Slotting shear wall performance-based reinforcement and slot length selection method
By establishing a quantitative mapping between slot length, reinforcement ratio, and axial compression ratio through a single-exponential degradation model and parameterized relationships, the problem of selecting slot length and reinforcement in existing technologies is solved. This enables controllable degradation performance and design safety margin of slotted shear walls in high and medium intensity zones, and provides a performance-based design tool.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- HUNAN UNIV
- Filing Date
- 2026-05-09
- Publication Date
- 2026-06-23
Smart Images
Figure CN122263246A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of seismic design of prefabricated concrete shear wall structures, specifically to a performance-based reinforcement and slot length selection method for slotted shear walls based on a single-index stiffness degradation model, and its software implementation module, applicable to the performance-based seismic design of prefabricated monolithic slotted shear wall structures in high and medium seismic intensity zones. Background Technology
[0002] As an important load-bearing component of prefabricated concrete structures, slotted shear walls are connected through vertical or horizontal slots between precast wall segments, as well as additional reinforcing bars and grouting materials. Compared with monolithic cast-in-place shear walls, they have advantages such as convenient assembly, high degree of industrialization, and replaceability or repairability, and have been gradually promoted in residential and public buildings. In current seismic design codes and engineering practices, slotted shear walls are still mostly modeled as equivalent to ordinary reinforced concrete shear walls. The stiffness degradation, connection ductility, and energy dissipation mechanism of the slotted area are mostly indirectly controlled by empirical reduction coefficients or structural requirements, which makes it difficult to reflect the actual degradation process under multiple strong earthquakes.
[0003] In recent years, scholars both at home and abroad have conducted low-cycle repeated tests on prefabricated shear walls and slotted / grooved shear walls, proposing to use equivalent stiffness degradation curves to characterize the damage evolution of components under cyclic loading, and employing single-exponential models in some studies. Fitting stiffness degradation, the degradation coefficient 'b' is often used as a performance index to compare the rate of degradation of different structural types or different reinforcement schemes. Existing literature shows that measures such as increasing the trench length, increasing additional reinforcement within a reasonable range, and optimizing the axial compression ratio can mitigate stiffness degradation to some extent. A decrease in stiffness can lead to rapid stiffness decay and brittle failure; conversely, excessively short groove length, insufficient constraint, or excessively high axial compression ratio can result in rapid stiffness decay and brittle failure. However, existing publicly available technologies generally suffer from the following shortcomings:
[0004] 1. Degradation coefficient Remaining at the experimental and inductive level: Existing research is mostly based on a limited number of component specimens, and studies on different structural measures. The values are statistically and qualitatively compared, and only empirical conclusions such as "a certain type of structure has a smaller b value and degenerates more slowly" are given, and are based on... The values are categorized into several performance levels. Designers often find it difficult to determine the appropriate performance level based on the target specifications in actual engineering projects. The specific feasible combinations of groove length, reinforcement, and axial compression ratio can be derived from these values. It is more often used as an academic evaluation indicator rather than a design variable that can directly drive the choice of construction.
[0005] 2. Lack Quantitative functional relationship between controllable design parameters: Existing methods typically do not... Further build upon the model Explicit or semi-explicit functions cannot systematically quantify the combined effects of trench length, additional reinforcement ratio, wall limb distribution reinforcement ratio, and axial compression ratio on stiffness degradation. Even if some studies provide certain linear or nonlinear regression relationships, they are mostly limited to sensitivity analyses of specific structures or single parameters, and have not yet formed a generalized calculation model that can be directly embedded into the engineering design process.
[0006] 3. Lack of "back-calculation methods" that can be directly used in design software or standards: Most existing standards, guidelines, and engineering software employ a dual verification approach of bearing capacity and deformation, but for stiffness degradation performance under multiple strong earthquakes, most use uniform reduction or structural limit control. There is a lack of methods that start with "target degradation performance" and use mathematical models to calculate the stiffness degradation performance from the target... The design process involves back-calculating the trench length, reinforcement, and axial compression ratio, and then substituting these values back into the design parameters to perform a complete reverse design process for bearing capacity and "strong shear, weak bending" verification. Designers often have to rely on experience to find structural parameters that are difficult to adapt to ensure the consistency and controllability of degradation performance across different projects.
[0007] 4. Insufficient control over degradation risks associated with high axial compression ratios and unfavorable short-groove structures: In actual engineering projects, constraints such as building layout and electromechanical pipeline arrangement often result in short vertical groove lengths while simultaneously employing high axial compression ratios to improve vertical bearing capacity. Current technologies mostly rely on post-hoc constraints through structural requirements or overall ductility calculations, lacking the introduction of axial compression ratio correction factors at the stiffness degradation model level. The values are corrected bidirectionally, and short slots are prohibited from being used in high-performance degradation levels by explicit constraints, thereby systematically avoiding severe brittle degradation.
[0008] 5. The integrated design and calculation tool for "target performance - parameter combination" has not yet been formed: Although some software has the function of internal force analysis and bearing capacity verification of prefabricated shear walls, it generally lacks the function of parameter back calculation and automatic screening based on stiffness degradation performance. Furthermore, it lacks a calculation tool that can chart and tabulate the relationship between target degradation level, groove length, reinforcement ratio and axial compression ratio. This is not conducive to promoting the concept of "performance-based structural design" in code provisions, enterprise standards and engineering practice.
