A static and dynamic shear visualization geotechnical centrifuge test system for pile-soil interface

Abstract

The present invention provides a static and dynamic shear visualization geotechnical centrifuge test system for a pile-soil interface, which relates to the technical field of geotechnical centrifuge testing. The system comprises: a static and dynamic shear visualization geotechnical centrifuge test device for a pile-soil interface, comprising: a middle portion of a crossbar connected to an upper portion of a rotating shaft, a counterweight being provided at one end of the crossbar, and a centrifuge basket being provided at the other end; a transparent plate being provided at the middle portion of the centrifuge basket, a first space on one side of the transparent plate being used for filling soil samples, and a second space on the other side being used for placing a camera; a semi-cylindrical model pile being provided in the first space, and a plane side of the semi-cylindrical model pile being in contact with the transparent plate; a model loading system being provided above the semi-cylindrical model pile; and a plurality of through holes being provided on the transparent plate. Through the system of the present invention, the actual stress and deformation behavior of the interface between the soil and the structure can be reproduced in a controlled laboratory environment, thereby providing an effective testing means for geotechnical engineering design and research.

Description

Technical Field

[0001] The invention relates to the technical field of geotechnical centrifuge testing, in particular to a pile-soil interface static and dynamic shear visualization geotechnical centrifuge testing system. Background Art

[0002] Pile foundations are widely used in various engineering structures, both on land and at sea, such as nuclear power plants, high-rise buildings, and offshore wind turbines. Pile-soil interaction, particularly the shear effect at the pile-soil interface during penetration, under top loads, and under cyclic loads such as earthquakes, is crucial to the safety and stability of pile foundations and has been a hot topic of research in academia and a focus of attention in the engineering community.

[0003] Research on pile-soil interface shear includes the development and degradation patterns of shear bands under different roughness conditions, the variations in displacement and strain fields of the soil around the pile during pile penetration and under different loads, and the crushing and quantitative characterization of sand particles near the interface around the pile. Existing technologies mostly use indoor 1g model test methods. Although some models are large in size, they still cannot avoid the scale problem and cannot simulate the actual stress state and conditions of the soil under in-situ conditions, which can easily lead to deviations in the results and make it difficult to guide actual engineering practice. In addition, most model test methods can only simply consider the penetration or uplift of the pile foundation under pseudo-static loads, making it difficult to realize combined static load conditions such as VHM (Vertical, Horizontal, Moment Load) and pile-soil interface shear under cyclic loads. The visualization operation process and image processing methods for pile-soil interface shear are not described in detail. Summary of the Invention

[0004] In view of the above technical problems, the technical solution adopted by the present invention is:

[0005] According to a pile-soil interface static and dynamic shear visualization geotechnical centrifuge test system provided by this application, the system includes:

[0006] A device and processor for visualizing static and dynamic shear at the pile-soil interface; the device comprises a rotating shaft, a crossbar, a counterweight, and a centrifuge basket; wherein the middle portion of the crossbar is connected to the upper portion of the rotating shaft, one end of the crossbar is provided with a counterweight, and the other end is provided with a centrifuge basket;

[0007] A transparent plate is provided in the middle of the centrifuge basket, a first space on one side of the transparent plate is used to fill the soil sample, and a second space on the other side is used to place a camera; a semi-cylindrical model pile is provided in the first space, and the flat side of the semi-cylindrical model pile is in contact with the transparent plate; a model loading system is provided above the semi-cylindrical model pile, and the model loading system is used to apply a vertical downward force to the semi-cylindrical model; a plurality of through holes are provided on the transparent plate, and the through holes are used to calibrate the movement distance of the soil sample;

[0008] The processor is configured to perform the following steps:

[0009] S100, controlling the model loading system to apply a preset force F to the semi-cylindrical model pile and controlling the shaft of the pile-soil interface static and dynamic shear visualization geotechnical centrifuge test device to rotate at a preset speed S;

[0010] S200, using a camera to obtain the displacement of the soil sample in each through hole on the transparent plate within each preset time period, so as to obtain a list set of displacement time periods A = (A1, A2, ..., A i ,…,A n ), i=1, 2,...,n; among them, A i is the displacement duration list corresponding to the soil sample within the i-th preset duration on the transparent plate, and n is the number of preset durations; A i =(A i，1 , A i，2 ,…,A i，j ,…,A i，m ), j = 1, 2, ..., m; where A i，j is the displacement of the soil sample in the jth through hole during the i-th preset time, and m is the number of through holes on the transparent plate;

[0011] S300: According to A, determine the overall displacement of the soil sample within each preset time period, and then obtain the overall displacement list of the soil sample B = (B1, B2, ..., B i ,…,B n ); Among them, B i is the overall displacement of the soil sample within the i-th preset time period;

[0012] S400 , according to B, determining a displacement curve of the soil sample over time under the conditions of a preset force F and a preset rotation speed S.

