Design method of deep foundation pit bracing blade wall based on stiffness matching and deformation control

Abstract

The application discloses a design method of a deep foundation pit support replacement blade wall based on stiffness matching and deformation control, and the method comprises the following steps: obtaining equivalent stiffness of original support and deformation control indexes of a retaining structure; establishing a shear-bending coupling stiffness model of a blade wall surface; setting a stiffness matching coefficient, constructing a stiffness matching equation, and solving recommended section parameter combinations; establishing a deformation control equation of the retaining structure based on the principle of an elastic foundation beam, inversely calculating a maximum allowable spacing, and outputting a standardized spacing; establishing a double-control reinforcement model, introducing an importance reduction coefficient of a temporary structure, calculating edge longitudinal reinforcement area and horizontal distribution reinforcement reinforcement rate, and outputting complete design parameters. The application realizes rapid design of the blade wall based on stiffness matching and deformation control for the first time, and the efficiency is improved by more than 80% compared with a traditional finite element trial method, and the deformation of a supporting system before and after support replacement is continuous, and a failure mode is controllable.

Description

Technical Field

[0001] This invention belongs to the field of building construction technology, and specifically relates to a design method for deep foundation pit replacement blade wall based on stiffness matching and deformation control. Background Technology

[0002] Currently, to guide the formwork and reinforcement processing of cast-in-place reinforced concrete blade wall projects, or for the industrial production of prefabricated blade wall units suitable for various deep foundation pit support replacement projects, existing design methods for deep foundation pit support replacement blade walls rely on experience or finite element analysis. This results in long design times for individual cases and low design efficiency. Furthermore, existing design methods for deep foundation pit support replacement blade walls often result in inconsistencies between the blade wall stiffness and the original support, easily leading to uncontrolled stress redistribution in the retaining structure before and after support replacement. Finally, existing design methods for deep foundation pit support replacement blade walls cannot ensure "strong shear and weak bending," leading to wasted reinforcement materials. Summary of the Invention

[0003] This invention aims to provide a design method for deep foundation pit replacement blade wall based on stiffness matching and deformation control. It transforms the traditional design mode, which relies on experience or finite element trial calculations, into a step-by-step, formulaic explicit calculation method. The design time for a single working condition is controlled within 20 minutes, improving efficiency by over 80%, thus filling a gap in replacement blade wall design methods. Through a shear-bending coupled stiffness model and a graded matching coefficient "α", the stiffness of the blade wall is coordinated with the original support, avoiding uncontrolled redistribution of stress in the retaining structure before and after replacement, thereby ensuring stiffness coordination and deformation continuity. By setting an importance coefficient γ according to the replacement layer, and controlling the target failure mode to ensure "strong shear and weak bending", graded reinforcement is achieved, effectively saving materials.

[0004] To solve the above-mentioned technical problems, the present invention provides the following technical solution:

[0005] A design method for deep foundation pit replacement blade wall based on stiffness matching and deformation control includes the following steps:

[0006] Step 1: Parameter Acquisition

[0007] Obtain the equivalent stiffness of the original support at the layer to be replaced. And deformation control indicators of the retaining structure under the condition of support replacement. ;

[0008] Step 2: Stiffness Matching Design

[0009] Establish a calculation model for the lateral stiffness of the blade wall. ,in For the length of the blade wall, For blade wall thickness, For the height of the blade wall, These are the elastic modulus and shear modulus of the wall material for the blade wall; a stiffness matching coefficient is set. Construct stiffness matching equations By combining the preset structural constraints, at least one set of recommended blade wall section parameters can be obtained. combination;

[0010] Step 3: Deformation Control Design

[0011] Based on the cross-sectional parameters determined in step 2, a deformation control equation for the enclosure structure under the support of discrete blade walls is established, using the aforementioned deformation control index. As boundary conditions, calculate the maximum allowable spacing of the blade walls. Based on the principle of modularization, the standardized blade wall layout spacing is output. ;

[0012] Step 4: Reinforcement Design

[0013] Based on the blade wall section parameters output in step 2 and the standardized blade wall arrangement spacing output in step 3 A stress analysis model of the blade wall was established, and the design bending moment of the blade wall under the condition of bracing replacement was calculated. and shear design value Calculate the area of ​​longitudinal reinforcement at the edge of the blade wall according to the formulas for the bearing capacity of reinforced concrete normal and oblique sections. and horizontal distribution reinforcement ratio and output the blade wall section parameters. Standardized blade wall layout spacing Edge longitudinal reinforcement area and horizontal distribution reinforcement ratio .