[0009] In summary, current technologies have not yet addressed the single-exponential degradation coefficient. The evaluation criteria have been upgraded from "experimental evaluation indicators" to "design parameters for drive channel length and reinforcement selection," but a parametric degradation model and its software implementation for engineering applications are still not provided. There is an urgent need for a method that can... Establish under the framework This invention proposes a quantitative relationship between key design parameters of slotted shear walls and, starting with the target degradation performance, provides inverse calculation methods and constraint strategies for slot length, reinforcement, and axial compression ratio, thereby improving the controllability of degradation performance and the safety margin of design for slotted shear walls in high- and medium-intensity seismic zones. Summary of the Invention
[0010] To address the aforementioned technical problems, this invention provides a method for performance-based reinforcement and slot length selection in slotted shear walls, along with its software module, mainly comprising the following:
[0011] 1. Single-exponential degradation model and construction of parameterized relationships
[0012] (1) The equivalent stiffness degradation of the slotted shear wall is characterized by a single-exponential degradation model: ,in, For initial stiffness, For the first Equivalent stiffness of the second cycle This is the stiffness degradation coefficient.
[0013] (2) Based on a large amount of test data of vertical and horizontal slotted shear walls, parameters such as slot length, reinforcement ratio, and axial compression ratio are introduced to evaluate the degradation coefficient. Establish empirical or semi-theoretical parametric functional relationships: ,in: This is the length of the vertical groove; The length of the horizontal groove; The reinforcement ratio for adding longitudinal or transverse reinforcement bars inside the trench; The reinforcement ratio of the wall piers; Number of loops to consider in the design; This is the axial compression ratio.
[0014] (3) For the vertical groove structure, establish and Experience lower bound relationship: ,in, and For the regression constant, The yield diameter of the longitudinal reinforcement in the confined zone; when When increasing from 300mm to 420mm, the corresponding It decreased from approximately 0.25 to approximately 0.15.
[0015] (4) For the construction of the horizontal groove, under reasonable conditions , And within the range of groove width and grouting strength, through the function Degradation coefficient: This ensures that the horizontally slotted shear wall has a relatively slow stiffness decay performance.
[0016] (5) Introduce a high axial compression ratio correction factor The corrected degradation coefficient is obtained as follows: ,in, axial compression ratio A function that simultaneously reflects the dual effect of axial compression ratio on ductility and stiffness degradation; when the axial compression ratio is high... Appropriately amplify the degree of degradation.
[0017] 2. Target degradation performance classification and constraint setting
[0018] (1) Based on the seismic fortification intensity and performance-based design requirements, the target degradation level is divided into: high-intensity zone: Moderate intensity zone: Low-intensity areas: .
[0019] (2) Specific usage constraints are set for vertical short slots: when the length of the vertical slot is... When the value is mm, the system prohibits the use of this construct for the target degradation level. Under certain operating conditions, dangerous parameter combinations can be directly masked through program logic or design diagrams.
[0020] 3. Back-calculation design steps based on target degradation performance
[0021] The method of the present invention includes the following design flow (see Figure 3 , Figure 4 ):
[0022] (1) The designer selects the target degradation level and determines the target based on the seismic fortification intensity of the project location and the expected component damage control target. .
[0023] (2) Select the number of cycles to be considered in the design. (For example, corresponding to earthquakes designed for earthquake resistance, rare earthquakes, or frequent earthquake scenarios), by Backwards Lower limit of allowable stiffness decay under the next cycle:
[0024] (3) The target (or after axial compression ratio correction) Substitute into the parameterized relation The solution that satisfies the conditions can be obtained through analytical inverse calculation, numerical iteration, or table lookup. , , , and axial compression ratio The feasible region of the construction parameters.
[0025] (4) Apply constraints to the obtained parameter combinations, including: lower limit constraint on the length of the vertical short groove. mm (when target) (Time); the axial compression ratio is limited to not exceeding the upper limit allowed by the specification and within the safe range recommended by this invention; the reinforcement ratio is not lower than the minimum reinforcement ratio and must not exceed the upper limit of the structure or construction, etc. One or more sets of alternative trench length and reinforcement schemes are obtained through constraint screening.
[0026] (5) For each set of alternative parameter combinations, call the parameter list containing the groove interface bonding strength. The modified bending moment bearing capacity formula is used to check the bending moment bearing capacity, displacement ductility, and the "strong shear weak bending" condition; if the requirements are not met, the target is adjusted automatically or manually. Alternatively, modify parameters such as trench length and reinforcement, and repeat the above steps until all design requirements are met.
[0027] 4. Software Modules and Graphical Implementation
[0028] This invention further provides a performance-based design software module for slotted shear walls that implements the above method (see...). Figure 5 It includes: a target performance input unit, used to input the fortification intensity, target degradation level, and target... and expected number of cycles Degradation model computation unit, used to calculate based on and Complete stiffness degradation analysis and inverse calculation of groove length, reinforcement, and axial compression ratio; constrained judgment unit, used to adjust the axial compression ratio based on the correction factor. The system includes a short groove length constraint and specification limit unit for automatically filtering parameter combinations; a bearing capacity verification unit for performing "strong shear and weak bending" and ductility verification based on the modified bending moment bearing capacity formula; and a result output and chart generation unit for outputting a multi-dimensional combination table of "target degradation level - groove length - reinforcement ratio - axial compression ratio" and recommended parameter ranges, which can be further exported as design charts for quick paper-based calculations.
