Correction method of undrained shear strength of soft clay obtained by self-drilling lateral pressure test

Abstract

This application discloses a method, apparatus, equipment, and storage medium for correcting the undrained shear strength of soft clay obtained from a self-drilling pressuremeter test. The method includes collecting undrained shear strength and pore pressure dissipation data of soft clay at multiple test points obtained through self-drilling pressuremeter tests, and undrained shear strength of soft clay at multiple test points obtained through vane tests. For the current test point, the degree to which the undrained shear strength of the soft clay at the current test point is underestimated is determined, and the consolidation state parameters of the current test point are determined. Based on the correspondence between the degree of underestimation of the undrained shear strength of the soft clay and the consolidation state parameters, a correction coefficient for the undrained shear strength of the soft clay at the target test point is determined. This correction coefficient is used to correct the undrained shear strength of the soft clay at the target test point obtained through the self-drilling pressuremeter test. This method can improve the accuracy of the undrained shear strength of soft clay obtained from self-drilling pressuremeter tests.

Description

Technical Field

[0001] This application relates to the field of in-situ testing technology in geotechnical engineering, and more specifically, to a method, apparatus, equipment, and storage medium for correcting the undrained shear strength of soft clay obtained by a self-drilling pressuremeter test. Background Technology

[0002] Soft clay, as a geological material, has low strength and low natural bearing capacity. When the overburden load on the foundation is too large, the cumulative deformation of the foundation will gradually increase, posing a huge safety hazard to high-speed rail operation and related projects. The pressuremeter test can obtain a variety of important soil mechanical parameters, apply large loads to the soil, and simulate the actual stress conditions of the soil during engineering construction and use.

[0003] Pressuremeter tests include pre-drilled pressuremeter tests and self-drilled pressuremeter tests. Compared to pre-drilled pressuremeter tests, self-drilled pressuremeter tests can drill to the test point independently, significantly reducing disturbance to the soil around the borehole. This reduces the likelihood of decreased lateral pressure and unloading of the borehole wall, resulting in higher accuracy and better reliability. Therefore, self-drilled pressuremeter tests are suitable for soft cohesive soils.

[0004] The undrained shear strength of soft clay can be obtained using both theoretical and experimental methods, but there are often discrepancies between the theoretical and experimental results, and the reasons for these discrepancies are not yet fully understood.

[0005] Currently, there is a discrepancy between the undrained shear strength of soft clay obtained through self-drilling pressuremeter tests (test results) and the theoretical results of the undrained shear strength of soft clay, resulting in very low accuracy of the undrained shear strength of soft clay obtained through self-drilling pressuremeter tests. Summary of the Invention

[0006] To address at least one deficiency or improvement requirement of the prior art, the present invention provides a method, apparatus, equipment, and storage medium for correcting the undrained shear strength of soft clay obtained by a self-drilling pressuremeter test. By taking into account the degree of consolidation of the soft clay and the geometric size effect of the pressuremeter, the accuracy of the undrained shear strength of soft clay obtained by the self-drilling pressuremeter test can be improved.

[0007] To achieve the above objectives, according to a first aspect of the present invention, a method for correcting the undrained shear strength of soft clay obtained by a self-drilling pressuremeter test is provided, the method comprising:

[0008] Data on undrained shear strength and pore pressure dissipation of soft clay at multiple test points were collected through self-drilling pressuremeter tests, and data on undrained shear strength of soft clay at multiple test points were collected through vane tests.

[0009] For the current test site, the degree to which the undrained shear strength of the soft clay at the current test site is underestimated is determined by the ratio of the undrained shear strength of the soft clay at the current test site obtained by the self-drilling pressure meter test to the undrained shear strength of the soft clay at the current test site obtained by the vane test.

[0010] For the current test site, the consolidation state parameters of the current test site are determined based on the pore pressure dissipation data of the current test site obtained through the self-drilling pressure difference test.

[0011] Based on the degree of underestimation of the undrained shear strength of soft clay at multiple test sites and the corresponding consolidation state parameters, the correspondence between the degree of underestimation of the undrained shear strength of soft clay and the consolidation state parameters was determined.

[0012] Based on the correspondence between the degree of underestimation of the undrained shear strength of soft clay and the consolidation state parameters, a correction factor for the undrained shear strength of soft clay at the target test site is determined. This correction factor is used to correct the undrained shear strength of soft clay at the target test site obtained through a self-drilling pressuremeter test.

[0013] Furthermore, based on the correspondence between the degree of underestimation of the undrained shear strength of soft clay and the consolidation state parameters, the correction factor for the undrained shear strength of soft clay at the target test site is determined, including: determining the degree of overestimation of the undrained shear strength of soft clay at the target test site based on the geometric size effect of the pressuremeter; and determining the correction factor for the undrained shear strength of soft clay at the target test site based on the correspondence between the degree of overestimation of the undrained shear strength of soft clay, the degree of underestimation of the undrained shear strength of soft clay, and the consolidation state parameters.

[0014] Furthermore, for the current test site, the degree to which the undrained shear strength of the soft clay at the current test site is underestimated is determined based on the ratio of the undrained shear strength of the soft clay at the current test site obtained through the self-drilling pressuremeter test to the undrained shear strength of the soft clay at the current test site obtained through the vane test. This includes: for the current test site, determining the ratio of the undrained shear strength of the soft clay at the current test site obtained through the self-drilling pressuremeter test to the undrained shear strength of the soft clay at the current test site obtained through the vane test, as the test ratio for the current test site; determining the maximum test ratio based on the test ratios of all test sites; and normalizing the test ratio for the current test site based on the maximum test ratio to obtain the degree to which the undrained shear strength of the soft clay at the current test site is underestimated.

