A method for predicting mechanical response of saturated soil under cyclic loading in elliptical path

Abstract

This invention relates to a method for predicting the mechanical response of saturated soil under elliptical path cyclic loading conditions, comprising the following steps: S1, obtaining the strength parameters of saturated soil through indoor geotechnical tests, and establishing a conventional cyclic contour map of saturated soil through single-shear axis cyclic loading single-shear tests; S2, establishing a mechanical parameter system for saturated soil under elliptical path cyclic loading conditions based on the cyclic single-shear test characteristics where the loading direction changes around the average direction; S3, calculating the cyclic shear stress equivalent to that of the conventional cyclic shear test based on the setting parameters of the elliptical path cyclic loading test of saturated soil; S4, using the equivalent normalized combined shear stress, predicting the number of failure cycles of the test through interpolation calculation methods. N f pore water pressure u p The evolution process and mean shear strain c a Combined Cyclic Shear Strain c cy(syn) The evolutionary process of the invention. Compared with existing technologies, this invention has the advantages of simplicity, convenience, and high precision.

Description

Technical Field

[0001] This invention belongs to the field of geotechnical investigation technology and relates to a method for predicting the mechanical response of saturated soil under elliptical path cyclic loading conditions. Background Technology

[0002] Complex marine environmental loads are composed of various load forms such as wind, waves, and currents. Under natural conditions, these loads typically manifest as cyclic loads. However, the directions of wind and wave loads are often inconsistent, and their amplitudes are also asynchronous. This time-varying characteristic of wind-wave anisotropy is a typical feature prevalent in complex marine environmental loads.

[0003] The introduction of shared anchors significantly alters the directionality of loads applied to the anchor. In conventional independent mooring systems, because only one anchor chain connects to the anchor foundation, the load direction on the anchor foundation is always consistent with the anchor chain direction. However, in shared mooring systems, an anchor point is simultaneously connected to multiple anchor chains and bears anchor chain tensions from multiple directions. Due to the phase difference between multiple anchor chains and the time-varying anisotropic characteristics of marine environmental loads (wind and wave), the net mooring load applied to the shared anchor foundation generally aligns with the direction of the environmental load, but varies within a certain angular range. Studies show that the angular variation range of the net load direction experienced by a shared anchor point connected by three anchor chains under marine environmental loads is approximately 30°.

[0004] However, there is currently no simple and convenient quantitative prediction method for the mechanical properties of saturated soil under elliptical path cyclic loading conditions related to shared anchors, such as shear strength, cumulative excess pore water pressure, and shear strain. Summary of the Invention

[0005] The purpose of this invention is to provide a method for predicting the mechanical response of saturated soil under elliptical path cyclic loading conditions. This method enables simple, convenient, and highly accurate quantitative calculation and prediction of mechanical properties of saturated soil under elliptical path cyclic loading conditions related to shared anchors, such as shear strength, cumulative excess pore water pressure, and shear strain. The calculation and prediction results can be directly used for parameter optimization in the design of shared anchor foundations for offshore wind power.

[0006] The objective of this invention can be achieved through the following technical solutions: In a first aspect, the present invention provides a method for predicting the mechanical response of saturated soil under elliptical path cyclic loading conditions, comprising the following steps: S1. The strength parameters of saturated soil were obtained through indoor geotechnical tests, and a conventional cyclic contour map of saturated soil was established through single shear axis cyclic loading single shear test, including contour maps of failure cycle number, average shear strain and cyclic shear strain, and normalized permanent pore water pressure. S2. Based on the characteristics of the cyclic single shear (DSS) test where the loading direction changes around the average direction, establish the mechanical parameter system of saturated soil under elliptical path cyclic loading conditions. S3. Establish an equivalent cyclic shear stress method for saturated soil under elliptical path cyclic loading conditions. Based on the setting parameters of the saturated soil elliptical path cyclic loading test, calculate the cyclic shear stress equivalent to that of the conventional cyclic shear test. S4. Using equivalent normalized combined shear stress, the number of failure cycles in the experiment is predicted from the failure cycle contour map using interpolation methods. N f Predicting pore water pressure from normalized permanent pore water pressure contour maps u p The evolutionary process is used to predict the mean shear strain in the contour maps of mean shear strain and cyclic shear strain. c a Combined Cyclic Shear Strain c cy(syn) The evolutionary process.

[0007] Furthermore, in S1, the strength parameters of the saturated soil are obtained, including the shear strength of the saturated soil. s u DSS It is based on at least one single-shear axis monotonic loading single-shear test; The process of establishing a conventional cyclic contour map for saturated soil includes: A) At least five single-shear axis cyclic loading single-shear (DSS) tests, where the normalized mean shear stress t a / s u DSS There shall be no fewer than three cyclic loading single shear tests with a value of 0; B) Select at least one non-zero normalized mean shear stress. t a / s u DSS Conduct experiments, and each non-zero normalized mean shear stress t a / s u DSS Conduct no fewer than two cyclic loading single shear tests; C) Based on the results of the single shear axis cyclic loading single shear (DSS) test, a complete set of conventional cyclic contour maps of saturated soil was drawn by interpolation and extrapolation in the corresponding coordinate space, including contour maps of failure cycle number, average shear strain and cyclic shear strain, and normalized permanent pore water pressure.

[0008] It should be noted that the specific methods for constructing contour maps and using contour map interpolation to predict corresponding results are standard techniques in this field. For details, please refer to the following existing literature: Andersen K H. Cyclicsoil parameters for offshore foundation design[C]. The 3 rd ISSMGE McClellandLecture. Frontiers in Offshore Geotechnics Ⅲ, ISFOG'2015, Meyer (Ed). Taylor& Francis Group, London, ISBN: 978-1-138-02848-7, 2015: 5-82.; Li Shuzhao, Fu Dianfu, Sun Guodong, Bi Qian, Zhang Youhu. Study on cyclic loading characteristics and prediction methods of saturated cohesive soil [J / OL]. Marine Bulletin, 1-14.

[0009] Furthermore, in S1, the failure cycle count contour map can be used to determine the failure envelope of the mean shear strain and cyclic shear strain contour maps, as well as the normalized permanent pore water pressure contour map.

