent to the first side surface 14 (e.g., ...). Figure 5The image acquisition device 63 (camera) faces the first side 14 and is used to capture the flow of sand during the tunneling process of the pipe jacking 2. The tracer particles 61 are particles that can be distinguished from the fill soil, such as colored particles whose size and density are similar to the test fill soil. The test fill soil can be selected and surface-stained to serve as the tracer particles 61, or other particles whose color is far different from that of the fill soil.

[0061] As another implementation, the sand flow monitoring component 6 employs existing PIV technology and equipment, such as... Figure 2 The system includes tracer particles 61, a light source 62, an image acquisition device 63, and a data processing system. A plurality of the tracer particles 61 are distributed in the fill soil adjacent to the first side 14. The light source 62 illuminates the tracer particles 61, and the image acquisition device 63 (camera) faces the first side 14 to capture images of the sand flow during the tunneling process of the pipe jacking 2. The tracer particles 61 in the PIV technology have good light scattering properties and uniform following characteristics, and are generally composed of pollen, silver-plated hollow spheres, hollow glass spheres, fluorescent particles, nylon particles, alumina powder, plexiglass powder, polystyrene microspheres, aluminum powder, titanium dioxide particles, etc. In this invention, the size and density of the tracer particles 61 need to be similar to the particle size of the test fill soil to avoid affecting the normal flow of the sand. Plexiglass particles and titanium dioxide particles are preferred. The light source 62 provides light for the entire testing process; it is typically a laser light source 62. The image acquisition device 63 is used to record position images at different times within the velocity field. During the experiment, the tracer particles 61 are continuously illuminated by the laser at very short time intervals, and then continuously photographed by the image acquisition device 63. Typically, the laser generator emits laser pulses at certain time intervals. Due to the synchronizer, the image acquisition device 63 can accurately capture multiple clear particle distribution images.

[0062] After these raw images undergo a series of post-processing steps, including digitization, interpretation area division, and cross-correlation calculation by the data processing system, the displacement and velocity fields of the tracer particle 61 image can be obtained. Based on the time interval of the images, the flow of the soil, including the laws of displacement and velocity, can be derived, providing a variety of basic data for the pipe jacking construction process.

[0063] Alternatively, the second side 15 can be made of transparent material, similar to the first side 14, and equipped with corresponding tracer particles 61, light source 62 and image acquisition device 63 to monitor the backfill perpendicular to the cross section of the jacking pipe 2 during pipe jacking construction. The data monitored by the first side 14 can be corroborated and supplemented to obtain more accurate and comprehensive basic data on the flow of backfill around the jacking pipe 2 to guide actual production.

[0064] A method for simulating pipe jacking construction, using the aforementioned pipe jacking construction simulation test device, includes the following steps:

[0065] S1. Install a jacking material in the penetration area 151 between the upper and lower transverse support bars 19 on the second side 15 and the exit area 181 between the upper and lower transverse support bars 19 on the third side 18, and seal it. Adjust the position of the slide rail on the transverse support bar 19 according to the position of the jacking pipe 2 in the test chamber 1 and fix it.

[0066] S2. Fill the test chamber 1 layer by layer with test soil. During the filling process, place tracer particles 61 one by one at the corresponding positions on the first side 14 or the first side 14 and the second side 15. The placement of tracer particles 61 can be as follows: Figure 5 As shown, earth pressure cells 7 are pre-embedded at corresponding positions in the backfill. The pre-embedding of earth pressure cells 7 is as follows: Figure 14 As shown, fill the soil to the designated position and compact it; install the infiltration flow component 4, the leakage monitoring component 5 and the sand flow monitoring component 6; turn on the infiltration flow component 4 and observe and record the data of the leakage monitoring component 5.

[0067] S3. After the leakage rate stabilizes, open the jacking pipe inlet hole 17 at the corresponding position in the penetration area 151, insert the jacking pipe 2 into the jacking pipe inlet hole 17, and use the cooperation of the sliding groove 21 and the sliding rail to make the jacking pipe 2 enter the test chamber 1 slightly, and connect the jacking pipe 2 to the jacking pipe drive assembly 3.