[0015] Furthermore, for the current test site, based on the pore pressure dissipation data obtained through the self-drilling pressuremeter test, the consolidation state parameters of the current test site are determined, including: calculating the consolidation state parameters of the current test site according to the following formula:

[0016]

[0017] Where U is the consolidation state parameter at the current test site, u f u represents the peak pore pressure at the initial moment when penetration stops and the pore pressure dissipation test begins at a certain measuring point in the current test site. t u represents the pore pressure at the soil yielding time during a self-drilling pressuremeter test. w This represents the static water pressure at the current test point.

[0018] Furthermore, the correlation between the degree to which the undrained shear strength of soft clay is underestimated and the consolidation state parameters includes a linear relationship.

[0019] Furthermore, based on the geometrical effect of the pressuremeter, the degree to which the undrained shear strength of the soft clay at the target test site is overestimated is determined, including: calculating the degree to which the undrained shear strength of the soft clay at the target test site is overestimated according to the following formula:

[0020]

[0021] Wherein, K2 represents the degree to which the undrained shear strength of the soft clay at the target test point is overestimated, Cu represents the undrained shear strength of the soft clay at the target test point obtained by a self-drilling pressuremeter test when the ratio of the length of the pressuremeter to its diameter is infinite (∞), Cu6 represents the undrained shear strength of the soft clay at the target test point obtained by a self-drilling pressuremeter test when the ratio of the length of the pressuremeter to its diameter is 6, and G represents the shear modulus of the soil, obtained from the pressuremeter curve, which is obtained by conducting a self-drilling pressuremeter test on the target test point.

[0022] Furthermore, based on the correlation between the degree to which the undrained shear strength of soft clay at the target test site is overestimated, the degree to which the undrained shear strength of soft clay is underestimated, and the consolidation state parameters, the correction factor for the undrained shear strength of soft clay at the target test site is determined, including:

[0023] K1 = 2.42U - 2.04

[0024] Where K is the correction factor for the undrained shear strength of soft clay at the target test point, K2 is the degree to which the undrained shear strength of soft clay at the target test point is overestimated, U is the consolidation state parameter of the target test point, and K1 is the degree to which the undrained shear strength of soft clay at the target test point is underestimated.

[0025] According to a second aspect of the present invention, a correction device for the undrained shear strength of soft clay obtained by a self-drilling pressuremeter test is also provided, comprising:

[0026] The data acquisition module is configured to acquire undrained shear strength and pore pressure dissipation data of soft clay at multiple test points obtained through self-drilling pressuremeter tests, and undrained shear strength data of soft clay at multiple test points obtained through vane tests.

[0027] The first determining module is configured to, for the current test point, determine the degree to which the undrained shear strength of the soft clay at the current test point is underestimated based on the ratio of the undrained shear strength of the soft clay at the current test point obtained by the self-drilling pressure meter test to the undrained shear strength of the soft clay at the current test point obtained by the vane test.

[0028] The second determining module is configured to determine the consolidation state parameters of the current test point based on the pore pressure dissipation data of the current test point obtained through the self-drilling pressure difference test.

[0029] The third determination module is configured to determine the correspondence between the underestimation of the undrained shear strength of soft clay and the consolidation state parameters based on the degree of underestimation of the undrained shear strength of soft clay at multiple test sites and the corresponding consolidation state parameters.

[0030] The correction module is configured to determine a correction coefficient for the undrained shear strength of soft clay at the target test point based on the correspondence between the degree to which the undrained shear strength of soft clay is underestimated and the consolidation state parameters. The correction coefficient is used to correct the undrained shear strength of soft clay at the target test point obtained by the self-drilling pressuremeter test.

[0031] According to a third aspect of the present invention, a computer device is also provided, comprising at least one processing unit and at least one storage unit, wherein the storage unit stores a computer program that, when executed by the processing unit, causes the processing unit to perform the steps of any of the above methods.

[0032] According to a fourth aspect of the invention, a storage medium is also provided, which stores a computer program executed by a computer device, which, when run on the computer device, causes the computer device to perform the steps of any of the above methods.

[0033] In summary, compared with the prior art, the above-described technical solutions conceived by this invention can achieve the following beneficial effects:

[0034] (1) The present invention provides a method for correcting the undrained shear strength of soft clay obtained by self-drilling pressuremeter test. By conducting self-drilling pressuremeter test and vane test on multiple test points respectively, the undrained shear strength of soft clay at multiple test points under the two tests is obtained. Based on the ratio of the undrained shear strength of soft clay at each test point under the two tests, the degree to which the undrained shear strength of soft clay at each test point is underestimated is determined. Combined with the consolidation state parameters of each test point, the correspondence between the degree to which the undrained shear strength of soft clay is underestimated and the consolidation state parameters is determined. Then, based on the correspondence, the correction coefficient of the undrained shear strength of soft clay at the target test point can be determined. The correction coefficient is used to correct the undrained shear strength of soft clay at the target test point obtained by self-drilling pressuremeter test. Since the correction coefficient is related to the degree of consolidation of soft clay, the accuracy of the undrained shear strength of soft clay at the target test point obtained by self-drilling pressuremeter test can be improved.

