Calculation method, system, electronic device and storage medium for hoop stiffness of ground-connected wall

Abstract

The present invention discloses a method, system, electronic device, and storage medium for calculating the circumferential stiffness of a ground-connected wall. The method comprises the following steps: S100, collecting design schemes and related parameters of a circular ground-connected wall structure, equating the spatial circumferential effect of the circular ground-connected wall to a distributed spring deformed in the radial direction under load, and obtaining an equivalent distributed elastic support coefficient of the circumferential effect of the circular wall based on the coordination between the circumferential deformation and the radial deformation; S200, determining a circumferential stiffness reduction coefficient based on the distribution of the slot concrete and the joint mud skin in the ground-connected wall structure; S300, describing the nonlinear compression characteristics of the joint mud skin and determining the initial stress-strain state of the ground-connected wall concrete and mud skin before excavation; and S400, establishing a transcendental equation based on the stress-strain relationship between the concrete and the mud skin to solve the equivalent elastic modulus and circumferential stiffness reduction coefficient of the ground-connected wall. By considering the nonlinear compression characteristics of the joint mud skin, the law that the circumferential stiffness of the ground-connected wall increases with increasing deformation is more accurately described.

Description

Technical Field

[0001] The present invention belongs to the technical field of ground-connected walls, and more specifically, relates to a method, system, electronic equipment and storage medium for calculating the hoop stiffness of a ground-connected wall. Background Art

[0002] Circular diaphragm walls, due to their unique spatial circumferential effect and superior deformation resistance, have been widely used in deep foundation pit projects, becoming a crucial support structure for major projects such as anchorages for cross-river bridges, ultra-deep vertical shafts, and shield tunneling launch shafts. However, due to limitations in construction techniques, a certain thickness of mud crust inevitably remains between the diaphragm wall segments. This mud crust significantly weakens the diaphragm wall's overall stiffness, becoming a key factor affecting the wall's load-bearing capacity, structural stability, and construction safety.

[0003] Common design methods currently treat ground-connected walls as a single concrete material, using a fixed reduction factor (e.g., 0.4-0.7) to approximate the effect of the joint mud skin on the hoop stiffness. However, the properties of the joint mud skin resemble those of soft soil, and its compressibility exhibits significant nonlinear characteristics. In the initial stages of compression, the mud skin's low stiffness prevents the ground-connected wall from forming an effective hoop effect, thereby weakening the structure's deformation resistance. As the mud skin further compresses, its stiffness gradually increases, and the hoop effect of the ground-connected wall strengthens accordingly. This pattern of increasing hoop effect with increasing deformation cannot be described by a fixed reduction factor.

[0004] Because existing design methods fail to fully consider the impact of joint mud skin on the circumferential stiffness of ground-connected walls, design accuracy fails to meet refinement requirements, further limiting the optimization of the safety and economic efficiency of circular ground-connected wall structures. Based on this, this paper explains the principle of weakening the circumferential effect of joints on ground-connected walls and, incorporating the nonlinear compression characteristics of mud skin, proposes a method for calculating circumferential stiffness. This method also establishes that the circumferential stiffness of ground-connected walls increases with deformation. Summary of the Invention

[0005] To address the aforementioned shortcomings and improvements in existing technologies, the present invention provides a method for calculating the hoop stiffness of ground-connected walls. By considering the nonlinear compression characteristics of the joint mud skin, a method for calculating the hoop stiffness reduction coefficient is proposed. This method more accurately describes how the hoop stiffness of a ground-connected wall increases with deformation. Compared to the traditional fixed reduction coefficient method, this method more accurately reflects the actual stress conditions of the ground-connected wall, thereby improving design accuracy and ensuring the safety and stability of the structure.

[0006] To achieve the above objectives, according to a first aspect of an embodiment of the present invention, a method for calculating the hoop stiffness of a ground-connected wall is provided, comprising the following steps:

[0007] S100. Collect design solutions and related parameters of the circular ground-connected wall structure, equate the spatial circumferential effect of the circular ground-connected wall to a distributed spring that deforms in the radial direction under load, and obtain the equivalent distributed elastic support coefficient of the circumferential effect of the circular wall based on the coordination between the circumferential deformation and the radial deformation.

[0008] S200, determining the hoop stiffness reduction factor based on the distribution of the groove section concrete and joint mud skin in the ground-connected wall structure;

[0009] S300, describing the nonlinear compression characteristics of the joint mud skin, and determining the initial stress-strain state of the ground-connected wall concrete and mud skin before excavation;

[0010] S400. Based on the stress-strain relationship between concrete and mud skin, a transcendental equation is established to solve the equivalent elastic modulus and hoop stiffness reduction coefficient of the ground-connected wall.

[0011] Furthermore, in step S200, when considering the circumferential stress and deformation of the ground-connected wall, the smallest repeatable ground-connected wall unit is used for stress analysis. The angle between adjacent groove segments is not considered. It is assumed that the axial forces at both ends are equal in magnitude and opposite in direction, and that the concrete-mud skin exhibits a series stress characteristic, that is, the axial forces applied to the two materials are equal in magnitude, and the resulting deformations are superimposed on each other. The equivalent elastic modulus and reduction factor of the ground-connected wall considering the mud skin are then determined.

[0012] The equivalent elastic modulus of the ground-connected wall considering the mud skin for:

[0013] ,

[0014] in, is the length of concrete in the repeatable unit,

[0015] is the length of the mud skin in the repeatable unit,

[0016] is the elastic modulus of the mud skin;

[0017] The reduction factor for:

[0018] .