[0013] Furthermore, step S300 includes the following steps:

[0014] S310, obtaining the fluctuation rate corresponding to the displacement of soil samples in all through holes within each preset time period, so as to obtain a list of fluctuation rates of soil sample displacement corresponding to A γ = (γ1, γ2, ..., γ i ,…,γ n ); where γi A i The corresponding soil sample displacement fluctuation rate; γ i =(1 / m)×∑ m j=1 (A i，j -((1 / m)×∑ m j=1 A i，j )) 2 ;

[0015] S320, traverse γ, if γ i <γ', then determine B i =(1 / m)×∑ m j=1 A i，j ; Otherwise, go to S330; where γ' is the preset soil sample displacement fluctuation rate threshold;

[0016] S330, get A i The corresponding average soil sample displacement BA i ;

[0017] S340, traverse A i , if |A i，j -BA i | / A i，j <α, then A i，j Determine the displacement of the specified soil sample within the i-th preset time length to obtain A i The corresponding specified soil sample displacement list β i = (β i，1 , β i，2 ,…,β i，r ,…,β i，f（i） ), r=1, 2,..., f(i); among them, β i，r is the displacement of the rth designated soil sample within the i-th preset time length, and f(i) is the number of displacements of the designated soil samples within the i-th preset time length;

[0018] S350, according to β i , determine B i =(1 / f(i))×∑ f（i） r=1 β i，r .

[0019] Furthermore, a micro pore pressure sensor and a strain gauge are provided around the semi-cylindrical model pile. The micro pore pressure sensor is used to monitor the interface pore pressure value under the shear action of the pile and soil, and the strain gauge is used to monitor the friction between the semi-cylindrical model pile and the soil sample.

[0020] Furthermore, after step S400, the following steps are further included:

[0021] S500, obtaining the first interface friction force of the semi-cylindrical model pile at different preset depths through the strain gauge to obtain a first interface friction force list C=(C1, C2, ..., C p ,…,C q ), p = 1, 2, ..., q; where C p is the first interface friction force of the semi-cylindrical model pile corresponding to the pth preset depth, and q is the number of preset depths;

[0022] S510, obtaining the second interface friction force of the semi-cylindrical model pile at different preset depths through the model loading system to obtain a second interface friction force list D=(D1, D2, ..., D p ,…,D q ), where D p is the second interface friction force corresponding to the p-th preset depth of the semi-cylindrical model pile obtained by the model loading system;

[0023] S520, determining the third interface friction force of the semi-cylindrical model pile at different preset depths according to C and D, to obtain a third interface friction force list E=(E1, E2, ..., E p ,…,E q ); where E p is the third interface friction force of the semi-cylindrical model pile corresponding to the pth preset depth; E p =(C p +D p ) / 2;

[0024] S530, based on E, determine the stress and strain values ​​corresponding to each third interface friction force in E to obtain a stress and strain value group list G=(G1, G2, ..., G p ,…,G q ); where G p For E p Corresponding stress and strain value group; G p =(G p，1 , G p，2 );G p，1 For E p The corresponding stress, G p，2 is the strain value of the semi-cylindrical model pile at the pth preset depth; G p =E p / SA p ;SA p is the actual contact area between the semi-cylindrical model pile and the soil sample at the pth preset depth; G p，2 =SD p / SD;SD pis the distance that the semi-cylindrical model pile penetrates into the soil sample at the pth preset depth, and SD is the total length of the semi-cylindrical model pile;

[0025] S530: Determine the stress-strain curve corresponding to the semi-cylindrical model pile according to G.

[0026] Furthermore, after step S400, the following steps are further included:

[0027] S610, obtaining the pore water pressure corresponding to each preset depth of the semi-cylindrical model pile by using a micro pore pressure sensor;

[0028] S620: Determine a graph showing a change in effective friction coefficient corresponding to the semi-cylindrical model pile as the pile depth develops, based on the pore water pressure and stress-strain curve corresponding to the semi-cylindrical model pile at each preset depth.

[0029] Furthermore, after step S100 and before step S200, the method further includes the following steps:

[0030] S110, obtaining the interface pore pressure value under the pile-soil shear action by the micro pore pressure sensor and obtaining the friction force between the semi-cylindrical model pile and the soil sample by the strain gauge;

[0031] S120, obtaining a downward displacement distance of the semi-cylindrical model pile according to a displacement sensor at the top of the semi-cylindrical model pile;

[0032] S130: Determine a relevant parameter curve based on the interface pore pressure value, friction force, and displacement distance.

[0033] Furthermore, after step S400, the method further includes the following steps:

[0034] S700: Controlling the model loading system to apply a variable force to the semi-cylindrical model pile so that the semi-cylindrical model pile moves downward at a preset rate, and controlling the rotating shaft of the pile-soil interface static and dynamic shear visualization geotechnical centrifuge test device to rotate at a preset speed S;

[0035] S710, obtaining the interface pore pressure value under the pile-soil shear action by the micro pore pressure sensor and obtaining the friction force between the semi-cylindrical model pile and the soil sample by the strain gauge;

[0036] S720, determining a downward movement distance of the semi-cylindrical model pile based on a downward movement duration and a movement rate of the semi-cylindrical model pile;

[0037] S730: Determine a relevant parameter curve based on the interface pore pressure value, friction force, and displacement distance.

