A segmented checking method for bending moment bearing capacity of slotted shear wall

Abstract

The present application relates to the design of flexural capacity of hybrid shear walls, which are assembled and cast-in-situ, and proposes a method and device for the sectional checking of the flexural capacity of slotted shear walls. The wall near the opening or vertical slot is divided into slot-controlled and non-slot-controlled zones along the wall height. In the slot-controlled zone, a three-stage stress evolution model of additional reinforcement is established by using a parametric bond-slip relationship at the new and old concrete interface. Then, the flexural capacity of the non-slot-controlled zone is superimposed to determine the plastic hinge length and overall ultimate bending moment. The design flexural capacity and the correction coefficient compared with the test peak value are obtained by numerical integration or simplified formula. The device modularizes the above method, which can automatically output the three-stage load curve and design value by inputting geometric and reinforcement parameters. It takes into account the interface bond degradation and overall bending response, and is suitable for the integration of design specification provisions and engineering software.

Description

Technical Field

[0001] This invention relates to the field of seismic design of civil engineering structures, specifically to a method and apparatus for segmented verification of the bending moment bearing capacity of slotted shear walls, considering the bonding degradation and slippage effect at the interface between new and old concrete. It can be used for the analysis and engineering design of the bending bearing capacity of prefabricated shear walls, cast-in-place-prefabricated hybrid shear walls with vertical post-cast grooves, and similar shear wall structures with vertical grooves or vertical joints. Background Technology

[0002] With the widespread application of prefabricated concrete structures in high-rise and super high-rise buildings, various prefabricated monolithic shear wall systems are constantly emerging, such as grooved shear walls, vertical post-cast strip shear walls, and mortise and tenon joint prefabricated monolithic shear walls. These systems often have vertical grooves or toothed grooves at the ends or middle of the wall segments to achieve reliable connection between new and old concrete and facilitate construction.

[0003] Current design codes and standards for calculating flexural capacity mostly rely on the rigid-plastic or equivalent elastic-plastic section theory of integral shear walls. This treats walls with vertical joints or post-cast grooves as continuous integral sections, correcting only by adjusting the effective section height, reducing concrete strength, or increasing reinforcement area. However, it fails to explicitly consider the impact of the distribution and evolution of bond-slip at the interface between new and old concrete on flexural capacity and plastic hinge length. For shear walls with openings, post-cast strips, or vertical grooves, engineering practice typically involves directly applying the flexural capacity formula for ordinary shear walls in high-rise building codes, or using a "whole section, single-stage" ultimate bearing capacity verification method in the groove area.

[0004] On the other hand, numerous experimental and model studies have been conducted on bond-slip relationships at interfaces between new and old concrete, and steel-concrete composite interfaces, leading to the development of various bilinear or multilinear bond-slip relationships. Relationships and corresponding bearing capacity calculation methods. Some studies attempt to introduce interfacial bond strength into the design of prefabricated shear walls or composite components. Correcting the longitudinal reinforcement stress or shear force transfer capacity can improve the prediction of structural member bearing capacity. However, such methods are often limited to: performing "single-section, single-stage" ultimate bearing capacity correction for a single calculation section, which makes it difficult to reflect the development process of interface bond degradation and slip along the wall height; treating the grooved and non-grooved areas as simultaneously reaching the peak or simultaneously entering the yielding stage, failing to reflect the control effect of "grooved control area slipping first, and then working together with non-grooved control area"; and lacking segmented and coupled modeling of plastic hinge length and moment-curvature (or moment-displacement) envelope curves, making it difficult to provide a reliable basis for performance-based design and displacement control.

[0005] Studies have shown that the failure evolution of prefabricated shear walls with vertical grooves or toothed grooves under seismic loading often exhibits the following characteristics: bond cracking and slippage first appear at the interface near the groove, limiting the increase of stress in the additional reinforcement in the groove area, and the overall stiffness and bearing capacity of the member lag significantly behind the predictions of traditional rigid-plastic models; only after slippage has developed to a certain extent does the wall segment gradually form a bending yielding mechanism similar to that of an integral shear wall. For members with a small shear span and short groove length, directly applying the standard rigid-plastic bending bearing capacity formula will significantly overestimate the actual peak bearing capacity and ductility level of the specimen, posing a risk of design insecurity.

[0006] An analysis of existing publicly available literature and current regulations revealed no method for comprehensively coupling the following elements in the engineering design of the flexural bearing capacity of slotted shear walls: explicitly dividing the wall height into slot-controlled and non-slot-controlled zones, and performing segmented control and separate modeling of the slot-controlled zone; within the slot-controlled zone, establishing a three-stage stress evolution model of "bond integrity – bond degradation – complete slip" for the additional reinforcement near the opening or vertical slot, and parametrically... The relationship is directly coupled with the calculation of steel reinforcement stress and the formula for flexural bearing capacity; the moment-curvature relationship between the channel-controlled zone and the non-channel-controlled zone is superimposed in segments to uniformly determine the plastic hinge length and the overall ultimate bending moment, and a simplified calculation process and correction coefficient suitable for engineering software implementation are given.

[0007] Therefore, it is necessary to propose a segmented verification method and corresponding device for the bending moment bearing capacity of slotted shear walls that can reflect the interface bonding degradation and slip development process while maintaining ease of calculation and suitability for the compilation of code provisions and rapid implementation in engineering software. This is to avoid the systematic overestimation of the bearing capacity of short-slot structures and better support the safe and reliable design of prefabricated shear wall structures. Summary of the Invention

[0008] This invention addresses the following problems in the existing design of the bending moment bearing capacity of slotted shear walls: Engineering designs generally directly apply the rigid-plastic bending capacity formula for integral shear walls, treating wall segments with vertical slots or post-cast strips as integral sections, without explicitly considering the bonding degradation and slip development process at the interface between new and old concrete. This is especially true for short-slot members, which tends to significantly overestimate the ultimate bending moment. Existing calculation methods are mostly based on a single control section and a single ultimate state, relying on interfacial bond strength. A uniform reduction of longitudinal reinforcement stress or bearing capacity cannot reflect the stress characteristics of "slippage followed by synergy" in the trench control area, nor can it reasonably determine the length of the plastic hinge and the moment-displacement envelope along the wall height. Although some high-precision numerical methods can simulate interface bonding-slippage, they are complex to model and have a large amount of calculation, making them unsuitable for direct inclusion in engineering design specifications or general design software.

