Pile-sinking multi-point loading model test device and method for permeability test using the same

Abstract

The present application belongs to the technical field of building pile foundation engineering, and provides a pile sinking multi-point loading model test device and a method for water permeability test using the same. The adopted technical scheme is as follows: the pile sinking multi-point loading model test device comprises an upper open model box and a counterforce frame, height adjusting mechanisms are installed on the outer walls of two opposite side plates of the model box, the counterforce frame comprises a counterforce beam and two counterforce side plates, the two counterforce side plates are symmetrically arranged and are respectively installed on the two opposite side plates of the model box through the height adjusting mechanisms, the two ends of the counterforce beam are respectively connected with the two counterforce side plates, a jack is fixedly installed on the lower surface of the counterforce beam, a high-speed camera is placed on one side of the model box, and a method for water permeability test using the pile sinking multi-point loading model test device is disclosed. The present application is mainly applied to the pile sinking multi-point loading model test of water permeable rigid piles.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of building pile foundation engineering, and particularly relates to a pile sinking multi-point loading model test device and a method for water permeability test using the same. BACKGROUND

[0002] In the field of building pile foundation engineering, it is an inevitable requirement for the development of the industry to replace the old high-cost and high-energy-consumption technology with new efficient, economical and energy-saving construction technology. First, the water permeable rigid pile is made into a prefabricated pile, and then the static pressure method is used to sink the pile to press the water permeable rigid pile into the foundation to form a new type of composite foundation, which has the advantages of large strength of rigid pile and good water permeability of bulk pile.

[0003] The pile sinking process of the water permeable rigid pile includes steps such as mold loading, vibration and tamping molding and demolding. During the pile sinking process, the water permeable rigid pile will have a soil compaction effect on the surrounding soil. At present, the research on the stress deformation of the water permeable rigid pile under vertical load is mainly based on the research on rigid pile composite foundation, and the stress deformation and excess pore pressure dissipation of the water permeable rigid pile are studied. The mechanism of interaction between the pile and the soil and the influence of the stress field and displacement field of the soil around the pile are not clear. Although the stress deformation of the pile and the surrounding soil can be directly monitored through field tests, a large amount of manpower, material resources and time cost is required, and the repeatability of field tests is poor, and it is difficult to conduct multi-parameter sensitivity analysis. Compared with field tests, indoor model tests have the advantages of low cost and good repeatability, so a model test device that can simulate the pile sinking and vertical loading of the water permeable rigid pile is proposed, which can effectively promote the research on the water permeable rigid pile and promote its application in engineering practice.

[0004] To test the water permeability coefficient of the test rigid pile, multi-point loading is required on the soil, and the pile sinking loading model test device used at present is mostly only single-point loading, which is mostly used for the research on the vertical bearing mechanism of composite piles, but cannot be applied to the data test of the water permeability coefficient. Therefore, in order to realize the research data monitoring of the water permeability coefficient, it is necessary to design a multi-point loading model test device suitable for the water permeability coefficient detection of the rigid pile. SUMMARY

[0005] In order to solve one of the above technical defects, the present application provides a pile sinking multi-point loading model test device and a method for water permeability test using the same.

[0006] In order to solve the above technical problems, the technical scheme adopted by the present application is: a pile sinking multi-point loading model test device, comprising an open-top model box and a counterforce frame, height adjustment mechanisms are installed on the outer walls of the two opposite side plates of the model box, the counterforce frame comprises a counterforce beam and two counterforce side plates, the two counterforce side plates are symmetrically arranged and are respectively installed on the two opposite side plates of the model box through the height adjustment mechanisms, the two ends of the counterforce beam are respectively connected with the two counterforce side plates, a jack is fixedly installed on the lower surface of the counterforce beam, and a high-speed camera is placed on one side of the model box.