[0038] Furthermore, the camera is used to reveal the interface failure form and action mechanism under different influencing factors and determine the thickness of the shear zone at the pile-soil interface.

[0039] Furthermore, the transparent plate is made of transparent organic glass.

[0040] Furthermore, the centrifuge hanging basket is in the shape of a cuboid.

[0041] The present invention has at least the following beneficial effects:

[0042] The pile-soil interface static and dynamic shear visualization geotechnical centrifuge test system of the present invention comprises: a pile-soil interface static and dynamic shear visualization geotechnical centrifuge test device, the pile-soil interface static and dynamic shear visualization geotechnical centrifuge test device comprises: a rotating shaft, a cross bar, a counterweight and a centrifuge basket; wherein, the middle part of the cross bar is connected to the upper part of the rotating shaft, one end of the cross bar is provided with a counterweight, and the other end is provided with a centrifuge basket; a transparent plate is provided in the middle of the centrifuge basket, a first space on one side of the transparent plate is used to fill soil samples, and a second space on the other side is used to place a camera; a semi-cylindrical model pile is provided in the first space, and the plane side of the semi-cylindrical model pile is in contact with the transparent plate; the semi-cylindrical model pile is provided in the first space, and the plane side of the semi-cylindrical model pile is in contact with the transparent plate; A model loading system is arranged above the pile, which is used to apply a vertical downward force to the semi-cylindrical model; a plurality of through holes are provided on the transparent plate, which are used to calibrate the movement distance of the soil sample; the static and dynamic shear visualization geotechnical centrifuge test device for the pile-soil interface can be used to measure the displacement curve of the soil sample over time under the conditions of a preset force F and a preset speed S; the device adds a pile-soil interaction module and a visualization module to the geotechnical centrifuge test equipment, overcoming the shortcomings of existing research, reproducing the actual stress and deformation behavior of the interface between the soil and the structure in a controlled laboratory environment, and providing an effective testing means for geotechnical engineering design and research. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0044] Figure 1 A schematic structural diagram of a static and dynamic shear visualization geotechnical centrifuge test device for pile-soil interface provided by an embodiment of the present invention;

[0045] Figure 2 A top view of a centrifuge basket provided in an embodiment of the present invention;

[0046] Figure 3 A front view of a centrifuge basket provided in an embodiment of the present invention;

[0047] Figure 4 A front view of a transparent plate provided in an embodiment of the present invention;

[0048] Figure 5 The present invention provides a flowchart of the steps executed by a processor of a pile-soil interface static and dynamic shear visualization geotechnical centrifuge testing system. DETAILED DESCRIPTION

[0049] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. 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 those skilled in the art without making any creative efforts shall fall within the scope of protection of the present invention.

[0050] It should be noted that, based on this disclosure, those skilled in the art will appreciate that an aspect described herein can be implemented independently of any other aspect, and that two or more of these aspects can be combined in various ways. For example, any number of the aspects described herein can be used to implement an apparatus and / or practice a method. In addition, other structures and / or functionalities other than one or more of the aspects described herein can be used to implement such an apparatus and / or practice such a method.

[0051] The following is an introduction to a static and dynamic shear visualization geotechnical centrifuge test system for pile-soil interface.

[0052] The pile-soil interface static and dynamic shear visualization geotechnical centrifuge test system includes: Figure 1 The pile-soil interface static and dynamic shear visualization geotechnical centrifuge testing device and processor shown in the figure; the pile-soil interface static and dynamic shear visualization geotechnical centrifuge testing device includes: a rotating shaft, a cross bar, a counterweight and a centrifuge basket; wherein the middle part of the cross bar is connected to the upper part of the rotating shaft, one end of the cross bar is provided with a counterweight, and the other end is provided with a centrifuge basket.

[0053] like Figure 2 and Figure 3 As shown, a transparent plate is provided in the middle of the centrifuge basket, a first space on one side of the transparent plate is used to fill the soil sample, and a second space on the other side is used to place the camera; a semi-cylindrical model pile is provided in the first space, and the plane side of the semi-cylindrical model pile is in contact with the transparent plate; a model loading system is provided above the semi-cylindrical model pile, and the model loading system is used to apply a vertical downward force to the semi-cylindrical model; Figure 4 As shown, the transparent plate is provided with a plurality of through holes, and the through holes are used to calibrate the moving distance of the soil sample.

[0054] The processor is used to execute Figure 5 Steps shown:

[0055] S100 , controlling the model loading system to apply a preset force F to the semi-cylindrical model pile and controlling the shaft of the pile-soil interface static and dynamic shear visualization geotechnical centrifuge test device to rotate at a preset speed S.

[0056] In this embodiment, the model loading system can be controlled to apply a preset force F to the semi-cylindrical model pile and the rotating shaft of the pile-soil interface static and dynamic shear visualization geotechnical centrifuge test device can be controlled to rotate at a preset speed S. Driven by the rotating shaft, the soil sample will be displaced.