[0035] (2) The correction method for the undrained shear strength of soft clay obtained by self-drilling pressuremeter test provided by the present invention is adopted. Based on the geometric size effect of the pressuremeter, the degree to which the undrained shear strength of soft clay at the target test point is overestimated is determined. According to the correspondence between the degree to which the undrained shear strength of soft clay at the target test point is overestimated, the degree to which the undrained shear strength of soft clay at the target test point is underestimated and the consolidation state parameters, the correction coefficient of the undrained shear strength of soft clay at the target test point is determined. The correction coefficient is used to correct the undrained shear strength of soft clay at the target test point obtained by self-drilling pressuremeter test. Since the correction coefficient is related to the degree of consolidation of soft clay and the geometric size effect of the pressuremeter, the accuracy of the undrained shear strength of soft clay at the target test point obtained by self-drilling pressuremeter test can be improved. Attached Figure Description

[0036] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0037] Figure 1 A schematic flowchart illustrating a method for correcting the undrained shear strength of soft clay obtained by a self-drilling pressuremeter test, as provided in an embodiment of this application.

[0038] Figure 2 A schematic diagram showing the ratio of undrained shear strength of soft clay obtained by self-drilling pressuremeter test and vane test, respectively, as a function of consolidation state parameters, provided for embodiments of this application.

[0039] Figure 3 A schematic diagram illustrating the degree to which the undrained shear strength of soft clay obtained by a self-drilling pressure meter test is underestimated as a function of consolidation state parameters, provided for an embodiment of this application.

[0040] Figure 4 A schematic diagram of a device for correcting the undrained shear strength of soft clay obtained by a self-drilling pressure meter test, provided for an embodiment of this application;

[0041] Figure 5 This is a schematic diagram of the structure of a computer device provided in an embodiment of this application. Detailed Implementation

[0042] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0043] The terms "first," "second," "third," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish different objects, not to describe a specific order. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or apparatus that includes a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to these processes, methods, products, or apparatuses.

[0044] like Figure 1 As shown, a method for correcting the undrained shear strength of soft clay obtained from a self-drilling pressuremeter test is provided. This method can be executed by a terminal or by a server communicating with the terminal via a network. The terminal can be, but is not limited to, various personal computers, laptops, smartphones, tablets, IoT devices, and portable wearable devices. The server can be a standalone server or a server cluster consisting of multiple servers. The method is illustrated using a terminal as an example, including the following steps:

[0045] Step 101: Collect data on the undrained shear strength and pore pressure dissipation of soft clay at multiple test points obtained through self-drilling pressuremeter tests, and the undrained shear strength of soft clay at multiple test points obtained through vane tests.

[0046] Among them, the test point is the location where the undrained shear strength of soft clay needs to be measured, also known as the test site.

[0047] Pore ​​pressure dissipation data, obtained from self-drilling pressuremeter tests, are used to evaluate the degree of consolidation of soft clay at the test site. Pore pressure dissipation data includes the peak pore pressure (u) at the initial moment when penetration stops and the pore pressure dissipation test begins at a specific measuring point within the test site. f ), the pore pressure at the yield time of the soil during the self-drilling pressuremeter test (u) t ), static water pressure at the test point (u) w ).

[0048] For a certain test point, the undrained shear strength (Cu1) and pore pressure dissipation data of the soft clay at that test point were measured by self-drilling pressuremeter test, and the undrained shear strength (Cu2) of the soft clay at that test point was measured by vane test.

[0049] Step 102: For the current test point, determine the degree to which the undrained shear strength of the soft clay at the current test point is underestimated based on the ratio of the undrained shear strength of the soft clay at the current test point obtained by the self-drilling pressuremeter test to the undrained shear strength of the soft clay at the current test point obtained by the vane test.

[0050] The current test site is any one of multiple test sites. The degree to which the undrained shear strength of the soft clay at the current test site is underestimated refers to the degree to which the undrained shear strength of the soft clay at the current test site is underestimated as obtained through a self-drilling pressuremeter test.

[0051] For example, for the current test point, the ratio of the undrained shear strength of the soft clay at the current test point obtained by the self-drilling pressuremeter test to the undrained shear strength of the soft clay at the current test point obtained by the vane test is determined as the test ratio (ω, where ω = Cu1 / Cu2) for the current test point; based on the test ratios of all test points, the maximum test ratio (ω) is determined. m Based on the maximum test ratio, the test ratio of the current test point is normalized to obtain the degree to which the undrained shear strength of the soft clay at the current test point is underestimated (K1).

[0052] Normalize the test ratio at the current test site, including: calculating the difference (ω) between the maximum test ratio and the test ratio at the current test site. m -ω); the difference (ω) m -ω) and the ratio of the maximum test value ω m The ratio of ω to ω represents the degree to which the undrained shear strength of the soft clay at the current test site is underestimated, K1, i.e.: K1=(ω m -ω) / ω m .

[0053] Step 103: For the current test point, determine the consolidation state parameters of the current test point based on the pore pressure dissipation data obtained through the self-drilling pressure difference test.

[0054] Among them, the consolidation state parameter (U) is used to quantitatively evaluate the degree of consolidation of soft clay. The larger the consolidation state parameter, the higher the degree of consolidation of soft clay.

[0055] Step 104: Based on the degree to which the undrained shear strength of soft clay was underestimated at multiple test sites and the corresponding consolidation state parameters, determine the correspondence between the degree to which the undrained shear strength of soft clay was underestimated and the consolidation state parameters.

[0056] Among them, the relationship between the degree to which the undrained shear strength of soft clay is underestimated and the consolidation state parameters is linear.