[0068] S4. According to the test procedure, turn on the pipe jacking drive assembly 3 and the sand flow monitoring assembly 6, and record the data of water leakage on the backfill side 12, the displacement data of the tracer particles 61, and the pressure data of each earth pressure cell 7 in the backfill during the pipe jacking process; when the pipe jacking 2 penetrates the partition 11, record the water leakage data on the well side 13.

[0069] S5. Repeat steps S1 to S4, replacing non-cylindrical pipes with different central angles and adjusting the distance between the cylindrical pipe and the first side 14. Maintain the same pipe diameter for both the non-cylindrical and cylindrical pipes, with the opening of the non-cylindrical pipe tightly against the first side 14. Obtain flow and pressure data of the backfill at different locations during the jacking process of the pipe jacking 2 to guide the assessment of displacement and settlement of the soil layer near the pipe jacking 2 in actual production. To comprehensively study the backfill conditions at different locations around the pipe jacking 2, tests need to be conducted using one cylindrical pipe and multiple non-cylindrical pipes with different central angles. The central angle gradually increases from 180° to nearly 360°, with 360° corresponding to the cylindrical pipe. The cylindrical pipe gradually moves away from the first side 14 to a distance equal to the radius of a cylinder. This yields the flow of the backfill on multiple vertical sections from the center of the pipe to two radii away from the center. Figure 15As shown, the flow direction and displacement of the backfill on section AE can be obtained. The radius of the jacking pipe section is r, and section AE are vertical sections at distances of 0, 0.5r, r, 1.5r, and 2r from the axis of the jacking pipe. The simulation of the backfill on sections A and B can be conducted using non-cylindrical pipes with central angles of 180° and 240° and a cross-sectional radius of r, respectively. The simulation of the backfill on sections C, D, and E can also be conducted using non-cylindrical pipes with a cross-sectional radius of r, at distances of 0, 0.5r, and r from the first side surface, respectively. The earth pressure cell 7 can be buried at different vertical and horizontal positions around the jacking pipe 2 to obtain the soil pressure at different locations.

[0070] To simulate the impact of underground loads during actual construction, in step S2, after filling the backfill to the set position, a vertical loading component 8 is installed and activated on top of the backfill to apply vertical loads to the backfill. When the vertical load reaches the set value (such as the earth pressure value at the actual construction site), the load is kept constant, and steps S3 to S5 are continued for testing. The value of the vertical load is changed according to a certain pattern, such as following an arithmetic sequence, and steps S1 to S5 are repeated to study the impact of the vertical load on the flow of backfill and soil pressure around the jacking pipe 2.

[0071] To simulate the impact of backfill moisture content on pipe jacking construction, in step S2, when the infiltration flow component 4 is activated, the water spraying flow rate is changed according to a certain pattern (such as an arithmetic sequence). Steps S1 to S5 are repeated to study the relationship between backfill moisture content and leakage velocity, as well as the impact of backfill moisture content on the flow (flow mechanism) and soil pressure of the backfill around pipe jacking 2.

[0072] The above detailed description is a specific description of feasible embodiments of the present invention. These embodiments are not intended to limit the patent scope of the present invention. All equivalent implementations or modifications that do not depart from the present invention should be included in the patent scope of this case.