[0019] Furthermore, the concrete length in the repeatable unit , specifically:

[0020] ,

[0021] in, 、 They are the concrete lengths of the first-phase diaphragm wall trench section I and the first-phase diaphragm wall trench section II respectively;

[0022] The length of the mud skin in the repeatable unit , specifically:

[0023] ,

[0024] in, 、 are the thickness of mud skin at the two joints respectively.

[0025] Furthermore, in step S300, the elastic modulus of the mud skin It is not a fixed value, but increases with the stress of the mud skin; at this time, the elastic modulus of the mud skin The tangent elastic modulus should be taken as is the derivative of stress with respect to strain; the compression curve of the mud skin is drawn up in The coordinates are linearly distributed. is the void ratio, is stress, at this time, the tangent elastic modulus of the mud skin , specifically:

[0026] ,

[0027] in, The porosity ratio of the mud skin when the axial compressive stress is 1 kPa,

[0028] is the compression index,

[0029] is the current stress.

[0030] Furthermore, the porosity ratio With current stress The relationship between them is:

[0031] ,

[0032] The total strain of the mud skin for:

[0033] ,

[0034] Then the stress-strain relationship of the mud skin is obtained as follows:

[0035] ,

[0036] Therefore, the current stress By strain Expressed as:

[0037] ;

[0038] Finally, the tangent elastic modulus of the mud skin is obtained. for:

[0039] .

[0040] Furthermore, to calculate the hoop stiffness of the circular ground wall, in step S300 , the initial stress-strain state of the wall must be determined;

[0041] The initial stress-strain state of the wall includes the initial horizontal stress of the stratum, the initial circumferential stress and radial stress of the ground-connected wall, the initial strain of the ground-connected wall concrete, the initial strain of the mud skin, and the equivalent initial strain of the ground-connected wall in the concrete-mud skin series load model.

[0042] Furthermore, in step S400, the radial deformation of the ground wall caused by excavation , and the corresponding circumferential deformation of the ground wall is obtained , specifically:

[0043] ,

[0044] Then the equivalent current strain of the ground wall is obtained :

[0045] ,

[0046] Equivalent current strain on ground wall Introducing initial strain The equivalent total strain of the ground wall is obtained ,

[0047] ,

[0048] Then, the equivalent total strain of the ground and wall Equivalent elastic modulus of the ground-connected wall , get the current hoop stress , specifically:

[0049] ,

[0050] The current hoop stress Elastic modulus of concrete for ground and wall , calculate the total strain of the ground wall concrete , specifically:

[0051] ,

[0052] The total strain of the ground wall concrete and initial strain Get the current strain of concrete , specifically:

[0053] ,

[0054] The current hoop stress Current strain introduced into concrete The current strain of concrete is obtained Equivalent elastic modulus of ground-connected wall The relationship between them is specifically:

[0055] .

[0056] Furthermore, the circular ground connection wall is actually composed of multiple repeatable units, and the circumferential deformation of each repeatable unit is for:

[0057] ,

[0058] in, is the number of repeatable units.

[0059] By circumferential deformation of each repeatable unit , the deformation of concrete in each repeatable unit is obtained :

[0060] ,

[0061] Then the circumferential deformation of each repeatable unit and the deformation of concrete in each repeatable unit The difference between them is the deformation of the mud skin in each repeatable unit, specifically:

[0062] ,

[0063] Then the current strain of the mud skin after excavation is obtained :

[0064] .

[0065] Furthermore, the initial strain of the mud skin and the current strain of the mud skin after excavation are used to calculate the , and the total strain of the mud skin is obtained :

[0066] ,

[0067] Introducing the stress-strain relationship of the mud skin, we get:

[0068] ,

[0069] Combining the above two equations, we can get the equivalent elastic modulus of the ground-connected wall: The relationship is:

[0070] ,

[0071] The equivalent elastic modulus of the ground-connected wall The transcendental equation is obtained by simplifying the relationship:

[0072] ,

[0073] in, is an unknown quantity,

[0074] 、 、 All are known coefficients;

[0075] The known coefficients 、 、 They are:

[0076] ,

[0077] The unknown quantity Equivalent elastic modulus of ground-connected wall The relationship between them is:

[0078] .

[0079] Furthermore, the unknown quantity is solved by the transcendental equation through numerical methods. , and then the equivalent elastic modulus of the ground-connected wall is obtained and hoop stiffness reduction factor ;

[0080] The equivalent elastic modulus of the ground-connected wall for:

[0081] ,

[0082] The hoop stiffness reduction factor for:

[0083] .

[0084] According to another aspect of an embodiment of the present invention, a system for calculating the hoop stiffness of a ground-connected wall is provided, comprising:

[0085] Model Equivalence Module: This module collects design schemes and related parameters of circular ground-connected wall structures, equating the spatial circumferential effect of the circular ground-connected wall to a distributed spring that deforms in the radial direction. Based on the coordination between the circumferential deformation and the radial deformation, the equivalent distributed elastic support coefficient of the circular wall's circumferential effect is obtained.

