Method and system for calculating circumferential stiffness of diaphragm wall, electronic equipment and storage medium

Abstract

The invention discloses an underground diaphragm wall annular rigidity calculation method and system, electronic equipment and a storage medium, and the method comprises the steps: S100, collecting a design scheme and related parameters of a circular underground diaphragm wall structure, enabling the space annular effect of a circular underground diaphragm wall to be equivalent to a distribution spring which deforms under stress along the radial direction, and calculating the annular rigidity of the circular underground diaphragm wall according to the coordination of annular deformation and radial deformation; obtaining an equivalent distribution elastic support coefficient of the circular wall circumferential effect; s200, according to the distribution condition of groove section concrete and joint mud cakes in the underground diaphragm wall structure, the annular rigidity reduction coefficient is determined; s300, describing the nonlinear compression characteristics of the joint mud cake, and determining the initial stress-strain state of the concrete and the mud cake of the diaphragm wall before excavation; and S400, a transcendental equation is established according to the stress-strain relation between the concrete and the mud cake, and the equivalent elastic modulus and the circumferential rigidity reduction coefficient of the diaphragm wall are solved. By considering the nonlinear compression characteristic of the joint mud cake, the rule that the circumferential rigidity of the diaphragm wall is increased along with the increase of deformation is described more accurately.

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 annular stiffness of a ground-connected wall. Background Art

[0002] Circular ground-connected walls have been widely used in deep foundation pit projects due to their unique spatial annular effect and superior anti-deformation ability. They have become an important support type for major projects such as anchorages of cross-river bridges, ultra-deep shafts, and shield launch shafts. However, due to construction process limitations, a certain thickness of mud skin is inevitably left between the groove sections of the ground-connected wall. These joint mud skins significantly weaken the overall stiffness of the ground-connected wall, becoming a key factor affecting the wall's stress, structural stability, and construction safety.

[0003] In the current commonly used design methods, the ground-connected wall is usually regarded as a single concrete material, and the influence of the joint mud skin on the hoop stiffness is approximately considered by using a fixed reduction coefficient (such as 0.4-0.7). However, the properties of the joint mud skin are similar to those of soft soil, and its compressibility shows significant nonlinear characteristics: in the early stage of compression, the mud skin stiffness is low, which makes it difficult for the ground-connected wall to form an effective hoop effect, thereby weakening the deformation resistance of the structure; as the mud skin is further compressed, its stiffness gradually increases, and the hoop effect of the ground-connected wall is enhanced accordingly. This law that the hoop effect gradually increases with the increase of deformation cannot be described by a fixed reduction coefficient.

[0004] Since the existing design methods fail to fully consider the influence of the joint mud skin on the circumferential stiffness of the ground-connected wall, the design accuracy is difficult to meet the refinement requirements, which in turn limits the optimization of the safety and economy of the circular ground-connected wall structure. Based on this, the present invention explains the principle of weakening the circumferential effect of the joint on the ground-connected wall, combines the nonlinear compression characteristics of the mud skin, proposes a calculation method for the circumferential stiffness, and determines the law that the circumferential stiffness of the ground-connected wall increases with the increase of deformation. Summary of the invention

[0005] In view of the above defects or improvement needs of the prior art, the present invention provides a method for calculating the annular stiffness of the ground-connected wall. By considering the nonlinear compression characteristics of the joint mud skin, a method for calculating the annular stiffness reduction coefficient is proposed, which can more accurately describe the law that the annular stiffness of the ground-connected wall increases with the increase of deformation. Compared with the traditional fixed reduction coefficient method, this method can more accurately reflect the actual stress condition of the ground-connected wall, thereby improving the 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 annular stiffness of a ground-connected wall is provided, comprising the following steps: S100, collecting design schemes and related parameters of the circular ground-connected wall structure, equating the spatial annular effect of the circular ground-connected wall to a distributed spring that is deformed in the radial direction under stress, and obtaining an equivalent distributed elastic support coefficient of the annular effect of the circular wall according to the coordination between the annular deformation and the radial deformation; S200, determine the annular stiffness reduction factor according to the distribution of the groove section 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 the 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 annular stiffness reduction coefficient of the ground-connected wall.