[0007] The inner side surface of the counterforce side plate is provided with a plurality of transverse adjustment grooves, a plurality of sliding rollers are installed at the two ends of the counterforce beam, the two ends of the counterforce beam are movably installed in the transverse adjustment grooves of the counterforce side plate through the sliding rollers, and at least one locking mechanism matched with the adjustment groove is installed at the two ends of the counterforce beam.

[0008] The locking mechanism comprises a thin shaft, a rotating pipe, a connecting plate, a support column and a friction rubber pad, the thin shaft is fixedly installed on one side of the end of the counterforce beam, the rotating pipe is sleeved on the thin shaft, the support column is fixedly connected with the rotating pipe through the connecting plate, the upper and lower ends of the support column are both fixedly connected with the friction rubber pad, the friction rubber pad is a conical structure with a small outer end and a large inner end, and the friction rubber pad is deformed by being pressed when the support column is completely located in the transverse adjustment groove.

[0009] The plurality of sliding rollers are installed on the end surface of the counterforce beam through a cover plate dismounting mechanism, the cover plate dismounting mechanism comprises a cover plate with a C-shaped cross section, a plurality of groups of shaft holes are arranged on the end surface of the counterforce beam and the end surface of the cover plate in a corresponding manner, one shaft is rotatably installed at the center of the sliding roller, and the two ends of the shaft are inserted into the shaft holes in the end surface of the counterforce beam and the cover plate.

[0010] The structure of the model box is that a plurality of steel plates are welded to form a box frame, a metal plate is installed on the bottom surface of the box frame, and the inner sides of the other four surfaces are adhesively connected with tempered glass through glass cement.

[0011] The height adjustment mechanism comprises a slot and a fixed bolt, the two oppositely arranged slots are fixed on the side plate outer wall of the model box, a plurality of mounting holes are arranged on the slots, the bottom of the counterforce side plate is provided with two insertion strips, the two insertion strips are respectively inserted into the slots and are fixedly connected with the mounting holes through the fixed bolts.

[0012] A plurality of universal rollers are arranged on the bottom of the model box, and a locking mechanism is arranged on the universal rollers.

[0013] A water storage guide pipe is installed on the side wall of the model box, a water permeable hole at the top of the rigid pile is connected with the inside of the water storage guide pipe through a rubber guide pipe, and a capacity scale is arranged on the outer wall of the water storage guide pipe.

[0014] A rubber pad is installed at the top of the rigid pile, and the rubber guide pipe penetrates from below the rubber pad and exits from the side.

[0015] The method for performing a rigid pile water permeation test using a pile sinking multi-point loading model test device comprises the following steps:

[0016] S1, waterproof plastic cloth is laid on the bottom surface and side wall of the model box, and the saturated soil required for the test is slowly poured into the model box in layers, with 20-30 cm as a layer of soil, and after each layer is laid, it is left to stand for a period of time to allow the saturated soil to fully consolidate, and at the same time, when the filling height reaches the position of the embedded sensor, the sensor is arranged according to the test requirements, and after the filling is completed, it is left to stand until the saturated soil is fully consolidated, and when the pore pressure measured by the pore pressure gauge is equal to the hydrostatic pressure, it is considered that the soil has been consolidated;

[0017] S2, the position of the water permeation pile is marked on the surface of the saturated soil with a ruler, the height of the counterforce beam is adjusted up and down using the height adjustment mechanism, and it is installed in the corresponding height transverse adjustment groove of the counterforce side plate, and then the position of the jack on the counterforce beam is adjusted to align with the marked point;

[0018] S3, before the pile is sunk, the small hole at the top of the water permeation pile is connected with the rubber conduit, and the other end of the rubber conduit is connected with the water storage conduit on the side wall of the model box, wherein the rubber conduit serves as a drainage function to flow the pore water from the rigid pile along the rubber conduit into the water storage conduit;