[0057] For example, a two-dimensional coordinate system is established. The horizontal axis of the two-dimensional coordinate system represents the consolidation state parameter U at the test point, and the vertical axis represents the degree to which the undrained shear strength of the soft clay at the test point is underestimated, K1. Based on the degree to which the undrained shear strength of the soft clay at each test point is underestimated and the consolidation state parameter at that test point, a point is determined in the two-dimensional coordinate system, resulting in multiple points. Based on these multiple points, a straight line is fitted to represent the correspondence between the degree to which the undrained shear strength of the soft clay is underestimated and the consolidation state parameter.

[0058] Step 105: Based on the correspondence between the degree of underestimation of the undrained shear strength of soft clay and the consolidation state parameters, determine the correction coefficient of the undrained shear strength of soft clay at the target test point. The correction coefficient is used to correct the undrained shear strength of soft clay at the target test point obtained by the self-drilling pressuremeter test.

[0059] The target test point is the location where the undrained shear strength of the soft clay needs to be measured. It can be any one of the multiple test points in step 101, or any other location other than the multiple test points in step 101.

[0060] For example, a correction factor (K) is used to adjust the undrained shear strength (Cu) of soft clay at the target test site obtained by self-drilling pressuremeter tests. 测 The correction is made, including calculating the corrected undrained shear strength of the soft clay at the target test site according to the following formula:

[0061] Cu 实 =KCu 测

[0062] In the above formula, Cu 测K represents the undrained shear strength of the soft clay at the target test point obtained through a self-drilling pressuremeter test, and Cu represents the correction factor for the undrained shear strength of the soft clay at the target test point. 实 The corrected target test point is the undrained shear strength of soft clay.

[0063] Cu 实 Cu 测 The corrected value is closer to the true value of the undrained shear strength of soft clay at the target test point, meaning the corrected undrained shear strength of soft clay at the target test point is more accurate.

[0064] In this embodiment, self-drilling pressuremeter tests and vane tests were conducted at multiple test points to obtain the undrained shear strength of soft clay at these test points under both tests. Based on the ratio of the undrained shear strength of soft clay at each test point under these two tests, the degree to which the undrained shear strength of soft clay at each test point was underestimated was determined. Combined with the consolidation state parameters of each test point, the correspondence between the degree of underestimation of the undrained shear strength of soft clay and the consolidation state parameters was determined. Based on this correspondence, a correction coefficient for the undrained shear strength of soft clay can be determined. Since the correction coefficient for the undrained shear strength of soft clay is related to the degree of consolidation of the soft clay, correcting the undrained shear strength of soft clay obtained from the self-drilling pressuremeter test using this correction coefficient can improve the accuracy of the undrained shear strength of soft clay obtained from the self-drilling pressuremeter test.

[0065] In one embodiment, step 105 above, determining the correction coefficient for the undrained shear strength of soft clay at the target test point based on the correspondence between the degree of underestimation of the undrained shear strength of soft clay and the consolidation state parameters, includes: determining the degree of overestimation of the undrained shear strength of soft clay at the target test point based on the geometric size effect of the pressuremeter; and determining the correction coefficient for the undrained shear strength of soft clay at the target test point based on the correspondence between the degree of overestimation of the undrained shear strength of soft clay at the target test point, the degree of underestimation of the undrained shear strength of soft clay, and the consolidation state parameters.

[0066] The geometric size effect of the pressuremeter refers to the fact that data analysis methods for data obtained through self-drilling pressuremeter tests assume the pressuremeter to be infinitely long, i.e., the ratio of the pressuremeter's length to its diameter is infinite (∞). In reality, the length of the pressuremeter is approximately 6 times its diameter. The overestimation of the undrained shear strength of the soft clay at the target test site refers to the degree to which the undrained shear strength of the soft clay at the target test site obtained through self-drilling pressuremeter tests is overestimated.

[0067] In this embodiment, based on the geometrical effect of the pressuremeter, the degree to which the undrained shear strength of the soft clay at the target test point is overestimated is determined. Based on the correspondence between the degree of overestimation and underestimation of the undrained shear strength of the soft clay at the target test point and the consolidation state parameters, a correction coefficient for the undrained shear strength of the soft clay at the target test point is determined. Since the correction coefficient is related to both the degree of consolidation of the soft clay and the geometrical effect of the pressuremeter, correcting the undrained shear strength of the soft clay obtained through the self-drilling pressuremeter test using this correction coefficient can improve the accuracy of the undrained shear strength of the soft clay obtained through the self-drilling pressuremeter test.

[0068] In one embodiment, a method for correcting the undrained shear strength of soft clay obtained by a self-drilling pressuremeter test is provided, comprising the following steps:

[0069] Step 1: Conduct self-drilling pressuremeter tests at multiple test points to obtain raw data. Based on the raw data, plot the pressuremeter curve. The pressuremeter curve is used to represent the relationship between the total pressure (p) exerted by the pressuremeter on the borehole wall and the expansion volume (ΔV or ΔV / V) of the pressuremeter's expansion film.

[0070] Step 2: Using Gibson and Anderson solutions, analyze the raw data to obtain the undrained shear strength Cu of the soft clay at the current test site. The calculation formula is as follows:

[0071] p = p L +Cu[In(ΔV / V)] Formula (1)

[0072] In formula (1), p is the total pressure exerted by the pressure gauge on the orifice wall. L V is the ultimate pressure when the soil yields and reaches its ultimate state, V is the current volume of the expansion membrane of the pressure meter, and ΔV is the expansion volume of the expansion membrane of the pressure meter.