[0057] S200, using a camera to obtain the displacement of the soil sample in each through hole on the transparent plate within each preset time period, so as to obtain a list set of displacement time periods A = (A1, A2, ..., A i ,…,A n ), i=1, 2,...,n; among them, A i is the displacement duration list corresponding to the soil sample within the i-th preset duration on the transparent plate, and n is the number of preset durations; A i =(A i，1 , A i，2 ,…,A i，j ,…,A i，m ), j = 1, 2, ..., m; where A i，j is the displacement of the soil sample in the jth through hole during the i-th preset time, and m is the number of through holes on the transparent plate.

[0058] In this embodiment, the camera can capture an image at intervals of a preset time length, and then compare it with the previous image to determine the displacement of the soil sample in each through hole within each preset time length, so as to obtain a list set A of displacement time lengths under the conditions of a preset force F and a preset rotation speed S.

[0059] S300: According to A, determine the overall displacement of the soil sample within each preset time period, and then obtain the overall displacement list of the soil sample B = (B1, B2, ..., B i ,…,B n ); Among them, B i is the overall displacement of the soil sample within the i-th preset time period.

[0060] Furthermore, step S300 may include the following steps:

[0061] S310, obtaining the fluctuation rate corresponding to the displacement of soil samples in all through holes within each preset time period, so as to obtain a list of fluctuation rates of soil sample displacement corresponding to A γ = (γ1, γ2, ..., γ i ,…,γ n ); where γ i Ai The corresponding soil sample displacement fluctuation rate; γ i =(1 / m)×∑ m j=1 (A i，j -((1 / m)×∑ m j=1 A i，j )) 2 .

[0062] S320, traverse γ, if γ i <γ', then determine B i =(1 / m)×∑ m j=1 A i，j ; Otherwise, go to S330; where γ' is the preset soil sample displacement fluctuation rate threshold.

[0063] In this embodiment, if γ i <γ', indicating that the displacement fluctuation of the soil sample in each through hole is small within the i-th preset time length, and B can be determined i =(1 / m)×∑ m j=1 A i，j Otherwise, it means that the displacement of the soil sample in each through hole fluctuates greatly within the i preset time periods, and there may be abnormal soil sample displacement.

[0064] S330, get A i The corresponding average soil sample displacement BA i .

[0065] S340, traverse A i , if |A i，j -BA i | / A i，j <α, then A i，j Determine the displacement of the specified soil sample within the i-th preset time length to obtain A i The corresponding specified soil sample displacement list β i = (β i，1 , β i，2 ,…,β i，r ,…,β i，f（i） ), r=1, 2,..., f(i); among them, β i，r is the displacement of the rth designated soil sample within the i-th preset time length, and f(i) is the number of designated soil sample displacements within the i-th preset time length.

[0066] In this embodiment, through the above steps, abnormal soil sample displacements can be screened out and relatively balanced soil sample displacements can be retained.

[0067] S350, according to β i , determine B i=(1 / f(i))×∑ f（i） r=1 β i，r .

[0068] In this embodiment, the B determined by the above steps is i More accurate and avoids the influence of abnormal soil sample displacement.

[0069] S400 , according to B, determining a displacement curve of the soil sample over time under the conditions of a preset force F and a preset rotation speed S.

[0070] In this embodiment, after obtaining B, the existing difference method can be used to perform difference on B, thereby obtaining a displacement curve of the soil sample over time under the conditions of a preset force F and a preset rotation speed S, providing a reference for the research of the soil sample.

[0071] Furthermore, a micro pore pressure sensor and a strain gauge are provided around the semi-cylindrical model pile. The micro pore pressure sensor is used to monitor the interface pore pressure value under the shear action of the pile and soil, and the strain gauge is used to monitor the friction between the semi-cylindrical model pile and the soil sample.

[0072] In this embodiment, strain gauges and pore water pressure holes are evenly spaced on the surface of the semi-cylindrical model pile. The strain gauges measure the variation in pile-soil interface friction as pile depth increases, while the pore water pressure holes are embedded with micro-pore pressure sensors to measure the pore pressure at the interface under pile-soil shear, enabling conversion of the effective stress coefficient.

[0073] Furthermore, after step S400, the following steps are further included:

[0074] S500, obtaining the first interface friction force of the semi-cylindrical model pile at different preset depths through the strain gauge to obtain a first interface friction force list C=(C1, C2, ..., C p ,…,C q ), p = 1, 2, ..., q; where C p is the first interface friction force of the semi-cylindrical model pile corresponding to the pth preset depth, and q is the number of preset depths.

[0075] S510, obtaining the second interface friction force of the semi-cylindrical model pile at different preset depths through the model loading system to obtain a second interface friction force list D=(D1, D2, ..., D p ,…,D q ), where D p is the second interface friction force corresponding to the pth preset depth of the semi-cylindrical model pile obtained by the model loading system.

[0076] S520, determining the third interface friction force of the semi-cylindrical model pile at different preset depths according to C and D, to obtain a third interface friction force list E=(E1, E2, ..., E p ,…,E q ); where E p is the third interface friction force of the semi-cylindrical model pile corresponding to the pth preset depth; E p =(C p +D p ) / 2.

[0077] In this embodiment, the third interface friction force of the semi-cylindrical model pile at different preset depths is obtained by the above two methods, which can reduce the influence of abnormal data and improve the accuracy of determining the interface friction force of the semi-cylindrical model pile.