[0019] S4, during the whole process of pile sinking, the data of the relevant sensors are collected in real time by the high-speed camera, and during the process of static pressure pile sinking, the excess static pore water pressure will inevitably be generated due to soil squeezing, assuming that the hydrostatic pressure at a certain point is P, and during the process of pile sinking, the water pressure at this point is increased to P1 due to soil squeezing, wherein ΔP=P-P1 is the excess static pore water pressure generated due to the soil squeezing effect during the process of pile sinking, and by comparing the value of ΔP at this point during the process of pile sinking of the water permeation pile with different water permeation coefficients, the water permeation performance of the water permeation pile is preliminarily evaluated;

[0020] S5, after the pile sinking is completed, a layer of sand cushion is laid on the composite foundation formed by the water permeation pile and the saturated soil, wherein a layer of waterproof geotextile is laid between the sand cushion and the saturated soil to ensure that water can only overflow from the water permeation pile, and a circular load plate is placed on the sand cushion, with the center of the load plate corresponding to the center of the water permeation pile;

[0021] S6, after the excess pore water pressure on the side of the water permeation pile dissipates, the position of the jack is adjusted so that the bottom thereof is aligned with the center of the load plate, and the verticality of the pile body is checked, and then the vertical load is applied to the water permeation pile composite foundation through the jack, and when multiple point loading tests are required in the test, the height and lateral position are adjusted at any time according to the experimental requirements;

[0022] S7, observe the water level change in the water storage conduit in real time during the loading process, the water permeability of the water permeable pile is preliminarily judged by comparing the water level height in the water storage conduit of the water permeable pile with different water permeability coefficients at the same time, and the overall permeability performance index k can be represented according to the Darcy law:

[0023]

[0024] In the formula, k is the overall permeability performance index, the unit is cm / s, h0 and h t are the initial height and the height at t time of the water level in the water storage conduit, the unit is mm;

[0025] S8, after the loading is completed, the jack and the counterforce beam are disassembled, and the deformation and damage of the pile soil are observed.

[0026] Compared with the prior art, the present application has the following beneficial effects:

[0027] 1, the present application uses the jack to apply pressure to the water permeable rigid pile composite foundation to press the water permeable rigid pile into the saturated soil, so as to simulate the construction process of the static pressure pile sinking method, and the high-speed camera is used to record the stress deformation of the soil through the tempered glass during the pile sinking process, so as to study the soil compaction effect in the pile sinking process, which is more suitable and more versatile, and saves time and effort.

[0028] 2, the present application can realize the height adjustment of the counterforce beam and the jack according to the connection of the different height installation holes on the counterforce side plate and the model box side plate, the installation of the counterforce beam in the lateral adjustment groove at different heights, and the lateral position adjustment of the jack through the displacement of the counterforce beam in the lateral adjustment groove, so as to realize the function of loading at different points in the model box, which is convenient and fast to use;

[0029] 3, the present application can preliminarily judge the permeability of the water permeable pile by observing the water level change in the water storage conduit. BRIEF DESCRIPTION OF DRAWINGS

[0030] The present application will be further described in detail below with reference to the accompanying drawings;

[0031] Figure 1 It is a structural schematic view of the pile sinking multi-point loading model test device of the present application;

[0032] Figure 2 It is a side view of the pile sinking multi-point loading model test device of the present application;

[0033] Figure 3 It is a structural schematic view of the installation of the end of the counterforce beam in the lateral adjustment groove;

[0034] Figure 4 It is Figure 3A cross-sectional structural schematic view. DETAILED DESCRIPTION

[0035] In order to make the purposes, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions of the present application will be described clearly and completely below in combination with the embodiments in the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all the other embodiments obtained by those skilled in the art without any creative work fall within the scope of protection of the present application.