[0073] According to formula (1), the slope of the straight section of the pressure lateral curve can be obtained, that is, the slope of the straight section of the curve in the p-ΔV / V logarithmic coordinate system, which is the undrained shear strength Cu of the soft clay at the current test point.

[0074] It should be noted that when determining the undrained shear strength of soft clay through self-drilling pressuremeter tests, the Gibson and Anderson solutions are typically used to obtain the undrained shear strength, and the analytical results are often higher than those of other in-situ tests and laboratory tests. Considering that factors affecting the accuracy of self-drilling pressuremeter test results include the degree of consolidation of the soft clay and the geometric size effect of the pressuremeter, the correction method for the undrained shear strength of soft clay obtained by self-drilling pressuremeter tests provided in this embodiment further includes steps 3-5.

[0075] Step 3: Calculate the degree to which the undrained shear strength of soft clay obtained by self-drilling pressuremeter test is underestimated under the influence of the degree of consolidation of soft clay. The specific process is as follows:

[0076] Step 3a: Evaluate the degree of consolidation of the soft clay at the test site based on the pore pressure dissipation data obtained from the self-drilling pressuremeter test.

[0077] The consolidation state parameters at each test site are calculated according to the following formula (2):

[0078]

[0079] In formula (2), U is the consolidation state parameter at the test site, u f u is the peak pore pressure at the initial moment when penetration stops and the pore pressure dissipation test begins at a certain measuring point in the test site. t u represents the pore pressure at the soil yielding time during a self-drilling pressuremeter test. w The static water pressure at the test point.

[0080] Step 3b: Calculate the degree to which the undrained shear strength of soft clay obtained by the self-drilling pressuremeter test is underestimated, and establish the correspondence between the degree to which the undrained shear strength of soft clay is underestimated and the consolidation state parameters.

[0081] To investigate the influence of the degree of consolidation on the undrained shear strength of soft clay obtained by self-drilling pressuremeter tests, the ratio of the undrained shear strength of soft clay obtained by self-drilling pressuremeter tests and vane tests, Cu1 / Cu2, was fitted with the consolidation state parameter U. The analysis results are as follows: Figure 2 As shown. Figure 2 The ratio of Cu1 / Cu2 of the undrained shear strength of soft clay, obtained by self-drilling pressuremeter test and vane test respectively, is shown as a function of the consolidation state parameter U.

[0082] like Figure 2 As shown, the relationship between Cu1 / Cu2 and U is close to linear, which can be expressed as: y = -2.7788x + 3.9378. Furthermore, the reference value (R0) used to represent the goodness of fit... 2 The value of 0.947 indicates a high degree of fit. The higher the degree of fit, the more reliable the correspondence between Cu1 / Cu2 and U obtained from the fitting analysis.

[0083] The maximum value of ω = Cu1 / Cu2 among multiple test points. m Based on this, normalization is performed to obtain the degree to which the undrained shear strength of soft clay at each test point obtained through the self-drilling pressuremeter test is underestimated, K1, i.e.: K1=(ω m -ω) / ωm Fitting analysis was performed on K1 and the consolidation state parameter U. The results are shown in [link to analysis]. Figure 3 . Figure 3 This shows how the underestimation of the undrained shear strength of soft clay obtained by self-drilling pressuremeter test, K1, varies with the consolidation state parameter U.

[0084] like Figure 3 As shown, the relationship between K1 and U is close to linear, which can be expressed as: K1 = 2.417U - 2.0448. Furthermore, the reference value (R0) used to represent the goodness of fit... 2 The value of 0.9505 indicates a high degree of fit. The higher the degree of fit, the more reliable the correspondence between K1 and U obtained from the fitting analysis.

[0085] Establish the correspondence between K1 and U:

[0086] K1=2.42U-2.04 Formula (3)

[0087] This reveals the degree to which the undrained shear strength of soft clay obtained through self-drilling pressuremeter tests is underestimated under the influence of consolidation state parameters.

[0088] Step 4: Calculate the degree to which the undrained shear strength of soft clay obtained by the self-drilling pressuremeter test is overestimated under the influence of the geometric size effect of the pressuremeter.

[0089] All methods for analyzing data from self-drilling pressure gauges assume that the pressure gauge is infinitely long, meaning the ratio of its length to its diameter is infinite (∞). In reality, the length of the pressure gauge is approximately 6 times its diameter.

[0090] The following formula can be used to calculate the degree to which the undrained shear strength of soft clay at the target test site obtained through a self-drilling pressuremeter test is overestimated:

[0091]

[0092] In formula (4), K2 represents the degree to which the undrained shear strength of the soft clay at the target test point obtained by the self-drilling pressuremeter test is overestimated, Cu represents the undrained shear strength of the soft clay at the target test point obtained by the self-drilling pressuremeter test when the ratio of the length of the pressuremeter to its diameter is infinite (i.e., the undrained shear strength Cu of the soft clay at the target test point obtained according to steps 1 and 2 above), Cu6 represents the undrained shear strength of the soft clay at the target test point obtained by the self-drilling pressuremeter test when the ratio of the length of the pressuremeter to its diameter is 6, and G represents the shear modulus of the soil, which is obtained from the pressuremeter curve. The method for obtaining the pressuremeter curve is the same as in step 1 above.

[0093] In formula (4), the ratio of the soil shear modulus G to Cu6 is the hardening coefficient Ir, i.e., Ir = G / Cu6. Therefore, K2 is directly proportional to the logarithm of the hardening coefficient Ir.

[0094] Step 5: Establish the correction factor K for the undrained shear strength of soft clay at the target test point, and correct the undrained shear strength of soft clay at the target test point obtained by the self-drilling pressuremeter test using the correction factor K.