[0009] Therefore, the technical problem of the present invention is to provide a method and device for segmented verification of the bending moment bearing capacity of slotted shear walls that can reflect the bonding degradation and slip evolution of the interface between new and old concrete, and has a simple calculation process, clear parameters, and is easy to implement in engineering software, so as to avoid the systematic overestimation of the bearing capacity of short-slot structures, and take into account both the requirements of code provisions and performance-based design.

[0010] To address the aforementioned technical problems, this invention proposes a segmented verification method for the bending moment bearing capacity of slotted shear walls, comprising the following core steps:

[0011] 1. Structural Parameter Acquisition and Segment Division: Acquire the geometric parameters of the slotted shear wall (including wall height, thickness, slot length, slot location, opening size, etc.), concrete and steel reinforcement material parameters, and interface normal pressure, etc. Figure 1 As shown, the wall segment is divided into at least two control zones along the wall height direction with the vertical groove as the reference: the groove-controlled zone, which is the area with a height of 1.0 to 1.5 times the groove length from the bottom (or center) of the groove, is the area where the bonding degradation and slippage of the new and old concrete interface are most significant; the non-groove-controlled zone is the wall segment area other than the groove-controlled zone, where the bending moment bearing capacity can be calculated according to the traditional integral shear wall section.

[0012] 2. Three-stage stress evolution modeling of additional reinforcement in the trench-controlled area: Within the trench-controlled area, a three-stage stress evolution model directly coupled with the interface bond-slip relationship is established for the additional longitudinal reinforcement arranged along the vertical trench and related interface areas, such as... Figure 2 As shown, this includes: the bond integrity stage: interfacial shear stress. No significant bond degradation occurred at the interface, and the stress of the additional reinforcing steel was determined according to the linear elastic relationship. Calculations show that the groove-controlled and non-groove-controlled regions undergo essentially coordinated deformation; in the bond degradation stage, a bilinear bond-slip relationship is employed. (Parameters include peak bond strength) Limit slip and residual bond strength The relationship between reinforcement stress, cross-sectional curvature, and slip is established through the interface slip compatibility equation, and the additional reinforcement stress is solved. This reflects the constraint effect of bond softening on the stress of the reinforcing steel; in the complete slip stage: the interfacial bond is basically destroyed, and shear force is provided only through friction, resulting in frictional shear stress. The contribution of additional reinforcement to the flexural bearing capacity is reduced to ,in To be related to the experimental degradation coefficient Relevant empirical reduction factors, range of values .

[0013] 3. Determining the moment-curvature (or moment-displacement) relationship in the three stages of the trench control: Calculate the reinforcement stress in the three stages mentioned above. Substituting these values ​​into the modified section flexural capacity formula, layered integration or equivalent fiber section analysis is performed on the key sections of the groove-controlled zone to obtain the moment-curvature curves corresponding to the three bonding stages of the groove-controlled zone. When performing displacement control analysis, the moment-displacement envelope curve of the groove-controlled zone can be further obtained through numerical integration, such as... Figure 3 As shown in the lower middle curve.

[0014] 4. Moment-curvature relationship and coupling with the trench-controlled zone in the non-trench-controlled zone: Moment-curvature calculations are performed in the non-trench-controlled zone using the current shear wall section design method, considering the stress contributions of the conventional concrete compression zone, the longitudinal reinforcement of the edge members, and the distributed reinforcement, to obtain the moment-curvature relationship in the non-trench-controlled zone. For example... Figure 3 As shown, the groove-controlled area and the non-groove-controlled area are discretized into several elements along the wall height, and corresponding moment-curvature relationships are assigned to them. The piecewise integration method is used to calculate the wall top rotation angle and displacement under a given bottom bending moment, thereby obtaining the overall moment-curvature (or moment-displacement) response. The equivalent plastic hinge length and the overall ultimate bending moment are determined according to the degree of bending deformation concentration.

[0015] 5. Design bending bearing capacity Determination and Correction: Based on the overall moment-curvature analysis results above, the corresponding bearing moment is determined under different performance targets (such as yield state, significantly degraded bond state, and near-collapse state of complete slippage). Combined with the structural displacement ductility or rotation limit, the design flexural bearing capacity that meets the performance requirements is obtained. Furthermore, this invention proposes, based on a batch of representative experimental results, to compare the calculated peak bending moment with the measured peak bending moment, and to regress a correction coefficient for rapid engineering design, thereby correcting the bending moment. This improves the consistency between the calculated results and the measured values.

[0016] 6. Device and Software Implementation: To facilitate engineering applications, this invention further provides a device for calculating the bending moment bearing capacity of slotted shear walls and its computer program implementation, such as... Figure 4 and Figure 5 As shown. The device includes: a data input module for inputting geometry, material, interface parameters, and target performance indicators; a segmentation module for automatically identifying controlled and non-controlled areas based on the trench location and dimensions; and an interface adhesion-slip calculation module for calculating parameters based on parametric bilinear... The system utilizes curves and interface normal pressure to determine interface shear stress and reinforcement stress at each stage; a flexural capacity calculation module: in the trench-controlled zone, it corrects the section flexural capacity based on three-stage reinforcement stress; in the non-trench-controlled zone, it calculates the section flexural capacity using conventional methods; a moment-curvature combination module: it performs piecewise moment-curvature superposition and numerical integration along the wall height to determine the plastic hinge length and overall ultimate moment; a results output module: it outputs the three-stage moment-displacement envelope curve and the design flexural capacity. It can also generate correction factors and result reports in the format of design calculation sheets or standard clause verification.