[0036] As shown in the drawings, Figures 1-4 The pile sinking multi-point loading model test device of the present application comprises an upper open model box 1 and a counterforce frame 2. Height adjustment mechanisms 4 are installed on the outer walls of two opposite side plates of the model box 1. The counterforce frame 2 comprises a counterforce beam 21 and two counterforce side plates 22. The two counterforce side plates 22 are symmetrically arranged and are respectively installed on the two opposite side plates of the model box 1 through the height adjustment mechanisms. The two ends of the counterforce beam 21 are respectively connected with the two counterforce side plates 22. A jack 3 is fixedly installed on the lower surface of the counterforce beam 21. A high-speed camera 5 is placed on one side of the model box 1. In use, when the counterforce side plates 22 are connected with the side plates of the model box 1, the height adjustment of the counterforce beam and the jack is realized through the height adjustment mechanisms 4.

[0037] The inner side surfaces of the counterforce side plates 22 are provided with a plurality of transverse adjustment grooves 23. The two ends of the counterforce beam 21 are respectively provided with a plurality of sliding rollers 24. The two ends of the counterforce beam 21 are movably installed in the transverse adjustment grooves 23 of the counterforce side plates 22 through the sliding rollers 24. At least one locking mechanism adapted to the adjustment grooves 23 is installed on the two ends of the counterforce beam 21. In use, the counterforce beam 21 is moved in the transverse adjustment grooves 23 through the sliding rollers 24 and is locked and fixed by the locking mechanism, so as to realize the transverse displacement adjustment of the jack. The height adjustment of the counterforce beam and the jack can also be further realized through the installation of the counterforce beam in the transverse adjustment grooves at different heights.

[0038] The locking mechanism in the present application can be realized in various schemes, such as Figure 3The shown discloses one embodiment of the locking mechanism. The locking mechanism comprises a thin shaft 26, a rotating tube 27, a connecting plate 28, a support column 29 and a friction rubber pad 30, the thin shaft 26 is fixedly installed on one side of the end of the counterforce beam 21, the rotating tube 27 is sleeved on the thin shaft 26, the support column 29 is fixedly connected with the rotating tube 27 through the connecting plate 28, the upper and lower ends of the support column 29 are fixedly connected with the friction rubber pad 30, the friction rubber pad 30 is a conical structure with a small outer end and a large inner end, and the friction rubber pad 30 is deformed when the support column 29 is completely located in the horizontal adjustment groove 23. When different horizontal point loads are applied, the support column 29 of the locking mechanism is pried out of the horizontal adjustment groove 23, and then the entire counterforce beam 21 can be moved in the horizontal adjustment groove 23 through the plurality of sliding rollers 24, and when the counterforce beam 21 is moved to a predetermined point, the support column 29 is turned and pushed into the horizontal adjustment groove 23, and the conical structure of the friction rubber pad 30 is more conducive to being pushed into the groove. At this time, the friction rubber pad 30 is deformed to form a large friction force. During the test, the displacement force applied to the counterforce beam 21 can be effectively overcome to prevent the counterforce beam 21 from deviating from the loading point. The support column 29 can be manually pried open by applying more force, which is convenient and effective.

[0039] The sliding roller 24 in the present application can adopt a large roller with a diameter greater than that of the counterforce beam 21, or a small-diameter roller as shown. Figures 3-4 The small-diameter rollers are respectively installed on the upper and lower ends of the counterforce beam 21 to contact the upper and lower surfaces of the horizontal adjustment groove 23, and the installation mode can also adopt a detachable structure for replacement. One embodiment is that a plurality of sliding rollers 24 are installed on the end surface of the counterforce beam 21 through a cover plate dismounting mechanism. The cover plate dismounting mechanism comprises a cover plate with a C-shaped cross section. The end surface of the counterforce beam 21 and the end surface of the cover plate are provided with a plurality of groups of shaft holes corresponding to each other. A wheel shaft 25 is rotatably installed at the center of the sliding roller 24. The two ends of the wheel shaft 25 are inserted into the shaft holes in the end surface of the counterforce beam 21 and the cover plate.

[0040] The model box 1 is formed by welding a plurality of steel plates to form a box frame. A metal plate is installed on the bottom surface of the box frame, and the inner sides of the other four surfaces are bonded to tempered glass through glass cement. The transparent tempered glass is conducive to recording the changes of the internal soil body by the high-speed camera. The box frame welded by the steel plates provides sufficient support and extrusion resistance for the model box 1.