[0029] Compared with the prior art, the present invention has the following beneficial effects:
[0030] 1. Achieve degradation coefficient Quantitative mapping to design parameters: transforming the single-exponential degradation coefficient, originally used only for experimental evaluation... By establishing a functional relationship with controllable parameters such as groove length, reinforcement ratio, and axial compression ratio, direct coupling between stiffness degradation performance and structural design is achieved. It becomes a practical design parameter for selecting the length of the drive channel and the reinforcement configuration.
[0031] 2. Forming a back-calculation design process that can be embedded in specifications and software: A complete closed-loop process of "target degradation performance → allowable stiffness attenuation → back calculation of groove length and reinforcement → bearing capacity and strong shear and weak bending verification" has been constructed, which is convenient to be encapsulated as a module in design software or to compile corresponding design charts in specifications and enterprise standards, so as to realize the engineering application of performance-based structural indicators.
[0032] 3. System control of high axial compression ratio and short slot brittle degradation risk: by introducing an axial compression ratio correction factor. The use constraints of vertical short slots, and the explicit amplification of high axial compression ratio and unfavorable short slots at the degradation model level. The system automatically shields unsafe parameter combinations to mitigate adverse effects and prevents the misuse of dangerous short trench structures in high- and medium-intensity seismic zones.
[0033] 4. Improve the controllability and consistency of slotted assembled shear walls in different seismic intensity zones: by following... The target degradation level of the value classification quantifies the performance requirements of different seismic intensity zones into a unified degradation index. Using the method of this invention, similar degradation performance can be uniformly controlled in different projects, thereby improving the safety margin and recoverability of the structure under multiple seismic events. Attached Figure Description
[0034] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the embodiments of the present invention will be further described in detail below with reference to the accompanying drawings. In the accompanying drawings of the present invention:
[0035] Figure 1 Schematic diagram of vertical slotted shear wall construction
[0036] Figure 1 This diagram illustrates a typical arrangement of a vertically slotted shear wall and the detailed construction of the slotted area, including: 1 — Integral slotted shear wall unit: An integral shear wall unit consisting of a left wall segment, a right wall segment, and a central vertical slot, used to withstand horizontal shear force and axial compression. 2 — Left wall segment: A precast or cast-in-place wall segment on the left side of the shear wall, internally reinforced with vertical and horizontal distributed reinforcement, making a significant contribution to the wall's bending and shear bearing capacity. 3 — Right wall segment: A precast or cast-in-place wall segment on the right side of the shear wall, with a similar construction and reinforcement to the left wall segment, forming a lateral force resisting system together with the left wall segment. 4 — Vertical slot (vertical connection joint): A vertical slot-shaped opening or groove along the wall height, located between two wall segments, providing space for post-grouting and the installation of additional reinforcement; its effective length is [missing information]. 5 — Grouting material in the trench: High-strength grout or fine aggregate concrete filled in the vertical trench opening 4, used to achieve integral connection between the two wall segments and provide bond strength for the additional longitudinal reinforcement in the trench. 6 — Additional longitudinal reinforcement in the trench: Additional longitudinal reinforcing bars penetrating the vertical trench opening 4, with a reinforcement ratio denoted as […]. Used to enhance the flexural bearing capacity and connection ductility of the groove region, and to improve the stiffness degradation coefficient. Significant impact. 7 — Groove stirrups (confined reinforcement): Closed stirrups or tie bars arranged around the groove or in the grouting area to confine the grouting material and additional longitudinal reinforcement, preventing cracking and propagation of concrete in the groove area, and indirectly mitigating stiffness degradation. 8 — Vertical reinforcement of wall segments: Main load-bearing longitudinal reinforcement embedded in the left wall segment 2 and right wall segment 3, providing bending capacity and ductility to the wall segment, and its reinforcement ratio is involved in the determination. 9 — Horizontal Reinforcement in Wall Members: Horizontal reinforcement bars arranged in the wall members form a steel mesh, which, together with the vertical reinforcement bars, improves the shear resistance and crack control capacity of the wall members. Their reinforcement ratio is also included in the determination of the wall member's strength. 10 — End Edge Members (Constrained Edges): These are reinforced areas located at the ends of wall members, typically equipped with denser longitudinal reinforcement and stirrups. They enhance the ductility of the end compression zone and, together with the groove area, control the development of plastic hinges in the member. 11 — Axial Compression N: The vertical pressure acting on the top of the wall, usually originating from dead and live loads from upper floors and the roof. Its value is proportional to the cross-sectional area. and concrete strength Together they constitute the axial compression ratio 12 — Horizontal shear force V: Shear force generated by earthquake or wind loads, mainly borne by the slotted shear wall, used to induce stiffness degradation in low-cycle cyclic loading tests. Figure 1 In the structure shown, the groove length is... The changes, the reinforcement ratio of the additional longitudinal reinforcement 6 in the trench Distribution reinforcement ratio of wall reinforcement bars 8 and 9 The degradation coefficient is affected by both the axial compression ratio and 11. And through the relational formula given in this invention Quantify it.