[0007] Furthermore, in step S200, when considering the stress and deformation of the ground-connected wall in the circumferential direction, the smallest repeatable ground-connected wall unit is taken for stress analysis, and the angle between adjacent groove sections is not considered. It is assumed that the axial forces at both ends are equal in magnitude and opposite in direction, and the concrete-mud skin presents the characteristics of series stress, that is, the axial forces on the two materials are equal in magnitude, and the deformations generated are superimposed on each other, and then the equivalent elastic modulus and reduction factor of the ground-connected wall considering the mud skin are determined; The equivalent elastic modulus of the ground-connected wall considering the 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; The reduction factor for: .

[0008] Furthermore, the concrete length in the repeatable unit is , specifically: , in, , They are the concrete lengths of the first-phase diaphragm wall groove section I and the first-phase diaphragm wall groove 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.

[0009] Furthermore, in step S300, the elastic modulus of the mud skin It is not a fixed value, but as the stress of the mud skin increases, the elastic modulus of the mud skin The tangent elastic modulus should be taken as is the derivative of stress to strain; the compression curve of the mud skin is proposed 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.

[0010] Furthermore, the porosity ratio 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 It is expressed as: ; Finally, the tangent elastic modulus of the mud skin is obtained. for: .

[0011] Furthermore, to calculate the hoop stiffness of the circular ground wall, in step S300, the initial stress-strain state of the wall needs to be determined; The initial stress-strain state of the wall includes the initial horizontal stress of the stratum, the initial annular 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 stress model.

[0012] Further, in step S400, the radial deformation of the ground wall caused by excavation , and the corresponding ground wall annular deformation is obtained , specifically: , Then the equivalent current strain of the ground wall is obtained : , Equivalent current strain on ground wall The initial strain is introduced into Then the equivalent total strain of the ground wall is obtained , , Then the equivalent total strain of the ground and wall Equivalent elastic modulus of ground-connected wall , get the current hoop stress , specifically: , The current hoop stress is Elastic modulus of concrete for ground and wall , the total strain of the ground wall concrete is calculated , specifically: , The total strain of the ground wall concrete and initial strain Get the current strain of concrete , specifically: , The current hoop stress The current strain in the concrete The current strain of concrete is obtained Equivalent elastic modulus of ground-connected wall The relationship between them is specifically: .

[0013] Furthermore, the circular ground connection wall is actually composed of multiple repeatable units, and the annular deformation of each repeatable unit for: , in, is the number of repeatable units.

[0014] Through the 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 the concrete in each repeatable unit The difference between them is the deformation of the mud skin in each repeatable unit, which is: , Then the current strain of the mud skin after excavation is obtained : .

[0015] Furthermore, 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 as follows: , The equivalent elastic modulus of the ground-connected wall The transcendental equation is obtained by simplifying the relational expression: , in, is the 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: .

[0016] 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 the hoop stiffness reduction factor ; The equivalent elastic modulus of the ground-connected wall for: , The annular stiffness reduction factor for: .

[0017] 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: Model equivalent module: used to collect the design scheme and related parameters of the circular ground-connected wall structure, and to equate the spatial annular effect of the circular ground-connected wall to a distributed spring that is deformed in the radial direction. Based on the coordination between the annular deformation and the radial deformation, the equivalent distributed elastic support coefficient of the annular effect of the circular wall is obtained. Preliminary calculation module: used to determine the annular stiffness reduction factor according to 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-strain state of the ground-connected wall concrete and mud skin before excavation; Depth calculation module: used to establish transcendental equations based on the stress-strain relationship between concrete and mud skin, and solve the equivalent elastic modulus and annular stiffness reduction coefficient of the ground-connected wall.

[0018] An embodiment of the present invention further provides an electronic device, including: at least one memory for storing a computer program; At least one processor is used to implement the steps of the hoop stiffness calculation method when executing the computer program.

[0019] An embodiment of the present invention further provides a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, the steps of the method for calculating the hoop stiffness are implemented.

[0020] In general, the above technical solutions conceived by the present invention can achieve the following beneficial effects compared with the prior art: 1. The hoop stiffness calculation method of the present invention proposes a calculation method for the hoop stiffness reduction coefficient by considering the nonlinear compression characteristics of the joint mud skin, which can more accurately describe the law that the hoop stiffness of the ground-connected wall increases with the increase of deformation. Compared with the traditional fixed reduction coefficient method, this method can more accurately reflect the actual stress condition of the ground-connected wall, thereby improving the design accuracy and ensuring the safety and stability of the structure.