[0078] S530, based on E, determine the stress and strain values ​​corresponding to each third interface friction force in E to obtain a stress and strain value group list G=(G1, G2, ..., G p ,…,G q ); where G p For E p Corresponding stress and strain value group; G p =(G p，1 , G p，2 );G p，1 For E p The corresponding stress, G p，2 is the strain value of the semi-cylindrical model pile at the pth preset depth; G p =E p / SA p ;SA p is the actual contact area between the semi-cylindrical model pile and the soil sample at the pth preset depth; G p，2 =SD p / SD;SD p is the distance that the semi-cylindrical model pile penetrates into the soil sample at the pth preset depth, and SD is the total length of the semi-cylindrical model pile.

[0079] S530: Determine the stress-strain curve corresponding to the semi-cylindrical model pile according to G.

[0080] In this embodiment, it should be noted that after obtaining G, those skilled in the art can use existing stress-strain curve generation methods according to actual needs to determine the stress-strain curve corresponding to the semi-cylindrical model pile, which will not be elaborated here.

[0081] Furthermore, after step S400, the following steps are further included:

[0082] S610, obtaining the pore water pressure corresponding to each preset depth of the semi-cylindrical model pile through a micro pore pressure sensor.

[0083] S620: Determine a graph showing a change in effective friction coefficient corresponding to the semi-cylindrical model pile as the pile depth develops, based on the pore water pressure and stress-strain curve corresponding to the semi-cylindrical model pile at each preset depth.

[0084] In this embodiment, in actual engineering, more attention is paid to the friction coefficient of the pile surface. Since the foundation soil of engineering structures such as land and ocean is usually affected by water, the excess pore water pressure caused by the shear process cannot be ignored. According to the effective stress principle, when solving the effective friction coefficient of the interface, the measured friction stress should be divided by the effective lateral pressure value of the current state, where the effective lateral pressure value is the soil pressure at the current burial depth minus the excess pore water pressure value.

[0085] In some embodiments, after step S100 and before step S200, the method further includes the following steps:

[0086] S110, obtaining the interface pore pressure value under the pile-soil shear action by the micro pore pressure sensor and obtaining the friction force between the semi-cylindrical model pile and the soil sample by the strain gauge.

[0087] S120 , obtaining a downward displacement distance of the semi-cylindrical model pile according to a displacement sensor at the top of the semi-cylindrical model pile.

[0088] S130: Determine a relevant parameter curve based on the interface pore pressure value, friction force, and displacement distance.

[0089] In this embodiment, when the model loading system is controlled to apply a preset force F to the semi-cylindrical model pile and the shaft of the pile-soil interface static and dynamic shear visualization geotechnical centrifuge test device is controlled to rotate at a preset speed S, the friction between the semi-cylindrical model pile and the soil sample can be measured by strain gauges of different burial depths, and the displacement of the semi-cylindrical model pile can be directly measured by a displacement sensor installed at the top of the semi-cylindrical model pile; thereby, the relevant parameter curve is determined according to the measured interface pore pressure value, friction force and displacement distance; it should be noted that those skilled in the art can use existing methods according to actual needs to determine the relevant parameter curve according to the measured interface pore pressure value, friction force and displacement distance, which will not be elaborated here.

[0090] In some embodiments, after step S400, the method further includes the following steps:

[0091] S700, controlling the model loading system to apply a variable force to the semi-cylindrical model pile so that the semi-cylindrical model pile moves downward at a preset rate, and controlling the rotating shaft of the pile-soil interface static and dynamic shear visualization geotechnical centrifuge test device to rotate at a preset speed S.

[0092] S710, obtaining the interface pore pressure value under the pile-soil shear action by the micro pore pressure sensor and obtaining the friction force between the semi-cylindrical model pile and the soil sample by the strain gauge.

[0093] S720: Determine a downward movement distance of the semi-cylindrical model pile according to a downward movement duration and a movement speed of the semi-cylindrical model pile.

[0094] S730: Determine a relevant parameter curve based on the interface pore pressure value, friction force, and displacement distance.

[0095] Specifically, all friction forces can be divided by the actual contact area to obtain the interface friction stress at different burial depths. Then, according to the effective stress principle, when solving the interface effective friction coefficient, the measured interface friction stress is divided by the effective lateral pressure value in the current state, where the effective lateral pressure value is the soil pressure at the current burial depth minus the excess pore water pressure value.

[0096] In this embodiment, in combination with the above-mentioned device, the model loading system can also be controlled to apply a variable force to the semi-cylindrical model pile, so that the semi-cylindrical model pile moves downward at a preset rate, and the rotating shaft of the pile-soil interface static and dynamic shear visualization geotechnical centrifuge test device is controlled to rotate at a preset speed S, thereby obtaining the interface pore pressure value in this case and obtaining the friction force between the semi-cylindrical model pile and the soil sample through the strain gauge, and then obtaining the relevant parameter curve; that is, through the above-mentioned device, the characteristics between the pile and the soil under different situations can be simulated.

[0097] Furthermore, the camera is used to reveal the interface failure form and action mechanism under different influencing factors and determine the thickness of the shear zone at the pile-soil interface.