[0037] Figure 2 Schematic diagram of horizontal slotted shear wall construction
[0038] Figure 2 The diagram illustrates a prefabricated shear wall structure with horizontal slots, including: 1 — an integral slotted shear wall component (same as above). Figure 1 (Chapter 1, numbering continues) Here, it is formed by connecting the upper wall segment and the lower wall segment through a horizontal groove. 13 — Upper wall segment: A shear wall unit set above the horizontal groove 15, which can be a precast panel wall or a cast-in-place wall segment, and is integrated with the lower wall segment 14 through the groove and additional reinforcement to achieve overall load-bearing. 14 — Lower wall segment: A shear wall unit set below the horizontal groove 15, bearing the loads transmitted from the upper wall segment and the superstructure. 15 — Horizontal groove (horizontal connection joint): A groove-shaped notch that runs horizontally through the thickness of the wall, and its length is defined as It is mainly used for vertical additional reinforcement passing through and post-grouting, and is the main connection part between the upper and lower wall segments. 16 — Additional vertical reinforcement in the groove: The additional vertical reinforcement passing through the horizontal groove 15 is usually connected by sleeves or anchored in the upper and lower wall segments. It has an important influence on the vertical bearing capacity and connection ductility of the wall, and its reinforcement ratio is also included. 17 — Grouting material inside the trench (same as above) Figure 1 5 (Standard designation retained): High-strength grout or fine-aggregate concrete filled inside the horizontal groove 15 to ensure effective bonding and force transfer between the vertical additional reinforcement 16 and the concrete of the upper and lower wall segments. 18 — Vertical reinforcement of the upper wall segment: The main load-bearing reinforcement arranged in the upper wall segment 13, anchored to the additional vertical reinforcement 16 in the groove, forming continuous load-bearing reinforcement. 19 — Vertical reinforcement of the lower wall segment: The main load-bearing reinforcement arranged in the lower wall segment 14, forming an integral load-bearing system with the additional vertical reinforcement 16 and the grouting material 17. 20 — Horizontal construction joint interface: The concrete contact surface area between the upper and lower wall segments, subject to the interface bond strength... This interface controls one of the key parameters in the modified bending moment bearing capacity formula. This is achieved by optimizing the horizontal slot length. The quantity and diameter of the additional vertical reinforcing bars 16 inside the trench, as well as the strength of the grouting material 17, can be determined under the guidance of the parametric model of this invention, with the degradation coefficient... Controlling the value to 0.12 or below improves the seismic performance and recoverability of horizontally slotted shear walls.
[0039] Figure 3 Schematic diagram of single-exponential stiffness degradation model and parameterization relationship
[0040] Figure 3 This is a schematic diagram of the single-exponential stiffness degradation model and parameterized relationship of degradation coefficients used in this invention, including: 21— Family of stiffness degradation curves: multiple curves plotted in a coordinate system. The curves correspond to different degradation coefficients. ,For example etc., intuitively reflecting the differences The rate at which stiffness decays with the number of cycles at the specified value. 22 — Target degradation performance grading region: in -High-intensity zones labeled along the axis ( ), medium intensity zone ( ) and low-intensity areas ( (e.g., partitions) allow designers to select the target degradation level. 23 — Parameter Space Axis: Design parameter axes expressed in simplified form, such as slot length. Additional reinforcement ratio in the trench Reinforcement ratio of wall limbs axial compression ratio Number of loops etc., used to indicate the degradation coefficient Variations in a multidimensional parameter space. 24 — Parametric relation surfaces or contour lines: plotted in a simplified two-dimensional or three-dimensional parameter space. Contour lines or surfaces reflect the different trench lengths and reinforcement combinations corresponding to these features. Equivalent intervals, such as Contour lines separate the safe zone from the unsafe zone. 25— Axial compression ratio correction arrow: The arrow indicates that an increase in the axial compression ratio leads to a correction for the degradation factor. The increasing trend vividly illustrates the adverse effects of high axial compression ratio on degradation performance. Figure 3 This invention helps to understand how it establishes a quantitative mapping between target degradation performance and specific construction parameters through a single exponential model and parameterized relationships.
[0041] Figure 4 Design flowchart based on target degradation performance
[0042] Figure 4 This is a schematic diagram of the process structure of the method of the present invention, including: 31 — Target performance input step: The designer inputs the project location, seismic intensity, and target degradation level (corresponding to the target). Design the number of loops And the initially selected axial compression ratio range. 32 — Allowable stiffness attenuation calculation steps: Based on , using the target and Calculate the lower limit of allowable stiffness attenuation. This forms stiffness performance constraints. 33 — Degradation coefficient parameterization solution steps: The target... (or Substitute the parameterized relation The feasible set of trench length and reinforcement combinations is obtained through analytical, numerical, or table lookup methods. 34 — Construction and Code Constraint Judgment Steps: Apply constraints to the parameter combinations obtained in step 33: Check the trench length. Is it greater than 400mm (in) Under certain circumstances, whether the axial compression ratio meets the code limit and whether the reinforcement ratio is within the structurally feasible range, those that do not meet the requirements should be rejected. 35— Bearing capacity and strong shear and weak bending verification steps: using methods including interfacial bond strength The modified bending moment bearing capacity formula is used to check the bending moment bearing capacity, displacement ductility, and "strong shear weak bending" condition of the parameter combinations that have passed the constraint screening. 36 — Design Scheme Output Steps: Output the final combination of trench length, reinforcement, and axial compression ratio that meets the requirements of degradation performance, structural constraints, and bearing capacity. Recommended intervals, sensitivity analysis results, and lookup tables can be generated simultaneously. 37 — Iterative Return Arrow When Not Met: When the check in step 34 or 35 fails, guide the process back to step 31 or 33 and prompt for adjustment of the target. The design process involves determining the trench length or reinforcement scheme until a design that meets the requirements is obtained. Figure 4 This invention visually demonstrates the complete design process of the present invention, starting from the target degradation performance and gradually back-calculating and verifying the structural parameters of the slotted shear wall.
