Centrifuge model test device and method for pile-soil interaction considering large temperature variation effect of extraterrestrial environment

Abstract

The application discloses a pile-soil interaction centrifugal model test device considering the large temperature variation effect of an extraterrestrial environment, and belongs to the technical field of extraterrestrial construction, which comprises a servo model box, a model pile, a heat exchange plate, a heat-force control device and a monitoring system; the servo model box is fixed in a centrifuge basket, is internally filled with model soil, and is used for applying simulated gravity according to a scale ratio and an extraterrestrial gravity environment by using a centrifuge; the model pile is arranged at the center of the axis of the servo model box, is buried in the model soil at the lower part, and is exposed to the ground surface at the upper part; the heat exchange plate is fixed to the top of the servo model box and is arranged above the ground surface of the model soil; the heat-force control device is arranged on the heat exchange plate, penetrates through the heat exchange plate at the lower end, is aligned with the model pile, and is used for loading and temperature control on the boundary of the pile top; the monitoring system collects the thermal-mechanical behavior of the pile and the stratum in real time; and the application further discloses a test method, which adjusts a pre-confining pressure of a confining pressure support rod, adjusts a model pile loading of a pile foundation loading jack, and collects data by using a data collector.

Description

Technical Field

[0001] This invention belongs to the field of extraterrestrial construction technology, and more specifically, it relates to a centrifugal model test device and method for pile-soil interaction considering the large temperature variation effect of extraterrestrial environment. Background Technology

[0002] As humanity gradually ventures into extraterrestrial environments such as the Moon and Mars for long-term scientific research and survival, the extreme temperature variations and different gravitational fields present a significant challenge. Ensuring the load-bearing capacity, adaptability, and durability of infrastructure built in these unique environments has become a pressing technical problem. Differences in extraterrestrial gravitational fields, such as the Moon's gravity being one-sixth and Mars' gravity one-third, significantly alter the stress state of the foundation soil and pile foundations. Furthermore, the extreme temperature variations in extraterrestrial environments—for example, the diurnal temperature range on the Moon can exceed 300°C, and on Mars, it can exceed 100°C—cause material expansion and contraction, altering the interaction between the piles and the foundation soil and thus affecting the long-term stability of the pile foundation.

[0003] Centrifuge model testing, a commonly used method for testing the bearing capacity of foundations, can effectively reproduce the mechanical response of pile foundations under external gravity conditions by simulating the effects of different gravity fields on pile foundations. However, the boundaries of traditional model boxes are generally fixed in shape, which cannot coordinate with the deformation of the model soil under conditions of drastic thermal expansion and contraction, resulting in significant changes in the confining pressure at the model soil boundary and causing obvious boundary effects. Furthermore, the need for a loading device at the pile top affects the temperature field in the air interlayer, making it impossible for traditional heat exchange devices to effectively achieve independent control of the temperature boundaries at the pile top and the model soil surface. Therefore, it is necessary to invent a theoretically reliable and easy-to-operate centrifuge model testing device to study the interaction between piles and soil in external environments, thereby supporting the smooth development of external construction engineering technologies. Summary of the Invention

[0004] In view of this, the present invention provides a centrifugal model test device and method for pile-soil interaction considering the effects of large temperature variations in the extraterrestrial environment, and adopts the following technical solution:

[0005] A centrifuge model test device for pile-soil interaction considering the large temperature variation effect of the extraterrestrial environment includes a servo model box, a model pile, a heat exchange plate, a thermo-mechanical control device, and a monitoring system. The servo model box is fixed in a centrifuge basket and filled with model soil for applying simulated gravity according to the scale and extraterrestrial gravity environment using the centrifuge. An air gap is provided on the upper part of the model soil. The model pile is located at the center of the central axis of the servo model box, with its lower part buried in the model soil and its upper part exposed above the ground surface. The heat exchange plate is fixed on the top of the servo model box and is located above the model soil surface. The thermo-mechanical control device is located on the heat exchange plate, with its lower end penetrating the heat exchange plate and aligned with the model pile, for loading and temperature control of the pile top boundary. The monitoring system is used to collect the thermo-mechanical behavior of the model pile and the strata in real time and provide feedback for model boundary control.