[0014] Preferably, the calculation model for the lateral stiffness of the blade wall in step 2 is a coupled stiffness model considering bending deformation and shear deformation, and its expression is:

[0015]

[0016] in, Let the moment of inertia of the cross section be... For cross-sectional area, The coefficient for shear stress non-uniformity is 1.2 for rectangular sections.

[0017] Preferably, the stiffness matching coefficient in step 2 Based on the distance from the bottom of the pit to the support layer The hierarchical settings are as follows:

[0018] When d≤3m, it is defined as the lower support layer, and is taken as... ;

[0019] When 3 < d ≤ 6m, it is defined as the middle strut replacement layer, and take ;

[0020] When d > 6m, it is defined as the upper strut replacement layer, and take .

[0021] Preferably, the construction constraint conditions in step 2 include: the thickness of the blade wall ; the height-width ratio of the blade wall .

[0022] Preferably, in step 3, establishing the deformation control equation of the retaining structure under the discrete blade wall support specifically includes: equivalent the discrete support of the blade wall to an elastic point support, and establish the deflection differential equation of the retaining pile or retaining wall based on the elastic foundation beam or the finite difference method; take the deformation control index as the limit condition of the lateral displacement of the retaining structure, and iteratively solve or analytically solve the maximum allowable spacing of the blade wall; round down the maximum allowable spacing of the blade wall to the preset modular spacing series, and output the standardized blade wall layout spacing .

[0023] ​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​

[0029]

[0030] in, The horizontal distribution reinforcement ratio, This is the design value for the tensile strength of the stirrups. The spacing between horizontally distributed reinforcing bars.

[0031] Preferably, in the above-described design method for deep foundation pit replacement blade wall based on stiffness matching and deformation control, step 4 further includes a target failure mode control step:

[0032] Based on the target failure mode instructions input by the designers, the importance coefficient of the temporary structure is determined differentially. Reinforcement control conditions:

[0033] If the target failure mode instruction is "ductile bending failure", then... And configure horizontally distributed reinforcement according to the principle of strong shear and weak bending to meet the requirements. ;

[0034] If the target failure mode instruction is "economic reinforcement mode", then... Reinforcement is configured according to the principle of simultaneous bending and shear, to meet the requirements. ;

[0035] in, The flexural bearing capacity is calculated based on the actual reinforcement. This represents the shear capacity calculated based on the actual reinforcement.

[0036] Preferably, in the above-mentioned design method for deep foundation pit replacement blade wall based on stiffness matching and deformation control, step 4 further includes a failure mode determination step:

[0037] Calculate the ultimate load based on flexural reinforcement and the ultimate load according to shear reinforcement ,in, ;like If so, a "Bending Failure Control" message will be output; if If the condition is not met, a "shear failure control" message will be output, and it will be suggested that the reinforcement scheme be adjusted.

[0038] Preferably, in the above-mentioned deep foundation pit replacement blade wall design method based on stiffness matching and deformation control, the blade wall section parameters output in step 4 are... Standardized blade wall layout spacing Edge longitudinal reinforcement area and horizontal distribution reinforcement ratio Used for the industrial production of prefabricated blade wall units, or for the processing of formwork and reinforcing bars for cast-in-place reinforced concrete blade walls.