[0098] Furthermore, the transparent plate is made of transparent organic glass.

[0099] Furthermore, the centrifuge hanging basket is in the shape of a cuboid.

[0100] The pile-soil interface static and dynamic shear visualization geotechnical centrifuge test system of the present embodiment includes: a pile-soil interface static and dynamic shear visualization geotechnical centrifuge test device, the pile-soil interface static and dynamic shear visualization geotechnical centrifuge test device includes: a rotating shaft, a cross bar, a counterweight and a centrifuge basket; wherein, the middle part of the cross bar is connected to the upper part of the rotating shaft, one end of the cross bar is provided with a counterweight, and the other end is provided with a centrifuge basket; a transparent plate is provided in the middle of the centrifuge basket, a first space on one side of the transparent plate is used to fill soil samples, and a second space on the other side is used to place a camera; a semi-cylindrical model pile is provided in the first space, and the plane side of the semi-cylindrical model pile is in contact with the transparent plate; the semi-cylindrical model pile is provided in the first space, and the plane side of the semi-cylindrical model pile is in contact with the transparent plate; A model loading system is provided above the profiled pile, and the model loading system is used to apply a vertical downward force to the semi-cylindrical model; a plurality of through holes are provided on the transparent plate, and the through holes are used to calibrate the movement distance of the soil sample; the static and dynamic shear visualization geotechnical centrifuge test device of the pile-soil interface can be used to measure the displacement curve of the soil sample over time under the conditions of a preset force F and a preset speed S; the device adds a pile-soil interaction module and a visualization module to the geotechnical centrifuge test equipment, overcoming the above-mentioned research deficiencies, reproducing the actual stress and deformation behavior of the interface between the soil and the structure in a controlled laboratory environment, and providing an effective testing method for geotechnical engineering design and research.

[0101] Furthermore, although the steps of the method of the present disclosure are described in a particular order in the accompanying drawings, this does not require or imply that the steps must be performed in this particular order, or that all steps shown must be performed to achieve the desired results. Additionally or alternatively, some steps may be omitted, multiple steps may be combined into one step, and / or one step may be decomposed into multiple steps.

[0102] An embodiment of the present invention also provides a non-transitory computer-readable storage medium, which can be set in an electronic device to store at least one instruction or at least one program related to implementing a method in a method embodiment. The at least one instruction or the at least one program is loaded and executed by the processor to implement the method provided in the above embodiment.

[0103] The program product may utilize any combination of one or more readable media. The readable medium may be a readable signal medium or a readable storage medium. The readable storage medium may be, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, device, or component, or any combination thereof. More specific examples (a non-exhaustive list) of readable storage media include: an electrical connection having one or more wires, a portable disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination thereof.

[0104] A computer-readable signal medium may include a data signal propagated in baseband or as part of a carrier wave, which carries readable program code. Such propagated data signals may take a variety of forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination thereof. A readable signal medium may also be any readable medium other than a readable storage medium that can transmit, propagate, or transfer a program for use by or in conjunction with an instruction execution system, apparatus, or device.

[0105] The program code embodied on the readable medium may be transmitted using any appropriate medium, including but not limited to wireless, wireline, optical fiber cable, RF, etc., or any suitable combination of the foregoing.

[0106] The program code for performing the operations of the present application can be written in any combination of one or more programming languages, including object-oriented programming languages ​​such as Java, C++, etc., and conventional procedural programming languages ​​such as "C" or similar programming languages. The program code can be executed entirely on the user computing device, partially on the user device, as a separate software package, partially on the user computing device and partially on a remote computing device, or entirely on a remote computing device or server. In the case of a remote computing device, the remote computing device can be connected to the user computing device through any type of network, including a local area network (LAN) or a wide area network (WAN), or can be connected to an external computing device (e.g., via the Internet using an Internet service provider).

[0107] An embodiment of the present invention further provides an electronic device including a processor and the aforementioned non-transitory computer-readable storage medium.

[0108] The electronic device is merely an example and should not limit the functions and scope of use of the embodiments of the present application.

[0109] The electronic device is implemented as a general-purpose computing device. Components of the electronic device may include, but are not limited to, the aforementioned at least one processor, the aforementioned at least one memory, and a bus connecting different system components (including the memory and the processor).

[0110] The memory stores program codes, which can be executed by the processor, so that the processor performs the steps of various embodiments described in this specification.

[0111] The memory may include readable media in the form of volatile memory, such as random access memory (RAM) and / or cache memory, and may further include read-only memory (ROM).

[0112] The memory may also include a program / utility having a set (at least one) of program modules, such program modules including but not limited to: an operating system, one or more application programs, other program modules, and program data, each of which or some combination may include an implementation of a network environment.

[0113] The bus may represent one or more of several types of bus structures, including a memory bus or memory controller, a peripheral bus, an accelerated graphics port, a processor, or a local bus using any of a variety of bus architectures.