[0006] The servo model box includes arc-shaped side plates, confining pressure support rods, double-folded plates, and a base plate. Multiple sets of arc-shaped side plates are arranged circumferentially along the central axis of the servo model box. Adjacent sets of arc-shaped side plates are connected by double-folded plates. The base plate is located below the arc-shaped side plates and double-folded plates, forming a cylindrical model boundary. Model soil is placed inside the model boundary. The outer side of the arc-shaped side plates is connected to the confining pressure support rods. The confining pressure support rods are configured as servo jacks, with their fixed ends fixedly connected to the side wall of the centrifuge basket and their movable ends fixedly connected to the outer side wall of the arc-shaped side plates.

[0007] The heat exchange plate is provided with several circular through holes for heat conduction to the air interlayer above the model soil.

[0008] The thermal-force control device includes a thermal-force transmission cylinder, a pile foundation loading jack, an annular heat exchanger, and a reaction frame; the thermal-force transmission cylinder is coaxially arranged with the model pile, with its lower end penetrating through the heat exchange plate and extending into the servo model box, and its upper end penetrating through the annular heat exchanger and fixed to the pile foundation loading jack;

[0009] The lower half of the surface of the heat-transfer cylinder extending into the servo model box is wrapped with aerogel felt to provide insulation.

[0010] The annular heat exchanger controls the temperature boundary at the top of the model pile through heat conduction in the heat-force transfer cylinder.

[0011] Furthermore, an aerogel felt is also provided on the inner side of the arc-shaped side plate to provide heat insulation.

[0012] Furthermore, a circular through groove is provided at the center of the heat exchange plate for accommodating the heat-force control device; an aerogel felt is also provided inside the circular through hole of the heat exchange plate.

[0013] Furthermore, the upper end of the pile foundation loading jack is fixedly connected to the reaction frame; the annular heat exchanger is disposed above the heat exchange plate; the reaction frame is erected outside the servo model box, and its lower end is fixedly connected to the centrifuge basket to provide reaction force for the pile foundation loading jack.

[0014] Furthermore, the heat-transfer cylinder is made of a molybdenum alloy.

[0015] Furthermore, the monitoring system includes several earth pressure gauges, several strain gauges, several temperature sensors, and a data acquisition instrument; several earth pressure gauges are evenly distributed along the longitudinal direction of the servo model box on the inner side of the servo model box to provide real-time feedback on the boundary confining pressure state of the model soil; several strain gauges are evenly distributed along the longitudinal direction of the model pile on the outer side of the model pile; several temperature sensors are placed on the surface of the model soil and the top of the model pile to provide real-time feedback on the temperature at the boundary between the surface of the model soil and the top of the model pile; the data acquisition instrument is connected to the earth pressure gauges, strain gauges, and temperature sensors to collect test data.

[0016] A test method for a centrifugal model test device for pile-soil interaction considering the effects of large temperature variations in the external environment includes the following steps:

[0017] Step 1, Preliminary Preparations

[0018] Complete the preparation of model soil and the fabrication of model piles. Connect the soil pressure gauge, strain gauge, and temperature sensor to the data acquisition instrument and confirm that the servo model box, heat exchange plate, thermo-mechanical control device and monitoring system are operating normally.

[0019] Step 2, Sample loading and centrifugation acceleration

[0020] The prepared model soil was layered and filled into the servo model box. During the process, soil pressure gauges, strain gauges, temperature sensors, and model piles were embedded according to the test plan. The servo model box was placed in the centrifuge basket, and the confining pressure support rod was adjusted to apply a jacking force to the inner wall of the centrifuge basket, so that the arc side plate applied the predetermined confining pressure to the model soil. The data acquisition instrument was turned on to start collecting data, and the centrifuge acceleration was gradually increased to the design value of the test plan. The confining pressure of the model soil was servo controlled.

[0021] Step 3, Experimental Operation

[0022] Adjust the pile foundation loading jack to make the lower end of the heat-force transfer cylinder abut against the top of the model pile; according to the test plan, the temperature of the top of the model pile and the surface of the model soil is controlled by the annular heat exchanger and the heat exchange plate respectively; by controlling the downward displacement of the pile foundation loading jack, the design load is applied to the top of the model pile.