[0043] Figure 5 Software module functional structure diagram
[0044] Figure 5 The functional structure of the performance-based design software module for slotted shear walls of the present invention is shown in the diagram, including: 101 — User interface unit: used to receive engineering parameters, target degradation level, and target parameters input by the designer. The calculation results, including seismic intensity and preliminary structural parameters, are displayed graphically or tabularly. 102 — Database Unit: Stores experimental data and regression results. Model parameters, recommended indicators for different fortification intensities, standard limits, and existing design charts provide support for the calculations. 103 — Degradation Model Calculation Unit: Implements... Model and parametric relationship Numerical calculations are used to determine the target. Back-calculation of parameter combinations. 104 — Axial compression ratio correction and constraint judgment unit: Calculates correction coefficients based on input axial compression ratio. The corrected degradation coefficient is obtained. It automatically checks constraints such as the lower limit of the vertical groove length, axial compression ratio, and reinforcement ratio, and eliminates combinations that do not meet the requirements. 105 — Bearing Capacity and Ductility Check Unit: Calls the unit containing interfacial bond strength... The modified bending moment bearing capacity formula and shear bearing capacity formula are used to verify the bending and shear bearing capacity and ductility of candidate parameter combinations, ensuring that the "strong shear and weak bending" design objective is achieved. 106 — Result Processing and Chart Generation Unit: The verified parameter combinations are summarized to generate a "target degradation level—groove length—reinforcement ratio—axial compression ratio" correspondence diagram, recommended interval diagram, and electronic lookup table, allowing engineers to quickly access the data regardless of whether they have a computer. 107 — Report Output Unit: Automatically generates design calculation sheets, parameter recommendation tables, and appendix charts for easy archiving and review. Through the integration of the above functional modules, Figure 5The software shown can fully implement the performance-based design method of the present invention, so that the selection of groove length and reinforcement of slotted shear walls can be directly driven by the target degradation performance index, which significantly improves the reliability and efficiency of the design work. Detailed Implementation
[0045] The embodiments of the present invention will be described in detail below with reference to the accompanying drawings and specific examples. However, it should be understood that the following embodiments are only for illustrating the present invention and are not intended to limit the scope of protection of the present invention. Various changes and substitutions made by those skilled in the art to the specific parameter forms, step sequences, and implementation carriers without departing from the concept of the present invention should fall within the scope of protection of the present invention.
[0046] Example 1: Performance-based reinforcement and slot length selection method for vertical slotted shear walls
[0047] This embodiment is for Figure 1 The vertical slotted shear wall 1 shown is constructed by using a parametric degradation model and target performance back-calculation steps to determine the vertical slot length. Additional longitudinal reinforcement ratio in the trench Reinforcement ratio of wall limbs and axial compression ratio Collaborative design.
[0048] 1. Construction of Parametric Degradation Model: In the single-exponential stiffness degradation model Based on this, this embodiment will consider the degradation coefficient of the vertical slotted shear wall. It is expressed as a function of controllable parameters. For the construction of vertical slots, the following empirical relationship can be used:
[0049] 1) Basic form: ,in: This is the baseline degradation factor for vertically slotted shear walls under the most unfavorable structural conditions; Characterizing the length of the vertical groove The degree of improvement in degradation; , The reinforcement ratio of the additional longitudinal bars in the trench are respectively Reinforcement ratio of wall limbs The influence coefficient; Reflecting axial compression ratio Adverse effects of degradation; It is the yield diameter of the vertical reinforcing steel.
[0050] 2) Specialized form of the lower limit relationship of vertical groove length: when only groove length is considered When affected by the above conditions, the above formula can be degenerated into the lower limit formula described in claim 2 of this invention: ,in , Determined by experimental regression. Taking a series of experiments as an example, when... When the diameter is increased from 300mm to 420mm, the experimental fitting results are approximately: , The above linear lower bound relationship is satisfied.
[0051] 3) Axial compression ratio correction: Considering the combined effect of the axial compression ratio, this embodiment introduces a correction factor. The corrected degradation coefficient is obtained as follows: ,in A typical form can be given by the following formula: , This represents the "positive part" of the function, and is set to 0 when it is less than 0. This is a reference value for the axial compression ratio (e.g., 0.10 to 0.15). This is the influence coefficient. Thus: when the axial compression is relatively small or moderate, The degradation is not significantly amplified; when the axial compression ratio exceeds the reference value... The degradation coefficient is appropriately amplified to reflect the combined effects of reduced ductility and accelerated degradation.
[0052] 4) Extension terms for construction and material effects (optional): If necessary, the strength of the grouting material can be further introduced into the above model. Interface roughness coefficient Equal terms, forming a more complete expression: This extension does not change the basic idea of the present invention.
[0053] 2. Target Degradation Performance Setting: Based on the engineering fortification intensity and performance requirements, the designer selects the target degradation level and target... Values, for example: high-intensity areas: take Medium intensity zone: take Low-intensity areas: take Meanwhile, the design cycle number is selected based on the expected damage to the structure under multiple earthquakes. For example, when considering rare earthquake scenarios, one can take... This is an equivalent cycle.