[0114] The electronic device may also communicate with one or more external devices (e.g., keyboards, pointing devices, Bluetooth devices, etc.), one or more devices that enable a user to interact with the electronic device, and / or any device that enables the electronic device to communicate with one or more other computing devices (e.g., routers, modems, etc.). Such communication may be performed via an input / output (I / O) interface. Furthermore, the electronic device may also communicate with one or more networks (e.g., local area networks (LANs), wide area networks (WANs), and / or public networks, such as the Internet) via a network adapter. The network adapter communicates with other modules of the electronic device via a bus. It should be understood that, although not shown in the figures, other hardware and / or software modules may be used in conjunction with the electronic device, including but not limited to: microcode, device drivers, redundant processors, external disk drive arrays, RAID systems, tape drives, and data backup storage systems.

[0115] Through the description of the above embodiments, it is easy for those skilled in the art to understand that the example embodiments described herein can be implemented by software or by combining software with necessary hardware. Therefore, the technical solution according to the embodiments of the present disclosure can be embodied in the form of a software product, which can be stored in a non-volatile storage medium (which can be a CD-ROM, a USB flash drive, a mobile hard disk, etc.) or on a network, and includes several instructions to enable a computing device (which can be a personal computer, a server, a terminal device, or a network device, etc.) to execute the method according to the embodiments of the present disclosure.

[0116] An embodiment of the present invention further provides a computer program product comprising program code. When the program product is run on an electronic device, the program code is used to enable the electronic device to execute the steps of the method according to various exemplary embodiments of the present invention described above in this specification.

[0117] Although some specific embodiments of the present invention have been described in detail by way of examples, it should be understood by those skilled in the art that the above examples are for illustration only and are not intended to limit the scope of the present invention. It should also be understood by those skilled in the art that various modifications may be made to the embodiments without departing from the scope and spirit of the present invention.

Claims

1. A static and dynamic shear visualization geotechnical centrifuge test system for pile-soil interface, characterized by: The system includes: a static and dynamic shear visualization geotechnical centrifuge test device for the pile-soil interface and a processor; the static and dynamic shear visualization geotechnical centrifuge test device for the pile-soil interface includes: a rotating shaft, a crossbar, a counterweight, and a centrifuge basket; wherein the middle portion of the crossbar is connected to the upper portion of the rotating shaft, one end of the crossbar is provided with a counterweight, and the other end is provided with a centrifuge basket; A transparent plate is provided in the middle of the centrifuge basket, a first space on one side of the transparent plate is used to fill the soil sample, and a second space on the other side is used to place a camera; a semi-cylindrical model pile is provided in the first space, and the flat side of the semi-cylindrical model pile is in contact with the transparent plate; a model loading system is provided above the semi-cylindrical model pile, and the model loading system is used to apply a constant preset force or a constant loading rate to the semi-cylindrical model; a plurality of through holes are provided on the transparent plate, and the through holes are used to calibrate the movement distance of the soil sample; The processor is configured to perform the following steps: S100, controlling the model loading system to apply a preset force F to the semi-cylindrical model pile and controlling the shaft of the pile-soil interface static and dynamic shear visualization geotechnical centrifuge test device to rotate at a preset speed S; S200, using a camera to obtain the displacement of the soil sample in each through hole on the transparent plate within each preset time period, so as to obtain a list set of displacement time periods A = (A1, A2, ..., A i ,…,A n ), i=1, 2,...,n; among them, A i is the displacement duration list corresponding to the soil sample within the i-th preset duration on the transparent plate, and n is the number of preset durations; A i =(A i，1 , A i，2 ,…,A i，j ,…,A i，m ), j = 1, 2, ..., m; where A i，j is the displacement of the soil sample in the jth through hole during the i-th preset time, and m is the number of through holes on the transparent plate; S300: According to A, determine the overall displacement of the soil sample within each preset time period, and then obtain the overall displacement list of the soil sample B = (B1, B2, ..., B i ,…,B n ); Among them, B i is the overall displacement of the soil sample within the i-th preset time period; S400 , according to B, determining a displacement curve of the soil sample over time under the conditions of a preset force F and a preset rotation speed S.

2. The static and dynamic shear visualization geotechnical centrifuge testing system for pile-soil interface according to claim 1 is characterized in that: Step S300 includes the following steps: S310, obtaining the fluctuation rate corresponding to the displacement of soil samples in all through holes within each preset time period, so as to obtain a list of fluctuation rates of soil sample displacement corresponding to A γ = (γ1, γ2, ..., γ i ,…,γ n ); where γ i A i The corresponding soil sample displacement fluctuation rate; γ i =(1 / m)×∑ m j=1 (A i，j -((1 / m)×∑ m j=1 A i，j )) 2 ; S320, traverse γ, if γ i <γ', then determine B i =(1 / m)×∑ m j=1 A i，j ; Otherwise, go to S330; where γ' is the preset soil sample displacement fluctuation rate threshold; S330, get A i The corresponding average soil sample displacement BA i ; S340, traverse A i , if |A i，j -BA i | / A i，j <α, then A i，j Determine the displacement of the specified soil sample within the i-th preset time length to obtain A i The corresponding specified soil sample displacement list β i = (β i，1 , β i，2 ,…,β i，r ,…,β i，f（i） ), r=1, 2,..., f(i); among them, β i，r is the displacement of the rth designated soil sample within the i-th preset time length, and f(i) is the number of displacements of the designated soil samples within the i-th preset time length; S350, according to β i , determine B i =(1 / f(i))×∑ f（i） r=1 β i，r .