[0039] As can be seen from the above-disclosed technical solutions, compared with the prior art, the beneficial effects of the deep foundation pit replacement blade wall design method based on stiffness matching and deformation control provided by the present invention are as follows:

[0040] (1) Filling the gap in the design method of blade wall replacement: For the first time, an integrated explicit design method of "stiffness matching - deformation control - reinforcement design" for blade wall replacement is proposed, which transforms the traditional design mode that relies on experience or finite element trial calculation into a step-by-step, formulaic explicit calculation. The design time for a single working condition is controlled within 20 minutes, and the efficiency is improved by more than 80%.

[0041] (2) Stiffness compatibility ensures deformation continuity: through a shear-bending coupled stiffness model and graded matching coefficients. This ensures that the stiffness of the blade wall is coordinated with the original support, preventing uncontrolled redistribution of forces in the enclosure structure before and after the support replacement.

[0042] (3) Graded reinforcement to save materials: The importance coefficient is set according to the layer of the replacement support. The "strong shear and weak bending" principle is ensured through target destruction mode control.

[0043] (4) Wide range of applications: It can guide the formwork and steel bar processing of cast-in-place reinforced concrete blade walls, and can also be used for the industrial production of prefabricated assembled blade wall units. It is suitable for various deep foundation pit replacement projects. Attached Figure Description

[0044] Figure 1 A side view of the blade wall for replacing the support in the deep foundation pit, the retaining structure, and the original support of the layer to be replaced.

[0045] Figure 2 A top-view schematic diagram of the blade wall for deep foundation pit replacement, the retaining structure, and the original supports of the layer to be replaced.

[0046] In the diagram: 1-Original support of the layer to be replaced, 2-Enclosure structure, 3-Blade wall. Detailed Implementation

[0047] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. The technical content and features of the present invention will be described in detail below with reference to the listed embodiments and the accompanying drawings. It should be noted that the drawings are all in a very simplified form and use non-precise proportions, and are only used to facilitate and clarify the illustration of the embodiments of the present invention. For ease of description, the terms "upper" and "lower" used below are consistent with the upper and lower directions in the accompanying drawings, but this should not be construed as a limitation of the technical solution of the present invention.

[0048] Please see Figures 1 to 2 This embodiment discloses a design method for a deep foundation pit replacement blade wall based on stiffness matching and deformation control, including the following steps:

[0049] Step 1: Parameter Acquisition

[0050] Obtain the equivalent stiffness of the original support 1 at the layer to be replaced. And the deformation control index of the retaining structure 2 under the support replacement condition. ;

[0051] Step 2: Stiffness Matching Design

[0052] Establish a calculation model for the lateral stiffness of the blade wall. ,in For the blade wall 3 wall length, For blade wall thickness, For the height of the blade wall, These are the elastic modulus and shear modulus of the wall material for the blade wall; a stiffness matching coefficient is set. Construct stiffness matching equations By combining the preset structural constraints, at least one set of recommended blade wall section parameters can be obtained. combination;

[0053] Step 3: Deformation Control Design

[0054] Based on the cross-sectional parameters determined in step 2, a deformation control equation for the enclosure structure under the support of discrete blade walls is established, using the aforementioned deformation control index. As boundary conditions, calculate the maximum allowable spacing of the blade walls. Based on the principle of modularization, the standardized blade wall layout spacing is output. ;

[0055] Step 4: Reinforcement Design

[0056] Based on the blade wall section parameters output in step 2 and the standardized blade wall arrangement spacing output in step 3 A stress analysis model of the blade wall was established, and the design bending moment of the blade wall under the condition of bracing replacement was calculated. and shear design value Calculate the area of ​​longitudinal reinforcement at the edge of the blade wall according to the formulas for the bearing capacity of reinforced concrete normal and oblique sections. and horizontal distribution reinforcement ratio and output the blade wall section parameters. Standardized blade wall layout spacing Edge longitudinal reinforcement area and horizontal distribution reinforcement ratio .

[0057] Preferably, in the above-mentioned design method for deep foundation pit replacement blade wall based on stiffness matching and deformation control, the calculation model for the lateral stiffness of the blade wall in step 2 is a coupled stiffness model considering bending deformation and shear deformation, and its expression is:

[0058]

[0059] in, Let the moment of inertia of the cross section be... For cross-sectional area, The coefficient for shear stress non-uniformity is 1.2 for rectangular sections.