[0095] Calculate the correction factor K for the undrained shear strength of soft clay at the target test site using the following formula:

[0096]

[0097] In formula (5), K2 represents the degree to which the undrained shear strength of the soft clay at the target test point obtained by the self-drilling pressure meter test is overestimated, and K1 represents the degree to which the undrained shear strength of the soft clay at the target test point obtained by the self-drilling pressure meter test is underestimated.

[0098] Substituting formulas (3) and (4) into formula (5), we get:

[0099]

[0100] For the target test site, the corrected undrained shear strength of the soft clay is calculated according to the following formula:

[0101] Cu 实 =KCu 测 Formula (7)

[0102] In the above formula, K is the correction factor for the undrained shear strength of soft clay at the target test point, and Cu 测 To determine the undrained shear strength (also known as the test value of undrained shear strength) of soft clay at the target test point obtained through a self-drilling pressuremeter test, Cu 实 This refers to the corrected undrained shear strength of soft clay at the target test site (also known as the theoretical value of undrained shear strength).

[0103] In this embodiment, considering the influence of the degree of consolidation of soft clay and the geometric size effect of the pressuremeter, a correction coefficient and calculation formula for the undrained shear strength of soft clay obtained by the self-drilling pressuremeter test are provided. This can improve the accuracy of the test results of the self-drilling pressuremeter test, that is, improve the accuracy of the undrained shear strength of soft clay obtained by the self-drilling pressuremeter test.

[0104] Based on the same inventive concept, this application also provides a device for correcting the undrained shear strength of soft clay obtained by a self-drilling pressuremeter test, which is used to implement the correction method for the undrained shear strength of soft clay obtained by the self-drilling pressuremeter test described above. The solution provided by this device is similar to the solution described in the above method. Therefore, the specific limitations of one or more embodiments of the device for correcting the undrained shear strength of soft clay obtained by a self-drilling pressuremeter test provided below can be found in the limitations of the correction method for the undrained shear strength of soft clay obtained by the self-drilling pressuremeter test described above, and will not be repeated here.

[0105] like Figure 4 As shown, this application also provides a correction device 400 for the undrained shear strength of soft clay obtained by a self-drilling pressuremeter test, comprising: a data acquisition module 401 configured to acquire undrained shear strength and pore pressure dissipation data of soft clay at multiple test points obtained by a self-drilling pressuremeter test, and undrained shear strength of soft clay at multiple test points obtained by a vane test; a first determination module 402 configured to, for the current test point, determine the degree to which the undrained shear strength of the soft clay at the current test point is underestimated based on the ratio of the undrained shear strength of the soft clay at the current test point obtained by the self-drilling pressuremeter test to the undrained shear strength of the soft clay at the current test point obtained by the vane test; and a second determination module 403 configured to... For the current test point, based on the pore pressure dissipation data obtained through the self-drilling pressuremeter test, the consolidation state parameters of the current test point are determined; the third determining module 404 is configured to determine the correspondence between the underestimation degree of the undrained shear strength of soft clay and the consolidation state parameters based on the degree of underestimation of the undrained shear strength of soft clay at multiple test points and the corresponding consolidation state parameters; the correction module 405 is configured to determine the correction coefficient of the undrained shear strength of soft clay at the target test point based on the correspondence between the underestimation degree of the undrained shear strength of soft clay and the consolidation state parameters, the correction coefficient being used to correct the undrained shear strength of soft clay at the target test point obtained through the self-drilling pressuremeter test.

[0106] In one embodiment, the correction module 405 includes a fourth determining module and a correction coefficient determining module. The fourth determining module is configured to determine the degree to which the undrained shear strength of the soft clay at the target test point is overestimated based on the geometric size effect of the pressuremeter. The correction coefficient determining module is configured to determine a correction coefficient for the undrained shear strength of the soft clay at the target test point based on the correspondence between the degree to which the undrained shear strength of the soft clay at the target test point is overestimated, the degree to which the undrained shear strength of the soft clay is underestimated, and the consolidation state parameters.

[0107] In one embodiment, the first determining module 402 is further configured to, for the current test point, determine the ratio of the undrained shear strength of the soft clay at the current test point obtained by the self-drilling pressuremeter test to the undrained shear strength of the soft clay at the current test point obtained by the vane test, as the test ratio of the current test point; determine the maximum test ratio based on the test ratios of all test points; and normalize the test ratio of the current test point based on the maximum test ratio to obtain the degree to which the undrained shear strength of the soft clay at the current test point is underestimated.

[0108] In one embodiment, the second determining module 403 is further configured to calculate the consolidation state parameters of the current test site according to the following formula:

[0109]

[0110] Where U is the consolidation state parameter at the current test site, u f u represents the peak pore pressure at the initial moment when penetration stops and the pore pressure dissipation test begins at a certain measuring point in the current test site. t u represents the pore pressure at the soil yielding time during a self-drilling pressuremeter test. w This represents the static water pressure at the current test point.

[0111] In one embodiment, the relationship between the degree to which the undrained shear strength of soft clay is underestimated and the consolidation state parameters includes a linear relationship.

[0112] In one embodiment, the fourth determining module is further configured to calculate the degree to which the undrained shear strength of the soft clay at the target test site is overestimated, according to the following formula:

[0113]

[0114] Wherein, K2 represents the degree to which the undrained shear strength of the soft clay at the target test point is overestimated, Cu represents the undrained shear strength of the soft clay at the target test point obtained by a self-drilling pressuremeter test when the ratio of the length of the pressuremeter to its diameter is infinite (∞), Cu6 represents the undrained shear strength of the soft clay at the target test point obtained by a self-drilling pressuremeter test when the ratio of the length of the pressuremeter to its diameter is 6, and G represents the shear modulus of the soil, obtained from the pressuremeter curve, which is obtained by conducting a self-drilling pressuremeter test on the target test point.