[0041] Preferably, the height adjusting mechanism 4 comprises a slot 41 and a fixing bolt 42. The two oppositely arranged slots 41 are fixed on the outer wall of the side plate of the model box 1. A plurality of mounting holes are arranged on the slot 41. The bottom of the counterforce side plate 22 is provided with two insertion strips which are respectively inserted into the slots 41 and fixedly connected with the mounting holes through the fixing bolt 42. In this way, the up-down adjustment of the counterforce side plate 22 does not affect the observation of the deformation of the soil body on the side wall.

[0042] A plurality of universal rollers 6 are arranged on the bottom of the model box 1, and a locking mechanism is arranged on the universal rollers 6.

[0043] The side wall of the model box 1 is provided with a water storage guide pipe 7, and the water permeable hole at the top of the rigid pile is connected with the inside of the water storage guide pipe 7 through a rubber guide pipe 8. A capacity scale is arranged on the outer wall of the water storage guide pipe 7. The water quantity discharged into the water storage guide pipe 7 by the water permeable pile in the pile sinking test can be directly obtained to obtain the drainage data.

[0044] A rubber pad 9 is arranged at the top of the rigid pile, and the rubber guide pipe 8 penetrates from below the rubber pad 9 and exits from the side. The rubber pad 9 can protect the rubber guide pipe 8 from being damaged by the jack 3 during the loading process.

[0045] The method for performing the water permeable test of the rigid pile by using the pile sinking multi-point loading model test device comprises the following steps:

[0046] S1. Waterproof plastic cloth is laid on the bottom surface and the side wall of the model box 1. The saturated soil required for the test is slowly poured into the model box 1 layer by layer, and the thickness of each layer is 20-30 cm. After each layer is laid, it is required to be left for a period of time to allow the saturated soil to fully consolidate. Meanwhile, when the filling height reaches the position of the embedded sensor, the sensor is arranged according to the test requirements. After the filling is completed, it is left until the saturated soil is fully consolidated under its own weight. When the pore pressure measured by the pore pressure gauge is equal to the hydrostatic pressure, it is considered that the soil has been consolidated.

[0047] S2. The position of the water permeable pile is marked on the surface of the saturated soil by using a ruler. The height of the counterforce beam 21 is adjusted up and down by using the height adjustment mechanism 4, and the counterforce beam 21 is installed in the corresponding height transverse adjustment groove 23 on the counterforce side plate 22. Then, the position of the jack 3 on the counterforce beam 21 is adjusted to align with the marked point.

[0048] S3. Before the pile sinking, the small hole at the top of the water permeable pile is connected with the rubber guide pipe 8, and the other end of the rubber guide pipe 8 is connected with the water storage guide pipe 7 on the side wall of the model box 1. The rubber guide pipe 8 plays a role of drainage, and the pore water flows from the rigid pile along the rubber guide pipe 8 into the water storage guide pipe 7.

[0049] S4. During the pile sinking process, the data of the related sensors are collected in real time by the high-speed camera 5. During the static pressure method pile sinking process, the excess static pore water pressure is inevitably generated due to the soil squeezing. It is assumed that the hydrostatic pressure at a certain point is P. During the pile sinking process, the water pressure at the point is increased to P1 due to the soil squeezing. ΔP=P-P1 is the excess static pore water pressure generated due to the soil squeezing effect during the pile sinking process. By comparing the value of ΔP at the point during the pile sinking process of the water permeable pile with different water permeable coefficients, the water permeable performance of the water permeable pile is preliminarily evaluated.