[0086] Preliminary calculation module: used to determine the annular stiffness reduction factor based on the distribution of the groove section concrete and joint mud skin in the ground-connected wall structure;

[0087] Data acquisition module: used to describe the nonlinear compression characteristics of the joint mud skin and determine the initial stress and strain state of the ground-connected wall concrete and mud skin before excavation;

[0088] Depth calculation module: used to establish a transcendental equation based on the stress-strain relationship between concrete and mud skin, and solve the equivalent elastic modulus and hoop stiffness reduction coefficient of the ground-connected wall.

[0089] An embodiment of the present invention further provides an electronic device, including:

[0090] at least one memory for storing a computer program;

[0091] At least one processor is configured to implement the steps of the hoop stiffness calculation method when executing the computer program.

[0092] An embodiment of the present invention further provides a computer-readable storage medium having a computer program stored thereon. When the computer program is executed by a processor, the steps of the hoop stiffness calculation method are implemented.

[0093] In general, the above technical solutions conceived by the present invention can achieve the following beneficial effects compared with the prior art:

[0094] 1. This method for calculating hoop stiffness considers the nonlinear compression characteristics of the joint mud skin and proposes a calculation method for the hoop stiffness reduction coefficient. This method more accurately describes the increase in hoop stiffness of the ground-connected wall with increasing deformation. Compared with the traditional fixed reduction coefficient method, this method more accurately reflects the actual stress conditions of the ground-connected wall, thereby improving design accuracy and ensuring the safety and stability of the structure.

[0095] 2. The present invention's hoop stiffness calculation method accurately calculates the hoop stiffness of ground-connected walls, thereby avoiding over- or under-design, optimizing their structural design, reducing material waste, and lowering project costs. This method enables a more economical design while ensuring safety.

[0096] 3. The hoop stiffness calculation method of this invention can dynamically adjust the hoop stiffness reduction factor based on different engineering conditions (such as ground-anchor wall diameter, number of trench sections, mud skin thickness, initial stress, etc.), adapting to various complex engineering environments. This is particularly useful in major projects such as deep foundation pits and cross-river bridge anchorages, enabling better response to diverse geological conditions and construction requirements.

[0097] 4. By taking into account the compressive properties of the joint mud skin, the present invention's hoop stiffness calculation method can more accurately predict the deformation behavior of the ground-connected wall under load, ensuring that the ground-connected wall has stronger deformation resistance when subjected to external loads. This is of great significance for improving the overall stability and durability of the structure, especially under high stress or complex geological conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0098] Figure 1 This is a flow chart of a method for calculating the hoop stiffness of a ground-connected wall according to an embodiment of the present invention;

[0099] Figure 2 Schematic diagram of radial deformation of a circular ground-connected wall according to an embodiment of the present invention;

[0100] Figure 3 Schematic diagram of the concrete-mud skin series load model of the minimum repeatable ground-connected wall unit according to an embodiment of the present invention;

[0101] Figure 4 Schematic diagram of the relationship between the porosity ratio and strain of the mud skin of the minimum repeatable ground-connected wall unit according to an embodiment of the present invention;

[0102] Figure 5 Schematic diagram of the stress-strain relationship of the mud skin of the minimum repeatable ground-wall unit according to an embodiment of the present invention;

[0103] Figure 6 Schematic diagram of the relationship between the compression modulus and stress of the mud skin of the minimum repeatable ground-wall unit according to an embodiment of the present invention;

[0104] Figure 7 Schematic diagram of the relationship between the compression modulus and strain of the mud skin of the minimum repeatable ground-connected wall unit according to an embodiment of the present invention;

[0105] Figure 8 Schematic diagram of the relationship between the equivalent elastic modulus of the ground wall and the mud skin strain of the minimum repeatable ground-wall unit according to an embodiment of the present invention;

[0106] Figure 9 Schematic diagram of the relationship between the ground wall hoop stiffness reduction coefficient α and the mud skin strain of the minimum repeatable ground wall unit according to an embodiment of the present invention;

[0107] Figure 10 Schematic diagram of linear coordinates showing the variation of the equivalent elastic modulus of the ground wall of the minimum repeatable ground-wall connection unit with radial deformation according to an embodiment of the present invention;

[0108] Figure 11 Schematic diagram of logarithmic coordinates of the variation of the equivalent elastic modulus of the ground wall of the minimum repeatable ground-wall unit with radial deformation according to an embodiment of the present invention;

[0109] Figure 12Schematic diagram of linear coordinates showing the variation of the ground wall hoop stiffness reduction coefficient with radial deformation of the minimum repeatable ground-wall unit according to an embodiment of the present invention;

[0110] Figure 13 Schematic diagram of logarithmic coordinates showing the variation of the ground wall hoop stiffness reduction coefficient with radial deformation of the minimum repeatable ground wall unit according to an embodiment of the present invention;

[0111] Figure 14 Schematic diagram showing the influence of the ground wall radius of the minimum repeatable ground-wall unit on the reduction coefficient in an embodiment of the present invention;

[0112] Figure 15 Schematic diagram of the influence of the initial horizontal stress of the minimum repeatable ground-wall unit on the reduction coefficient in an embodiment of the present invention;

[0113] Figure 16 Schematic diagram of the influence of the mud skin thickness of the minimum repeatable ground-connected wall unit on the reduction coefficient in an embodiment of the present invention;

[0114] Figure 17 The figure is a schematic diagram of the electronic device structure of a method for calculating the circumferential stiffness of a ground-connected wall according to an embodiment of the present invention. DETAILED DESCRIPTION

[0115] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only intended to illustrate the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.