[0054] In a given and Under the conditions, this embodiment is achieved through , and backwards in the first Stiffness lower limit during the second cycle For example: If , ,but ;like , ,but This lower limit of stiffness can be used as a performance constraint for subsequent back-calculation of structural parameters and verification of bearing capacity.
[0055] 3. Based on objectives Parameter back-calculation: Taking a vertically slotted shear wall in a high-intensity seismic zone as an example, assuming: seismic intensity is 8 degrees; target degradation level: Design the number of loops: Concrete strength grade: C40 MPa; Cross-sectional area: Longitudinal reinforcement uses HRB400. mm; Initial selection of axial compression ratio: .
[0056] 1) Calculate the corrected degradation factor: based on the reference axial compression ratio ,coefficient As an example: The corrected target degradation coefficient is then: .
[0057] 2) Calculate the trench length and reinforcement ratio from the parameterized relationship: Assume that the example coefficients for the vertical trench structure are obtained through experimental regression: ; ; ; ; .but: When the axial compression ratio is 0.15, the axial compression ratio term is: To meet It can be written as: Substitute And simplified: , , , .
[0058] If the reinforcement ratio of the wall segments is predetermined (i.e., 0.0025), then: , Two typical design approaches are further presented:
[0059] Approach A: Prioritize increasing the slot length
[0060] Pick (0.6%), then , , , That is, it is necessary to take mm, which significantly exceeds the lower limit of 400 mm for short grooves proposed in this invention, thus helping to slow down degradation.
[0061] Option B: Due to the limitations of the floor plan, appropriately increase the size.
[0062] If the building layout is restricted It should not exceed 450mm, then the required length can be calculated backwards. : , , The reinforcement ratio of the additional longitudinal bars in the trench needs to reach 5.2% or more (which is usually close to the upper limit of construction and anchorage). The software module will prompt "reinforcement ratio is too high" and suggest increasing the trench length or reducing the axial compression ratio.
[0063] Based on the above analysis, it can be achieved by changing , , The combination with the axial compression ratio satisfies the inequality constraints, resulting in a feasible design scheme.
[0064] 4. Implementation of constraints for short slots
[0065] In this embodiment, when the target degradation level At that time, the software is configured with the following logic: if the vertical groove length is input or calculated in reverse... If the length of the vertical groove is less than 400 mm, the program automatically determines that the combination violates the lower limit constraint of the short groove; marks the parameter group as "unavailable" and does not proceed to the subsequent bearing capacity verification step; a prompt message pops up in the user interface unit 101: "Under the condition of b≤0.20, the vertical groove length shall not be less than 400 mm. Please adjust the groove length or relax the target degradation level." This constraint is used to avoid the incorrect selection of short grooves like PW3 in high and medium intensity zones.
[0066] 5. Corrected bending moment bearing capacity and "strong shear and weak bending" check
[0067] For the parameter combinations obtained through the above screening, it is necessary to further utilize parameters including interfacial bond strength. The modified bending moment bearing capacity formula is checked. A typical form can be written as: ,in: This represents the bending moment bearing capacity obtained from conventional reinforced concrete section analysis; This represents the additional bending moment component provided by the joint bonding at the groove interface and the tensile force of the additional reinforcing steel. The effective height of the cross section, The thickness of the wall segment.
[0068] By calculating With shear bearing capacity By comparing the external and internal force requirements, the "strong shear and weak bending" condition is verified: ,in The length of the wall segment, This is the safety factor. If it is not met, a prompt will be made to increase reinforcement or adjust the geometric dimensions.
[0069] Example 2: Performance-based design method for horizontally slotted shear walls
[0070] This embodiment is for Figure 2 The degradation coefficient is established for the horizontal slotted shear wall 1 shown. With the length of the horizontal groove Vertical additional reinforcement ratio And the quantitative relationship between grouting materials and interfacial bonding properties, to achieve the goal of grouting in high and medium intensity zones. Keep it at 0.12 or below.
[0071] 1. Parametric Degeneracy Model of Horizontal Channel
[0072] Considering that the horizontal groove mainly bears bending tension and shear slip, this embodiment can adopt the following form: ,in: The baseline degradation coefficient for horizontally slotted shear walls; Characterizing the beneficial effect of horizontal groove length on stiffness degradation The height of the wall; Additional vertical reinforcement ratio for the trench The influence coefficient; Reflecting the adverse effects of axial compression ratio; Characterizing interfacial bond strength Contribution to improvement of degradation For reference bond strength, typical value ranges for each coefficient can be obtained by regression analysis of the experimental data, and stored in database unit 102 for software access. In high-intensity seismic zones, this invention proposes the following constraints for horizontally slotted shear walls: Therefore, we can... , , Perform inverse calculations and optimizations.
[0073] 2. Design Steps Example
[0074] Taking a 10-story prefabricated shear wall project as an example, considering the horizontal joint of a middle span of the wall under an 8-degree seismic intensity: Target degradation level: Design the number of loops: Initial selection of axial compression ratio: Design bond strength of grouting material in trench. MPa MPa.
[0075] 1) By It can be seen that after 12 cycles, the stiffness is allowed to decay to about 24% of the initial stiffness.