[0017] The above method can be stored in a computer-readable storage medium and implemented through software modularization, providing engineers with a dedicated tool for analyzing the flexural bearing capacity of slotted shear walls.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] 1. Avoid overestimating the bearing capacity of short grooves: By dividing the groove-controlled zone and non-groove-controlled zone along the wall height, and introducing a reduction mechanism for interface bonding degradation and complete slip stage in the groove-controlled zone, the shortcomings of the traditional single-section, single-stage rigid-plastic formula for systematically overestimating the bearing capacity of short groove shear walls are overcome.

[0020] 2. Explicitly reflects the "slippage followed by co-yield" stress mechanism: Through a three-stage additional reinforcement stress evolution model, the interface bond-slip relationship is directly coupled with the calculation of reinforcement stress and cross-sectional flexural bearing capacity, which can reflect the failure process of "slippage in the trench area first, followed by co-yield with the non-trench area" observed in actual tests.

[0021] 3. Unified consideration of interface degradation and overall bending response: This invention not only focuses on the ultimate bearing capacity of a single section, but also determines the plastic hinge length and the overall ultimate bending moment through the piecewise superposition analysis of bending moment and curvature, so that the interface degradation effect is coupled with the overall bending deformation, which is suitable for performance-based design.

[0022] 4. Suitable for engineering specifications and software implementation: This invention adopts a segmented, equivalent, and parameterized simplified engineering model, avoiding complex nonlinear finite element analysis, which is easy to solidify into verification formulas or design steps in specification clauses. It can also be used as a module of commercial structural analysis software or enterprise internal design tools.

[0023] 5. Parameters can be directly integrated with experiments: Interface bond-slip model parameters, degradation coefficients, and reduction coefficients can all be calibrated through new and old concrete interface tests and full-scale tests of slotted shear walls. This allows the method of the present invention to be continuously optimized as the experimental database becomes richer, and it has good scalability and engineering applicability. Attached Figure Description

[0024] To more clearly illustrate the technical solution of the present invention, the embodiments of the present invention will be further described below with reference to the accompanying drawings, in which:

[0025] Figure 1 This is a schematic diagram of the segmented wall height and stress state of the slotted shear wall according to the present invention;

[0026] Figure 2 This is a schematic diagram of the bonding-slip relationship at the interface of the trench control zone and the three-stage stress evolution of the additional reinforcing bars in this invention.

[0027] Figure 3 This is a schematic diagram of the moment-curvature coupling and plastic hinge formation between the groove-controlled and non-groove-controlled regions of the present invention.

[0028] Figure 4 This is a flowchart illustrating the segmented verification method for the bending moment bearing capacity of slotted shear walls according to the present invention.

[0029] Figure 5 The structural block diagram of the slotted shear wall bending moment bearing capacity verification device and its software system for realizing the method of the present invention is shown.

[0030] To facilitate understanding of the present invention, the main components and their reference numerals appearing in the accompanying drawings will now be described in detail.

[0031] Figure 1 The component labels in the diagram showing the segmentation and stress distribution of the slotted shear wall are as follows: 1 — Overall slotted shear wall component: a load-bearing wall consisting of wall segments, edge members, vertical slots, and foundations; 2 — Vertical slot (or post-cast strip): a vertical slot or post-cast strip located at the end or middle of the wall segment to connect new and old concrete; 3 — Slot-controlled zone: an area extending upwards from the bottom or center of the slot, with a height of 1.0 to 1.5 times the slot length, which is a critical section controlled by interface bonding degradation and slippage; 4 — Non-slot-controlled zone: the wall segment area other than the slot-controlled zone, whose stress characteristics can be treated as a traditional integral shear wall; 5 — Additional longitudinal reinforcement at openings (or near slots): additional longitudinal reinforcement arranged along both sides of the vertical slot or around the opening to strengthen interface connections, which is the main object of the three-stage stress evolution model in this invention; 6 — Longitudinal reinforcement of edge members: the main reinforcement located in the edge members at the end of the wall segment, mainly bearing the tensile and compressive forces caused by bending moments; 7 — Shear wall foundation or floor slab supporting members: foundation beams, raft slabs, or floor slabs that provide vertical and horizontal constraints for the shear wall; 8 — Axial pressure 9 — Resultant force of vertical dead load and live load acting on the top of the shear wall or transmitted along the wall height; 9 — Horizontal seismic action or lateral load : Horizontal shear force caused by earthquake or wind load and the bending moment formed at the base of the wall; 10 — Coordinates in the wall height direction 11 — Coordinate axis along the wall height direction, used to indicate the segment position and plastic hinge range; 12 — Groove interface position line: marks the position of the interface between new and old concrete, used to describe the interface bond-slip zone range; 13 — Plastic hinge equivalent section: the concentrated area of ​​plastic deformation determined in the overall analysis, usually spanning the groove-controlled area and extending into the non-groove-controlled area.

[0032] Figure 2 The component labeling for the schematic diagram of interfacial bond-slip and reinforcement stress evolution shown is as follows: 20 — Interfacial bond-slip bilinear curve : Represents interfacial shear stress With slip The bilinear relationship curve; 21 — Bonding integrity stage segment line: Follow Approximately linear growth to peak value The preceding curve segment corresponds to the stage where the interfacial bond has not significantly degraded; 22 — Bond degradation stage segment: from the peak bond strength Degraded to residual bond strength The softening curve segment corresponds to the development of interfacial microcracks and the bond failure process; 23 — residual friction stage segment: under large slip, the interface has residual shear stress. The maintained approximately horizontal curve segment corresponds to the full slip phase; 24 — Slip axis : Horizontal axis represents the relative slip of the interface; 25 — Shear stress axis : Vertical axis represents interfacial shear stress; 26 — Peak bond strength point : The point of maximum shear stress on the bond-slip curve, defining the starting point of the bond degradation stage; 27 — Limit slip point : Slip value at the end of the bond degradation stage and the beginning of the residual friction stage; 28 — Residual bond strength : Average frictional shear stress still provided by the interface under large slip; 30 — Schematic curve of stress-strain relationship of additional reinforcement: reflecting the stress-strain evolution of additional longitudinal reinforcement in three bond states; 31 — Reinforcement stress curve in the complete bond stage When the interface is well bonded, the reinforcing bars are installed according to... The relationship curve of linear elastic development; 32 — Stress curve of steel reinforcement in the bond degradation stage. : Stress curves of reinforcing steel bars whose stress growth is limited as interfacial bond degradation and slip development occur; 33 — Stress reduction curve of reinforcing steel bars in the complete slip stage. When the interface is completely slipping and there is only friction, the effective stress of the steel reinforcement is reduced to an approximately constant value. Relationship line; 34 — Reinforcing bar strain axis : The horizontal axis represents the strain of the additional reinforcing steel; 35 — Reinforcing steel stress axis : Vertical axis represents the axial stress of the additional reinforcement; 36 — Reduction factor Marking point: The position corresponding to the reduction factor marked on the curve during the full slip phase, used for illustration. The meaning of .