[0060] The derivation process of the coupled stiffness model considering bending and shear deformation is as follows:

[0061] For bottom consolidation, high ,Width ,thick The blade wall is subjected to a uniformly distributed load along its height. Its bottom bending moment The bottom shear force V = qH;

[0062] Vertex displacement calculation (bending + shear):

[0063] According to structural mechanics, the vertex displacement of a cantilever member under uniformly distributed load... It consists of two parts:

[0064] (1)

[0065] in:

[0066] Δb: Displacement caused by bending deformation

[0067] Δs: Displacement caused by shear deformation

[0068] The elastic modulus of concrete for blade walls.

[0069] The moment of inertia of the rectangular section of the blade wall.

[0070] : Shear modulus of blade wall

[0071] Lateral stiffness of blade wall Defined as the total horizontal force required to produce a unit vertex displacement:

[0072] (2)

[0073] Substituting equation (1) into equation (2), we can obtain the lateral stiffness of the blade wall considering bending and shear coupling. :

[0074]

[0075] Preferably, in the above-mentioned design method of the deep foundation pit replacement support blade wall based on stiffness matching and deformation control, in step 2, establish the "layered stiffness matching criterion":

[0076] Let the equivalent stiffness of the i-th support (reinforced concrete support or steel support) be K , <' , , , ,

[0085] ,

[0086] ;

[0077] Let the designed stiffness of the i-th replacement support (blade wall) be K w,i ;

[0078] Stiffness matching principle:

[0079] K w,i =α·K b,i , where α is the stiffness coordination coefficient, with a value range of 0.8 - 1.2, and is segmented according to the distance of the replacement support layer from the bottom of the pit: a larger value is taken for the lower replacement support layer, and a smaller value is taken for the upper replacement support layer.

[0080] After replacement support, the blade wall has a deformation resistance ability similar to the original support, avoiding the out-of-control redistribution of the force on the retaining structure caused by sudden stiffness changes.

[0081] In this embodiment, the stiffness matching coefficient in step 2 is set in grades according to the distance of the replacement support layer from the bottom of the pit , specifically:

[0082] When d ≤ 3m, it is defined as the lower replacement support layer, and take ;

[0083] When 3 < d ≤6m, it is defined as the middle replacement support layer, and take ;

[0084] When d > 6m, it is defined as the upper replacement support layer, and take .

[0085] Through the above shear-bending coupling stiffness model and the graded matching coefficient "α", the present invention coordinates the stiffness of the blade wall with the original support, avoiding the out-of-control redistribution of the force on the retaining structure before and after replacement support, thereby ensuring stiffness coordination and ensuring continuous deformation.

[0086] Preferably, in the above-mentioned design method of the deep foundation pit replacement support blade wall based on stiffness matching and deformation control, the structural constraint conditions (i.e., structural verification) in step 2 include: the thickness of the blade wall ; the height-width ratio of the blade wall , where the height-width ratio of the blade wall .

[0087] Preferably, in the above-mentioned deep foundation pit replacement blade wall design method based on stiffness matching and deformation control, step 3, establishing the deformation control equation of the retaining structure under the action of discrete blade wall support, specifically includes: equating the discrete blade wall support to elastic point support, and establishing the deflection differential equation of the retaining pile or retaining wall based on elastic foundation beam or finite difference method; using the deformation control index As a limit condition for the lateral displacement of the enclosure structure, the maximum allowable spacing of the blade walls is solved iteratively or analytically. The maximum allowable spacing of the blade walls. Round down to the preset modular spacing series to output standardized blade wall layout spacing. .

[0088] Recommended spacing range: S=0.8 ~1.0 Furthermore, standardized modular spacing (e.g., 3m, 4m, 5m, 6m) is provided based on the requirements of construction access. In other words, the standardized blade wall arrangement spacing... It can be selected from at least one of 2m, 2.5m, 3m, 4m, 5m, and 6m, or customized according to the modulus of the foundation pit side length.