[0076] 2) Substituting the parameterized relationship, let's assume the regression coefficient for a certain experiment is: ; ; ; ; .but: , , To meet Since the right side of the above equation is less than 0.12, it is only necessary to ensure that It's sufficient not to reduce it excessively. In fact, the above formula shows that under conditions of high interfacial bond strength and moderate axial compression ratio, a reasonable... and Able to The value should be controlled below 0.12 to meet the requirements for high-intensity seismic zones.
[0077] If the designer wishes to reduce [the number of units] due to construction or cost considerations... It is acceptable Assuming the wall height m, pending : To prevent excessively slow stiffness decay from causing the structure to become too "hard and brittle," an upper limit constraint can be set, for example... From this, the feasible range can be calculated. The specific values can be automatically generated by the software module, and will not be elaborated here.
[0078] 3) Further verify the parameter combination obtained by back calculation in terms of bearing capacity and ductility to ensure that the overall component meets the "strong shear and weak bending" requirements under the premise of meeting the target degradation performance.
[0079] Example 3: Software Module Implementation
[0080] This embodiment combines Figure 5 The specific implementation process of the performance-based design software module for slotted shear walls is explained.
[0081] 1. Content structure of database unit 102
[0082] Database unit 102 shall include at least the following data tables: Test data table: records the test degradation coefficient under different groove lengths, reinforcement ratios, axial compression ratios, and material parameters. Stiffness degradation curves; Regression coefficient table: storing vertical slots, horizontal slots, and corresponding values for different structural types. , Equal fitting coefficients; Table of fortification intensity and performance level: providing targets corresponding to different fortification intensities. Value range and recommendations Standard limit table: includes regulations such as the upper limit of axial compression ratio, minimum and maximum reinforcement ratio, and structural length limit.
[0083] 2. Implementation of the degradation model operation unit 103: The operation unit 103 mainly performs the following steps: 1) According to the target input by the user interface unit 101 , Initially select the trench length and reinforcement parameters, and call the parameterized relationship of the corresponding structural type. 2) For the vertical groove structure, the linear or polynomial model in Example 1 is used to obtain the solution. Then, the axial compression ratio correction unit 104 is used to obtain... ;3) Utilize Calculate the key points in the stiffness degradation curve and return the key values of the curve to the user interface for graphical display; 4) When the user selects "Inverse Calculation Mode", perform numerical solution: As a constraint, , , or The system searches or iterates through variables to find solutions and returns one or more solutions that meet the conditions.
[0084] 3. Axial compression ratio correction and constraint judgment unit 104: This unit performs the following for each candidate solution: 1) Calculate according to the set formula. ,get Determine whether the target is met. ;2) Inspection and Does the short slot constraint violate the constraint? and If the value is less than mm, then mark the solution as "invalid"; 3) Check if the reinforcement ratio is within the specification limit range. If the construction limit is exceeded or the minimum value is below, a warning is issued; 4) Check whether the axial compression ratio is not greater than the upper limit recommended by the specification and this invention. Through the above screening, only the solution set that meets the performance and structural constraints is passed to the bearing capacity and ductility verification unit 105.
[0085] 4. Bearing capacity and ductility verification unit 105: This unit is based on the traditional reinforced concrete section analysis method and incorporates the interfacial bond strength at the groove. The following indicators were checked to account for the impact of bending moment bearing capacity: 1) Bending moment bearing capacity Based on the reinforcement of the wall section and the additional reinforcement in the trench, calculations are performed using internal force balance and strain compatibility. And combined with the additional flexural strength contribution of the groove region for calculation To obtain the total bearing capacity 2) Shear bearing capacity Calculate the shear capacity by considering the combined shear contributions of concrete, stirrups, and interface, and ensure... The safety factor must be satisfied between the design shear force requirement and the structural requirements. 3) Ductility and deformation capacity: The displacement ductility coefficient is estimated based on the curvature distribution of the component, the length of the plastic hinge, and the material strain capacity. The system then determines whether the ductility requirements corresponding to the seismic intensity are met. If the check is not met, it returns to the constraint judgment unit 104 or the degradation model calculation unit 103, prompting for adjustments to the trench length, reinforcement, or axial compression ratio.
[0086] 5. Results Processing and Chart Generation Unit 106: For solutions that pass all checks, this unit will automatically generate: a list of parameter combinations, including... , , , , , , , etc.; Design recommendation range: partitioned according to the target degradation level, giving a suitable range of trench length and reinforcement ratio; Electronic lookup table: simplifying multi-dimensional parameters into two-dimensional charts (such as the feasible area in the "trench length-axial compression ratio" plane), which is convenient for quick lookup in a computer-free environment.
[0087] Example 4: Paper-based lookup process based on charts
[0088] In some engineering applications, designers are accustomed to using design atlases and lookup tables for quick selection. This embodiment, based on the software calculation results of Embodiment 3, generates a set of charts through offline processing that can be directly used for paper-based lookup.
[0089] 1. Chart generation method: 1) At reasonable parameter discrete points (such as several axial compression ratio levels, several groove length values, and several reinforcement ratios), call the software module to perform batch calculations and record the degradation coefficient under each set of parameters. , With bearing capacity index; 2) In the "groove length-axial compression ratio" plane, draw the corresponding... The isovalue curves are used to divide the parameter space into high, medium, and low degradation level areas; 3) Within the areas that meet the specifications and structural constraints, the areas with sufficient bearing capacity and areas with insufficient bearing capacity are further marked with different shades or line types; 4) The above charts are compiled into a booklet, with additional instructions on the calculation steps: Select the target degradation level curve according to the seismic intensity; Select the combination of trench length and axial compression ratio that meets the bearing capacity requirements above the curve; Determine the additional reinforcement ratio in the trench and the wall limb distribution reinforcement ratio according to the recommended relationship.