[0050] S5, after the completion of pile sinking, a layer of sand cushion of a certain thickness is laid on the composite foundation formed by the water permeable pile and the saturated soil, a layer of waterproof geotextile is laid between the sand cushion and the saturated soil to ensure that water can only overflow from the water permeable pile, a circular load plate is placed on the sand cushion, and the center of the load plate corresponds to the center of the water permeable pile;

[0051] S6, after the excess pore water pressure of the side of the water permeable pile dissipates, the position of the jack 3 is adjusted so that the bottom thereof is aligned with the position of the center of the load plate, and the verticality of the pile body is checked, and then the vertical load is applied to the water permeable pile composite foundation through the jack 3, and when multiple point loading tests are required in the test, the height and lateral position are adjusted at any time according to the experimental requirements;

[0052] S7, the water level change in the water storage conduit is observed in real time during the loading process, the water permeability of the water permeable pile is preliminarily judged by comparing the water level height in the water storage conduit at the same time under different water permeable coefficients, and the overall permeability index k can be expressed according to Darcy's law:

[0053]

[0054] In the formula: k is the overall permeability index, unit: cm / s; h0, h t are the initial height and the height at time t of the water level in the water storage conduit, respectively, unit: mm;

[0055] S8, after the loading is completed, the jack 3 and the counterforce beam 21 are removed, and the deformation and damage of the pile soil are checked.

[0056] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, and are not limited thereto; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for part or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A multi-point loading model test device for pile driving, characterized in that: The model box (1) with an open top and a reaction frame (2) are included. The model box (1) is equipped with a height adjustment mechanism (4) on the outer wall of the two opposite side plates. The reaction frame (2) includes a reaction beam (21) and two reaction side plates (22). The two reaction side plates (22) are symmetrically arranged and installed on the two opposite side plates of the model box (1) through the height adjustment mechanism. The two ends of the reaction beam (21) are connected to the two reaction side plates (22) respectively. A jack (3) is fixedly installed on the lower surface of the reaction beam (21). A high-speed camera (5) is placed on one side of the model box (1). The inner side of the reaction side plate (22) is provided with multiple transverse adjustment grooves (23), and multiple sliding rollers (24) are installed at both ends of the reaction beam (21). The two ends of the reaction beam (21) are movably installed in the transverse adjustment grooves (23) of the reaction side plate (22) through the sliding rollers (24). At least one locking mechanism adapted to the adjustment groove (23) is installed at both ends of the reaction beam (21). The locking mechanism includes a thin shaft (26), a rotating tube (27), a connecting plate (28), a support column (29), and a friction pad (30). The thin shaft (26) is fixedly installed on one side of the end of the reaction beam (21). The rotating tube (27) is fitted onto the thin shaft (26). The support column (29) is fixedly connected to the rotating tube (27) through the connecting plate (28). The upper and lower ends of the support column (29) are fixedly connected to the friction pad (30). The friction pad (30) is a conical structure with a small outer end and a large inner end. When the support column (29) is completely inside the transverse adjustment groove (23), the friction pad (30) is squeezed and deformed. The model box (1) is equipped with a water storage pipe (7) on its side wall. The permeable hole at the top of the rigid pile is connected to the inside of the water storage pipe (7) through a rubber pipe (8). The water storage pipe (7) is equipped with a capacity scale on its outer wall. A rubber pad (9) is installed on the top of the rigid pile, and a rubber conduit (8) is inserted from below the rubber pad (9) and exits from the side.

2. The multi-point loading model test device for pile driving according to claim 1, characterized in that: The multiple sliding rollers (24) are installed on the end face of the reaction beam (21) through a cover plate disassembly and assembly mechanism. The cover plate disassembly and assembly mechanism includes a cover plate with a C-shaped cross section. The end face of the reaction beam (21) and the end face of the cover plate are provided with multiple sets of corresponding shaft holes. A wheel axle (25) is rotatably installed at the center of the sliding roller (24). The two ends of the wheel axle (25) are inserted into the shaft holes on the end faces of the reaction beam (21) and the cover plate.

3. The multi-point loading model test device for pile driving according to claim 1 or 2, characterized in that: The structure of the model box (1) is formed by welding multiple steel plates to form a box frame. The bottom surface of the box frame is fitted with a metal plate and the other four inner sides are bonded with tempered glass by glass glue.

