Pile-soil interaction centrifugal model test device and method considering large temperature change effect of extraterrestrial environment

Abstract

The invention discloses a pile-soil interaction centrifugal model test device considering an extraterrestrial environment large temperature change effect, and belongs to the technical field of extraterrestrial construction, and the pile-soil interaction centrifugal model test device 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 fixedly arranged in a centrifugal machine hanging basket, is filled with model soil, and is used for applying simulation gravity according to a reduced scale proportion and an extraterrestrial gravity environment by utilizing a centrifugal machine; the model pile is arranged at the center of the central axis of the servo model box, the lower part is buried in the model soil, and the upper part is exposed out of the earth surface; the heat exchange plate is fixedly arranged at the top of the servo model box and is arranged above the model land surface; the heat-force control device is arranged on the heat exchange plate, and the lower end of the heat-force control device penetrates through the heat exchange plate, is aligned with the model pile and is used for loading and temperature control of the pile top boundary; the monitoring system collects thermal-mechanical behaviors of the pile and the stratum in real time; the invention further discloses a test method, the confining pressure supporting rod is adjusted to set the pre-confining pressure, the pile foundation loading jack is adjusted to load the model pile, and the data acquisition instrument is used for acquiring data.

Description

Technical Field

[0001] The present invention belongs to the technical field of extraterrestrial construction, and more specifically relates to a centrifugal model test device and method for pile-soil interaction considering the large temperature change effect of the extraterrestrial environment. Background Art

[0002] As humans gradually enter the moon, Mars and other extraterrestrial spaces to carry out long-term scientific research and survival activities, there are extreme temperature differences and multiple effects of different gravity fields in the extraterrestrial environment. How to ensure that the infrastructure construction in these special environments has good bearing capacity, adaptability and durability has become a technical problem that needs to be solved urgently. In the extraterrestrial environment, the difference in extraterrestrial gravity fields, such as 1 / 6 gravity on the moon and 1 / 3 gravity on Mars, will significantly change the stress state of the foundation soil and pile foundation. At the same time, the temperature variation range in the extraterrestrial environment is extremely large. For example, the temperature difference between day and night on the surface of the moon can reach more than 300°C, and the temperature difference between day and night on Mars can also reach more than 100°C. This extreme temperature change condition will cause the material to expand and contract, causing the interaction between the pile and the foundation soil to change, thereby affecting the long-term stability of the pile foundation.

[0003] Centrifuge model test is a commonly used method for testing the bearing capacity of foundations. It can effectively reproduce the mechanical response of pile foundations under extraterrestrial gravity conditions by simulating the influence of different gravity fields on pile foundations. However, the boundary of the traditional model box is generally a fixed shape, which cannot coordinate the deformation of the model soil that undergoes drastic thermal expansion and contraction under large temperature changes, thereby causing a significant change in the confining pressure on the boundary of the model soil, resulting in an obvious boundary effect. At the same time, since a loading device needs to be set up at the top of the pile, it will affect the temperature field in the air interlayer, making it impossible for the traditional heat exchange device to effectively achieve independent control of the temperature boundary of the pile top and the model soil surface. Therefore, it is necessary to invent a set of theoretically reliable and easy-to-operate centrifuge model test devices to study the interaction between piles and soil in extraterrestrial environments, so as to support the smooth development of extraterrestrial construction engineering technology. 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 large temperature change effect of the extraterrestrial environment, which adopts the following technical solutions:

[0005] A centrifugal model test device for pile-soil interaction considering the large temperature change effect of the extraterrestrial environment comprises a servo model box, a model pile, a heat exchange plate, a thermal-mechanical control device and a monitoring system; the servo model box is fixedly arranged in a centrifuge basket, and is filled with model soil inside, and is used to use the centrifuge to apply simulated gravity according to the scale ratio and the extraterrestrial gravity environment, and an air interlayer is arranged on the upper part of the model soil; the model pile is arranged at the center position of the central axis of the servo model box, the lower part is buried in the model soil, and the upper part is exposed to the surface; the heat exchange plate is fixedly arranged on the top of the servo model box, and is arranged above the surface of the model soil; the thermal-mechanical control device is arranged on the heat exchange plate, and the lower end passes through the heat exchange plate and is aimed at the model pile, and is used for loading and temperature control of the pile top boundary; the monitoring system is used to collect the thermal-mechanical behavior of the model pile and the stratum in real time, and provide feedback for the model boundary control.