[0033] Figure 3The component labeling in the schematic diagram of moment-curvature coupling and plastic hinge shown is as follows: 40 — Family of moment-curvature curves for the trench-controlled section: Represents the set of moment-curvature relationships for the controlled section at different bonding stages; 41 — Moment-curvature curve for the fully bonded stage of the trench-controlled section: The moment-curvature curve for the trench-controlled section when the interface bonding is intact, with relatively high stiffness; 42 — Moment-curvature curve for the bonding degradation stage of the trench-controlled section: The moment-curvature curve for the section when the interface bonding is partially degraded, with a decreasing slope and degraded stiffness; 43 — Moment-curvature curve for the complete slip stage of the trench-controlled section: The moment-curvature curve when the interface is almost completely slipped, with significantly reduced stiffness and bearing capacity; 44 — Moment-curvature curve for the non-trench-controlled section: The moment-curvature relationship for the non-trench-controlled section obtained according to the conventional integral shear wall design; 45 — Overall shear wall moment-curvature composite curve: The overall moment-curvature relationship is obtained by piecewise integration and combination along the wall height for the channel-controlled and non-channel-controlled zones; 46—moment axis : Horizontal axis, representing the bending moment of a section or the entire structure; 47 — Curvature axis : Vertical axis, representing the average curvature of the cross section or the whole; 48 — Length of the control zone : The height of the groove control zone along the wall height direction, used to define the range of the three-stage bonding effect; 49 — Equivalent plastic hinge length The equivalent plastic hinge length determined based on the overall moment-curvature distribution and rotation concentration; 50 — limit state point. The ultimate bearing point on the overall moment-curvature composite curve is used to define the ultimate moment and the corresponding curvature.

[0034] Figure 4 The component labels in the flowchart shown are as follows: 60 — Method Startup and Parameter Input Step Box: This represents the steps to start the method of this invention and input geometric parameters, material parameters, interface parameters, and performance targets; 61 — Automatic Identification of Trench-Controlled and Non-Trench-Controlled Zones Step Box: This step automatically divides the trench-controlled and non-trench-controlled zones based on the input trench location, length, and wall height; 62 — Interface Bonding-Slip Parameter Calculation Step Box: This step determines the interface bonding-slip parameters based on experimental regression models or engineering empirical formulas. Steps for parameter calculation; 63 — Three-stage reinforcement stress calculation steps in the trench-controlled zone: Based on interface slip compatibility and bond-slip relationship, the steps for solving the stress of additional reinforcement in three bond states; 64 — Stage-by-stage calculation steps for flexural bearing capacity in the trench-controlled zone: Substituting the three-stage reinforcement stress into the section flexural bearing capacity formula to obtain the corresponding moment-curvature relationship; 65 — Calculation steps for flexural bearing capacity in the non-trench-controlled zone: Calculating the moment-curvature relationship in the non-trench-controlled zone according to the current standard method; 66 — Steps for segmented superposition of moment-curvature and determination of plastic hinge length: Performing segmented superposition of moment-curvature along the wall height to determine the overall moment-curvature curve and the equivalent plastic hinge length; 67 — Design flexural bearing capacity And the correction factor calculation step box: the steps to obtain the design flexural bearing capacity and correction factor based on the target performance and test comparison results; 68 — Result output and report generation step box: the steps to output the bearing capacity calculation results, three-stage bearing curves and related parameters, and generate the design report; 69 — Flow connection arrows: indicate the execution order and data transfer direction between each step;

[0035] Figure 5 The component labels in the structural block diagram of the device and software system shown are as follows: 70 — Overall structure of the slotted shear wall moment bearing capacity verification device: including the overall system of hardware platform and software modules; 71 — Data input module: used to receive and store input data such as geometric parameters, reinforcement information, material properties, interface normal pressure, and design conditions of the slotted shear wall, which can be realized through graphical interface or file import; 72 — Segment division module: connected to the data input module, used to automatically identify the slot-controlled area and non-slot-controlled area according to the slot length, slot position, and wall height, and output the segment division results; 73 — Interface bond-slip calculation module: based on the preset bilinear or multilinear bond-slip model and the input interface parameters, calculates the shear stress-slip relationship at each stage of the interface, and provides the calculation basis for the reinforcement stress evolution module; 74 — The module for calculating the stress evolution and flexural bearing capacity of reinforcing steel bars is used to determine the three-stage stress of additional reinforcing steel bars in the trench-controlled zone based on the interface slip compatibility equation, and to calculate the moment-curvature relationship of the sections in the trench-controlled and non-trench-controlled zones by combining the mechanical equilibrium of the section and the constitutive relation of the material; The module for analyzing moment-curvature combination and plastic hinges is used to perform piecewise superposition and numerical integration of the moment-curvature relationship of each section along the wall height to determine the overall moment-curvature or moment-displacement response, and to determine the equivalent plastic hinge length and ultimate bearing moment; The module for calculating the design flexural bearing capacity and correction coefficient is used to calculate the design flexural bearing capacity at each performance level based on the preset performance target and the experimental comparison relationship. 77 — Result Output and Visualization Module: Used to output the calculated three-stage moment-displacement envelope curve, plastic hinge length, design bearing capacity, and correction coefficients in tabular, curve, and graphical form, and can be exported as a report file; 78 — Memory: Used to store the computer program of the method of the present invention, the interface bonding-slip model parameter library, experimental comparison data, and user engineering project data; 79 — Processor: Runs the program stored in the memory and calls the above functional modules to execute the segmented verification method of the present invention; 80 — User Interaction Interface (Graphical Interface or Command Interface): Allows designers to input data, set analysis options, view and export calculation results; 81 — Data Bus and Inter-module Communication Connection: Represents the data interaction path between the processor, memory, and various software modules.