[0010] Furthermore, in the three conventional cyclic contour maps—the "failure cycle count contour map," the "mean shear strain and cyclic shear strain contour map," and the "normalized permanent pore water pressure contour map"—normalized mean shear stress and normalized cyclic shear stress are all used as functions. This function refers to the correspondence between physical parameters, not a functional expression. For example, in the mean shear strain and cyclic shear strain contour map, the horizontal axis represents the normalized mean shear stress, and the vertical axis represents the normalized cyclic shear stress. The contour lines in the coordinate space represent the physical quantities of mean shear strain and cyclic shear strain. Thus, a relationship is established between shear stress and shear strain through this map, i.e., a so-called functional relationship. In short, soil will produce a fixed shear strain under a fixed shear stress, and the contour map is used to represent this relationship.

[0011] Furthermore, in S2, the mechanical response of the saturated soil under elliptical path cyclic loading conditions needs to be reflected by a cyclic single shear (DSS) test in which the loading direction varies about the mean direction. The cyclic single shear (DSS) test requires a testing device capable of simultaneously applying cyclic loads in two mutually perpendicular directions (x-axis and y-axis) in the horizontal plane. The x-axis and y-axis loads need to be controlled independently. This is achieved by setting the reference values ​​and amplitudes of the loads on the two shear axes (x-axis and y-axis) to the same value, and by setting the phase difference Δ between the cyclic loads on the x-axis and y-axis. f To achieve cyclic loading of saturated soil under an elliptical path.

[0012] The characteristics of the above-mentioned cyclic single shear test include: The loading path is elliptical, with its major axis along a 45° direction; The position of the ellipse center is determined by the reference value of the load; The major axis of the ellipse is determined by the magnitude of the cyclic load; From the phase difference Δ f Determine the minor axis of the ellipse.

[0013] Furthermore, in S2, the mechanical parameter system includes angle and phase difference parameters, several shear stress parameters, several shear strain parameters, pore water pressure parameters, and soil failure criteria, among which... Among the angle and phase difference parameters, the angle parameter is the shear stress ellipse angle. i τ,ellipse Δ is defined as the angle between the two tangents drawn from the origin to the shear stress ellipse in a unidirectional cyclic loading test (defined as when the mean shear stress in the resultant direction exceeds the principal cyclic shear stress), and the phase difference Δ. f It is defined as the phase difference between the cyclic shear stresses on two mutually perpendicular horizontal shear axes; The shear stress parameters include the shear stress in the resultant direction. t Mean shear stress t a Main cyclic shear stress t cy,major Secondary cyclic shear stress t cy,minor The shear stress parameters are defined as follows: , , , , in, t (x) and t (y)These are the shear stress components applied along the x-axis and y-axis, respectively. t max and t min These represent the maximum and minimum shear stresses in the resultant direction during a cycle; t a(x) and t a(y) The average shear stresses on the x-axis and y-axis are respectively represented; while R τ Defined as t cy,major and t cy,minor The ratio of the length to the width of the shear stress ellipse is the aspect ratio of the shear stress ellipse.

[0014] Through mathematical derivation, R τ Phase difference (Δ) of cyclic shear stress between the two shear axes f The relationship between them is: , It should be noted that, despite the phase difference, the above formula is only valid when the same combination of average and cyclic loads is applied to the x-axis and y-axis.

[0015] When the resultant shear stress in the experiment is simplified to a direction along a 45° angle with the x-axis, in the experiment t a(x) = t a(y) and t cy(x) = t cy(y) At this point, the average shear stress t a and main cyclic shear stress t cy,major It can be simplified to: , , therefore, t cy,major / t a It can be expressed by the following formula: , The angle enclosed by the shear stress ellipse ( i τ,ellipse Then it can be passed t a(x) , t cy(x) and Δ f The calculation is as follows: , It should be noted that the above formula only applies to unidirectional circular loading (i.e., ... t a > t cy,major (Time) test. For bidirectional cyclic loading test (i.e. t a ≤ t cy,major When, the angle enclosed by the shear stress ellipse is 360°.

[0016] To comprehensively consider the mechanism of cyclic shear stress in a cyclic single shear (DSS) test where the loading direction varies around the average direction, a resultant cyclic shear stress is defined based on the definitions of primary cyclic shear stress and secondary cyclic shear stress. t cy(syn) The formula for defining this parameter is: t cy(syn) This is not the actual shear stress experienced by the soil at any given moment within a cycle. This parameter is a synthetic parameter used to capture the influence of sub-cycle shear stress. t cy(syn) It can be done t cy,major and Δ f The calculation yielded: .

[0017] The shear strain parameters include the shear strain in the resultant direction. c Mean shear strain c a Main circulation shear strain c cy,major Secondary cyclic shear strain c cy,minor The permanent shear strain γp is defined as the residual shear strain when the shear stress on the y-axis returns to its mean shear stress value (i.e., at the end of a complete cycle). The specific shear strain parameters are defined as follows: , , , , in, c (x) and c (y) These are the shear strain components applied along the x-axis and y-axis, respectively; cmax and c min These are defined as the maximum and minimum shear strain in the resultant direction during a loading cycle, respectively. c a(x) and c a(y) The average shear strain on the x-axis and y-axis are respectively represented; A γ,ellipse This is the area enclosed by the shear strain ellipse.

[0018] Combined cyclic shear stress t cy(syn) Corresponding combined cyclic shear strain c cy(syn) Defined as: according to t cy(syn) and c cy(syn) Definition of cyclic shear modulus G (syn) Defined as: .

[0019] The pore water pressure parameter is the cumulative excess pore water pressure. u p , is defined as the end of each loop, i.e. t = t a The cumulative excess pore water pressure over time; In marine geotechnical engineering, when the average shear strain ( c a ) or cyclic shear strain ( c cy When the average shear strain reaches 15% (whichever occurs first), the soil is considered to have reached a failure state under cyclic loading. Based on this, the soil failure criterion used in this invention is: when the average shear strain reaches 15% (whichever occurs first), the soil is considered to have reached a failure state. c a Or combined cyclic shear strain c cy(syn) When the soil reaches 15%, it is considered to have reached a state of failure, including the combined cyclic shear strain. c cy(syn) Defined as: .

[0020] More preferably, in S3, the equivalent cyclic shear stress t cy,eq and correction factor f mod The expression is: , , , Based on this, the setting parameters for the cyclic single shear (DSS) test, which measures the variation of the loading direction of the saturated soil around the mean direction, are determined. t a / s u DSS , t cy,major / s u DSS and Δ f The equivalent cyclic shear stress of the test to be predicted can be calculated using the above formula. t cy,eq .