[0089] Preferably, in the above-mentioned design method for deep foundation pit replacement blade wall based on stiffness matching and deformation control, in step 4, the edge longitudinal reinforcement area of ​​the blade wall is calculated according to the formula for the bearing capacity of reinforced concrete normal and oblique sections. and horizontal distribution reinforcement ratio Specifically, it includes:

[0090] Edge longitudinal reinforcement area of ​​blade wall Calculation, i.e., flexural reinforcement calculation:

[0091]

[0092] in, This is the importance coefficient for temporary structures. The effective height of the cross section, This is the distance from the resultant force point of the tensile reinforcement to the edge of the cross section;

[0093] Flat distribution reinforcement ratio That is, shear reinforcement calculation:

[0094]

[0095] in, The horizontal distribution reinforcement ratio, This is the design value for the tensile strength of the stirrups. The spacing between horizontally distributed reinforcing bars.

[0096] Preferably, in the above-described design method for deep foundation pit replacement blade wall based on stiffness matching and deformation control, step 4 further includes a target failure mode control step:

[0097] Based on the target failure mode instructions input by the designers, the importance coefficient of the temporary structure is determined differentially. Reinforcement control conditions:

[0098] If the target failure mode instruction is "ductile bending failure", then... And configure horizontally distributed reinforcement according to the principle of strong shear and weak bending to meet the requirements. ;

[0099] If the target failure mode instruction is "economic reinforcement mode", then... Reinforcement is configured according to the principle of simultaneous bending and shear, to meet the requirements. ;

[0100] in, The flexural bearing capacity is calculated based on the actual reinforcement. The shear capacity is calculated based on the actual reinforcement. The height of the blade wall.

[0101] Preferably, in the above-mentioned design method for deep foundation pit replacement blade wall based on stiffness matching and deformation control, step 4 further includes a failure mode determination step:

[0102] Calculate the ultimate load based on flexural reinforcement and the ultimate load according to shear reinforcement ,in, ;like If so, a "Bending Failure Control" message will be output; if If the condition is not met, a "shear failure control" message will be output, and it will be suggested that the reinforcement scheme be adjusted.

[0103] Preferably, in the above-mentioned deep foundation pit replacement blade wall design method based on stiffness matching and deformation control, the blade wall section parameters output in step 4 are... Standardized blade wall layout spacing Edge longitudinal reinforcement area and horizontal distribution reinforcement ratio Used for the industrial production of prefabricated blade wall units, or for the processing of formwork and reinforcing bars for cast-in-place reinforced concrete blade walls.

[0104] Specifically, let's take a deep foundation pit of a subway station as an example.

[0105] I. Project Overview and Parameter Acquisition

[0106] The excavation depth of the deep foundation pit of the subway station The support structure uses φ1000@1200 bored cast-in-place piles with a pile length of 25m. The foundation pit is vertically supported by three layers of reinforced concrete supports. The center elevation of the second support is -6.5m, which is the original support center elevation of the layer to be replaced. After the second support is removed, blade walls 3 are installed from the elevation of -6.5m to -11.5m for the replacement support.

[0107] Blade wall height

[0108] Distance from the bottom of the pit to the support layer This is the distance from the bottom of the blade wall to the bottom of the pit.

[0109] According to the grading rules, this belongs to the lower-level replacement support layer. The equivalent stiffness of the original support is: the second support section is 800×800mm, C30 concrete (E=3.0×10). 10 Pa), length 22m, axial stiffness Take the design for .

[0110] Deformation control indicators: Deformation control indicators of the retaining structure under the condition of support replacement The enclosure structure allows lateral displacement. .

[0111] II. Stiffness Matching Design (Step 2)

[0112] 1. Blade Wall Stiffness Model

[0113] The formula for shear-bending coupled stiffness under uniformly distributed load mode is as follows:

[0114] , , , =1.2

[0115] Material: C30 concrete, E=3.0×10 10 Pa, G = 0.4E = 1.2 × 10 10 Pa.

[0116] 2. Determine the stiffness matching coefficient by grade.

[0117] The lower support layer is α=1.0.