[0116] Example 1

[0117] like Figure 1 As shown, an embodiment of the present invention provides a method for calculating the hoop stiffness of a ground-connected wall, which specifically includes the following steps:

[0118] S100. Collect design solutions and related parameters of the circular ground-connected wall structure, equate the spatial circumferential effect of the circular ground-connected wall to a distributed spring that deforms in the radial direction under load, and obtain the equivalent distributed elastic support coefficient of the circumferential effect of the circular wall based on the coordination between the circumferential deformation and the radial deformation.

[0119] S200, determining the hoop stiffness reduction factor based on the distribution of the groove section concrete and joint mud skin in the ground-connected wall structure;

[0120] S300, describing the nonlinear compression characteristics of the joint mud skin, and determining the initial stress-strain state of the ground-connected wall concrete and mud skin before excavation;

[0121] S400. Based on the stress-strain relationship between concrete and mud skin, a transcendental equation is established to solve the equivalent elastic modulus and hoop stiffness reduction coefficient of the ground-connected wall.

[0122] In step S100, the design scheme and related parameters of the circular ground-anchored wall structure include: ground-anchored wall thickness and radius, concrete elastic modulus, ground-anchored wall groove section and joint distribution, foundation pit excavation depth and internal support type.

[0123] In step S100, for a given calculated depth, a ring wall of unit height is cut out horizontally from the circular ground wall, which will produce inward compression deformation under the action of pressure.

[0124] Step S100 specifically includes providing a beam-spring calculation model that considers the hoop effect of the ring beam or wall itself. In a planar problem, the spatial hoop effect of each supporting ring beam can be replaced by a supporting spring that deforms radially under load, and the spatial hoop effect of the wall itself can be replaced by distributed springs along the wall's depth.

[0125] like Figure 2 As shown in the figure, the ring beam produces compression deformation along the circumferential direction under the action of pressure, which shortens the circumference of the ring beam centerline and reduces the radius, that is, it produces both circumferential deformation and radial deformation. The axial force of the ring beam is calculated according to the formula for a homogeneous circular ring subjected to uniform radial pressure, specifically:

[0126] ,

[0127] in, is the axial force of the ring beam (kN),

[0128] is the initial centerline radius of the ring beam,

[0129] is the radial pressure (kN / m 2 ),

[0130] is the ring beam height (m),

[0131] is the annular pressure (kN / m 2 ),

[0132] is the width of the ring beam (m).

[0133] According to the axial force of the ring beam , and then the hoop compressive strain of the ring beam is obtained for:

[0134] ,

[0135] in, is the elastic modulus of the ring beam material (kN / m 2 ).

[0136] According to the hoop compressive strain of the ring beam Get the change in the circumference of the center line of the ring beam , specifically:

[0137] ,

[0138] in, is the perimeter of the ring beam (m);

[0139] And the change in the beam centerline circumference and radius change The relationship between them is:

[0140] ,

[0141] Then we can get:

[0142] .

[0143] The supporting function of the ring beam is replaced by an equivalent supporting spring that deforms in the radial direction to obtain the equivalent spring stiffness of the ring beam. (kN / m 2 ):

[0144] ,

[0145] Then substitute it into the equation:

[0146] .

[0147] Similarly, when calculating the equivalent elastic support coefficient of the spatial hoop effect of the wall itself, at the calculation depth, a ring wall of unit height is cut out from the circular wall horizontally. This ring wall is equivalent to a supporting ring beam. The equivalent distributed spring stiffness of the wall is calculated according to the above method. (kN / m 2 ):

[0148] ,

[0149] in, is the initial centerline radius of the ground wall (m),

[0150] is the ground wall thickness (m),

[0151] is the reduction coefficient. According to engineering experience, it is between 0.4 and 0.7. When the diameter is large or there are more ground and wall sections, the smaller value is taken.

[0152] In step S200, the circular ground-connected wall structure is composed of two materials: concrete in the trough sections and mud skin in the joints. The mud skin has high compressibility and a low elastic modulus, which weakens the overall stiffness of the ground-connected wall structure. Therefore, a concrete-mud skin tandem load model is used to treat it as a composite material, and the equivalent elastic modulus of the ground-connected wall is determined.

[0153] like Figure 3 As shown, when considering the circumferential forces and deformations of the ground-connected wall, the smallest repeatable ground-connected wall unit is used for the load analysis. The angle between adjacent slot segments is not considered, and the axial forces at both ends are assumed to be equal in magnitude and opposite in direction. The concrete-mud skin exhibits a tandem load characteristic, meaning that the axial forces acting on both materials are equal, and the resulting deformations are additive. The equivalent elastic modulus and reduction factor of the ground-connected wall, taking the mud skin into account, are then determined.

[0154] The equivalent elastic modulus of the ground-connected wall considering the mud skin (kPa) is:

[0155] ,

[0156] in, is the length of concrete in the repeatable unit (m),

[0157] is the length of the mud skin in the repeatable unit (m),

[0158] is the elastic modulus of the mud skin (kPa);

[0159] The reduction factor for:

[0160] .

[0161] The concrete length in the repeatable unit , specifically:

[0162] ,

[0163] in, 、 are the concrete lengths of the first-phase diaphragm wall trench section I and the first-phase diaphragm wall trench section II (m);

[0164] The length of the mud skin in the repeatable unit , specifically:

[0165] ,

[0166] in, 、 are the thickness of mud skin at the two joints (m).