[0006] Furthermore, the servo model box includes arc side panels, confining pressure support rods, double-fold plates and a bottom plate; the arc side panels are arranged in multiple groups along the circumferential direction of the central axis of the servo model box; two adjacent groups of arc side panels are connected by double-fold plates, and the bottom plate is arranged at the lower part of the arc side panels and the double-fold plates to form a cylindrical model boundary, and model soil is arranged inside the model boundary; the outer side of the arc side panel is connected to the confining pressure support rod; the confining pressure support rod is arranged as a servo jack, the fixed end of which is fixedly connected to the side wall of the centrifuge basket, and the movable end is fixedly connected to the outer wall of the arc side panel; the inner side of the arc side panel is also provided with aerogel felt to play a heat insulating role.

[0007] Furthermore, the heat exchange plate is provided with a plurality of circular through holes for conducting heat to the air interlayer above the model soil; a circular through groove is also provided at the center of the heat exchange plate for setting the thermal-mechanical control device; and aerogel felt is also provided inside the circular through holes of the heat exchange plate.

[0008] Furthermore, the thermal-mechanical control device includes a thermal-mechanical transfer cylinder, a pile foundation loading jack, an annular heat exchanger and a reaction frame; the thermal-mechanical transfer cylinder is coaxially arranged with the model pile, the lower end of which passes through the heat exchange plate and extends into the servo model box, and the upper end of which passes through the annular heat exchanger and is fixedly connected to the pile foundation loading jack; the upper end of the pile foundation loading jack is fixedly connected to the reaction frame; the annular heat exchanger is arranged above the heat exchange plate; the reaction frame is erected on the outside of the servo model box, and the lower end is fixedly connected to the centrifuge basket to provide reaction force for the pile foundation loading jack.

[0009] Furthermore, the heat-force transfer cylinder is made of molybdenum alloy, and the side surface of the lower half extending into the servo model box is wrapped with aerogel felt to play a heat insulation role.

[0010] Furthermore, the monitoring system includes a plurality of soil pressure gauges, a plurality of strain gauges, a plurality of temperature sensors and a data acquisition instrument; the plurality of soil pressure gauges are evenly arranged on the inner side of the servo model box along the longitudinal direction of the servo model box, and are used for real-time feedback of the boundary confining pressure state of the model soil; the plurality of strain gauges are evenly arranged on the outer side of the model pile along the longitudinal direction of the model pile; the plurality of temperature sensors are arranged on the surface of the model soil and the top of the model pile, and are used for real-time feedback of 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 pressure gauges, strain gauges, and temperature sensors, and is used for collecting test data.

[0011] A test method for a centrifugal model test device for pile-soil interaction considering large temperature change effects of an extraterrestrial environment comprises the following steps:

[0012] Step 1: Preliminary preparation

[0013] Complete the model soil preparation and model pile production, 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, thermal-mechanical control device, and monitoring system are operating normally;

[0014] Step 2, sample loading and centrifugal acceleration

[0015] The prepared model soil is filled into the servo model box in layers, and the soil pressure gauge, strain gauge, temperature sensor and model pile are buried according to the test plan during the process; the servo model box is placed in the centrifuge basket, and the confining pressure support rod is adjusted to apply a top thrust to the inner wall of the centrifuge basket, so that the arc side plate 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;

[0016] Step 3: Test operation

[0017] The pile foundation loading jack is adjusted to make the lower end of the heat-force transfer cylinder contact 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 are controlled by the annular heat exchanger and the heat exchange plate respectively, and the design load is applied to the top of the model pile by controlling the downward displacement of the pile foundation loading jack;

[0018] Step 4: After reaching the termination condition of the test scheme, close the annular heat exchanger and the heat exchange plate, control the pile foundation loading jack to move upward to complete the pile top unloading, and gradually reduce the centrifugal acceleration to 0; after the internal temperature of the servo model box is consistent with the normal temperature, remove the servo model box from the centrifuge basket and complete the soil unloading; finally, turn off the data acquisition instrument, recover the soil pressure gauge, strain gauge, temperature sensor and model pile; process and analyze the collected test data.

[0019] The beneficial effects of the present invention are:

[0020] 1. The side boundary of the cylindrical servo model box is formed by arc side plates, confining pressure servo jacks, and double folding plates. The cylindrical boundary can be freely expanded and contracted by adjusting the extension and contraction of the confining pressure support rod, thereby preventing the confining pressure on the boundary from changing dramatically under the significant temperature strain of the model soil;

[0021] 2. Heat exchange plates and thermal-mechanical control devices are used to control the temperature of the model soil surface and the top of the model pile, and thermal insulation measures are used to reduce the mutual interference between the two in the heat conduction process, thereby improving the accuracy of temperature boundary control;

[0022] 3. The control of pile top loading and temperature change is achieved through the combination of a heat-force transfer cylinder made of molybdenum alloy, a pile foundation loading jack and an annular heat exchanger. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0024] Figure 1 It is a structural schematic diagram of the present invention.