[0021] More preferably, in S4, the equivalent normalized combined shear stress includes t a / s u DSS and t cy,eq / s u DSS ; The number of failure cycles N f The prediction process is as follows: based on the equivalent normalized combined shear stress t a / s u DSS and t cy,eq / s u DSS Interpolation is performed on the conventional failure contour map to obtain the number of failure cycles in a cyclic single shear test where the loading direction varies around the average direction. N f The predicted value. The specific interpolation prediction process is as follows: the normalized shear stress combination ( t a / s u DSS , t cy,eq / s u DSS Plot the failure cycle contour lines in the coordinate space of the failure cycle contour map, determine the failure cycle number contour line closest to the coordinate point, and obtain the failure cycle number corresponding to that coordinate position by performing linear interpolation on its logarithm.N f .

[0022] The pore water pressure u p The prediction process for the evolution process is as follows: based on the equivalent normalized combined shear stress t a / s u DSS and t cy,eq / s u DSS and the predicted number of failure cycles. N f Interpolation prediction of excess pore water pressure during the entire elliptical path cyclic loading process was performed using a normalized permanent pore water pressure contour map. u p The accumulation process. The specific interpolation prediction process is as follows: The normalized shear stress combination ( t a / s u DSS , t cy,eq / s u DSS ) Plotted at a specific number of loops ( N In the coordinate space of a normalized permanent pore water pressure contour map (e.g., values ​​of 1, 10, 100, 1000, etc.), within a single contour map, the normalized pore water pressure contour line closest to a given coordinate point is identified. Linear interpolation is then performed on this contour line to obtain the corresponding normalized pore water pressure at that coordinate location for that number of cycles. u p / s vc Furthermore, for a specific number of cycles (… N The contour lines in a normalized permanent pore water pressure (PSB) contour map (e.g., values ​​of 1, 10, 100, 1000) can be linearly interpolated by logarithmically calculating the number of cycles to obtain a PSB contour map for any number of cycles. Furthermore, by predicting normalized pore water pressure from a single PSB contour map, the corresponding normalized pore water pressure result can be obtained from PSB contour maps for any number of cycles. This can be combined with the known effective consolidation stress of the soil. s vc This method allows us to obtain the excess pore water pressure throughout the elliptical path cyclic loading process. u p The cumulative process.

[0023] The mean shear strain c a Combined Cyclic Shear Strain c cy(syn) The prediction process for the development process is as follows: based on the equivalent normalized combined shear stress t a / s u DSS , t cy,eq / s u DSS and the predicted number of failure cycles. N f Interpolation was used to predict the average shear strain during the entire elliptical path cyclic loading process from the contour maps of average shear strain and cyclic shear strain. c a Combined Cyclic Shear Strain c cy(syn) The development history of the method. The specific interpolation prediction process is as follows: the normalized shear stress combination ( t a / s u DSS , t cy,eq / s u DSS ) Plotted at a specific number of loops ( N In the coordinate space of the contour maps of average shear strain and cyclic shear strain (e.g., =1, 10, 100, 1000, etc.), in a single contour map, the average shear strain and cyclic shear strain contour lines closest to a given coordinate point are identified. By performing bidirectional linear interpolation on these contour lines, the average shear strain corresponding to that coordinate position for that number of cycles is obtained. c a Combined Cyclic Shear Strain c cy(syn) Furthermore, for a specific number of iterations (... N The contour lines in the average shear strain and cyclic shear strain contour maps (e.g., =1, 10, 100, 1000, etc.) can be linearly interpolated by logarithmically converting the number of cycles to obtain the average shear strain and cyclic shear strain contour maps for any number of cycles. Furthermore, by predicting the average shear strain and combined cyclic shear strain from a single average shear strain and cyclic shear strain contour map, the corresponding average shear strain and combined cyclic shear strain results can be obtained from the average shear strain and cyclic shear strain contour maps for any number of cycles. This method can then be used to obtain the average shear strain throughout the entire elliptical path cyclic loading process. c a Combined Cyclic Shear Strain c cy(syn) Its development history.

[0024] The above-mentioned, further preferred, normalized permanent pore water pressure contour map uses effective consolidation stress. s vc 'Normalized permanent pore water pressure, i.e. u p / s vc ', among which, effective consolidation stress s vc The normalized permanent pore water pressure can be calculated based on the thickness of the overlying soil layer and the unit weight of the soil. This can be obtained by interpolating the normalized permanent pore water pressure contour map. u p / s vc Then, combined with the known effective consolidation stress of the soil... s vc That is, to calculate the required cumulative excess pore water pressure. u p Predicted value.

[0025] In a second aspect, the present invention provides a device for predicting the mechanical response of saturated soil under elliptical path cyclic loading conditions, for implementing the prediction method as described in the first aspect, the device comprising: The parameter input module is used to acquire and input the strength parameters of saturated soil, the results of single shear axis cyclic loading single shear test, and the mechanical parameter system of saturated soil under elliptical path cyclic loading conditions; The module for establishing contour maps of saturated soil under normal cycles is used to create contour maps of saturated soil under normal cycles, including contour maps of failure cycle count, average shear strain and cyclic shear strain, and normalized permanent pore water pressure. The data processing and prediction module is used to process the mechanical parameter system to obtain the equivalent normalized combined shear stress, and based on the equivalent normalized combined shear stress, to predict the number of failure cycles in the conventional cyclic contour map of the saturated soil using an interpolation method. N f pore water pressure u p The evolutionary process and mean shear strain c a Combined Cyclic Shear Strain c cy(syn) The evolutionary process.