[0036] The component reference numerals mentioned above may be used repeatedly in different drawings, and their specific functions and interrelationships shall be subject to the description in this specification and the claims. Detailed Implementation

[0037] The technical solution of the present invention will be further described below with reference to the accompanying drawings and specific embodiments. Those skilled in the art should understand that various equivalent substitutions and modifications can be made to the following embodiments without departing from the spirit and substance of the present invention, all of which fall within the protection scope of the present invention.

[0038] Example 1: Segmented Calculation Method for Bending Moment Bearing Capacity of Slotted Shear Walls

[0039] This embodiment corresponds to claims 1-5, and details a method for segmented verification of the bending moment bearing capacity of a slotted shear wall. This method is applicable to... Figure 1 The slotted shear wall integral component 1 is shown.

[0040] 1. Parameter Input and Model Assumptions

[0041] like Figure 4 As shown, the method first performs parameter input and basic assumption settings in step 60, including:

[0042] (1) Geometric parameters: wall height Wall thickness Wall segment length The length of vertical groove (post-cast strip) 2 The width of the groove and its relative position in the wall pier; the size of the opening (if present) and its relative relationship with the groove.

[0043] (2) Reinforcement and material parameters: Diameter, quantity, and yield strength of the additional longitudinal steel bars 5 on both sides of the trench and near the opening. Elastic modulus The reinforcement ratio, strength, and modulus of elasticity of the longitudinal reinforcement and distribution reinforcement of the edge members; the cubic compressive strength of new and old concrete. or axial compressive strength Elastic modulus .

[0044] (3) Interface and load parameters: normal pressure at the interface between new and old concrete (Can be derived from axial compression ratio and geometric dimensions); Axial compression ratio of shear wall under design conditions Horizontal design shear force Or bottom design bending moment Target performance indicators (such as inter-story drift angle limit, vertex displacement limit, or component rotation angle limit).

[0045] (4) Selection of interface bonding-slip model: Select a bilinear model. Relationships (such as) Figure 2 (As shown in curve 20), and specify the peak bond strength. Residual bond strength Limit slip Initial stiffness Degradation stiffness ;parameter Based on the regression results or empirical formulas of existing new and old concrete interface tests, the interface bond-slip parameter calculation module can automatically provide the parameters in step 62.

[0046] (5) Basic assumptions of numerical analysis: The shear wall adopts the plane section assumption, and the strain at any point in the section is linearly distributed in the wall thickness direction; the additional steel bars 5 on both sides of the vertical groove transmit force to the adjacent concrete through the interface shear stress-slip relationship, and the interface does not bear tensile stress; in the moment-curvature analysis, the second-order effect caused by axial compression eccentricity is ignored, or it is simplified by the amplification factor.

[0047] 2. Division of controlled and non-controlled areas

[0048] In step 61, the segmentation module 72 divides the segment according to the input slot length. The location of the groove and the height of the wall Automatically complete the division of the tank control area 3 and the non-tank control area 4, such as Figure 1 As shown:

[0049] (1) Height of the tank control zone Define the control zone 3 as the height extending upwards from the bottom (or center) of the tank. Preferably, take When the designer does not specify the default values, the software can use the default values. Automatic selection; when the groove is close to the bottom of the wall, the groove control area may partially or completely overlap with the plastic hinge equivalent section 12.

[0050] (2) Non-groove controlled area: Non-groove controlled area 4 is the wall limb area other than the groove controlled area, including the remaining part of the wall height above the groove controlled area; In the non-groove controlled area, the interface bonding-slip effect has little impact on the overall bending bearing capacity and can be treated as a traditional shear wall.

[0051] (3) Discretization along wall height: coordinates along the wall height direction (Label 10) Divide the wall segment into several units, for example, each unit has a height of... ;lie in The unit is assigned to the slot control area, located in The unit is classified into the non-slot control area.

[0052] 3. Three-stage calculation of interface bond-slip and additional reinforcement stress in the trench control zone.

[0053] In steps 62 and 63, the evolution of interface bond-slip and additional reinforcement stress within the trench control zone 3 is calculated, as follows: Figure 2 As shown.

[0054] (1) Bonding complete stage (stage I): the interfacial shear stress-slip relationship is in the stage of complete bonding. Figure 2 The range shown by midline 21: It was concluded that the interfacial bond did not show significant degradation, and there was essentially no relative slippage between the additional reinforcing steel and the concrete. The strain of the additional reinforcement 5 and the average curvature of the section at the corresponding height. Related to the position of the neutral axis, the present invention can use a simplified relationship: ,in, This represents the distance of the reinforcing bar from the neutral axis; the stress in the reinforcing bar is calculated based on linear elasticity. For all trench control zone units in the complete bonding stage, the contribution of additional reinforcement is fully included in the flexural capacity of the section.

[0055] (2) Adhesion degradation stage (stage II): When the interface slip reaches When the interface enters Figure 2 The softening stage is shown by line 22 in the middle section: At this point, significant relative slippage occurs between the additional reinforcing bars and the concrete. The strain of the reinforcing bars is no longer simply equal to the average strain of the cross section, and slip compatibility needs to be considered. ,in, The reference strain of the concrete at the height of the reinforcing steel is given. To ensure effective bonding anchorage length, the selection can be based on the rebar anchorage length and the groove geometry; the interface bonding-slip calculation module 73 establishes a relationship by balancing the additional rebar axial force and the total interface shear force: By combining the assumed slip distribution form (such as linear or parabolic), the average stress of the reinforcement is solved. ; obtained Typically lower than calculations based on the assumption of complete bonding under the same cross-sectional deformation. This reflects the limitation of bond degradation on the stress of steel bars.