[0025] Figure 2 It is a top view of the cylindrical servo model box of the present invention.

[0026] Figure 3 It is a schematic diagram of boundary expansion when adjusting the confining pressure of the present invention.

[0027] Figure 4 It is a schematic diagram of boundary contraction when adjusting the confining pressure of the present invention.

[0028] Among them, in the figure:

[0029] 1-servo model box; 2-model pile; 3-heat exchange plate; 4-thermal-mechanical control device; 5-monitoring system; 6-centrifuge basket; 11-arc side plate; 12-confining pressure support rod; 13-double-fold plate; 14-bottom plate; 41-thermal-mechanical transfer cylinder; 42-pile foundation loading jack; 43-annular heat exchanger; 44-reaction frame; 51-earth pressure gauge; 52-strain gauge; 53-temperature sensor. DETAILED DESCRIPTION

[0030] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0031] Please refer to the attached Figure 1-4 The present invention provides a centrifugal model test device for pile-soil interaction considering the large temperature change effect of the extraterrestrial environment, comprising a servo model box 1, a model pile 2, a heat exchange plate 3, a thermal-mechanical control device 4 and a monitoring system 5; the servo model box 1 is fixedly arranged in a centrifuge hanging basket 6, arranged in a cylindrical shape, and filled with model soil inside, and a centrifuge is used to apply simulated gravity according to the scale ratio and the extraterrestrial gravity environment, and an air interlayer is arranged on the upper part of the model soil; the model pile 2 is arranged at the center position of the central axis of the servo model box 1, the lower part is buried in the model soil, and the upper part is exposed to the surface; the heat exchange plate 3 is fixedly arranged on the top of the servo model box 1, and is arranged above the surface of the model soil; the thermal-mechanical control device 4 is arranged on the heat exchange plate 3, and the lower end passes through the heat exchange plate 3, is aligned with the model pile 2, and is used for loading and temperature control of the pile top boundary; the monitoring system 5 is used to collect the thermal-mechanical behavior of the model pile 2 and the stratum in real time, and provide feedback for the model boundary control.

[0032] The servo model box 1 includes an arc side panel 11, a confining pressure support rod 12, a double-fold plate 13 and a bottom plate 14; the arc side panel 11 is arranged in a plurality of groups along the circumferential direction of the central axis of the servo model box 1; two adjacent groups of arc side panels 11 are connected by the double-fold plate 13, and the bottom plate 14 is arranged at the lower part of the arc side panel 11 and the double-fold plate 13 to form a cylindrical model boundary, and model soil is arranged inside the model boundary; the outer side of the arc side panel 11 is connected to the confining pressure support rod 12; the confining pressure support rod 12 is arranged as a servo jack, the fixed end of which is fixedly connected to the side wall of the centrifuge basket 6, and the movable end is fixedly connected to the outer wall of the arc side panel 11; the inner side of the arc side panel 11 is also provided with aerogel felt to play a heat insulating role.

[0033] The confining pressure support rod 12 is fixedly connected to the arc side plate 11, and the centrifuge basket 6 is used as a reaction wall to apply a top thrust to the arc side plate 11. By adjusting the extension and contraction 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 large changes in the confining pressure caused by the expansion and contraction of the model soil under large temperature changes. With the extension and contraction of the confining pressure support rod 12, the spacing of the arc side plate 11 changes, and the double folding plate 13 folds and stretches accordingly to prevent the model soil from flowing out of the servo model box 1.

[0034] The heat exchange plate 3 is provided with a plurality of circular through holes, which can control the surface temperature boundary by generating heat conduction in the air interlayer. A circular through groove is also provided at the center of the heat exchange plate 3 for setting the thermal-mechanical control device 4; an aerogel felt is also provided inside the circular through hole of the heat exchange plate 3 to play a heat insulation role.

[0035] The thermal-mechanical control device 4 includes a thermal-mechanical transfer cylinder 41, a pile foundation loading jack 42, an annular heat exchanger 43 and a reaction frame 44; the thermal-mechanical transfer cylinder 41 is coaxially arranged with the model pile 2, the lower end of which penetrates the heat exchange plate 3 and extends into the servo model box 1, and the upper end of which penetrates the annular heat exchanger 43 and is 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 arranged above the heat exchange plate 3; the reaction frame 44 is erected outside the servo model box 1, and the lower end is fixedly connected to the centrifuge hanging basket 6 to provide reaction force for the pile foundation loading jack 42. The pile foundation loading jack 42 acts to extend the thermal-mechanical transfer cylinder 41 into the servo model box 1 and abuts against the model pile 2, so as to transfer the top thrust 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 of the heat-force transfer cylinder 41. The heat-force transfer cylinder 41 is made of molybdenum alloy, which has high thermal conductivity and good mechanical properties under extreme high and low temperatures. The lower half side surface of the heat-force transfer cylinder 41 extending into the servo model box 1 is wrapped with aerogel felt to play a heat insulation role.