Claims

1. A simulation test device for pipe jacking construction, characterized in that, The test chamber includes a test chamber, a jacking pipe, a jacking pipe drive assembly, an infiltration flow assembly, a leakage monitoring assembly, and a sand flow monitoring assembly. The test chamber has an open top and one side made of transparent material for easy observation and photography. This side is the first side. A partition is set in the middle of the test chamber to simulate the well wall of the receiving well. The partition is perpendicular to the first side and divides the test chamber into a backfill side and a well side. The backfill side is filled with test backfill, and the well side is empty to simulate the receiving well that the jacking pipe will reach. The side of the test chamber opposite the partition plate on the backfill side is the second side. A pipe entry hole is provided on the second side. The pipe enters the backfill side of the test chamber through the pipe entry hole and is driven by the pipe driving assembly to advance in the backfill side until it passes through the partition plate. The outlet of the infiltration flow component is located above the backfill side of the test chamber and is used to humidify the test backfill to simulate water seepage in the soil during pipe jacking. The leakage monitoring component is used to monitor the water seepage on the backfill side and the well side. The sand flow monitoring component is used to monitor the sand flow during pipe jacking through the first side. The test chamber is equipped with a horizontal slide rail along the direction of the jacking pipe excavation, and the jacking pipe is equipped with a sliding groove that matches the horizontal slide rail. The jacking pipe moves and advances along the direction of the horizontal slide rail through the cooperation of the horizontal slide rail and the sliding groove. The jacking pipe is a cylindrical pipe or / and a non-cylindrical pipe. The chute is set at the top and bottom of the jacking pipe. The non-cylindrical pipe is obtained by cutting off a portion of the cylindrical pipe with a plane parallel to the axis, and its cross-section perpendicular to the axis is an arc with a central angle of ≥180°. The opening of the non-cylindrical pipe is close to the first side of the test box to observe the deformation of the soil around the jacking pipe during the jacking process. The non-cylindrical pipes with different central angles correspond to the test backfill at different positions around the jacking pipe during the jacking process. When the jacking pipe is a cylindrical pipe, the jacking pipe is parallel to the first side, close to the first side or at a certain distance from the first side. The different intervals between the cylindrical pipe and the first side correspond to the test backfill at different positions around the jacking pipe during the jacking process. The test chamber is also equipped with a slide rail moving adjustment component for adjusting the installation position of the slide rail. The side where the upper partition of the test chamber is located is the third side. The slide rail moving adjustment component includes transverse support bars respectively set on the second side and the third side and positioned opposite each other. The transverse support bars are provided with transverse long slots. The two ends of the slide rail are provided with fixing holes. The two ends of the slide rail are fixed to the transverse support bars on the second side and the third side through the cooperation of the fixing holes and the transverse long slots. The installation position of the slide rail on the transverse support bars is adjusted by adjusting the transverse long slots, thereby adjusting the position of the jacking pipe in the test chamber. The infiltration flow component includes a water tank, a water pump, a control valve, and a water outlet module. The water tank, water pump, control valve, and water outlet module are connected in sequence by water pipes. The water outlet module is located directly above the test chamber, and several water outlet holes are evenly distributed at the bottom of the water outlet module for uniformly spraying water into the test chamber. The leakage monitoring component includes a first measuring cup and a second measuring cup. The bottom of the test chamber on the backfill side and the well side are respectively provided with a first water outlet and a second water outlet. The first water outlet and the second water outlet are respectively connected to the first measuring cup and the second measuring cup through pipes to receive the leakage water on the backfill side and the well side. The water entering through the first measuring cup can simulate the underground water leakage of the soil layer during the pipe jacking process. The water entering through the second measuring cup can simulate the situation of underground water leakage into the receiving well when the pipe jacking penetrates the receiving well. The sand flow monitoring component includes tracer particles, an image acquisition device, and a data processing system, or includes tracer particles, a light source, an image acquisition device, and a data processing system. Several tracer particles are distributed in the test fill adjacent to the first side or the first and second sides. The light source illuminates the tracer particles. The image acquisition device is positioned directly in front of the tracer particles to capture images of the sand flow during the pipe jacking process. The data processing system is connected to the image acquisition device and is used to extract the displacement and velocity fields of the tracer particle images based on their image displacements, and then determine the sand flow based on the time interval between the images.

2. The pipe jacking construction simulation test device according to claim 1, characterized in that, The area between the upper and lower horizontal support bars on the second side is the insertion area, and the area between the upper and lower horizontal support bars on the third side is the exit area. The insertion and exit areas are left empty. During the test, a jacking material that can be jacked through by the jacking pipe is pasted on the insertion and exit areas, and the edges are sealed.