[0021] 2. The hoop stiffness calculation method of the present invention can avoid over-design or under-design by accurately calculating the hoop stiffness of the ground-connected wall, thereby optimizing the structural design of the ground-connected wall, reducing material waste, and lowering engineering costs. The method can achieve a more economical design solution while ensuring safety.

[0022] 3. The hoop stiffness calculation method of the present invention can dynamically adjust the hoop stiffness reduction coefficient according to different engineering conditions (such as the diameter of the ground anchor wall, the number of slot sections, the thickness of the mud skin, the initial stress, etc.), and adapt to various complex engineering environments. In particular, in major projects such as deep foundation pits and cross-river bridge anchorages, it can better cope with different geological conditions and construction requirements.

[0023] 4. The hoop stiffness calculation method of the present invention, by considering the compression characteristics of the joint mud skin, can more accurately predict the deformation behavior of the ground-connected wall during the force process, ensuring that the ground-connected wall has a stronger anti-deformation ability 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

[0024] Figure 1 A schematic diagram of a flow chart of a method for calculating the annular stiffness of a ground-connected wall according to an embodiment of the present invention; Figure 2 Schematic diagram of radial deformation of a circular ground-connected wall according to an embodiment of the present invention; Figure 3 A schematic diagram of a concrete-mud series stress model of a minimum repeatable ground-to-wall unit according to an embodiment of the present invention; Figure 4 A schematic diagram of the relationship between the porosity ratio of the mud skin and the strain of the minimum repeatable ground-wall unit according to an embodiment of the present invention; Figure 5 A schematic diagram of the stress-strain relationship of the mud skin of the minimum repeatable ground-to-wall unit according to an embodiment of the present invention; Figure 6 Schematic diagram of the relationship between the compression modulus and stress of the mud skin of the minimum repeatable ground-to-wall unit according to an embodiment of the present invention; Figure 7 Schematic diagram of the relationship between the compression modulus and strain of the mud skin of the minimum repeatable ground-wall unit according to an embodiment of the present invention; Figure 8 Schematic diagram of the relationship between the ground wall equivalent elastic modulus and the mud skin strain of the minimum repeatable ground-to-wall unit according to an embodiment of the present invention; Fig. 9 Schematic diagram of the relationship between the ground wall annular stiffness reduction coefficient α and the mud skin strain of the minimum repeatable ground-to-wall unit according to an embodiment of the present invention; Fig.10 It is a linear coordinate schematic diagram of the variation law of the equivalent elastic modulus of the ground wall of the minimum repeatable ground-to-wall unit with radial deformation according to an embodiment of the present invention; Fig.11 It is a logarithmic coordinate diagram of the variation law of the equivalent elastic modulus of the ground wall of the minimum repeatable ground-to-wall unit with radial deformation according to an embodiment of the present invention; Fig.12It is a linear coordinate schematic diagram of the variation law of the ground wall annular stiffness reduction coefficient of the minimum repeatable ground-to-wall unit with radial deformation according to an embodiment of the present invention; Fig.13 It is a logarithmic coordinate diagram of the variation law of the ground wall annular stiffness reduction coefficient of the minimum repeatable ground-to-wall unit with radial deformation according to an embodiment of the present invention; Fig.14 Schematic diagram of 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; Fig.15 Schematic diagram of the influence of the initial horizontal stress of the minimum repeatable ground-to-wall unit on the reduction factor in an embodiment of the present invention; Fig.16 Schematic diagram of the influence of the mud skin thickness of the minimum repeatable ground-to-wall unit on the reduction coefficient in an embodiment of the present invention; Fig.17 The present invention is a schematic diagram of the structure of an electronic device for calculating the annular stiffness of a ground-connected wall according to an embodiment of the present invention. DETAILED DESCRIPTION

[0025] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain 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 can be combined with each other as long as they do not conflict with each other.