[0036] The monitoring system 5 includes a plurality of soil pressure gauges 51, a plurality of strain gauges 52, a plurality of temperature sensors 53 and a data acquisition instrument; the plurality of soil pressure gauges 51 are evenly arranged on the inner side of the circular arc side plate 11 along the longitudinal direction of the circular arc side plate 11, and are used to provide real-time feedback on the boundary confining pressure state of the model soil, as a basis for adjusting the confining pressure support rod 12; the plurality of 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 plurality of temperature sensors 53 are arranged on the surface of the model soil and the top of the model pile 2, and are used to provide real-time feedback on the temperature at the boundary of the surface of the model soil and the top of the model pile 2, as a 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 soil pressure gauge 51, the strain gauge 52, and the temperature sensor 53, and is used to collect test data. The soil pressure gauge 51, the strain gauge 52, and the temperature sensor 53 can also be arranged in the pile body of the model pile 2 and the model soil according to the test plan.

[0037] The present invention also provides a test method for the centrifugal model test device for pile-soil interaction considering the large temperature change effect of the extraterrestrial environment, comprising the following steps:

[0038] Step 1: Preliminary preparation

[0039] After the model soil preparation and model pile 2 production are completed, the soil pressure gauge 51, strain gauge 52, and temperature sensor 53 are connected to the data acquisition instrument to confirm whether the servo model box 1, heat exchange plate 3, thermal-mechanical control device 4, and monitoring system 5 can operate normally.

[0040] Step 2, sample loading and centrifugal acceleration

[0041] The prepared model soil is filled into the servo model box 1 in layers, and during the process, the soil pressure gauge 51, the strain gauge 52, the temperature sensor 53 and the model pile 2 are buried according to the test plan; the servo model box 1 is placed in the centrifuge hanging basket 6, and the confining pressure support rod 12 is adjusted to apply a top thrust to the inner wall of the centrifuge hanging 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.

[0042] Step 3: Test operation

[0043] The pile foundation loading jack 42 is adjusted to make the lower end of the heat-force transfer cylinder 41 abut 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 are controlled respectively by the annular heat exchanger 43 and the heat exchange plate 3, 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.

[0044] Step 4, after reaching the termination condition of the test scheme, close the annular heat exchanger 43 and the heat exchange plate 3, control the pile foundation loading jack 42 to move upward to complete the pile top unloading, and gradually reduce the centrifugal acceleration to 0; after the internal temperature of the servo model box 1 is consistent with the normal temperature, remove the servo model box 1 from the centrifuge basket 6 and complete the soil unloading; finally, turn off the data acquisition instrument, recover the soil pressure gauge 51, strain gauge 52, temperature sensor 53 and model pile 2; process and analyze the collected test data.

[0045] In this specification, each embodiment is described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the embodiments can be referred to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the method part.

[0046] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one 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 present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to 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 large temperature change effect of the extraterrestrial environment, characterized in that: The invention comprises a servo model box (1), a model pile (2), a heat exchange plate (3), a thermal-mechanical control device (4) and a monitoring system (5); the servo model box (1) is fixedly arranged in a centrifuge hanging basket (6), and is filled with model soil inside, and is used to apply simulated gravity according to the scale ratio and the extraterrestrial gravity environment by using the centrifuge, and an air interlayer is arranged on the upper part of the model soil; the model pile (2) is arranged at the center position of the central axis of the servo model box (1), the lower part is buried in the model soil, and the upper part is exposed on the surface; the heat exchange plate (3) is fixedly arranged on the top of the servo model box (1), and is arranged above the surface of the model soil; the thermal-mechanical control device (4) is arranged on the heat exchange plate (3), and the lower end passes through the heat exchange plate (3) and is aligned with the model pile (2), and is used to load and control the temperature of the pile top boundary; the monitoring system (5) is used to collect the thermal-mechanical behavior of the model pile (2) and the stratum in real time, and provide feedback for the model boundary control.