[0167] like Figure 4-9 As shown, in step S300, since the properties of the joint mud skin are similar to soft clay and have nonlinear compression characteristics, the elastic modulus of the mud skin is It is not a fixed value, but as the stress of the mud skin continues to increase, at this time, the elastic modulus of the mud skin should be the tangent elastic modulus. is the derivative of stress with respect to strain;

[0168] The compression curve of the mud skin is proposed The coordinates are linearly distributed. is the void ratio, is stress, at this time, the tangent elastic modulus of the mud skin , specifically:

[0169] ,

[0170] in, The porosity ratio of the mud skin when the axial compressive stress is 1 kPa,

[0171] is the compression index,

[0172] is the current stress.

[0173] The porosity of the mud skin at 1 kPa axial compressive stress is , specifically:

[0174] ,

[0175] in, is the initial porosity ratio of the mud skin in its natural state,

[0176] is the rebound index,

[0177] is the initial consolidation pressure.

[0178] The initial porosity of the mud skin in its natural state is , Rebound Index , early consolidation pressure and compression index All are determined by standard consolidation tests.

[0179] The porosity ratio is obtained With current stress The relationship between them is:

[0180] ,

[0181] The total strain of the mud skin for:

[0182] ,

[0183] Then the stress-strain relationship of the mud skin is obtained as follows:

[0184] ,

[0185] Therefore, the current stress By strain Expressed as:

[0186] .

[0187] Finally, the tangent elastic modulus of the mud skin is obtained. for:

[0188] .

[0189] According to the above derivation, the tangent compression modulus of the mud skin is , the equivalent elastic modulus of the ground-connected wall and reduction factor Therefore, to calculate the hoop stiffness of the circular ground wall, in step S300, it is necessary to determine the initial stress and strain state of the wall, that is, to determine the boundary conditions of the problem.

[0190] The initial stress-strain state of the wall includes the initial horizontal stress of the stratum, the initial circumferential stress and radial stress of the ground-connected wall, the initial strain of the ground-connected wall concrete, the initial strain of the mud skin, and the equivalent initial strain of the ground-connected wall in the concrete-mud skin series load model.

[0191] The initial horizontal stress of the stratum is considered based on the water and soil balance, specifically:

[0192] ,

[0193] in, is the initial horizontal stress of the formation (kN / m 2 ),

[0194] are the lateral pressure coefficient, density and thickness of each soil layer respectively;

[0195] The initial hoop stress and radial stress of the diaphragm wall are equal to the initial horizontal stress, that is:

[0196] ,

[0197] in, is the initial hoop stress of the diaphragm wall,

[0198] is the initial radial stress of the ground-connected wall;

[0199] The initial strain of the ground wall concrete , specifically:

[0200] ;

[0201] The initial strain of the mud skin , specifically:

[0202] ;

[0203] The equivalent initial strain of the ground-connected wall in the concrete-mud skin series load model , specifically:

[0204] .

[0205] It should be noted that the initial hoop strain of the ground-connected wall is caused by the initial stress of the stratum after construction. This strain affects the nonlinear compression characteristics of the mud skin, but is not included in the hoop and radial deformation of the ground-connected wall structure.

[0206] like Figure 10-16 As shown, in step S400, the total strain of the mud skin needs to be obtained , the total strain of the mud skin Including initial strain and the current strain of the mud skin after excavation Two parts, the initial strain The current strain of the mud skin after excavation does not cause radial deformation of the ground wall. This causes radial deformation of the ground wall.

[0207] In step S400, the radial deformation of the ground wall caused by excavation , and the corresponding circumferential deformation of the ground wall is obtained , specifically:

[0208] ,

[0209] Then the equivalent current strain of the ground wall is obtained :

[0210] ,

[0211] Equivalent current strain on ground wall Introducing initial strain The equivalent total strain of the ground wall is obtained ,

[0212] ,

[0213] Then, the equivalent total strain of the ground and wall Equivalent elastic modulus of the ground-connected wall , get the current hoop stress , specifically:

[0214] ,

[0215] The current hoop stress Elastic modulus of concrete for ground and wall , calculate the total strain of the ground wall concrete , specifically:

[0216] ,

[0217] The total strain of the ground wall concrete and initial strain Get the current strain of concrete , specifically:

[0218] ,

[0219] The current hoop stress Current strain introduced into concrete The current strain of concrete is obtained Equivalent elastic modulus of ground-connected wall The relationship between them is specifically:

[0220] .

[0221] The circular ground-connected wall is actually composed of multiple repeatable units, and the circumferential deformation of each repeatable unit is for:

[0222] ,

[0223] in, is the number of repeatable units.

[0224] By circumferential deformation of each repeatable unit , the deformation of concrete in each repeatable unit is obtained :

[0225] ,

[0226] Then the circumferential deformation of each repeatable unit and the deformation of concrete in each repeatable unit The difference between them is the deformation of the mud skin in each repeatable unit, specifically:

[0227] ,

[0228] Then the current strain of the mud skin after excavation is obtained :

[0229] .

[0230] The initial strain of the mud skin and the current strain of the mud skin after excavation , and the total strain of the mud skin is obtained :

[0231] ,

[0232] Introducing the stress-strain relationship of the mud skin, we get:

[0233] ,

[0234] Combining the above two equations, we can get the equivalent elastic modulus of the ground-connected wall: The relationship is:

[0235] ,

[0236] The equivalent elastic modulus of the ground-connected wall The transcendental equation is obtained by simplifying the relationship:

[0237] ,

[0238] in, is an unknown quantity,

[0239] 、 、 All are known coefficients.