[0026] Example 1 like Figure 1 As shown, an embodiment of the present invention provides a method for calculating the annular stiffness of a ground-connected wall, which specifically includes the following steps: S100, collecting design schemes and related parameters of the circular ground-connected wall structure, equating the spatial annular effect of the circular ground-connected wall to a distributed spring that is deformed in the radial direction under stress, and obtaining an equivalent distributed elastic support coefficient of the annular effect of the circular wall according to the coordination between the annular deformation and the radial deformation; S200, determine the annular stiffness reduction factor according to the distribution of the groove section 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 the 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 annular stiffness reduction coefficient of the ground-connected wall.

[0027] 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.

[0028] In step S100, for a given calculated depth, a unit-height annular wall is laterally cut out from the circular ground wall, which will produce inward compression deformation under the action of pressure.

[0029] In step S100, it is specifically also included: providing a beam-spring calculation model that considers the annular effect of the ring beam or the wall itself. In the plane problem, the spatial annular effect of each supporting ring beam can be replaced by a supporting spring that deforms in the radial direction, and the spatial annular effect of the wall itself can be replaced by a distributed spring along the depth direction of the wall.

[0030] 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 center line of the ring beam and reduces the radius, that is, the circumferential deformation and radial deformation occur simultaneously. The axial force of the ring beam is calculated according to the formula of a homogeneous ring under uniform radial pressure, which is: , in, is the axial force of the ring beam (kN), is the initial centerline radius of the ring beam, is the radial pressure (kN / m 2 ), is the ring beam height (m), is the annular pressure (kN / m 2 ), is the width of the ring beam (m).

[0031] According to the axial force of the ring beam , and then the hoop compressive strain of the ring beam is obtained for: , in, is the elastic modulus of the ring beam material (kN / m 2 ).

[0032] 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: , in, is the circumference of the ring beam (m); And the change in the beam centerline circumference and radius change The relationship between them is: , Then we combine them to get: .

[0033] The supporting function of the ring beam is replaced by an equivalent supporting spring that is deformed in the radial direction to obtain the equivalent spring stiffness of the ring beam: (kN / m 2 ): , Then substitute it into the equation: .

[0034] Similarly, when calculating the equivalent elastic support coefficient of the spatial annular effect of the wall itself, at the calculation depth, a ring wall of unit height is cut out horizontally from the circular wall. The 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 ): , in, is the initial centerline radius of the ground wall (m), is the thickness of the ground wall (m), 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.

[0035] In step S200, since the circular ground-connected wall structure is composed of two materials, the groove section concrete and the joint mud skin, the mud skin has strong compressibility and low elastic modulus, which will weaken the overall rigidity of the ground-connected wall structure. Therefore, through the concrete-mud skin series force model, it is regarded as a composite material, and then the equivalent elastic modulus of the ground-connected wall is determined.

[0036] like Figure 3 As shown in the figure, when considering the stress and deformation of the ground-connected wall in the circumferential direction, the smallest repeatable ground-connected wall unit is taken for stress analysis. The angle between adjacent slot sections is not considered, and the axial forces at both ends are assumed to be equal in magnitude and opposite in direction. Concrete-mud skin presents the characteristics of series stress, that is, the axial forces on the two materials are equal in magnitude, and the resulting deformations are superimposed on each other. Then the equivalent elastic modulus and reduction factor of the ground-connected wall considering the mud skin are determined.

[0037] The equivalent elastic modulus of the ground-connected wall considering the mud skin (kPa) is: , in, is the length of concrete in the repeatable unit (m), is the length of the mud skin in the repeatable unit (m), is the elastic modulus of the mud skin (kPa); The reduction factor for: .

[0038] 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 (m); The length of the mud skin in the repeatable unit , specifically: , in, , are the thickness of mud skin at the two joints (m).

[0039] 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; 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: , in, The porosity ratio of the mud skin when the axial compressive stress is 1 kPa, is the compression index, is the current stress.

[0040] The porosity ratio of the mud skin at 1 kPa axial compressive stress is , specifically: , in, is the initial porosity ratio of the mud skin in its natural state, is the rebound index, is the initial consolidation pressure.

[0041] The initial porosity of the mud skin in its natural state is , Rebound Index , initial consolidation pressure And the compression index All are determined by standard consolidation tests.

[0042] The porosity ratio is obtained 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 It is expressed as: .

[0043] Finally, the tangent elastic modulus of the mud skin is obtained. for: .