[0026] In a third aspect, the present invention provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the steps of the prediction method as described in any one of the first aspects above. Attached Figure Description

[0027] Figure 1 This is a flowchart of a specific embodiment of the present invention; Figure 2 This is a contour map of the conventional failure cycle number as a function of normalized average shear stress and normalized cyclic shear stress in a specific embodiment of the present invention. Figure 3 This is a contour map of conventional normalized permanent pore water pressure as a function of normalized average shear stress and normalized cyclic shear stress in a specific embodiment of the present invention. Figure 4 This is a contour map of conventional average shear strain and cyclic shear strain as functions of normalized average shear stress and normalized cyclic shear stress in a specific embodiment of the present invention. Figure 5 This is a schematic diagram of a typical shear load on two mutually perpendicular shear axes (x-axis and y-axis) in a cyclic single shear (DSS) test in a specific embodiment of the present invention, in which the loading direction varies around the average direction. Figure 6 This is a schematic diagram of the elliptical distribution of shear stress in the plane space of a cyclic single shear (DSS) test in which the loading direction varies around the average direction, according to a specific embodiment of the present invention. Figure 7 This is a schematic diagram illustrating the definition of shear stress and angle parameters in the plane space of a cyclic single shear (DSS) test in which the loading direction varies around the average direction, according to a specific embodiment of the present invention. Figure 8 This is a schematic diagram illustrating the definition of shear strain parameters in the plane space of a cyclic single shear (DSS) test in which the loading direction varies around the average direction, according to a specific embodiment of the present invention. Detailed Implementation

[0028] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. These embodiments are based on the technical solution of the present invention and provide detailed implementation methods and specific operating procedures. However, the scope of protection of the present invention is not limited to the following embodiments.

[0029] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0030] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0031] It should be understood that, when used in this specification and the appended claims, the term "comprising" indicates the presence of the described features, integrals, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or collections thereof.

[0032] It should also be understood that the terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the scope of the application. As used in this specification and the appended claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms unless the context clearly indicates otherwise.

[0033] It should also be further understood that the term “and / or” as used in this application specification and the appended claims means any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0034] As used in this specification and the appended claims, the term "if" may be interpreted, depending on the context, as "when," "once," "in response to determination," or "in response to detection." Similarly, the phrase "if determined" or "if [the described condition or event] is detected" may be interpreted, depending on the context, as "once determined," "in response to determination," "once [the described condition or event] is detected," or "in response to detection of [the described condition or event]."

[0035] Example 1: To achieve a simple, convenient, and highly accurate quantitative calculation of the mechanical properties of saturated soil under elliptical path cyclic loading conditions related to shared anchors, such as shear strength, cumulative excess pore water pressure, and shear strain, this embodiment provides a method for calculating the mechanical response of saturated soil under elliptical path cyclic loading conditions. The steps of this method can be found in [reference needed]. Figure 1 As shown, the specific steps are as follows: Step 1: Conduct indoor geotechnical tests to obtain the strength parameters of saturated soil; The specific number of indoor geotechnical tests to be conducted and the parameters to be obtained in step 1 are as follows: At least one monotonic loading shear test must be conducted, and the shear strength of the saturated soil must be obtained through this test. s u DSS No fewer than five cyclic loading single shear tests must be conducted, among which the normalized average shear stress... t a / s u DSS At least three cyclic loading single shear tests with a normalized average shear stress of 0 should be conducted, and at least one test with a normalized average shear stress of non-zero should be selected. t a / s u DSS Experiments were conducted, with each non-zero normalized average shear stress... t a / s u DSS Conduct at least two cyclic loading single shear tests. Through these tests, a cyclic contour map of the saturated soil can be established.

[0036] Step 2: Based on the cyclic loading single shear test, establish a cyclic contour map of saturated soil; Furthermore, the saturated soil cyclic contour maps required in step 2 of this embodiment include: a contour map of the failure cycle count as a function of normalized mean shear stress and normalized cyclic shear stress, and contour maps of mean shear strain and cyclic shear strain as functions of normalized mean shear stress and normalized cyclic shear stress (the cycle count can be plotted separately). N Contour maps of values ​​= 1, 10, 100, 1000, and 10000; contour maps of normalized permanent pore water pressure as functions of normalized average shear stress and normalized cyclic shear stress (the number of cycles can be plotted separately). N (Isometric contour maps of values ​​= 1, 10, 100, 1000, 10000).

[0037] Among them, the contour map of the failure cycle number, which is a function of the normalized mean shear stress and the normalized cyclic shear stress, is used to determine the failure cycle number at different cycles. N =1, 10, 100, 1000) The failure envelope of the contour maps of average shear strain and cyclic shear strain as functions of normalized average shear stress and normalized cyclic shear stress, and the contour map of normalized permanent pore water pressure as functions of normalized average shear stress and normalized cyclic shear stress.

[0038] For contour plots showing the number of failure cycles as a function of normalized mean shear stress and normalized cyclic shear stress, please refer to [link to relevant documentation]. Figure 2 As shown. Figure 2 In the figure, the horizontal axis represents the normalized mean shear stress. t a / s u DSS The vertical axis represents the normalized cyclic shear stress. t cy / s u DSS The diamond-shaped points represent data obtained from conventional cyclic DSS testing, showing the number of failure cycles in the test. N f Mean shear strain at failure c a and cyclic shear strain at failure c cy The solid black line represents a specific failure cycle number ( N The contour lines (e.g., =1, 10, 100, 1000) represent the failure modes; the black dashed line is the boundary line between failure modes, indicating cyclic shear failure to the left of the black dashed line and average shear failure to the right; the cross-shaped circular points are assumed interpolation prediction points. By interpolating the contour lines in this contour map, the number of failure cycles at the predicted point (the cross-shaped circular point) can be predicted. N f .

[0039] For contour maps of normalized permanent pore water pressure as functions of normalized mean shear stress and normalized cyclic shear stress, please refer to [link to relevant documentation]. Figure 3 As shown. Figure 3 In the figure, the horizontal axis represents the normalized mean shear stress. t a / s u DSS The vertical axis represents the normalized cyclic shear stress. t cy / s uDSS The solid circles represent data obtained from conventional cyclic DSS experiments, showing the data at the corresponding number of cycles. N Normalized pore water pressure under ) u p / s vc '; The black solid line represents the specific normalized pore water pressure.' u p / s vc '( u p / s vc The contour lines are defined as follows: '=0.05, 0.1, 0.15, 0.25, 0.3, 0.4, 0.5, 0.6'. The black dashed line represents the soil failure envelope for that number of cycles. Tests exceeding this envelope are considered failures. This line is taken from the contour lines corresponding to the number of cycles in the failure cycle contour map. The cross-shaped points are assumed interpolation prediction points. By interpolating the contour lines in this contour map, the normalized pore water pressure at the predicted point (cross-shaped point) for that number of cycles can be predicted. u p / s vc '.