[0023] Step 4: After the termination conditions of the test plan are met, shut down the annular heat exchanger and heat exchange plate, control the pile foundation loading jack to move upward to complete the unloading of the pile top, and gradually reduce the centrifugal acceleration to 0; after the internal temperature of the servo model box is consistent with the room temperature, remove the servo model box from the centrifuge basket and complete the unloading of soil; finally, shut down the data acquisition instrument, and recover the earth pressure gauge, strain gauge, temperature sensor and model pile; process and analyze the collected test data.

[0024] The beneficial effects of this invention are as follows:

[0025] 1. The side boundary of the cylindrical servo model box is composed of arc-shaped side plates, confining pressure servo jacks, and double-folded plates. This cylindrical boundary can be freely expanded and contracted by adjusting the extension and retraction of the confining pressure support rods, thereby avoiding drastic changes in the confining pressure on the boundary under significant temperature strain of the model soil;

[0026] 2. Heat exchange plates and thermal-mechanical control devices are used to control the surface temperature of the model soil and the top temperature of the model piles, respectively. Insulation measures are used to reduce the mutual interference between the two in the heat conduction process and improve the accuracy of temperature boundary control.

[0027] 3. By combining a heat-transfer cylinder made of molybdenum alloy, a pile foundation loading jack, and an annular heat exchanger, the control of pile top loading and temperature change was achieved. Attached Figure Description

[0028] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0029] Figure 1 This is a schematic diagram of the structure of the present invention.

[0030] Figure 2 This is a top view of the cylindrical servo model box of the present invention.

[0031] Figure 3 This is a schematic diagram of the boundary expansion during the adjustment of confining pressure according to the present invention.

[0032] Figure 4 This is a schematic diagram of boundary contraction during the adjustment of confining pressure according to the present invention.

[0033] In the figure:

[0034] 1-Servo model box; 2-Model pile; 3-Heat exchange plate; 5-Monitoring system; 6-Centrifuge basket; 11-Arc side plate; 12-Containing pressure support rod; 13-Double fold plate; 14-Base plate; 41-Heat-force transfer cylinder; 42-Pile foundation loading jack; 43-Annular heat exchanger; 44-Reaction frame; 51-Soil pressure gauge; 52-Strain gauge; 53-Temperature sensor. Detailed Implementation

[0035] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0036] Please see the appendix Figure 1-4 This invention provides a centrifuge model test device for pile-soil interaction considering the large temperature variation effect of the extraterrestrial environment, including a servo model box 1, a model pile 2, a heat exchange plate 3, a thermo-mechanical control device, and a monitoring system 5. The servo model box 1 is fixed in a centrifuge basket 6 and is cylindrical, filled with model soil. The centrifuge applies simulated gravity according to the scale and the extraterrestrial gravity environment. An air gap is set on the upper part of the model soil. The model pile 2 is set at the center of the central axis of the servo model box 1, with the lower part buried in the model soil and the upper part exposed above the ground surface. The heat exchange plate 3 is fixed on the top of the servo model box 1 and is set above the model soil surface. The thermo-mechanical control device is set on the heat exchange plate 3, with the lower end penetrating the heat exchange plate 3 and aligned with the model pile 2, for loading and temperature control of the pile top boundary. The monitoring system 5 is used to collect the thermo-mechanical behavior of the model pile 2 and the stratum in real time and provide feedback for model boundary control.

[0037] The servo model box 1 includes an arc-shaped side plate 11, a confining pressure support rod 12, a double-folded plate 13, and a base plate 14. Multiple sets of arc-shaped side plates 11 are arranged circumferentially along the central axis of the servo model box 1. Adjacent sets of arc-shaped side plates 11 are connected by the double-folded plate 13. The base plate 14 is located below the arc-shaped side plates 11 and the double-folded plate 13, forming a cylindrical model boundary. Model soil is placed inside the model boundary. The outer side of the arc-shaped side plate 11 is connected to the confining pressure support rod 12. The confining pressure support rod 12 is configured as a servo jack, with its fixed end fixedly connected to the side wall of the centrifuge basket 6 and its moving end fixedly connected to the outer side wall of the arc-shaped side plate 11. An aerogel felt is also provided on the inner side of the arc-shaped side plate 11 for heat insulation.