3. The pipe jacking construction simulation test device according to claim 1, characterized in that, The jacking pipe is a straight-through pipe body with open front and rear ends, and the jacking pipe driving assembly is a hydraulic jack, an electric telescopic rod, or a cylinder; or... The pipe jacking system includes a pipe body and a drill bit. The pipe jacking drive assembly includes a lead screw, a nut, a drive motor, a fixed base, a motor mounting base, and a motor slide rail. The drill bit is rotatably mounted on the front end face of the pipe body, and a soil inlet hole is provided on the front end face of the pipe body. The front end of the lead screw passes through the pipe body and is connected to the drill bit for transmission. The nut is fixed on the fixed base, and the middle part of the lead screw is screwed onto the nut. The rear end of the lead screw is connected to the drive motor for driving. The drive motor is mounted on the motor mounting base, and a slider is provided at the bottom of the motor mounting base. The motor slide rail is set parallel to the lead screw, and the slider is set on the motor slide rail. The motor mounting base can move back and forth along the motor slide rail. The lead screw rotates under the drive of the drive motor, driving the drill bit to rotate, and simultaneously driving the pipe body to move horizontally to excavate forward in the test backfill.

4. The pipe jacking construction simulation test device according to claim 3, characterized in that, The jacking drive assembly, including the lead screw and nut, also includes a gear set mounted on the front end face of the pipe body. The gear set includes a driving gear and several driven gears. The several driven gears mesh with the driving gear respectively. Each driven gear is coaxially connected to a drill bit. After the front end of the lead screw passes through the pipe body, it drives several drill bits to rotate through the gear set.

5. The pipe jacking construction simulation test device according to claim 1, characterized in that, The test chamber also needs to be equipped with a vertical loading component to pressurize the soil layer in the test chamber. The vertical loading component includes a pressure plate and a pressure plate driving component. The pressure plate covers the top of the soil layer in the test chamber, and the pressure plate driving component is connected to the pressure plate drive to drive the pressure plate to move downward to apply pressure to the soil. Soil pressure cells are pre-embedded at different locations in the test backfill to control the pressure applied to the soil by the vertical loading component and to monitor the pressure changes at each location during the pipe jacking process.

6. A method for simulating pipe jacking construction, using the pipe jacking construction simulation test device as described in claim 2, characterized in that, Includes the following steps: S1. Install a jacking material in the penetration area between the upper and lower transverse support bars on the second side and the exit area between the upper and lower transverse support bars on the third side, and seal it. Adjust the position of the slide rail on the transverse support bar according to the position of the jacking pipe in the test chamber and fix it. S2. Fill the test soil layer by layer in the test chamber. During the filling process, place tracer particles one by one at the corresponding positions on the first side or the first side and the second side, and pre-embed earth pressure cells at the corresponding positions in the test soil. After filling the test soil to the set position, compact it. Install the infiltration flow unit, leakage monitoring unit, and sand flow monitoring unit; turn on the infiltration flow unit, observe and record the data from the leakage monitoring unit; S3. After the leakage rate stabilizes, open the jacking pipe entry hole at the corresponding position in the penetration area, insert the jacking pipe into the jacking pipe entry hole, and use the cooperation of the chute and the slide rail to make the jacking pipe enter the test chamber slightly, and connect the jacking pipe to the jacking pipe drive assembly. S4. According to the test procedure, turn on the pipe jacking drive assembly and the sand flow monitoring assembly, and record the data of water leakage on the backfill side, displacement data of tracer particles, and pressure data of each earth pressure cell in the test backfill during the pipe jacking process; when the pipe jacking penetrates the partition, record the water leakage data on the well side. S5. Repeat steps S1 to S4, replacing non-cylindrical pipes with different central angles, and adjusting the distance between the cylindrical pipe and the first side surface. Keep the pipe diameters of the non-cylindrical pipe and the cylindrical pipe consistent, and ensure that the opening of the non-cylindrical pipe is close to the first side surface. Obtain the flow and pressure data of the backfill at different locations during the pipe jacking process to guide the assessment of the displacement and settlement of the soil layer near the pipe jacking in actual production.

7. The method for simulating pipe jacking construction according to claim 6, characterized in that, In step S2, after filling the test fill to the set position, install and activate the vertical loading component on top of the test fill to apply vertical load to the test fill. When the vertical load reaches the set value, keep the load unchanged and continue with steps S3 to S5. Change the value of the overburden load according to a certain rule and repeat steps S1 to S5 to study the influence of the overburden load on the deformation mechanism of the test fill around the pipe jacking. Or / and, when the infiltration flow component is turned on in step S2, the water flow rate is changed according to a certain pattern, and steps S1 to S5 are repeated to study the influence of the moisture content of the test fill on the flow mechanism of the soil around the pipe jacking.

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