[0040] For contour plots of mean shear strain and cyclic shear strain as functions of normalized mean shear stress and normalized cyclic shear stress, please refer to [link to relevant documentation]. Figure 4 As shown. Figure 4 In the figure, the horizontal axis represents the normalized mean shear stress. t a / s u DSS The vertical axis represents the normalized cyclic shear stress. t cy / s u DSS The solid circles represent data obtained from conventional cyclic DSS experiments, showing data including the number of cycles (…). N The average shear strain under ) c a and cyclic shear strain c cy The vertical black solid line represents a specific average shear strain. c a ( c aThe contour lines represent the values ​​of 0.05%, 0.1%, 0.25%, 0.5%, 1%, 2.5%, 5%, and 15%; the horizontal black solid lines represent specific cyclic shear strains. c cy ( c cy The contour lines are defined as follows: (0.05%, 0.1%, 0.25%, 0.5%, 1%, 2.5%, 5%, 15%). The bold black solid line represents the soil failure envelope for that number of cycles. Tests exceeding this line's range are considered failures. This line is taken from the contour lines corresponding to the number of cycles in the failure cycle contour map. The cross-shaped points are assumed interpolation prediction points. By interpolating the contour lines in this contour map, the average shear strain at the predicted point (cross-shaped point) for that number of cycles can be predicted. c a and cyclic shear strain c cy .

[0041] Step 3: The mechanical response of the saturated soil under elliptical path cyclic loading conditions needs to be reflected by a cyclic single shear (DSS) test with the loading direction varying around the mean direction. The DSS test requires a testing device capable of simultaneously applying cyclic loads in two mutually perpendicular directions (x-axis and y-axis) in the horizontal plane. The x-axis and y-axis loads need to be controlled independently. This is achieved by setting the reference values ​​and amplitudes of the loads on both shear axes (x-axis and y-axis) to the same value, and by setting the phase difference Δ between the cyclic loads on the x-axis and y-axis. f To achieve cyclic loading of saturated soil under an elliptical path.

[0042] The cyclic single shear (DSS) test with the loading direction varying around the average direction described above has the following characteristics: A) The loading path is elliptical, with its major axis along the 45° direction; B) The reference value of the load determines the position of the ellipse center; C) The magnitude of the cyclic load determines the major axis of the ellipse; D) Phase difference Δ f This determines the minor axis of the ellipse.

[0043] For a schematic diagram of a typical shear load setup on two mutually perpendicular shear axes (x-axis and y-axis) in a cyclic single shear (DSS) test with the loading direction varying about the mean direction, please refer to [link to diagram]. Figure 5 As shown. Figure 5 In the middle, the horizontal axis represents time. sThe vertical axis represents the shear load; the solid black line represents the cyclic shear load applied on the x-axis; the dashed black line represents the cyclic shear load applied on the y-axis; the nodes of the solid and dashed black lines have the same vertical axis position, waveform, and amplitude, with only a phase difference Δ between them. f The gray dashed lines correspond to the ordinate positions of the nodes, crests, and troughs of the cyclic shear load along the x and y axes, respectively. Figure 5 The method shown applies cyclic shear loads along the x and y axes to achieve the aforementioned elliptical path cyclic loading.

[0044] For a schematic diagram of the elliptical distribution of shear stress in the shear stress plane space during a cyclic single shear (DSS) test where the loading direction varies around the average direction, please refer to [link to diagram]. Figure 6 As shown. Figure 6 In the diagram, the horizontal axis represents the shear load on the x-axis; the vertical axis represents the shear load on the y-axis; the solid black line represents the complete loading path of the elliptical cyclic loading; the black arrows indicate the direction of the cyclic loading; and the gray dashed lines represent the two tangents between the origin and the elliptical loading path, with the angle between the two tangents being the shear stress ellipse angle of the elliptical cyclic loading. Figure 6 The loading process of the above-mentioned elliptical path cyclic loading in shear stress space is shown.

[0045] Furthermore, based on the characteristics of cyclic single shear (DSS) tests where the loading direction varies around the average direction, a mechanical parameter system for saturated soil under elliptical path cyclic loading conditions is established. The complete parameter system specifically includes angle and phase difference parameters, several shear stress parameters, several shear strain parameters, pore water pressure parameters, and soil failure criteria. Details are as follows: The angle parameter is the shear stress ellipse angle. i τ,ellipse , is defined as the angle between the two tangents drawn from the origin to the shear stress ellipse in a unidirectional cyclic loading test (defined as when the mean shear stress in the resultant direction exceeds the main cyclic shear stress).

[0046] Phase difference Δ f It is then defined as the phase difference between the cyclic shear stresses on two mutually perpendicular horizontal shear axes.

[0047] Shear stress parameters include shear stress in the resultant direction. t Mean shear stress t a Main cyclic shear stress t cy,major Secondary cyclic shear stress t cy,minor The specific shear stress parameter is defined as follows: in: t (x) and t (y) These are the shear stress components applied along the x-axis and y-axis, respectively. t max and t min These represent the maximum and minimum shear stresses in the resultant direction during a cycle; t a(x) and t a(y) The average shear stresses on the x-axis and y-axis are respectively represented; while R τ Defined as t cy,major and t cy,minor The ratio of the length to the width of the shear stress ellipse is the aspect ratio of the shear stress ellipse.

[0048] Through mathematical derivation, R τ Phase difference (Δ) of cyclic shear stress between the two shear axes f The relationship between them is: It should be noted that, despite the phase difference, the above formula is only valid when the same combination of average and cyclic loads is applied to the x-axis and y-axis.

[0049] When the resultant shear stress in the experiment is simplified to a direction along a 45° angle with the x-axis, in the experiment t a(x) = t a(y) and t cy(x) = t cy(y) At this point, the average shear stress t a and main cyclic shear stress t cy,major It can be simplified to: therefore, t cy,major / t a It can be expressed by the following formula: The angle enclosed by the shear stress ellipse ( i τ,ellipse Then it can be passed t a(x) , t cy(x) and Δ f The calculation is as follows: It should be noted that the above formula only applies to unidirectional circular loading (i.e., ... t a > t cy,major (Time) test. For bidirectional cyclic loading test (i.e. t a ≤ t cy,major When, the angle enclosed by the shear stress ellipse is 360°.