[0044] 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 Both gradually increase with the increase of wall stress and strain. Therefore, to calculate the hoop stiffness of the circular ground wall, in step S300, it is also necessary to determine the initial stress and strain state of the wall, that is, to determine the boundary conditions of the problem.

[0045] The initial stress-strain state of the wall includes the initial horizontal stress of the stratum, the initial annular 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 stress model.

[0046] The initial horizontal stress of the stratum is considered based on the water-soil balance, specifically: , in, is the initial horizontal stress of the formation (kN / m 2 ), are the lateral pressure coefficient, density and thickness of each soil layer respectively; The initial hoop stress and radial stress of the ground-connected wall are equal to the initial horizontal ground stress, that is: , in, is the initial hoop stress of the ground-connected wall, is the initial radial stress of the ground-connected wall; The initial strain of the ground wall concrete , specifically: ; The initial strain of the mud skin , specifically: ; The equivalent initial strain of the ground-connected wall in the concrete-mud series load model , specifically: .

[0047] It should be noted that the initial hoop strain of the ground-connected wall is caused by the initial stress of the stratum after its construction. This part of the 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.

[0048] 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.

[0049] In step S400, the radial deformation of the ground wall caused by excavation , and the corresponding ground wall annular deformation is obtained , specifically: , Then the equivalent current strain of the ground wall is obtained : , Equivalent current strain on ground wall The initial strain is introduced into Then the equivalent total strain of the ground wall is obtained , , Then the equivalent total strain of the ground and wall Equivalent elastic modulus of ground-connected wall , get the current hoop stress , specifically: , The current hoop stress is Elastic modulus of concrete for ground and wall , the total strain of the ground wall concrete is calculated , specifically: , The total strain of the ground wall concrete and initial strain Get the current strain of concrete , specifically: , The current hoop stress The current strain in the concrete The current strain of concrete is obtained Equivalent elastic modulus of ground-connected wall The relationship between them is specifically: .

[0050] The circular ground-connected wall is actually composed of multiple repeatable units, and the annular deformation of each repeatable unit for: , in, is the number of repeatable units.

[0051] Through the 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 the concrete in each repeatable unit The difference between them is the deformation of the mud skin in each repeatable unit, which is: , Then the current strain of the mud skin after excavation is obtained : .

[0052] 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 as follows: , The equivalent elastic modulus of the ground-connected wall The transcendental equation is obtained by simplifying the relational expression: , in, is the unknown quantity, , , All are known coefficients.

[0053] The known coefficients , , They are: , The unknown quantity Equivalent elastic modulus of ground-connected wall The relationship between them is: .

[0054] 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 the hoop stiffness reduction factor .

[0055] The equivalent elastic modulus of the ground-connected wall for: , The annular stiffness reduction factor for: .

[0056] In the embodiment of the present invention, a calculation example is given, specifically: 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.

[0057] 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.

[0058] .

[0059] If the elastic modulus of the joint mud skin is 30MPa, it can be calculated that α =0.67.

[0060] .

[0061] consider Figure 4 The ground-connected wall unit contains two trench sections, of which the length of the first-stage trench section is 6.671m, the length of the second-stage 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.

[0062] .

[0063] 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.

[0064] 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 exponentially related to the strain. Assume that the porosity of the mud skin at 1 kPa is e 1=2.5, the compression index is C c =0.6. The porosity ratio of the mud skin at 100 kPa is 1.3, and the compression modulus is E s1-2 It is 1.94MPa, which is consistent with relevant engineering experience.

[0065] 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 skin is 3mm. α As shown in the graph of the variation of mud skin strain, this theory can well describe the property that the hoop stiffness of the ground-connected wall gradually increases with the deformation of the mud skin. When the mud skin strain reaches 0.7, the reduction factor reaches 0.9. At this time, the equivalent tangent modulus of the ground-connected wall is about 27.5GPa, which is close to that of concrete material.

[0066] In step S400, it is assumed that the axial radius of the circular ground-connected wall is 64.25 m and the thickness is 1.5 m. The ground-connected wall is divided into 90 slots, 45 first-stage slots and 45 second-stage slots. The number of repeatable ground-connected wall units is n =45, which includes the first phase trench section, the second phase trench 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 100 kPa is 1.3, and the compression modulus 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 annular 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 annular 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.