[0240] The known coefficients 、 、 They are:

[0241] ,

[0242] The unknown quantity Equivalent elastic modulus of ground-connected wall The relationship between them is:

[0243] .

[0244] As a further preferred method, the unknown quantity is solved by the transcendental equation by numerical method. , and then the equivalent elastic modulus of the ground-connected wall is obtained and hoop stiffness reduction factor .

[0245] The equivalent elastic modulus of the ground-connected wall for:

[0246] ,

[0247] The hoop stiffness reduction factor for:

[0248] .

[0249] In an embodiment of the present invention, a calculation example is given, specifically:

[0250] In step S200 , the joint mud skin is regarded as a linear elastic material, that is, the nonlinear compression characteristics of the mud skin are not considered, and the equivalent elastic modulus of the ground-connected wall considering the joint mud skin can be obtained.

[0251] Assuming that the length of concrete in the ground-wall unit is 6m and the elastic modulus of concrete is 30GPa; the thickness of the joint mud skin is 3mm and the elastic modulus is 10MPa, it can be calculated that α=0.40.

[0252] .

[0253] If the elastic modulus of the joint mud skin is 30MPa, it can be calculated that α =0.67.

[0254] .

[0255] consider Figure 4 The ground-connected wall unit contains two trench sections, where the length of the first-phase trench section is 6.671m and the length of the second-phase trench section is 2.8m. The thickness of the mud skin at the two joints is 3mm and the elastic modulus is 20MPa. At this time, the concrete length is l =9.471m, the length of the mud skin is m =6mm, we can get α =0.513.

[0256] .

[0257] The reduction factor for the above case α It is between 0.4 and 0.7, which is consistent with the engineering experience in relevant specifications.

[0258] In step S300, the nonlinear compression characteristics of the mud skin are: the tangent compression modulus of the mud skin is proportional to the stress and has a power exponential relationship with the strain. Assume that the porosity of the mud skin at 1kPa is e 1=2.5, the compression index is Cc =0.6. The porosity of the mud skin at 100kPa is 1.3, and the compression modulus is E s1-2 It is 1.94MPa, which is consistent with relevant engineering experience.

[0259] In step S300, based on the nonlinear compression characteristics of the mud skin, the equivalent elastic modulus and the folding hoop stiffness reduction coefficient of the ground-connected wall can be calculated according to the current mud skin strain. α Assume that the length of the ground wall groove is 6m, the elastic modulus of the concrete is 30GPa, and the thickness of the joint mud is 3mm. α As shown in the graph of the variation in mud skin strain, this theory well describes the gradual increase in the hoop stiffness of the ground-connected wall as the mud skin deforms. When the mud skin strain reaches 0.7, the reduction factor reaches 0.9, and the equivalent tangent modulus of the ground-connected wall is approximately 27.5 GPa, close to that of concrete.

[0260] In step S400, it is assumed that the circular ground-connected wall has an axis radius of 64.25m and a thickness of 1.5m. The ground-connected wall is divided into 90 slots, 45 for the first phase and 45 for the second phase. n =45, which includes the first phase trough section, the second phase trough section and two joint mud skins, of which the concrete length is l =9.471m, the thickness of mud skin is m =6mm. The porosity of the mud skin at 1kPa is e 1=2.5, the compression index is C c =0.6, the porosity of the mud skin at 100kPa is 1.3, and the compression modulus is E s1-2 It is 1.94MPa. Assuming that the initial horizontal stress at the calculation depth is 100kPa, according to the calculation method proposed in the present invention, the variation law of the equivalent elastic modulus and the circumferential stiffness reduction coefficient of the ground wall with radial deformation can be obtained. The equivalent elastic modulus of the ground wall increases continuously with the increase of the radial deformation of the ground wall. Among them, when the radial deformation of the ground wall is 50mm, the equivalent elastic modulus of the ground wall is 15.13GPa. The circumferential stiffness reduction coefficient of the ground-connected wall increases continuously with the increase of the radial deformation of the ground wall. Among them, when the radial deformation of the ground wall is 30mm, 50mm and 80mm, the reduction coefficients are 0.35, 0.5 and 0.63 respectively.

[0261] In step S400, the calculation method of the present invention indicates that the annular stiffness reduction factor α of the circular ground-connected wall is not a constant value. In addition to the ground-connected wall deformation, it is also dependent on factors such as the ground-connected wall diameter, the number of slots, their depth, and the characteristics of the mud layer. By adjusting the input parameter values, the sensitivity of the annular stiffness reduction factor of the ground-connected wall is studied.

[0262] The axis radius of the ground wall Set to 42.83m, 64.25m and 85.67m, the corresponding number of ground and wall units n The reduction coefficients are calculated for 30, 45, and 60 radial segments, respectively. The following figure shows how the reduction coefficients change with radial deformation of the ground wall. It can be seen that the size of the circular ground wall has a significant impact on the reduction coefficient. A larger radius and a greater number of slot segments result in smaller equivalent elastic modulus and hoop stiffness.