[0115] In one embodiment, the correction coefficient determination module is further configured to

[0116] K1 = 2.42U - 2.04

[0117] Where K is the correction factor for the undrained shear strength of soft clay at the target test point, K2 is the degree to which the undrained shear strength of soft clay at the target test point is overestimated, U is the consolidation state parameter of the target test point, and K1 is the degree to which the undrained shear strength of soft clay at the target test point is underestimated.

[0118] The modules in the aforementioned correction device for the undrained shear strength of soft clay obtained from the self-drilling pressuremeter test can be implemented entirely or partially through software, hardware, or a combination thereof. These modules can be embedded in or independent of the processor in a computer device, or stored in the memory of a computer device as software, so that the processor can call and execute the corresponding operations of each module.

[0119] This application also provides a computer device, the internal structure diagram of which can be shown as follows: Figure 5 As shown, the computer device includes a processor, memory, input / output interface, communication interface, display unit, and input device. The processor, memory, and input / output interface are connected via a system bus, and the communication interface, display unit, and input device are also connected to the system bus via the input / output interface. The processor provides computing and control capabilities. The memory includes a non-volatile storage medium and internal memory. The non-volatile storage medium stores the operating system and computer programs. The internal memory provides an environment for the operation of the operating system and computer programs in the non-volatile storage medium. The input / output interface is used for exchanging information between the processor and external devices. The communication interface is used for wired or wireless communication with external terminals; wireless communication can be achieved through Wi-Fi, mobile cellular networks, NFC (Near Field Communication), or other technologies. When executed by the processor, the computer program implements a method for correcting the undrained shear strength of soft clay obtained from a self-drilling pressureside test.

[0120] Those skilled in the art will understand that Figure 5 The structure shown is merely a block diagram of a portion of the structure related to the present application and does not constitute a limitation on the computer device to which the present application is applied. Specific computer devices may include more or fewer components than those shown in the figure, or combine certain components, or have different component arrangements.

[0121] This application also provides a computer device including at least one processing unit and at least one storage unit, wherein the storage unit stores a computer program, and when the computer program is executed by the processing unit, the processing unit performs the steps in the above-described method embodiments.

[0122] This application also provides a computer-readable storage medium storing a computer program executable by a computer device. When the computer program is run on the computer device, it causes the computer device to perform the steps in the above-described method embodiments. The computer-readable storage medium may include, but is not limited to, any type of disk, including floppy disks, optical disks, DVDs, CD-ROMs, microdrives, magneto-optical disks, ROMs, RAMs, EPROMs, EEPROMs, DRAMs, VRAMs, flash memory devices, magnetic cards or optical cards, nanosystems (including molecular memory ICs), or any type of medium or device suitable for storing instructions and / or data.

[0123] It should be noted that, for the sake of simplicity, the foregoing method embodiments are all described as a series of actions. However, those skilled in the art should understand that this application is not limited to the described order of actions, as some steps may be performed in other orders or simultaneously according to this application. Furthermore, those skilled in the art should also understand that the embodiments described in the specification are preferred embodiments, and the actions and modules involved are not necessarily essential to this application.

[0124] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

[0125] In the several embodiments provided in this application, it should be understood that the disclosed apparatus can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of 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 coupling or direct coupling or communication connection shown or discussed may be through some service interface; the indirect coupling or communication connection between devices or units may be electrical or other forms.

[0126] 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.

[0127] 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.

[0128] If the integrated 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 device (CMD). Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a memory and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned memory includes various media capable of storing program code, such as a USB flash drive, read-only memory (ROM), random access memory (RAM), portable hard drive, magnetic disk, or optical disk.

[0129] Those skilled in the art will understand that all or part of the steps in the various methods of the above embodiments can be implemented by a program instructing related hardware. The program can be stored in a computer-readable storage medium, which may include: a flash drive, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk, etc.

[0130] The above description is merely an exemplary embodiment of this disclosure and should not be construed as limiting the scope of this disclosure. Any equivalent changes and modifications made in accordance with the teachings of this disclosure shall still fall within the scope of this disclosure. Those skilled in the art will readily conceive of embodiments of this disclosure upon considering the specification and practicing the disclosure herein. This application is intended to cover any variations, uses, or adaptations of this disclosure that follow the general principles of this disclosure and include common knowledge or customary techniques in the art not described herein. The specification and embodiments are to be considered exemplary only, and the scope and spirit of this disclosure are defined by the claims.

[0131] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0132] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for correcting the undrained shear strength of soft clay obtained from a self-drilling pressuremeter test, characterized in that, include: Data on undrained shear strength and pore pressure dissipation of soft clay at multiple test points were collected through self-drilling pressuremeter tests, and data on undrained shear strength of soft clay at multiple test points were collected through vane tests. For the current test site, the degree to which the undrained shear strength of the soft clay at the current test site is underestimated is determined by the ratio of the undrained shear strength of the soft clay at the current test site obtained by the self-drilling pressure meter test to the undrained shear strength of the soft clay at the current test site obtained by the vane test. For the current test site, the consolidation state parameters of the current test site are determined based on the pore pressure dissipation data of the current test site obtained through the self-drilling pressure difference test. Based on the degree of underestimation of the undrained shear strength of soft clay at multiple test sites and the corresponding consolidation state parameters, the correspondence between the degree of underestimation of the undrained shear strength of soft clay and the consolidation state parameters was determined. Based on the geometric size effect of the pressuremeter, the degree to which the undrained shear strength of the soft clay at the target test point is overestimated is determined. According to the correspondence between the degree to which the undrained shear strength of the soft clay at the target test point is overestimated, the degree to which the undrained shear strength of the soft clay at the target test point is underestimated, and the consolidation state parameters, a correction coefficient for the undrained shear strength of the soft clay at the target test point is determined. The correction coefficient is used to correct the undrained shear strength of the soft clay at the target test point obtained by the self-drilling pressuremeter test.