[0118] Target stiffness

[0119] 3. Solve for the length L of the blade wall.

[0120] Preset wall thickness t=0.3m

[0121] = =

[0122] =

[0123] Overall Flexibility:

[0124]

[0125] equation:

[0126]

[0127] =

[0128] Trial calculation:

[0129] When L=2.8m, 1 / left side = The error is 0.25%.

[0130] Let L = 2.8m.

[0131] 4. Construction and verification

[0132] Thickness t=300mm≥200mm, which satisfies the requirement.

[0133] Blade wall height-to-width ratio H / L

[0134] H / L = 5.0 / 2.8 ≈ 1.79 < 3.5, which is reasonable.

[0135] As can be seen from the above, the deep foundation pit replacement blade wall design method based on stiffness matching and deformation control provided by this invention is the first to propose an integrated explicit design method for replacement blade walls that integrates "stiffness matching - deformation control - reinforcement design". This transforms the traditional design mode, which relies on experience or finite element trial calculations, into a step-by-step, formulaic explicit calculation. The design time for a single working condition is controlled within 20 minutes, improving efficiency by more than 80%, thus filling the gap in replacement blade wall design methods. Furthermore, the method utilizes a shear-bending coupled stiffness model and graded matching coefficients... This ensures that the stiffness of the blade wall is coordinated with the original support, preventing uncontrolled redistribution of stress in the enclosure structure before and after the support replacement, thereby ensuring stiffness coordination and deformation continuity; importance coefficients are set according to the layer of support replacement. By controlling the target failure mode, "strong shear and weak bending" is ensured, thereby achieving graded reinforcement and effectively saving materials.

[0136] Furthermore, this invention has a wide range of applications. It can guide the formwork and reinforcement processing of cast-in-place reinforced concrete blade walls, and can also be used for the industrial production of prefabricated assembled blade wall units, making it suitable for various deep foundation pit support replacement projects.

[0137] The above description is merely a description of preferred embodiments of the present invention and is not intended to limit the scope of the present invention in any way. Any changes or modifications made by those skilled in the art based on the above disclosure shall fall within the protection scope of the claims.

Claims

1. A design method for deep foundation pit replacement blade wall based on stiffness matching and deformation control, characterized in that, Includes the following steps: Step 1: Parameter Acquisition Obtain the equivalent stiffness of the original support system at the layer to be replaced. And deformation control indicators of the retaining structure under the condition of support replacement. ; Step 2: Stiffness Matching Design Establish a calculation model for the lateral stiffness of the blade wall. ,in For the length of the blade wall, For blade wall thickness, For the height of the blade wall, These are the elastic modulus and shear modulus of the wall material for the blade wall; a stiffness matching coefficient is set. Construct stiffness matching equations By combining the preset structural constraints, at least one set of recommended blade wall section parameters can be obtained. combination; Step 3: Deformation Control Design Based on the cross-sectional parameters determined in step 2, a deformation control equation for the enclosure structure under the support of discrete blade walls is established, using the aforementioned deformation control index. As boundary conditions, calculate the maximum allowable spacing of the blade walls. Based on the principle of modularization, the standardized blade wall layout spacing is output. ; Step 4: Reinforcement Design Based on the blade wall section parameters output in step 2 and the standardized blade wall arrangement spacing output in step 3 A stress analysis model of the blade wall was established, and the design bending moment of the blade wall under the condition of bracing replacement was calculated. and shear design value ; Calculate the edge longitudinal reinforcement area of ​​the blade wall according to the formulas for the bearing capacity of reinforced concrete normal and oblique sections. and horizontal distribution reinforcement ratio and output the blade wall section parameters. Standardized blade wall layout spacing Edge longitudinal reinforcement area and horizontal distribution reinforcement ratio .

2. The design method for deep foundation pit replacement blade wall based on stiffness matching and deformation control according to claim 1, characterized in that, In step 2, the calculation model for the lateral stiffness within the blade wall surface is a coupled stiffness model considering bending and shear deformation, and its expression is: in, Let the moment of inertia of the cross section be... For cross-sectional area, The coefficient for shear stress non-uniformity is 1.2 for rectangular sections.