[0263] The following figure shows how the reduction factor changes with radial deformation of the ground wall, with the initial horizontal stress at the calculation location set to 50 kPa, 100 kPa, and 200 kPa. It can be seen that the higher the initial stress level, the greater the initial modulus of the mud skin and the greater the hoop stiffness of the ground wall. When the radial deformation is less than 50 mm, the initial stress level has a certain influence on the reduction factor; when the radial deformation exceeds 50 mm, the effect of the initial stress level on the reduction factor is not significant.

[0264] The thickness of the mud skin in each unit m The following figure shows how the reduction coefficient changes with radial deformation of the ground wall when the thickness is set to 3mm, 6mm, and 9mm, respectively. It can be seen that the thickness of the mud skin has a significant impact on the reduction coefficient: the thicker the mud skin, the smaller the equivalent elastic modulus and hoop stiffness of the ground wall.

[0265] Example 2

[0266] An embodiment of the present invention provides a system for calculating the hoop stiffness of a ground-connected wall, specifically comprising:

[0267] Model Equivalence Module: This module collects design schemes and related parameters of circular ground-connected wall structures, equating the spatial circumferential effect of the circular ground-connected wall to a distributed spring that deforms in the radial direction. Based on the coordination between the circumferential deformation and the radial deformation, the equivalent distributed elastic support coefficient of the circular wall's circumferential effect is obtained.

[0268] Preliminary calculation module: used to determine the annular stiffness reduction factor based on the distribution of the groove section concrete and joint mud skin in the ground-connected wall structure;

[0269] Data acquisition module: used to describe the nonlinear compression characteristics of the joint mud skin and determine the initial stress and strain state of the ground-connected wall concrete and mud skin before excavation;

[0270] Depth calculation module: used to establish a transcendental equation based on the stress-strain relationship between concrete and mud skin, and solve the equivalent elastic modulus and hoop stiffness reduction coefficient of the ground-connected wall.

[0271] According to the above examples, the present application also provides an electronic device, including: a memory, a processor, and a program or instruction stored in the memory and executable on the processor. When the processor executes the program or instruction, the data device of the present invention may further include a communication interface and a bus. Figure 17 , which is a schematic diagram of the structure of the electronic device provided by the present invention, includes: at least one processor 100, at least one memory 101, a communication interface 102 and a bus 103.

[0272] The processor 100, memory 101, and communication interface 102 communicate with each other via a bus 103. The communication interface 102 is used to transmit information between the data device and the database device. The memory 101 stores a program or instruction that can be run on the processor 100. When the processor 100 executes the program or instruction, the steps of the above-described method for automatically tightening a battery pack are implemented.

[0273] In one possible implementation, the memory 101 may include a program storage area and a data storage area, wherein the program storage area may store an operating system and applications required for at least one function, etc.; the data storage area may store data created during use.

[0274] In addition, the memory 101 may include a high-speed random access memory and may also include a non-volatile memory, such as at least one disk storage device or other volatile solid-state storage device.

[0275] The communication interface 102 may be an interface of a communication module, used to connect to other devices or systems.

[0276] Of course, it needs to be explained that Figure 17 The structure shown does not constitute a limitation on the electronic device in the embodiment of the present application. In actual applications, the electronic device may include Figure 17 More or fewer components than shown, or combinations of certain components.

[0277] An embodiment of the present invention further provides a computer-readable storage medium based on the above examples, wherein a computer program is stored on the computer-readable storage medium. When the computer program is executed by a processor, the steps of the automatic tightening method of a battery pack described in the above embodiment are implemented.

[0278] The computer-readable storage medium may include: a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk, etc., which can store program codes.

[0279] It will be easily understood by those skilled in the art that the above description is only 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 in the scope of protection of the present invention.

Claims

1. A method for calculating the hoop stiffness of a ground-connected wall, characterized in that: The following steps are involved: S100. Collect design solutions and related parameters of the circular ground-connected wall structure, equate the spatial circumferential effect of the circular ground-connected wall to a distributed spring that deforms in the radial direction under load, and obtain the equivalent distributed elastic support coefficient of the circumferential effect of the circular wall based on the coordination between the circumferential deformation and the radial deformation. S200, determining the hoop stiffness reduction factor based on the distribution of the groove section concrete and joint mud skin in the ground-connected wall structure; S300, describing the nonlinear compression characteristics of the joint mud skin, and determining the initial stress-strain state of the ground-connected wall concrete and mud skin before excavation; S400. Based on the stress-strain relationship between concrete and mud skin, a transcendental equation is established to solve the equivalent elastic modulus and hoop stiffness reduction factor of the ground-connected wall; In step S300, the elastic modulus of the mud skin It is not a fixed value, but increases with the stress of the mud skin; at this time, the elastic modulus of the mud skin The tangent elastic modulus should be taken , is the derivative of stress with respect to strain; the compression curve of the mud skin is drawn up in The coordinates are linearly distributed. is the void ratio, is stress, at this time, the tangent elastic modulus of the mud skin , specifically: ， in, The porosity ratio of the mud skin when the axial compressive stress is 1 kPa, is the compression index, is the current stress; Current porosity With current stress The relationship between them is: ， The total strain of the mud skin for: ， Then the stress-strain relationship of the mud skin is obtained as follows: ， Therefore, the current stress By strain Expressed as: ； Finally, the tangent elastic modulus of the mud skin is obtained. for: ； To calculate the hoop stiffness of the circular ground wall, in step S300 , the initial stress and strain state of the wall must be determined; The initial stress-strain state of the wall includes the initial horizontal stress of the stratum, the initial circumferential stress and radial stress of the ground-connected wall, the initial strain of the ground-connected wall concrete, the initial strain of the mud skin, and the equivalent initial strain of the ground-connected wall in the concrete-mud skin series load model.