[0038] The confining pressure support rod 12 is fixedly connected to the arc-shaped side plate 11. Using the centrifuge basket 6 as a reaction wall, a jacking force is applied to the arc-shaped side plate 11. By adjusting the extension and retraction of the confining pressure support rod 12, active control of the confining pressure of the model soil inside the servo model box 1 can be achieved, thereby reducing the significant changes in confining pressure caused by the expansion and contraction of the model soil under large temperature variations. As the confining pressure support rod 12 extends and retracts, the spacing of the arc-shaped side plates 11 changes, and the double-folded plate 13 folds and extends accordingly, preventing the model soil from flowing out of the servo model box 1.

[0039] The heat exchange plate 3 has several circular through holes, which can control the surface temperature boundary by generating heat conduction in the air gap. A circular through groove is also provided at the center of the heat exchange plate 3 for housing the thermal control device; aerogel felt is also provided inside the circular through holes of the heat exchange plate 3 to provide heat insulation.

[0040] The thermal-force control device includes a thermal-force transfer cylinder 41, a pile foundation loading jack 42, an annular heat exchanger 43, and a reaction frame 44. The thermal-force transfer cylinder 41 is coaxially arranged with the model pile 2, with its lower end penetrating the heat exchange plate 3 and extending into the servo model box 1, and its upper end penetrating the annular heat exchanger 43 and fixedly connected to the pile foundation loading jack 42. The upper end of the pile foundation loading jack 42 is fixedly connected to the reaction frame 44. The annular heat exchanger 43 is located above the heat exchange plate 3. The reaction frame 44 is erected outside the servo model box 1, with its lower end fixedly connected to the centrifuge basket 6, providing a reaction force for the pile foundation loading jack 42. The pile foundation loading jack 42, when in operation, extends the thermal-force transfer cylinder 41 into the servo model box 1 and abuts against the model pile 2, transferring the jacking force of the pile foundation loading jack 42 to the model pile 2. The annular heat exchanger 43 controls the temperature boundary at the top of the model pile 2 through heat conduction via the heat-transfer cylinder 41. The heat-transfer cylinder 41 is made of molybdenum alloy, possessing high thermal conductivity and good mechanical properties under extreme high and low temperatures. The lower half of the heat-transfer cylinder 41 extending into the servo model box 1 is wrapped with aerogel felt for insulation.

[0041] The monitoring system 5 includes several earth pressure gauges 51, several strain gauges 52, several temperature sensors 53, and a data acquisition instrument. The earth pressure gauges 51 are evenly distributed along the longitudinal direction of the arc-shaped side plate 11 on the inner side surface of the arc-shaped side plate 11, used to provide real-time feedback on the boundary confining pressure state of the model soil, serving as the basis for adjusting the confining pressure support rod 12. The strain gauges 52 are evenly distributed along the longitudinal direction of the model pile 2 on the outer side surface of the model pile 2. The temperature sensors 53 are arranged on the surface of the model soil and the top of the model pile 2, used to provide real-time feedback on the temperature at the boundary between the surface of the model soil and the top of the model pile 2, serving as the basis for adjusting the output temperature of the annular heat exchanger 43 and the heat exchange plate 3. The data acquisition instrument is connected to the earth pressure gauges 51, strain gauges 52, and temperature sensors 53 for collecting test data. The earth pressure gauges 51, strain gauges 52, and temperature sensors 53 can also be arranged in the pile body of the model pile 2 and in the model soil according to the test plan.

[0042] This invention also provides a test method for the above-mentioned pile-soil interaction centrifuge model test device considering the large temperature variation effect of the extraterrestrial environment, comprising the following steps:

[0043] Step 1, Preliminary Preparations

[0044] After completing the preparation of the model soil and the fabrication of model pile 2, connect the soil pressure gauge 51, strain gauge 52, and temperature sensor 53 to the data acquisition instrument to confirm whether the servo model box 1, heat exchange plate 3, thermal-mechanical control device, and monitoring system 5 can operate normally.

[0045] Step 2, Sample loading and centrifugation acceleration

[0046] The prepared model soil is filled into the servo model box 1 in layers. During the process, soil pressure gauges 51, strain gauges 52, temperature sensors 53, and model piles 2 are buried according to the test plan. The servo model box 1 is placed in the centrifuge basket 6, and the confining pressure support rod 12 is adjusted to apply a jacking force to the inner wall of the centrifuge basket 6, so that the arc side plate 11 applies a predetermined confining pressure to the model soil. The data acquisition instrument is turned on to start collecting data, the centrifuge acceleration is gradually increased to the design value of the test plan, and the confining pressure of the model soil is servo controlled.