3. The static and dynamic shear visualization geotechnical centrifuge testing system for pile-soil interface according to claim 1 is characterized in that: A micro pore pressure sensor and a strain gauge are provided around the semi-cylindrical model pile. The micro pore pressure sensor is used to monitor the interface pore pressure value under the shear action of the pile and soil, and the strain gauge is used to monitor the friction between the semi-cylindrical model pile and the soil sample.

4. The static and dynamic shear visualization geotechnical centrifuge testing system for pile-soil interface according to claim 3 is characterized in that: After step S400, the following steps are further included: S500, obtaining the first interface friction force of the semi-cylindrical model pile at different preset depths through the strain gauge to obtain a first interface friction force list C=(C1, C2, ..., C p ,…,C q ), p = 1, 2, ..., q; where C p is the first interface friction force of the semi-cylindrical model pile corresponding to the pth preset depth, and q is the number of preset depths; S510, obtaining the second interface friction force of the semi-cylindrical model pile at different preset depths through the model loading system to obtain a second interface friction force list D=(D1, D2, ..., D p ,…,D q ), where D p is the second interface friction force corresponding to the p-th preset depth of the semi-cylindrical model pile obtained by the model loading system; S520, determining the third interface friction force of the semi-cylindrical model pile at different preset depths according to C and D, to obtain a third interface friction force list E=(E1, E2, ..., E p ,…,E q ); where E p is the third interface friction force of the semi-cylindrical model pile corresponding to the pth preset depth; E p =(C p +D p ) / 2; S530, based on E, determine the stress and strain values ​​corresponding to each third interface friction force in E to obtain a stress and strain value group list G=(G1, G2, ..., G p ,…,G q ); where G p For E p Corresponding stress and strain value group; G p =(G p，1 , G p，2 );G p，1 For E p The corresponding stress, G p，2 is the strain value of the semi-cylindrical model pile at the pth preset depth; G p =E p / SA p ;SA p is the actual contact area between the semi-cylindrical model pile and the soil sample at the pth preset depth; G p，2 =SD p / SD;SD p is the distance that the semi-cylindrical model pile penetrates into the soil sample at the pth preset depth, and SD is the total length of the semi-cylindrical model pile; S530: Determine the stress-strain curve corresponding to the semi-cylindrical model pile according to G.

5. The static and dynamic shear visualization geotechnical centrifuge testing system for pile-soil interface according to claim 4 is characterized in that: After step S400, the following steps are further included: S610, obtaining the pore water pressure corresponding to each preset depth of the semi-cylindrical model pile by using a micro pore pressure sensor; S620: Determine a graph showing a change in effective friction coefficient corresponding to the semi-cylindrical model pile as the pile depth develops, based on the pore water pressure and stress-strain curve corresponding to the semi-cylindrical model pile at each preset depth.

6. The static and dynamic shear visualization geotechnical centrifuge testing system for pile-soil interface according to claim 3 is characterized in that: After step S100 and before step S200, the method further includes the following steps: S110, obtaining the interface pore pressure value under the pile-soil shear action by the micro pore pressure sensor and obtaining the friction force between the semi-cylindrical model pile and the soil sample by the strain gauge; S120, obtaining a downward displacement distance of the semi-cylindrical model pile according to a displacement sensor at the top of the semi-cylindrical model pile; S130: Determine a relevant parameter curve based on the interface pore pressure value, friction force, and displacement distance.

7. The static and dynamic shear visualization geotechnical centrifuge testing system for pile-soil interface according to claim 3 is characterized in that: After step S400, the method further includes the following steps: S700: Controlling the model loading system to apply a variable force to the semi-cylindrical model pile so that the semi-cylindrical model pile moves downward at a preset rate, and controlling the rotating shaft of the pile-soil interface static and dynamic shear visualization geotechnical centrifuge test device to rotate at a preset speed S; S710, obtaining the interface pore pressure value under the pile-soil shear action by the micro pore pressure sensor and obtaining the friction force between the semi-cylindrical model pile and the soil sample by the strain gauge; S720, determining a downward movement distance of the semi-cylindrical model pile based on a downward movement duration and a movement rate of the semi-cylindrical model pile; S730: Determine a relevant parameter curve based on the interface pore pressure value, friction force, and displacement distance.

8. The static and dynamic shear visualization geotechnical centrifuge testing system for pile-soil interface according to claim 1 is characterized in that: The camera is used to reveal the interface failure form and action mechanism under different influencing factors and determine the thickness of the shear zone at the pile-soil interface.

9. The static and dynamic shear visualization geotechnical centrifuge testing system for pile-soil interface according to claim 1, characterized in that: The transparent plate is made of transparent organic glass.

10. The static and dynamic shear visualization geotechnical centrifuge testing system for pile-soil interface according to claim 1, characterized in that: The centrifuge hanging basket is in a rectangular parallelepiped shape.

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