2. The method as described in claim 1, characterized in that, For the current test point, the degree to which the undrained shear strength of the soft clay at the current test point is underestimated is determined based on the ratio of the undrained shear strength of the soft clay at the current test point obtained through the self-drilling pressuremeter test to the undrained shear strength of the soft clay at the current test point obtained through the vane test. This includes: For the current test site, the ratio of the undrained shear strength of the soft clay at the current test site obtained by the self-drilling pressure meter test to the undrained shear strength of the soft clay at the current test site obtained by the vane test is determined as the test ratio for the current test site. Determine the maximum test ratio based on the test ratios of all test sites; Based on the maximum test ratio, the test ratio of the current test point is normalized to obtain the degree to which the undrained shear strength of the soft clay at the current test point is underestimated.

3. The method as described in claim 1, characterized in that, For the current test site, based on the pore pressure dissipation data obtained through the self-drilling pressuremeter test, the consolidation state parameters of the current test site are determined, including: Calculate the consolidation state parameters at the current test site using the following formula: in, These are the consolidation state parameters at the current test site. This represents the peak pore pressure at the initial moment when penetration stops and the pore pressure dissipation test begins at a certain measuring point in the current test site. This represents the pore pressure at the soil yielding time point during the self-drilling pressuremeter test. This represents the static water pressure at the current test point.

4. The method as described in claim 1, characterized in that, The relationship between the degree to which the undrained shear strength of soft clay is underestimated and the consolidation state parameters includes a linear relationship.

5. The method as described in claim 1, characterized in that, The determination of the degree to which the undrained shear strength of soft clay at the target test site is overestimated based on the geometric size effect of the pressuremeter includes: The degree to which the undrained shear strength of the soft clay at the target test site is overestimated is calculated using the following formula: in, The extent to which the undrained shear strength of the soft clay at the target test site was overestimated. The ratio of the length to the diameter of the pressure gauge is infinite. The undrained shear strength of soft clay at the target test point obtained by self-drilling pressuremeter test. The undrained shear strength of soft clay at the target test point obtained by a self-drilling pressuremeter test when the ratio of the length to the diameter of the pressuremeter is 6. The shear modulus of the soil is obtained from the pressure meter curve, which is obtained by performing a self-drilling pressure meter test on the target test point.

6. The method as described in claim 5, characterized in that, The step of determining the correction coefficient for the undrained shear strength of the soft clay at the target test point based on the degree to which the undrained shear strength of the soft clay at the target test point is overestimated, the degree to which the undrained shear strength of the soft clay is underestimated, and the correspondence between the consolidation state parameters includes: ， in, The correction factor is used to measure the undrained shear strength of the soft clay at the target test site. The extent to which the undrained shear strength of the soft clay at the target test site was overestimated. The consolidation state parameters at the target test site, The extent to which the undrained shear strength of the soft clay at the target test site was underestimated.

7. A correction device for the undrained shear strength of soft clay obtained by a self-drilling pressuremeter test, characterized in that, include: The data acquisition module is configured to acquire undrained shear strength and pore pressure dissipation data of soft clay at multiple test points obtained through self-drilling pressuremeter tests, and undrained shear strength data of soft clay at multiple test points obtained through vane tests. The first determining module is configured to, for the current test point, determine the degree to which the undrained shear strength of the soft clay at the current test point is underestimated based on the ratio of the undrained shear strength of the soft clay at the current test point obtained by the self-drilling pressure meter test to the undrained shear strength of the soft clay at the current test point obtained by the vane test. The second determining module is configured to determine the consolidation state parameters of the current test point based on the pore pressure dissipation data of the current test point obtained through the self-drilling pressure difference test. The third determination module is configured to determine the correspondence between the underestimation of the undrained shear strength of soft clay and the consolidation state parameters based on the degree of underestimation of the undrained shear strength of soft clay at multiple test sites and the corresponding consolidation state parameters. A correction module is configured to determine the degree to which the undrained shear strength of the soft clay at the target test site is overestimated based on the geometric size effect of the pressuremeter; and to determine a correction coefficient for the undrained shear strength of the soft clay at the target test site based on the correspondence between the degree to which the undrained shear strength of the soft clay at the target test site is overestimated, the degree to which the undrained shear strength of the soft clay at the target test site is underestimated, and the consolidation state parameters. The correction coefficient is used to correct the undrained shear strength of the soft clay at the target test site obtained by the self-drilling pressuremeter test.

8. A computer device, characterized in that, It includes at least one processing unit and at least one storage unit, wherein the storage unit stores a computer program that, when executed by the processing unit, causes the processing unit to perform the steps of the method according to any one of claims 1-6.

9. A storage medium, characterized in that, It stores a computer program that is executed by a computer device, which, when run on the computer device, causes the computer device to perform the steps of the method according to any one of claims 1-6.

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