2. The method for calculating the hoop stiffness of a ground-connected wall according to claim 1, characterized in that: In step S200, a concrete-mud skin tandem stress model is used, treating it as a composite material. When considering the stress and deformation of the ground-connected wall in the circumferential direction, the smallest repeatable ground-connected wall unit is used for stress analysis. The angle between adjacent groove segments is not considered. The axial forces at both ends are assumed to be equal in magnitude and opposite in direction. The concrete-mud skin exhibits a tandem stress characteristic, that is, the axial forces applied to the two materials are equal in magnitude, and the resulting deformations are superimposed on each other. The equivalent elastic modulus and reduction factor of the ground-connected wall are then determined. Equivalent elastic modulus of the ground-connected wall considering mud skin for: ， in, is the length of concrete in the repeatable unit, is the length of the mud skin in the repeatable unit, is the elastic modulus of the mud skin, is the elastic modulus of the ground wall concrete; The reduction factor for: 。 3. The method for calculating the hoop stiffness of a ground-connected wall according to claim 2, characterized in that: The concrete length in the repeatable unit , specifically: ， in, 、 They are the concrete lengths of the first-phase diaphragm wall trench section I and the first-phase diaphragm wall trench section II respectively; The length of the mud skin in the repeatable unit , specifically: ， in, 、 are the thickness of mud skin at the two joints respectively.

4. A method for calculating the hoop stiffness of a ground-connected wall according to any one of claims 1 to 3, characterized in that: In step S400, the radial deformation of the ground wall caused by excavation , and the corresponding circumferential deformation of the ground wall is obtained , specifically: ， Then the equivalent current strain of the ground wall is obtained : ， in, is the perimeter of the ring beam, is the initial centerline radius of the ring beam; Equivalent current strain on ground wall Introducing initial strain The equivalent total strain of the ground wall is obtained , ， Then, the equivalent total strain of the ground and wall Equivalent elastic modulus of the ground-connected wall , get the current hoop stress , specifically: ， The current hoop stress Elastic modulus of concrete for ground and wall , calculate the total strain of the ground wall concrete , specifically: ， The total strain of the ground wall concrete and initial strain Get the current strain of concrete , specifically: ， in, is the initial horizontal stress of the formation; The current hoop stress Current strain introduced into concrete The current strain of concrete is obtained Equivalent elastic modulus of ground-connected wall The relationship between them is specifically: 。 5. The method for calculating the hoop stiffness of a ground-connected wall according to claim 4, characterized in that: The circular ground-connected wall is actually composed of multiple repeatable units, and the circumferential deformation of each repeatable unit is for: ， in, is the number of repeatable units; By circumferential deformation of each repeatable unit , the deformation of concrete in each repeatable unit is obtained : ， Then the circumferential deformation of each repeatable unit and the deformation of concrete in each repeatable unit The difference between them is the deformation of the mud skin in each repeatable unit, specifically: ， Then the current strain of the mud skin after excavation is obtained : 。 6. A method for calculating the hoop stiffness of a ground-connected wall according to claim 5, characterized in that: The initial strain of the mud skin and the current strain of the mud skin after excavation , and the total strain of the mud skin is obtained : ， Introducing the stress-strain relationship of the mud skin, we get: ， Combining the above two equations, we can get the equivalent elastic modulus of the ground-connected wall: The relationship is: ， The equivalent elastic modulus of the ground-connected wall The transcendental equation is obtained by simplifying the relationship: ， in, is an unknown quantity, 、 、 All are known coefficients; The known coefficients 、 、 They are: ， The unknown quantity Equivalent elastic modulus of ground-connected wall The relationship between them is: 。 7. The method for calculating the hoop stiffness of a ground-connected wall according to claim 6, characterized in that: Solving unknown quantities from transcendental equations using numerical methods , and then the equivalent elastic modulus of the ground-connected wall is obtained and hoop stiffness reduction factor ; The equivalent elastic modulus of the ground-connected wall for: ， in, is the radial pressure; The hoop stiffness reduction factor for: 。 8. A system for calculating the hoop stiffness of a ground-connected wall, for implementing a method for calculating the hoop stiffness of a ground-connected wall as claimed in any one of claims 1 to 7, characterized in that: include: Model Equivalence Module: This module collects design schemes and related parameters of circular ground-connected wall structures, equating the spatial circumferential effect of the circular ground-connected wall to a distributed spring that deforms in the radial direction. Based on the coordination between the circumferential deformation and the radial deformation, the equivalent distributed elastic support coefficient of the circular wall's circumferential effect is obtained. Preliminary calculation module: used to determine the annular stiffness reduction factor based on the distribution of the groove section concrete and joint mud skin in the ground-connected wall structure; Data acquisition module: used to describe the nonlinear compression characteristics of the joint mud skin and determine the initial stress and strain state of the ground-connected wall concrete and mud skin before excavation; Depth calculation module: used to establish a transcendental equation based on the stress-strain relationship between concrete and mud skin, and solve the equivalent elastic modulus and hoop stiffness reduction coefficient of the ground-connected wall.

9. An electronic device, characterized in that: include at least one memory for storing a computer program; At least one processor is configured to implement the steps of the hoop stiffness calculation method according to any one of claims 1 to 7 when executing the computer program.

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