[0056] (3) Fully Slide Stage (Stage III): When the interface slides At this point, the interfacial adhesion is essentially destroyed, and shear force is provided solely by friction, such as... Figure 2 As shown in line 23: ,in, The coefficient of interfacial friction, This refers to the interface contact area; at this stage, there is no effective bond anchorage between the additional reinforcing steel and the concrete, and its stress is difficult to fully develop. This invention employs an equivalent reduction factor. Characterizing the effective stress level of the additional reinforcement: Reduction factor It can be compared with the stiffness or bearing capacity degradation coefficient in the test. Empirical relationships are obtained, for example: ,in The empirical coefficients obtained from regression are automatically provided by the interface bond-slip parameter calculation module 73 or the reinforcement stress evolution module 74; in the limit state analysis, the effective cross-sectional area of ​​the additional reinforcement can be equivalent to... and according to yield strength Bending capacity should be taken into account.

[0057] 4. Determination of the moment-curvature relationship in the channel-controlled zone

[0058] In step 64, the flexural bearing capacity calculation module 74 performs moment-curvature analysis on typical sections within the channel control zone to obtain... Figure 3 Medium curve family 40.

[0059] (1) Section discretization: The selected control section of the trench control area is discretized into several fibers or layers along the wall thickness direction and the wall length direction, corresponding to concrete fibers, steel fibers and interface areas respectively; a multi-segment or bi-segment constitutive relationship is adopted for concrete, and an ideal elastic-plastic or bi-segment constitutive relationship is adopted for steel reinforcement.

[0060] (2) Three-stage analysis

[0061] Stage I: Bond Integrity: Under a given axial force Next, gradually increase the curvature of the cross section. The stress and bending moment of each fiber are obtained by balancing the internal forces of the cross section. Additional reinforcement 5 according to Incorporate this information; and obtain the first moment-curvature curve 41 of the cross section of the channel control area.

[0062] Stage II: Bond Degradation: Gradually Increase Cross-Section Curvature Until the interface is slidable For interface regions that have reached the degradation condition, Phase II is adopted. Relationship; for each incremental step, update the additional reinforcement stress through the interface slip compatibility equation. The internal forces of the cross section were rebalanced, and the second moment-curvature curve 42 of the channel-controlled section was obtained, which reflects the gradual degradation of stiffness and bearing capacity.

[0063] Stage III: Full Slip: When the cross-section reaches its limit slip. Subsequently, residual shear stress was applied to the relevant interface areas. Additional reinforcement stress reduced to Continue to increase curvature Calculate bending moment Until the concrete is crushed or the steel bars yield extensively; a third moment-curvature curve 43 is obtained, reflecting the remaining bearing capacity and ductility under complete slip conditions.

[0064] Combine the three-stage envelope curves: Combine the three curves 41, 42, and 43 to form the overall moment-curvature envelope 40 of the channel control area, corresponding to different bonding stages; when performing displacement control design, the curvature can be further integrated along the length of the channel control area to obtain the moment-displacement relationship of the channel control area.

[0065] 5. Moment-curvature relationship and overall coupling in non-trough-controlled regions

[0066] In steps 65 and 66, moment-curvature calculations are performed on the non-channel-controlled region 4, and the region is segmentally superimposed with the channel-controlled region, as follows: Figure 3 As shown.

[0067] (1) Moment-curvature analysis of non-groove controlled zone: For a representative non-groove controlled zone section, under a given axial force Under the given conditions, the section analysis method for ordinary shear walls in the current specifications is used to obtain the moment-curvature curve 44; this curve generally does not consider the explicit interface slip effect and can be regarded as a characteristic of the integrally cast wall segment.

[0068] (2) Unitization along wall height: For each height unit Within the groove-controlled zone, the moment-curvature relationship is specified as the value of the groove-controlled zone characteristic curve 40 at the corresponding bonding stage; in the non-groove-controlled zone, it is specified as curve 44; when the bottom moment When adding, update the curvature of each unit sequentially. The vertex rotation angle and displacement are obtained through numerical integration: .

[0069] (3) Plastic hinge length Determined by: the curvature distribution Based on the analysis, the present invention can determine the equivalent plastic hinge length using energy equivalence or rotation equivalence methods. ,like Figure 3 As shown in reference numeral 49; for example, it can be assumed that: of ,in For yield curvature, The average curvature of the plastic hinge region.

[0070] (4) Overall bending moment-curvature composite curve: The bottom bending moment With overall average curvature The corresponding plots yield the overall moment-curvature composite curve 45; the limit state point is then determined on this curve. (Label 50) is used as an uncorrected peak bearing capacity assessment.

[0071] 6. Design bending capacity and amendments

[0072] In step 67, the design bearing capacity and correction factor calculation module 76 calculates the design flexural bearing capacity based on the performance target. :

[0073] (1) Selection of bearing capacity based on performance target: When the performance target is "non-yielding under minor earthquakes", the bending moment value corresponding to the moment before significant changes in cross-sectional or overall stiffness can be selected. As a control value; when the performance target is "repairable under moderate earthquakes", the bending moment value corresponding to the interface of the trench control zone entering the obvious bond degradation stage (midpoint of stage II) can be selected. When the performance objective is "no collapse under major earthquakes", the limit point of the overall bending moment-curvature composite curve at 45° can be selected. Or slightly less than the bending moment value at that point.

[0074] (2) Partial factors and resistance classification: Different resistance partial factors correspond to different performance targets. The design bending bearing capacity can be calculated as follows: ,in The control bending moment selected above or .

[0075] (3) Test comparison correction coefficient: Using the established database of full-scale or scaled-down tests of slotted shear walls, the calculated peak bending moment is compared with the corrected value. Compared with the measured peak value Compare: Through multiple sets of components Statistical analysis of the values ​​yields empirical correction coefficients related to trench length, axial compression ratio, and reinforcement ratio; in rapid engineering design, the design flexural bearing capacity can be calculated as follows: Corrections were made to improve consistency with the measured peak value.