[0090] 2. Example of use: In the paper diagram: based on the project's seismic fortification intensity of 8 degrees, the designer selects... The area; find the desired axial compression ratio around 0.15 on the corresponding graph; along the vertical line and... Read the recommended slot length at the intersection of contour lines mm; then determine the area and spacing of the additional longitudinal reinforcement in the trench according to the reinforcement diagram.
[0091] In this way, even without a computer, the performance-oriented design concept and parameter control requirements proposed in this invention can be roughly met.
[0092] The above embodiments demonstrate that the present invention, starting from a single-exponential degradation model, constructs degradation coefficients... The parameterized relationships transform the target degradation performance into a back-calculation process of specific design parameters such as slot length, reinforcement, and axial compression ratio. Multiple implementation methods are provided, including vertical slotted shear walls, horizontal slotted shear walls, software modules, and paper charts. Those skilled in the art can adjust the parameter forms and implementation details based on engineering characteristics and specification requirements, and this should not be considered a departure from the inventive concept.
Claims
1. A method for performance-based reinforcement and slot length selection in slotted shear walls, characterized in that, Includes the following steps: (1) Adopting a single exponential stiffness degradation model (1) Characterize the equivalent stiffness degradation characteristics of the slotted shear wall under cyclic loading; (2) Establish the functional relationship between the degradation coefficient b and the controllable design parameters of the slotted shear wall. ,in: This is the length of the vertical groove; The length of the horizontal groove; The reinforcement ratio for adding longitudinal or transverse reinforcement bars inside the trench; The reinforcement ratio of the wall piers; Number of loops to consider in the design; (3) The designer selects the target degradation level and determines the target based on the seismic fortification requirements of the project location. Value; (4) From the target Value and Determined at Lower limit of allowable stiffness decay in the next cycle and the target Substitute the value into the function relationship The required slot length can be calculated by reverse calculation. or 1. Additional reinforcement diameter and spacing, stirrup ratio and axial compression ratio range; (5) Use a method that includes interfacial bond strength The modified bending moment bearing capacity formula is used to check the bending moment bearing capacity and the "strong shear weak bending" condition of the structural parameter combination determined in step (4). If the condition is not met, the target is iteratively adjusted. Values or construction parameters are used until the requirements are met.
2. The method according to claim 1, characterized in that, The degradation coefficient With the length of the vertical groove The following empirical lower bound relationship exists between them: ,in, and For the regression constant, The yield diameter of the longitudinal reinforcement in the confined zone; when When increasing from 300mm to 420mm, the corresponding It decreased from approximately 0.25 to approximately 0.
15.
3. The method according to claim 1 or 2, characterized in that, For horizontally slotted shear walls, with a pre-defined and reasonable additional reinforcement ratio... and wall reinforcement ratio Within the range, through the aforementioned functional relationship and constraint degradation coefficient To achieve a more gradual stiffness degradation performance.
4. The method according to any one of claims 1 to 3, characterized in that, Introducing a high axial compression ratio correction factor degradation coefficient After correction, the corrected degradation coefficient is obtained. ,in axial compression ratio The function is used to simultaneously reflect the dual effect of axial compression ratio on ductility and stiffness degradation.
5. The method according to any one of claims 1 to 4, characterized in that, Constraints are applied to vertical slots: when the length of the vertical slot... When the value is mm, the system prohibits the use of this construct for the target degradation level. The operating conditions were described, and designers were advised to improve... Or reduce the target degradation performance requirements.
6. The method according to any one of claims 1 to 5, characterized in that, The target degradation level includes at least: high-intensity areas: Moderate intensity zone: Low-intensity areas: Designers select the appropriate degradation level based on the fortification intensity and performance-based design objectives.
7. The method according to any one of claims 1 to 6, characterized in that, The modified bending moment bearing capacity formula in step (5) takes into account the bond strength at the groove interface. Additional reinforcement yield strength , groove length parameters or The combined effect of the effective height of the wall piers ensures that the slotted shear wall meets the requirements of "strong shear and weak bending" and ductility while satisfying the target degradation performance.
8. A software module for performance-based design of slotted shear walls for implementing the method according to any one of claims 1 to 7, characterized in that, This software module includes: a target performance input unit, used to input fortification intensity, target degradation level, and target... and expected number of cycles Degradation model computation unit, used to calculate based on and Complete stiffness degradation analysis and inverse calculation of groove length, reinforcement, and axial compression ratio; constrained judgment unit, used to adjust the axial compression ratio based on the correction factor. The system includes short groove length constraints and specification limits, which automatically filter parameter combinations; and a bearing capacity verification unit, used to complete "strong shear and weak bending" and ductility verification based on the modified bending moment bearing capacity formula.
9. The software module according to claim 8, characterized in that, The software module further generates multi-dimensional design charts or electronic calculation tables for "target degradation level - trench length - reinforcement ratio - axial compression ratio", which can be used for rapid paper-based calculations in a computer-free environment.