3. The design method for deep foundation pit replacement blade wall based on stiffness matching and deformation control according to claim 1, characterized in that, stiffness matching coefficient in step 2 Based on the distance from the bottom of the pit to the support layer The hierarchical settings are as follows: When d≤3m, it is defined as the lower support layer, and is taken as... ; When 3 < d ≤ 6m, it is defined as the middle strut replacement layer, and take ; When d > 6m, it is defined as the upper support layer, and is taken as... .

4. The design method for deep foundation pit replacement blade wall based on stiffness matching and deformation control according to claim 1, characterized in that, The construction constraints in step 2 include: blade wall thickness. The aspect ratio of the blade wall .

5. The design method for deep foundation pit replacement blade wall based on stiffness matching and deformation control according to claim 1, characterized in that, Step 3, which establishes the deformation control equations of the enclosure structure under the support of discrete blade walls, specifically includes: The discrete support of the blade wall is equivalent to an elastic point support, and the deflection differential equation of the retaining pile or retaining wall is established based on the elastic foundation beam or the finite difference method; the deformation control index is used as the basis for this equation. As a limit condition for the lateral displacement of the enclosure structure, the maximum allowable spacing of the blade walls is solved iteratively or analytically. ; will the Round down to the preset modular spacing series to output standardized blade wall layout spacing. .

6. The design method for deep foundation pit replacement blade wall based on stiffness matching and deformation control according to claim 5, characterized in that, The standardized blade wall arrangement spacing It can be selected from at least one of 2m, 2.5m, 3m, 4m, 5m, and 6m, or customized according to the modulus of the foundation pit side length.

7. The design method for deep foundation pit replacement blade wall based on stiffness matching and deformation control according to claim 1, characterized in that, In step 4, the area of ​​the longitudinal reinforcement at the edge of the blade wall is calculated according to the formulas for the bearing capacity of the normal and oblique sections of reinforced concrete. and horizontal distribution reinforcement ratio Specifically, it includes: Edge longitudinal reinforcement area of ​​blade wall calculate: in, This is the importance coefficient for temporary structures. The effective height of the cross section, This is the distance from the resultant force point of the tensile reinforcement to the edge of the cross section; Calculation of horizontal distribution reinforcement ratio: in, The horizontal distribution reinforcement ratio, This is the design value for the tensile strength of the stirrups. The spacing between horizontally distributed reinforcing bars.

8. The design method for deep foundation pit replacement blade wall based on stiffness matching and deformation control according to claim 7, characterized in that, Step 4 also includes a target destruction mode control step: Based on the target failure mode instructions input by the designers, the importance coefficient of the temporary structure is determined differentially. Reinforcement control conditions: If the target failure mode instruction is "ductile bending failure", then take... And configure horizontally distributed reinforcement according to the principle of strong shear and weak bending to meet the requirements. ; If the target failure mode instruction is "economic reinforcement mode", then... Reinforcement is configured according to the principle of simultaneous bending and shear, to meet the requirements. ; in, The flexural bearing capacity is calculated based on the actual reinforcement. This represents the shear capacity calculated based on the actual reinforcement.

9. The design method for deep foundation pit replacement blade wall based on stiffness matching and deformation control according to claim 8, characterized in that, Step 4 also includes a destruction mode determination step: Calculate the ultimate load based on flexural reinforcement and the ultimate load according to shear reinforcement ,in, ;like If so, then output the "Bending Failure Control" message; if If the condition is not met, a "shear failure control" message will be output, and it will be suggested that the reinforcement scheme be adjusted.

10. The design method for deep foundation pit replacement blade wall based on stiffness matching and deformation control according to any one of claims 1 to 9, characterized in that, Step 4 output blade wall section parameters Standardized blade wall layout spacing Edge longitudinal reinforcement area and horizontal distribution reinforcement ratio Used for the industrial production of prefabricated blade wall units, or for the processing of formwork and reinforcing bars for cast-in-place reinforced concrete blade walls.

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