[0076] (4) Result Output: In step 68, the result output module 77 outputs the three-stage moment-displacement envelope curve, the overall moment-curvature composite curve, and the plastic hinge length. Under various performance targets With correction value Output in chart form for designers to use directly for structural measures and reinforcement adjustments.

[0077] Example 2: Device for Calculating the Bending Moment Bearing Capacity of Slotted Shear Walls

[0078] This embodiment corresponds to claim 6, and describes a device structure for implementing the above method, such as... Figure 5 As shown.

[0079] 1. Hardware Structure: The overall structure 70 of the slotted shear wall bending moment bearing capacity verification device includes: a processor 79, which can be a general-purpose CPU, GPU, or other programmable processing unit, used to execute program instructions related to the method of this invention; a memory 78, including cache, random access memory, and non-volatile memory, used to store the analysis software program of this invention, the interface bonding-slip parameter library, experimental comparison data, and user engineering project files; a user interface 80, which can be a graphical user interface or a command-line interface, providing functions such as parameter input, result display, and graphical visualization; and a data bus and communication connection 81, connecting the processor 79, the memory 78, and various software functional modules to complete the transmission of data and instructions.

[0080] 2. Software module structure: such as Figure 5As shown, the verification device of the present invention includes the following software functional modules, all of which are implemented by the processor 79 calling the program in the memory 78: a data input module 71, which provides a wall geometry modeling interface, allowing input of the geometric information of the shear wall integral component 1 through parameter forms or CAD / model import methods; input of reinforcement information, including the diameter, spacing, and arrangement position of the additional longitudinal reinforcement 5 near the groove and the longitudinal reinforcement 6 of the edge component; input of the constitutive parameters of concrete and steel reinforcement materials, as well as the interface normal pressure and friction coefficient. etc.; supports user-defined or parameter library-selected interface bonding-slip model types. Segment division module 72, based on the geometric position and length of vertical slot 2. Automatically identify the controlled area 3 and the non-controlled area 4; establish finite element or segmented model along the wall height direction, and generate the height of each element. The interface section is marked with its identifier; the boundary between the old and new concrete is marked at interface location line 11 to provide a reference for subsequent bond-slip analysis. The interface bond-slip calculation module 73 provides several selectable bilinear or multilinear bond-slip models, allowing users to select the appropriate model. The source (standard recommendation or experimental regression); based on the input interface normal pressure. and coefficient of friction Calculate the residual frictional shear stress Establish corresponding [facilities] for each height unit. Curve 20, and updates the interface state (bonded integrity, degraded, complete slip) according to the slip increment during the analysis. The reinforcement stress evolution and flexural bearing capacity calculation module 74 establishes fiber section or layered section models for the control sections within the control zone 3; in stage I, according to... The additional reinforcement stress was calculated, resulting in the moment-curvature curve 41; in Stage II, the interface bond-slip module was invoked, and the slip compatibility equations were solved. Update the internal force equilibrium of the section to obtain curve 42; in stage III, reduce the additional reinforcement stress to Curve 43 is obtained; for the non-groove-controlled zone 4, the moment-curvature curve 44 is calculated according to the traditional section theory. The moment-curvature combination and plastic hinge analysis module 75 distributes the moment-curvature relationship between the groove-controlled and non-groove-controlled zones to each height element, forming a segmented characteristic along the wall height; under a given bottom moment loading history, the vertex rotation angle and displacement are obtained by numerical integration method, resulting in the overall moment-curvature composite curve 45; the equivalent plastic hinge length is obtained by statistical or equivalent methods on the curvature distribution. (Label 49) and ultimate bending moment The design load-bearing capacity and correction factor calculation module 76 automatically selects the corresponding control bending moment (such as yield bending moment) based on the user-defined performance targets. Bond degradation control moment, ultimate bending moment (This is) used as the basic bearing capacity; according to the set resistance partial factor. Calculate the design flexural bearing capacity Access the experimental database in memory 78, compare the calculated values ​​with the experimental peak values, and obtain or update the correction coefficients. Output the corrected design value The results output and visualization module 77 graphically displays the moment-curvature curves (41-44) of the groove-controlled and non-groove-controlled regions, the overall composite curve 45, and the three-stage moment-displacement envelope curve; it also outputs the plastic hinge length. It includes the distribution of internal forces and strains at key sections, and the design bearing capacity and correction values ​​under various performance targets; it supports exporting engineering calculation reports in PDF / Word / Excel formats for easy archiving and review.

[0081] Example 3: Implementation based on computer-readable storage media

[0082] This embodiment corresponds to claim 7, illustrating how the method of the present invention can be implemented using a computer-readable storage medium.

[0083] 1. Storage medium form: The computer-readable storage medium may be any form of read-only memory (ROM), random access memory (RAM), disk, optical disk, USB flash drive, solid-state drive or cloud storage; the medium stores program instructions that can run on the processor 79.

[0084] 2. Program content: The program includes: parameter input subroutine, segment division subroutine, interface bond-slip calculation subroutine, reinforcement stress evolution subroutine, section bending moment-curvature analysis subroutine, overall bending moment-curvature combination subroutine, plastic hinge analysis subroutine, design bearing capacity and correction coefficient calculation subroutine, result output and visualization subroutine, etc.; these subroutines work together to realize all steps 60 to 68 described in Example 1.

[0085] 3. Execution Process: When the program is loaded into processor 79 for execution, it first calls data input module 71 to receive engineering parameters; then, it sequentially executes steps such as segment division, interface bonding-slip analysis, moment-curvature calculation of channel-controlled and non-channel-controlled zones, overall coupling and plastic hinge analysis, and calculation of design bearing capacity and correction coefficient; finally, result output module 77 outputs the three-stage bearing curves and design flexural bearing capacity. Output to the user.

[0086] Example 4: Engineering Application Process

[0087] To further illustrate the engineering applicability of this invention, a typical application process is given below (without limiting specific values):

[0088] 1. The designer inputs the geometric and reinforcement information of shear wall 1 of a high-rise prefabricated residential building into the user interface 80. The vertical groove 2 is set in the middle of the wall segment, and the groove length is... It is 1.8 m.