[0047] Step 3, Experimental Operation

[0048] Adjust the pile foundation loading jack 42 so that the lower end of the heat-force transfer cylinder 41 abuts against the top of the model pile 2; according to the test plan, the temperature of the top of the model pile 2 and the surface of the model soil is controlled by the annular heat exchanger 43 and the heat exchange plate 3 respectively, and the design load is applied to the top of the model pile 2 by controlling the downward displacement of the pile foundation loading jack 42.

[0049] Step 4: After the termination conditions of the test plan are met, shut down the annular heat exchanger 43 and the heat exchange plate 3, control the pile foundation loading jack 42 to move upward to complete the unloading of the pile top, and gradually reduce the centrifugal acceleration to 0; after the internal temperature of the servo model box 1 is consistent with the room temperature, remove the servo model box 1 from the centrifuge basket 6 and complete the unloading of soil; finally, shut down the data acquisition instrument, and recover the soil pressure gauge 51, strain gauge 52, temperature sensor 53 and model pile 2; process and analyze the collected test data.

[0050] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the apparatus disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple; relevant parts can be referred to the method section.

[0051] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A centrifugal model test device for pile-soil interaction considering the effect of large temperature variation of extraterrestrial environment, characterized in that, The servo model box (1), the model pile (2), the heat exchange plate (3), the heat-power control device and the monitoring system (5); The servo model box (1) is fixed in the centrifuge basket (6), and the inside is filled with model soil, which is used to simulate gravity according to the scale ratio and extraterrestrial gravity environment by using the centrifuge, and the upper part of the model soil is provided with an air sandwich layer; The model pile (2) is arranged at the central position of the axis of the servo model box (1), the lower part is buried in the model soil, and the upper part is exposed to the ground; The heat exchange plate (3) is fixed on the top of the servo model box (1), and is arranged above the ground surface of the model soil; The heat-power control device is arranged on the heat exchange plate (3), the lower end penetrates through the heat exchange plate (3), is aligned with the model pile (2), and is used for loading and temperature control on the pile top boundary; The monitoring system (5) is used for real-time collection of the thermal-mechanical behavior of the model pile (2) and the stratum, and provides feedback for model boundary control; The servo model box (1) includes a circular arc side plate (11), a confining pressure support rod (12), a double folding plate (13) and a bottom plate (14); A plurality of groups of circular arc side plates (11) are circumferentially arranged along the central axis of the servo model box (1); The adjacent two groups of circular arc side plates (11) are connected by the double folding plate (13), and the bottom plate (14) is arranged at the lower part of the circular arc side plate (11) and the double folding plate (13), forming a cylindrical model boundary, and the model soil is arranged inside the model boundary; The outer side of the circular arc side plate (11) is connected with the confining pressure support rod (12); The confining pressure support rod (12) is arranged as a servo jack, the fixed end is fixedly connected with the side wall of the centrifuge basket (6), and the moving end is fixedly connected with the outer side wall of the circular arc side plate (11); A plurality of circular through holes are arranged on the heat exchange plate (3), which are used for heat conduction to the upper air sandwich layer of the model soil; The heat-power control device includes a heat-power transmission cylinder (41), a pile foundation loading jack (42), a ring-shaped heat exchanger (43) and a counterforce frame (44); The heat-power transmission cylinder (41) is coaxially arranged with the model pile (2), the lower end penetrates through the heat exchange plate (3) and extends into the servo model box (1), and the upper end penetrates through the ring-shaped heat exchanger (43) and is fixedly connected with the pile foundation loading jack (42); The lower half of the heat-power transmission cylinder (41) extending into the servo model box (1) is wrapped with aerogel felt, which plays a heat insulation role. The ring-shaped heat exchanger (43) controls the temperature boundary of the top of the model pile (2) through heat conduction of the heat-power transmission cylinder (41).

2. The pile-soil interaction centrifugal model test device considering the effect of large temperature variation of extraterrestrial environment according to claim 1, characterized in that, The inner side of the circular arc side plate (11) is also provided with aerogel felt, which plays a heat insulation role.