[0067] In step S400, the calculation method of the present invention shows that the annular stiffness reduction coefficient α of the circular ground-connected wall is not a constant value. In addition to the ground wall deformation, it is also related to factors such as the ground wall diameter, the number of groove sections, the position depth, and the mud skin characteristics. By adjusting the input parameter value, the sensitivity of the annular stiffness reduction coefficient of the ground-connected wall is studied.

[0068] The radius of the axis of the ground wall Set to 42.83m, 64.25m and 85.67m, the corresponding number of ground and wall units n The number of grooves is 30, 45 and 60 respectively. The change law of the reduction coefficient with the radial deformation of the ground wall is shown in the figure below. It can be seen that the size of the circular ground-connected wall has a greater influence on the reduction coefficient. The larger the radius and the more grooves there are, the smaller the equivalent elastic modulus and annular stiffness of the ground-connected wall.

[0069] The initial horizontal stress at the calculation position is set to 50kPa, 100kPa and 200kPa, and the change law of the reduction coefficient with the radial deformation of the ground wall is calculated as shown in the figure below. 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 50mm, the initial stress level has a certain influence on the reduction coefficient; when the radial deformation exceeds 50mm, the initial stress level has no obvious influence on the reduction coefficient.

[0070] The thickness of the mud skin in each unit m The following figure shows the change of the reduction coefficient with the radial deformation of the ground wall when the thickness is set to 3mm, 6mm and 9mm. It can be seen that the thickness of the mud skin has a greater impact on the reduction coefficient. The greater the thickness of the mud skin, the smaller the equivalent elastic modulus and annular stiffness of the ground wall.

[0071] Example 2 The embodiment of the present invention provides a system for calculating the hoop stiffness of a ground-connected wall, which specifically includes: Model equivalent module: used to collect the design scheme and related parameters of the circular ground-connected wall structure, and to equate the spatial annular effect of the circular ground-connected wall to a distributed spring that is deformed in the radial direction. Based on the coordination between the annular deformation and the radial deformation, the equivalent distributed elastic support coefficient of the annular effect of the circular wall is obtained. Preliminary calculation module: used to determine the annular stiffness reduction factor according to 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-strain state of the ground-connected wall concrete and mud skin before excavation; Depth calculation module: used to establish transcendental equations based on the stress-strain relationship between concrete and mud skin, and solve the equivalent elastic modulus and annular stiffness reduction coefficient of the ground-connected wall.

[0072] 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. Fig.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.

[0073] The processor 100, the memory 101 and the communication interface 102 communicate with each other via the bus 103, and the communication interface 102 is used for information transmission between the data device and the database device; the memory 101 stores a program or instruction that can be run on the processor 100, and when the processor 100 executes the program or instruction, the steps of the above-mentioned method for automatically tightening a battery pack are implemented.

[0074] In a 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 an application required for at least one function, etc.; the data storage area may store data created during use.

[0075] 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.

[0076] The communication interface 102 may be an interface of a communication module, and is used to connect to other devices or systems.

[0077] Of course, it should be noted that Fig.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 Fig.17 More or fewer components than shown, or combinations of certain components.

[0078] An embodiment of the present invention further provides a computer-readable storage medium according to 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 a method for automatically tightening a battery pack described in the above embodiments are implemented.

[0079] 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, and other media that can store program codes.

[0080] 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 protection scope of the present invention.

Claims

1. A method for calculating the annular stiffness of a ground-connected wall, characterized in that: The following steps are involved: S100, collecting design schemes and related parameters of the circular ground-connected wall structure, equating the spatial annular effect of the circular ground-connected wall to a distributed spring that is deformed in the radial direction under stress, and obtaining an equivalent distributed elastic support coefficient of the annular effect of the circular wall according to the coordination between the annular deformation and the radial deformation; S200, determine the annular stiffness reduction factor according to the distribution of the groove section 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 the 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 annular stiffness reduction coefficient of the ground-connected wall.