2. A centrifugal model test device for pile-soil interaction considering the large temperature change effect of the extraterrestrial environment according to claim 1, characterized in that: The servo model box (1) comprises an arc side plate (11), a confining pressure support rod (12), a double folding plate (13) and a bottom plate (14); the arc side plates (11) are arranged in a plurality of groups along the circumferential direction of the central axis of the servo model box (1); two adjacent groups of arc side plates (11) are connected by the double folding plate (13); the bottom plate (14) is arranged at the lower part of the arc side plates (11) and the double folding plate (13) to form a cylindrical model boundary, and model soil is arranged inside the model boundary; the outer side of the arc side plate (11) is connected to the confining pressure support rod (12); the confining pressure support rod (12) is arranged as a servo jack, the fixed end of which is fixedly connected to the side wall of the centrifuge basket (6), and the movable end of which is fixedly connected to the outer wall of the arc side plate (11); the inner side of the arc side plate (11) is also provided with aerogel felt to play a heat insulation role.

3. The centrifugal model test device for pile-soil interaction considering the large temperature change effect of the extraterrestrial environment according to claim 1 is characterized in that: The heat exchange plate (3) is provided with a plurality of circular through holes for conducting heat to the air interlayer above the model soil; a circular through groove is also provided at the center of the heat exchange plate (3) for arranging the thermal-mechanical control device (4); and aerogel felt is also provided inside the circular through holes of the heat exchange plate (3).

4. The centrifugal model test device for pile-soil interaction considering the large temperature change effect of the extraterrestrial environment according to claim 1 is characterized in that: The heat-force control device (4) comprises a heat-force transfer cylinder (41), a pile foundation loading jack (42), an annular heat exchanger (43) and a reaction frame (44); the heat-force transfer cylinder (41) is coaxially arranged with the model pile (2), the lower end of which passes through the heat exchange plate (3) and extends into the servo model box (1), and the upper end of which passes through the annular heat exchanger (43) and is 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 arranged above the heat exchange plate (3); the reaction frame (44) is erected outside the servo model box (1), and the lower end of which is fixedly connected to the centrifuge hanging basket (6) to provide reaction force for the pile foundation loading jack (42).

5. The centrifugal model test device for pile-soil interaction considering the large temperature change effect of the extraterrestrial environment according to claim 4 is characterized in that: The heat-force transfer cylinder (41) is made of molybdenum alloy, and the lower half side surface extending into the servo model box (1) is wrapped with aerogel felt to play a heat insulation role.

6. The centrifugal model test device for pile-soil interaction considering the large temperature change effect of the extraterrestrial environment according to claim 2 is characterized in that: The monitoring system (5) comprises a plurality of soil pressure gauges (51), a plurality of strain gauges (52), a plurality of temperature sensors (53) and a data acquisition instrument; the plurality of 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) for real-time feedback of the boundary confining pressure state of the model soil; the plurality of 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 plurality of temperature sensors (53) are arranged on the surface of the model soil and the top of the model pile (2) for real-time feedback of the temperature at the boundary of the surface of the model soil and the top of the model pile (2); the data acquisition instrument is connected to the soil pressure gauges (51), the strain gauges (52) and the temperature sensors (53) for collecting test data.

7. The test method of the centrifugal model test device for pile-soil interaction considering the large temperature change effect of the extraterrestrial environment according to any one of claims 1 to 6, characterized in that: The steps include: Step 1: Preliminary preparation After the model soil preparation and model pile (2) production are completed, the soil pressure gauge (51), strain gauge (52), and temperature sensor (53) are connected to the data acquisition instrument to confirm that the servo model box (1), heat exchange plate (3), thermal-mechanical control device (4), and monitoring system (5) are operating normally; Step 2, sample loading and centrifugal acceleration The prepared model soil is filled into the servo model box (1) in layers, and during the process, a soil pressure gauge (51), a strain gauge (52), a temperature sensor (53) and a model pile (2) are buried according to the test plan; the servo model box (1) is placed in the centrifuge hanging basket (6), and the confining pressure support rod (12) is adjusted to apply a thrust force to the inner wall of the centrifuge hanging 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; Step 3: Test operation The pile foundation loading jack (42) is adjusted 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 are controlled by the annular heat exchanger (43) and the heat exchange plate (3), 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); Step 4, after reaching the termination condition of the test scheme, close the annular heat exchanger (43) and the heat exchange plate (3), control the pile foundation loading jack (42) to move upward to complete the pile top unloading, and gradually reduce the centrifugal acceleration to 0; after the internal temperature of the servo model box (1) is consistent with the normal temperature, remove the servo model box (1) from the centrifuge basket (6) and complete the soil unloading; finally, close the data acquisition instrument, recover the soil pressure gauge (51), the strain gauge (52), the temperature sensor (53) and the model pile (2); and process and analyze the collected test data.

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