3. The pile-soil interaction centrifugal model test device considering the effect of large temperature variation of extraterrestrial environment according to claim 1, characterized in that, The center of the heat exchange plate (3) is also provided with a circular through slot for arranging the heat-power control device; The inner side of the circular through hole of the heat exchange plate (3) is also provided with aerogel felt.

4. The pile-soil interaction centrifugal model test device considering the effect of large temperature variation of extraterrestrial environment according to claim 1, characterized in that, The pile foundation loading jack (42) is fixedly connected with the counterforce frame (44) at the upper end; the annular heat exchanger (43) is arranged above the heat exchange plate (3); the counterforce frame (44) is arranged outside the servo model box (1), and the lower end is fixedly connected with the centrifuge basket (6), so as to provide the counterforce for the pile foundation loading jack (42).

5. The pile-soil interaction centrifugal model test apparatus considering the effect of large temperature variation of extraterrestrial environment according to claim 4, wherein The heat-force transmission cylinder (41) is made of molybdenum alloy.

6. The pile-soil interaction centrifugal model test apparatus considering the effect of large temperature variation of extraterrestrial environment according to claim 2, wherein The monitoring system (5) comprises soil pressure gauges (51), strain gauges (52), temperature sensors (53) and a data acquisition instrument; the soil pressure gauges (51) are evenly arranged on the inner side of the servo model box (1) along the longitudinal direction of the servo model box (1), and are used for feeding back the boundary confining pressure state of the model soil in real time; the strain gauges (52) are evenly arranged on the outer side of the model pile (2) along the longitudinal direction of the model pile (2); the temperature sensors (53) are arranged on the model soil surface and the top end of the model pile (2), and are used for feeding back the temperature at the boundary of the model soil surface and the top end of the model pile (2) in real time; and the data acquisition instrument is connected with the soil pressure gauges (51), the strain gauges (52) and the temperature sensors (53), and is used for collecting test data.

7. The test method of the pile-soil interaction centrifugal model test apparatus considering the effect of large temperature variation of extraterrestrial environment according to claim 6, wherein The method comprises the following steps: Step 1, preliminary preparation After the model soil is prepared and the model pile (2) is made, the soil pressure gauges (51), the strain gauges (52) and the temperature sensors (53) are connected with the data acquisition instrument, and it is confirmed that the servo model box (1), the heat exchange plate (3), the heat-force control device and the monitoring system (5) are normally operated; Step 2, sample loading and centrifugal acceleration The prepared model soil is filled into the servo model box (1) in layers, and in the process, the soil pressure gauges (51), the strain gauges (52), the temperature sensors (53) and the model pile (2) are buried according to the test scheme; the servo model box (1) is placed in the centrifuge basket (6), the confining pressure supporting rod (12) is adjusted to apply a thrust force to the inner side wall of the centrifuge basket (6), so that the circular arc side plate (11) applies a predetermined confining pressure to the model soil; the data acquisition instrument is turned on to start collecting data, the centrifuge acceleration is gradually increased to the design value of the test scheme, and the confining pressure of the model soil is servo-controlled; Step 3, test operation The pile foundation loading jack (42) is adjusted so that the heat-force transmission cylinder (41) is in abutment with the top end of the model pile (2); according to the test scheme, the temperature of the top end of the model pile (2) and the model soil surface is controlled through the annular heat exchanger (43) and the heat exchange plate (3) respectively, and the design load is applied to the top end of the model pile (2) by controlling the downward displacement of the pile foundation loading jack (42); Step 4, test data processing The test data collected by the data acquisition instrument are processed, and the test results are obtained. Step 4, after reaching the termination condition of the test scheme, the annular heat exchanger (43) and the heat exchange plate (3) are closed, the pile foundation loading jack (42) is controlled to move upward to complete the unloading of the pile top, and the centrifugal acceleration is gradually reduced to 0; after the internal temperature of the servo model box (1) is consistent with the normal temperature, the servo model box (1) is disassembled from the centrifuge basket (6), and the soil unloading is completed; finally, the data acquisition instrument is closed, and the soil pressure gauge (51), the strain gauge (52), the temperature sensor (53) and the model pile (2) are recovered; the collected test data are processed and analyzed.

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