2. A method for calculating the annular stiffness of a ground-connected wall according to claim 1, characterized in that: In step S200, the concrete-mud skin is regarded as a composite material through a series stress model. When considering the stress and deformation of the ground-connected wall in the circumferential direction, the minimum repeatable ground-connected wall unit is taken for stress analysis, and the angle between adjacent groove sections is not considered. It is assumed that the axial forces at both ends are equal in magnitude and opposite in direction. The concrete-mud skin presents the characteristics of series stress, that is, the axial forces on the two materials are equal in magnitude, and the deformations generated are superimposed on each other. Then, the equivalent elastic modulus and reduction factor of the ground-connected wall considering the mud skin are determined; The equivalent elastic modulus of the ground-connected wall considering the 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; The reduction factor for: 。 3. A method for calculating the annular 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 annular stiffness of a ground-connected wall according to any one of claims 1 to 3, characterized in that: In step S300, the elastic modulus of the mud skin It is not a fixed value, but as the stress of the mud skin increases, the elastic modulus of the mud skin The tangent elastic modulus should be , is the derivative of stress to strain; the compression curve of the mud skin is proposed 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; The void ratio 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 It is expressed as: ； Finally, the tangent elastic modulus of the mud skin is obtained. for: 。 5. A method for calculating the annular stiffness of a ground-connected wall according to claim 4, characterized in that: To calculate the hoop stiffness of the circular ground wall, in step S300, the initial stress-strain state of the wall needs to be determined; The initial stress-strain state of the wall includes the initial horizontal stress of the stratum, the initial annular 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 stress model.

6. A method for calculating the annular stiffness of a ground-connected wall according to claim 5, characterized in that: In step S400, the radial deformation of the ground wall caused by excavation , and the corresponding ground wall annular deformation is obtained , specifically: ， Then the equivalent current strain of the ground wall is obtained : ， Equivalent current strain on ground wall The initial strain is introduced into Then the equivalent total strain of the ground wall is obtained , ， Then the equivalent total strain of the ground and wall Equivalent elastic modulus of ground-connected wall , get the current hoop stress , specifically: ， The current hoop stress is Elastic modulus of concrete for ground and wall , the total strain of the ground wall concrete is calculated , specifically: ， The total strain of the ground wall concrete and initial strain Get the current strain of concrete , specifically: ， The current hoop stress The current strain in the concrete The current strain of concrete is obtained Equivalent elastic modulus of ground-connected wall The relationship between them is specifically: 。 7. A method for calculating the hoop stiffness of a ground-connected wall according to claim 6, characterized in that: The circular ground-connected wall is actually composed of multiple repeatable units, and the annular deformation of each repeatable unit for: ， in, is the number of repeatable units; Through the 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 the concrete in each repeatable unit The difference between them is the deformation of the mud skin in each repeatable unit, which is: ， Then the current strain of the mud skin after excavation is obtained : 。 8. A method for calculating the annular stiffness of a ground-connected wall according to claim 7, 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 as follows: ， The equivalent elastic modulus of the ground-connected wall The transcendental equation is obtained by simplifying the relational expression: ， in, is the 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: 。 9. A method for calculating the hoop stiffness of a ground-connected wall according to claim 8, characterized in that: Solving the unknowns from transcendental equations by numerical methods , and then the equivalent elastic modulus of the ground-connected wall is obtained and the hoop stiffness reduction factor ; The equivalent elastic modulus of the ground-connected wall for: ， The annular stiffness reduction factor for: 。 10. A system for calculating the annular stiffness of a ground-connected wall, used to implement a method for calculating the annular stiffness of a ground-connected wall as claimed in any one of claims 1 to 9, characterized in that: include: Model equivalent module: used to collect the design scheme and related parameters of the circular ground-connected wall structure, and to equate the spatial annular effect of the circular ground-connected wall to a distributed spring that is deformed in the radial direction. Based on the coordination between the annular deformation and the radial deformation, the equivalent distributed elastic support coefficient of the annular effect of the circular wall is obtained. Preliminary calculation module: used to determine the annular stiffness reduction factor according to 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-strain state of the ground-connected wall concrete and mud skin before excavation; Depth calculation module: used to establish transcendental equations based on the stress-strain relationship between concrete and mud skin, and solve the equivalent elastic modulus and annular stiffness reduction coefficient of the ground-connected wall.

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

12. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the steps of the method for calculating the circumferential stiffness according to any one of claims 1 to 9 are implemented.

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