[0050] To comprehensively consider the mechanism of cyclic shear stress in a cyclic single shear (DSS) test where the loading direction varies around the average direction, a resultant cyclic shear stress is defined based on the definitions of primary cyclic shear stress and secondary cyclic shear stress. t cy(syn) The formula for defining this parameter is: t cy(syn) This is not the actual shear stress experienced by the soil at any given moment within a cycle. This parameter is a synthetic parameter used to capture the influence of sub-cycle shear stress. t cy(syn) It can be done t cy,major and Δ f The calculation yielded: For a schematic diagram illustrating the definition of shear stress and angular parameters in the shear stress plane space during a cyclic single shear (DSS) test with loading direction varying around the average direction, please refer to [link to diagram]. Figure 7 As shown.

[0051] Shear strain parameters include shear strain in the resultant direction. c Mean shear strain c a Main circulation shear strain c cy,major Secondary cyclic shear strain c cy,minor Permanent shear strain c pThe residual shear strain is defined as the shear stress on the y-axis returning to its mean shear stress value (i.e., at the end of a complete cycle). The specific shear strain parameter is defined as follows: in: c (x) and c (y) These are the shear strain components applied along the x-axis and y-axis, respectively; c max and c min These are defined as the maximum and minimum shear strain in the resultant direction during a loading cycle, respectively. c a(x) and c a(y) The average shear strains on the x-axis and y-axis are respectively represented; while A γ,ellipse This is the area enclosed by the shear strain ellipse.

[0052] Combined cyclic shear stress t cy(syn) Corresponding combined cyclic shear strain c cy(syn) Defined as: For a schematic diagram illustrating the definition of shear strain parameters in the shear strain plane space during a cyclic single shear (DSS) test with loading direction varying around the mean direction, please refer to [link to relevant documentation]. Figure 8 As shown.

[0053] according to t cy(syn) and c cy(syn) Definition of cyclic shear modulus G (syn) Defined as: Accumulated excess pore water pressure u p Defined as the end of each loop ( t = t a The cumulative excess pore water pressure.

[0054] In marine geotechnical engineering, when the average shear strain ( c a ) or cyclic shear strain ( c cy When the average shear strain reaches 15% (whichever occurs first), the soil is considered to have reached a failure state under cyclic loading. The mechanical parameter system for saturated soil under elliptical path cyclic loading conditions described in step S3 employs a similar failure criterion: when the average shear strain ( c a ) or combined cyclic shear strain ( c cy(syn) When the soil reaches 15%, it is considered to have reached a state of failure and damage.

[0055] Step 4: Based on the experimental characteristics and defined parameter system, the concept of equivalent cyclic shear stress parameter for cyclic single shear (DSS) tests where the loading direction varies around the average direction is further proposed. A prediction method for the mechanical response of cyclic single shear (DSS) tests where the loading direction varies around the average direction is constructed, specifically involving the equivalent cyclic shear stress. t cy,eq and correction factor f mod The expression is as follows: Furthermore, based on the settings parameters of the cyclic single shear (DSS) test, which measures the variation of the loading direction of the saturated soil around the mean direction, the parameters are determined as follows: t a / s u DSS , t cy,major / s u DSS and Δ f The equivalent cyclic shear stress of the test to be predicted is obtained by calculating using the above formula. t cy,eq .

[0056] Step 5: Combine the shear strength of the saturated soil obtained in Step 1. s u DSS The average shear stress in step 3 t a Combined cyclic shear stress t cy(syn) and phase difference Δ f Definition; Equivalent cyclic shear stress in step 4 t cy,eq The calculation method is as follows. The equivalent normalized combined shear stress of the experiment to be predicted is obtained. t a / s u DSS and t cy,eq / s u DSS ).

[0057] Furthermore, based on the equivalent normalized combined shear stress ( t a / s u DSS and t cy,eq / s u DSS The number of failure cycles of saturated soil under elliptical path cyclic loading conditions with preset parameters is obtained by interpolation in the conventional failure contour map. N f The predicted value.

[0058] The number of failure cycles of saturated soil under elliptical path cyclic loading conditions with preset parameters is obtained by interpolation in the conventional failure contour map. N f For a diagram illustrating the method for predicting values, please refer to [link / reference]. Figure 2 As shown.

[0059] Step 6: Based on the equivalent normalized combined shear stress ( t a / s u DSS , t cy,eq / s u DSS (and the number of failure cycles predicted in step 5) N f Interpolation prediction of excess pore water pressure during the entire elliptical path cyclic loading process was performed using conventional pore pressure contour maps. u p The cumulative process.

[0060] Furthermore, in step 6, the conventional pore pressure contour map uses effective consolidation stress. s vc 'Normalized permanent pore water pressure, i.e. u p / s vc '; The effective consolidation stress can be calculated based on the thickness of the overlying soil layer and the unit weight of the soil, and is a known parameter; the normalized permanent pore water pressure is obtained by interpolation using pore pressure contour maps. u p / s vc Then, combined with the known effective consolidation stress of the soil... s vcThe required cumulative excess pore water pressure can then be calculated.

[0061] Interpolation prediction of excess pore water pressure during elliptical path cyclic loading in conventional pore pressure contour maps u p For a schematic diagram of the accumulation process, please refer to [link / reference]. Figure 3 As shown.

[0062] Step 7: Based on the equivalent normalized combined shear stress ( t a / s u DSS , t cy,eq / s u DSS (and the number of failure cycles predicted in step 5) N f The average shear strain during the entire cyclic loading process along an elliptical path was predicted by interpolation in the conventional strain contour map. c a Combined Cyclic Shear Strain c cy(syn) Its development history.

[0063] Interpolation prediction of the average shear strain during the entire cyclic loading process of an elliptical path in a conventional strain contour map. c a Combined Cyclic Shear Strain c cy(syn) For a schematic diagram of the development process, please refer to [link / reference]. Figure 4 As shown.