[0089] 2. The software automatically determines the height of the control zone 3. m, the bottom 0 to 2.16 m range of units is assigned to the tank control area, and the rest is assigned to the non-tank control area 4.

[0090] 3. Based on the selected concrete strength grade, construction interface roughness, and axial compression level, the interface bond-slip module 73 provides... The recommended value is calculated, and a bilinear curve 20 is generated.

[0091] 4. The reinforcement stress evolution module 74 performs a three-stage analysis on the control section of the trench control zone, and obtains the moment-curvature curves 41, 42, and 43; and obtains curve 44 for the non-trench control zone section.

[0092] 5. Moment-Curvature Combination Module 75: As the bottom bending moment increases from 0 to the expected limit value, the curvature and deformation of each height element are gradually updated to obtain the overall moment-curvature composite curve 45 and the plastic hinge length. .

[0093] 6. Design Bearing Capacity Calculation Module 76 Under the performance objective of "repairable after moderate earthquake", the bending moment corresponding to the median value of the grooved control zone entering the bond degradation stage is selected as... Combining partial factors and measured correction factors The design flexural bearing capacity was calculated. .

[0094] 7. The software outputs reports showing: the stress process of the trench control zone during "sliding first and then coordinating", the three-stage moment-displacement envelope curve, the length of the plastic hinge, and the design bending capacity; if the current reinforcement is insufficient, it will prompt that additional reinforcement or trench length adjustment measures are needed.

[0095] As can be seen from the above embodiments, the present invention, while ensuring a clear understanding of the physical mechanism of the calculation process, organically couples the interface adhesion degradation, slip development and overall bending response, and controls the computational complexity within the acceptable range of engineering software, making it suitable for inclusion in design guidelines and dedicated software modules for widespread application.

Claims

1. A method for segmented verification of the bending moment bearing capacity of a slotted shear wall, characterized in that, The steps include: (1) Obtaining the geometric parameters, concrete and steel material parameters, and normal pressure at the interface between new and old concrete of the slotted shear wall; (2) Dividing the wall limbs near the opening or vertical slot into at least two control zones along the wall height direction, including: the slot-controlled zone, which is an area with a height of 1.0 to 1.5 times the slot length from the bottom of the slot; and the non-slot-controlled zone, which is the wall limb area other than the slot-controlled zone; (3) In the slot-controlled zone, establishing a three-stage stress evolution model for the additional steel reinforcement set along the slot: complete bond stage: interface shear stress Additional reinforcement stress is calculated according to Linear elasticity calculation; Bond degradation stage: Bilinear bond-slip relationship is used. Solving for additional reinforcement stress based on interface slip compatibility equation Full slip stage: The interface provides shear force solely through friction, and the frictional strength is... The contribution of additional reinforcement to bending resistance is reduced to ,in (4) Apply additional steel reinforcement stress in three stages Substitute the modified formula for calculating the flexural bearing capacity of the trench-controlled zone into the formulas to obtain three moment-curvature or moment-displacement envelope curves for the trench-controlled zone; (5) Calculate the moment-curvature relationship of the non-trench-controlled zone according to the current shear wall design method, and combine and superimpose it with the moment-curvature relationship of the trench-controlled zone along the wall height to determine the overall plastic hinge length and the corresponding ultimate moment; (6) Use numerical integration or analytical simplification formulas to obtain the design flexural bearing capacity of the structure under a given displacement ductility or rotation angle limit. And based on the experimental peak bending moment, a correction factor is determined for... Correct the output.

2. The method according to claim 1, characterized in that, The bilinear bond-slip relationship The parameters include peak bond strength. Limit slip and residual bond strength The parameters were obtained by regression fitting of the test results of the bond between new and old concrete interfaces.

3. The method according to claim 1 or 2, characterized in that, The additional reinforcement contributes a reduction factor Compared with the stiffness or bearing capacity degradation coefficient obtained from experiments Establish empirical functional relationships The selection is based on factors such as trench length, reinforcement ratio, and interface roughness.

4. The method according to claim 1, characterized in that, The superposition of the moment-curvature relationship between the groove-controlled zone and the non-groove-controlled zone includes: discretizing the wall limb into several elements along the wall height, calculating the moment-curvature relationship of the cross section of each element and considering the interface bonding stage, obtaining the relationship between the displacement at the top of the wall limb and the moment at the bottom by using a piecewise integration method, and determining the plastic hinge length and the ultimate state accordingly.

5. The method according to claim 1, characterized in that, The design flexural bearing capacity To optimize the partial factorization results for design under multi-level load conditions, the rotation angle limit for the groove-controlled zone entering the bond degradation stage or the complete slip stage can be used to determine different performance targets. .

6. A device for verifying the bending moment bearing capacity of a slotted shear wall for implementing the method described in any one of claims 1 to 5, characterized in that, include: The data input module is used to input the geometric, material, and load parameters of the slotted shear wall; The segmentation module is used to automatically identify the slot position and divide the slot-controlled and non-slot-controlled areas according to preset rules; the interface bonding-slip calculation module is used to establish a bilinear relationship based on input parameters. Relationships and calculations of the three-stage additional reinforcement stress; The module for calculating flexural capacity is used to calculate the flexural capacity of the section based on the three-stage additional reinforcement stress in the trench-controlled zone, and to calculate the flexural capacity in the non-trench-controlled zone using conventional methods. The moment-curvature combination module is used to perform piecewise superposition of the moment-curvature relationships in the trench-controlled and non-trench-controlled zones to determine the plastic hinge length and ultimate moment. The result output module outputs the three-stage moment-displacement envelope curve and the design flexural capacity. and correction factor.

7. A computer-readable storage medium having a computer program stored thereon, the computer program, when executed by a processor, implementing the functions of each module of the device of claim 6, thereby performing the segmented verification method for the bending moment bearing capacity of the slotted shear wall as described in any one of claims 1 to 5.

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