4. The multi-point loading model test device for pile driving according to claim 3, characterized in that: The height adjustment mechanism (4) includes a slot (41) and a fixing bolt (42). The two slots (41) with opposite openings are fixed to the outer wall of the side plate of the model box (1). The slots (41) are provided with multiple mounting holes. The bottom of the reaction side plate (22) is provided with two inserts. The two inserts are respectively inserted into the slots (41) and fixedly connected to the mounting holes by the fixing bolt (42).

5. The multi-point loading model test device for pile driving according to claim 1, characterized in that: The bottom of the model box (1) is provided with multiple universal casters (6), and the universal casters (6) are provided with locking mechanisms.

6. A method for conducting permeability tests using the multi-point loading model test apparatus for pile driving as described in any one of claims 1-5, characterized in that... Includes the following steps: S1. Cover the bottom and side walls of the model box (1) with waterproof plastic sheeting. Slowly pour the saturated soil required for the test into the model box (1) in layers of 20-30cm. After each layer is laid, let it stand for a period of time to allow the saturated soil to fully solidify. At the same time, when the filling height reaches the position of the buried sensor, arrange the sensor according to the test requirements. After the filling is completed, let it stand until the saturated soil completes self-weight consolidation. When the pore pressure measured by the pore pressure gauge is equal to the hydrostatic pressure, it is considered that the soil has been completely consolidated. S2. Mark the position of the permeable pile on the surface of the saturated soil with a ruler. Adjust the height of the reaction beam (21) up and down using the height adjustment mechanism (4). Install it in the transverse adjustment groove (23) at the corresponding height on the reaction side plate (22). Then adjust the position of the jack (3) on the reaction beam (21) so that it is aligned with the marked point. S3. Before driving the pile, connect the small hole at the top of the permeable pile to the rubber conduit (8). The other end of the rubber conduit (8) is connected to the water storage conduit (7) on the side wall of the model box (1). The rubber conduit (8) plays a role in guiding the pore water from the rigid pile into the water storage conduit (7) along the rubber conduit (8). S4. During the entire pile driving process, the data of relevant sensors are collected in real time by a high-speed camera (5). During the static pressure pile driving process, the excess pore water pressure will inevitably be generated due to soil squeezing. Assuming that the static water pressure at a certain point is P, during the pile driving process, the water pressure at this point will rise to P1 due to soil squeezing. ΔP = P - P1 is the excess pore water pressure generated due to soil squeezing effect during the pile driving process. By comparing the size of ΔP at this point during the pile driving process of permeable piles with different permeability coefficients, the permeability performance of the permeable pile can be preliminarily evaluated. S5. After the pile driving is completed, a sand cushion layer is laid on the composite foundation formed by the permeable pile and the saturated soil. A waterproof geotextile is laid between the sand cushion layer and the saturated soil to ensure that water can only overflow from the permeable pile. A circular load plate is placed on the sand cushion layer, with the center of the load plate corresponding to the center of the permeable pile. S6. After the excess pore water pressure on the side of the permeable pile dissipates, adjust the position of the jack (3) so that its bottom is aligned with the center of the load plate and check the verticality of the pile body. Then, apply vertical load to the permeable pile composite foundation step by step through the jack (3). When multiple loading tests are required in the test, adjust the height and lateral position at any time according to the experimental requirements. S7. During the loading process, the water level change in the water storage pipe is observed in real time. By comparing the water level height in the water storage pipe at the same moment for permeable piles with different permeability coefficients, the permeability performance of the permeable pile is preliminarily judged. Combining Darcy's law, the overall permeability performance index k can be expressed as: ； In the formula: k is the overall permeability performance index, in cm / s; h0, h t These represent the initial height of the water level in the water storage conduit and the height at time t, respectively, in mm; S8. After loading is completed, remove the jack (3) and the reaction beam (21) to check the deformation and damage of the pile soil.

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