[0064] Example 2: Corresponding to the method for predicting the mechanical response of saturated soil under elliptical path cyclic loading conditions described in Embodiment 1 above, this embodiment provides a device for predicting the mechanical response of saturated soil under elliptical path cyclic loading conditions, which may include: The parameter input module is used to acquire and input the strength parameters of saturated soil, the results of single shear axis cyclic loading single shear test, and the mechanical parameter system of saturated soil under elliptical path cyclic loading conditions; The module for establishing contour maps of saturated soil under normal cycles is used to create contour maps of saturated soil under normal cycles, including contour maps of failure cycle count, average shear strain and cyclic shear strain, and normalized permanent pore water pressure. The data processing and prediction module is used to process the mechanical parameter system to obtain the equivalent normalized combined shear stress, and based on the equivalent normalized combined shear stress, to predict the number of failure cycles in the conventional cyclic contour map of the saturated soil using an interpolation method. Nf pore water pressure u p The evolutionary process and mean shear strain c a Combined Cyclic Shear Strain c cy(syn) The evolutionary process.

[0065] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the devices, modules, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0066] In the above embodiments, the descriptions of each embodiment have different focuses. For parts that are not described in detail or recorded in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0067] Example 3: This embodiment provides an electronic device. For ease of explanation, only the parts related to the embodiments of this application are shown.

[0068] The electronic device of this embodiment includes a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the steps of the method for predicting the mechanical response of saturated soil under elliptical path cyclic loading conditions as described in Embodiment 1.

[0069] For example, the computer program may be divided into one or more modules / units, which are stored in the memory and executed by the processor to complete this application. The one or more modules / units may be a series of computer program instruction segments capable of performing a specific function, which describe the execution process of the computer program in the electronic device.

[0070] The electronic device may include, but is not limited to, computing devices such as desktop computers, laptops, handheld computers, and servers. Those skilled in the art will understand that the electronic device may include more or fewer components than described above, or a combination of certain components, or different components; for example, the electronic device may also include input / output devices, network access devices, buses, etc.

[0071] The processor can be a Central Processing Unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor can be a microprocessor or any conventional processor.

[0072] The memory can be an internal storage unit of the electronic device, such as a hard drive or RAM. The memory can also be an external storage device, such as a plug-in hard drive, Smart Media Card (SMC), Secure Digital (SD) card, or Flash Card. Furthermore, the memory can include both internal and external storage units. The memory is used to store the computer program and other programs and data required by the electronic device. The memory can also be used to temporarily store data that has been output or will be output.

[0073] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the above-described division of functional units and modules is merely an example. In practical applications, the above functions can be assigned to different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiments can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit. Furthermore, the specific names of the functional units and modules are only for easy differentiation and are not intended to limit the scope of protection of this application. The specific working process of the units and modules in the above system can be referred to the corresponding process in the foregoing method embodiments, and will not be repeated here.

[0074] In the above embodiments, the descriptions of each embodiment have different focuses. For parts that are not described in detail or recorded in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0075] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0076] In the embodiments provided in this application, it should be understood that the disclosed devices / electronic devices and methods can be implemented in other ways. For example, the device / electronic device embodiments described above are merely illustrative. For instance, the division of modules or units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the displayed or discussed mutual couplings or direct couplings or communication connections may be through some interfaces; indirect couplings or communication connections between devices or units may be electrical, mechanical, or other forms.

[0077] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0078] Furthermore, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0079] If the integrated module / unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, all or part of the processes in the methods of the above embodiments can also be implemented by a computer program instructing related hardware. The computer program can be stored in a computer-readable storage medium, and when executed by a processor, it can implement the steps of the various method embodiments described above. The computer program includes computer program code, which can be in the form of source code, object code, executable files, or certain intermediate forms. The computer-readable storage medium can include: any entity or device capable of carrying the computer program code, a recording medium, a USB flash drive, a portable hard drive, a magnetic disk, an optical disk, a computer memory, a read-only memory (ROM), a random access memory (RAM), an electrical carrier signal, a telecommunication signal, and a software distribution medium, etc. It should be noted that the content included in the computer-readable storage medium can be appropriately added or removed according to the requirements of legislation and patent practice in the jurisdiction. For example, in some jurisdictions, according to legislation and patent practice, the computer-readable storage medium does not include electrical carrier signals and telecommunication signals.

[0080] The above description of the embodiments is provided to enable those skilled in the art to understand and use the invention. It will be apparent to those skilled in the art that various modifications can be made to these embodiments, and the general principles described herein can be applied to other embodiments without inventive effort. Therefore, the present invention is not limited to the above embodiments, and any improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the invention should be within the protection scope of the present invention.

Claims

1. A method for predicting the mechanical response of saturated soil under elliptical path cyclic loading conditions, characterized in that, Includes the following steps: S1. The strength parameters of saturated soil were obtained through indoor geotechnical tests, and a conventional cyclic contour map of saturated soil was established through single shear axis cyclic loading single shear test, including contour maps of failure cycle number, average shear strain and cyclic shear strain, and normalized permanent pore water pressure. S2. Based on the characteristics of cyclic single shear test where the loading direction changes around the average direction, establish the mechanical parameter system of saturated soil under elliptical path cyclic loading conditions; S3. Establish an equivalent cyclic shear stress method for saturated soil under elliptical path cyclic loading conditions. Based on the setting parameters of the saturated soil elliptical path cyclic loading test, calculate the cyclic shear stress equivalent to that of the conventional cyclic shear test. S4. Using equivalent normalized combined shear stress, the number of failure cycles in the experiment is predicted from the failure cycle contour map using interpolation methods. N f Predicting pore water pressure from normalized permanent pore water pressure contour maps u p The evolutionary process is used to predict the mean shear strain in the contour maps of mean shear strain and cyclic shear strain. γ a Combined Cyclic Shear Strain γ cy(syn) The evolutionary process.

2. The method for predicting the mechanical response of saturated soil under elliptical path cyclic loading conditions according to claim 1, characterized in that, In S1, the strength parameters of the saturated soil include its shear strength. s u DSS It is based on at least one single-shear axis monotonic loading single-shear test; The process of establishing a conventional cyclic contour map for saturated soil includes: A) At least five single-shear axis cyclic loading single-shear (DSS) tests, where the normalized mean shear stress τ a / s u DSS There shall be no fewer than three cyclic loading single shear tests with a value of 0; B) Select at least one non-zero normalized mean shear stress. τ a / s u DSS Conduct experiments, and each non-zero normalized mean shear stress τ a / s u DSS Conduct no fewer than two cyclic loading single shear tests; C) Based on the results of single shear axis cyclic loading single shear test, a complete set of conventional cyclic contour maps of saturated soil was drawn by interpolation and extrapolation in the corresponding coordinate space, including contour maps of failure cycle number, average shear strain and cyclic shear strain, and normalized permanent pore water pressure.

3. The method for predicting the mechanical response of saturated soil under elliptical path cyclic loading conditions according to claim 1, characterized in that, In S1, the failure cycle count contour map can be used to determine the failure envelope of the average shear strain and cyclic shear strain contour maps, as well as the normalized permanent pore water pressure contour map.

4. The method for predicting the mechanical response of saturated soil under elliptical path cyclic loading conditions according to claim 1, characterized in that, In S2, the characteristics of the cyclic single shear test include: The loading path is elliptical, with its major axis along a 45° direction; The position of the ellipse center is determined by the reference value of the load; The major axis of the ellipse is determined by the magnitude of the cyclic load; From the phase difference Δ φ Determine the minor axis of the ellipse.

5. The method for predicting the mechanical response of saturated soil under elliptical path cyclic loading conditions according to claim 4, characterized in that, In S2, the mechanical parameter system includes angle and phase difference parameters, several shear stress parameters, several shear strain parameters, pore water pressure parameters, and soil failure criteria. Among the angle and phase difference parameters, the angle parameter is the shear stress ellipse angle. θ τ,ellipse Δ is defined as the angle between two tangents drawn from the origin to the shear stress ellipse in a unidirectional cyclic loading test, with a phase difference Δ. φ It is defined as the phase difference between the cyclic shear stresses on two mutually perpendicular horizontal shear axes; The shear stress parameters include the shear stress in the resultant direction. τ Mean shear stress τ a Main cyclic shear stress τ cy,major Secondary cyclic shear stress τ cy,minor The shear stress parameters are defined as follows: ， ， ， ， in, τ (x) and τ (y) These are the shear stress components applied along the x-axis and y-axis, respectively. τ max and τ min These represent the maximum and minimum shear stresses in the resultant direction during a cycle; τ a(x) and τ a(y) The average shear stresses on the x-axis and y-axis are respectively represented; while R τ Defined as τ cy,major and τ cy,minor The ratio of the length to the width of the shear stress ellipse; The shear strain parameters include the shear strain in the resultant direction. γ Mean shear strain γ a Main circulation shear strain γ cy,major Secondary cyclic shear strain γ cy,minor They are defined as follows: ， ， ， ， in, γ (x) and γ (y) These are the shear strain components applied along the x-axis and y-axis, respectively; γ max and γ min These are defined as the maximum and minimum shear strain in the resultant direction during a loading cycle, respectively. γ a(x) and γ a(y) The average shear strain on the x-axis and y-axis are respectively represented; A γ,ellipse This is the area enclosed by the shear strain ellipse; The pore water pressure parameter is the cumulative excess pore water pressure. u p , is defined as the end of each loop, i.e. τ = τ a The cumulative excess pore water pressure over time; The criterion for judging soil failure is: when the average shear strain... γ a Or combined cyclic shear strain γ cy(syn) When the soil reaches 15%, it is considered to have reached a state of failure, including the combined cyclic shear strain. γ cy(syn) Defined as: 。 6. The method for predicting the mechanical response of saturated soil under elliptical path cyclic loading conditions according to claim 5, characterized in that, In S3, the equivalent cyclic shear stress τ cy,eq The formula for calculation is: ， ， 。 7. The method for predicting the mechanical response of saturated soil under elliptical path cyclic loading conditions according to claim 6, characterized in that, In S4, the equivalent normalized combined shear stress includes τ a / s u DSS and τ cy,eq / s u DSS ; The number of failure cycles N f The prediction process is as follows: based on the equivalent normalized combined shear stress τ a / s u DSS and τ cy,eq / s u DSS Interpolation is performed on the conventional failure contour map to obtain the number of failure cycles in a cyclic single shear test where the loading direction varies around the average direction. N f The predicted value; The pore water pressure u p The prediction process for the evolution process is as follows: based on the equivalent normalized combined shear stress τ a / s u DSS and τ cy,eq / s u DSS and the predicted number of failure cycles. N f Interpolation prediction of excess pore water pressure during the entire elliptical path cyclic loading process was performed using a normalized permanent pore water pressure contour map. u p The process of accumulation; The mean shear strain γ a Combined Cyclic Shear Strain γ cy(syn) The prediction process for the development process is as follows: based on the equivalent normalized combined shear stress τ a / s u DSS , τ cy,eq / s u DSS and the predicted number of failure cycles. N f Interpolation was used to predict the average shear strain during the entire elliptical path cyclic loading process from the contour maps of average shear strain and cyclic shear strain. γ a Combined Cyclic Shear Strain γ cy(syn) Its development history.

8. The method for predicting the mechanical response of saturated soil under elliptical path cyclic loading conditions according to claim 7, characterized in that, Normalized permanent pore water pressure contour maps are constructed using effective consolidation stress. σ vc 'Normalized permanent pore water pressure, i.e. u p / σ vc ', among which, effective consolidation stress σ vc The normalized permanent pore water pressure can be calculated based on the thickness of the overlying soil layer and the unit weight of the soil. This can be obtained by interpolating the normalized permanent pore water pressure contour map. u p / σ vc Then, combined with the known effective consolidation stress of the soil... σ vc That is, to calculate the required cumulative excess pore water pressure. u p Predicted value.

9. A device for predicting the mechanical response of saturated soil under elliptical path cyclic loading conditions, characterized in that, For implementing the prediction method as described in claim 1, the prediction apparatus includes: The parameter input module is used to acquire and input the strength parameters of saturated soil, the results of single shear axis cyclic loading single shear test, and the mechanical parameter system of saturated soil under elliptical path cyclic loading conditions; The module for establishing contour maps of saturated soil under normal cycles is used to create contour maps of saturated soil under normal cycles, including contour maps of failure cycle count, average shear strain and cyclic shear strain, and normalized permanent pore water pressure. The data processing and prediction module is used to process the mechanical parameter system to obtain the equivalent normalized combined shear stress, and based on the equivalent normalized combined shear stress, to predict the number of failure cycles in the conventional cyclic contour map of the saturated soil using an interpolation method. N f pore water pressure u p The evolutionary process and mean shear strain γ a Combined Cyclic Shear Strain γ cy(syn) The evolutionary process.

10. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by the processor, it implements the steps of the prediction method as described in claim 1.

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