City-Scale Seismic Analysis Using Shear-Flexural Models
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Solution Overview
Problem
Current methods for analyzing seismic damage in urban buildings, such as the damage probability matrix method and the capacity spectrum method, are inadequate for accurately predicting seismic response in densely populated cities with limited seismic data, as they fail to effectively represent the time-domain properties of ground motions and are not suitable for diverse building structures.
Innovation Solution
A city-scale nonlinear time-history analysis method using multiple mass shear series or multiple mass shear-flexural parallel models, which acquire building data, determine model types based on structural characteristics, and perform nonlinear history analysis on ground motion acceleration data to assess seismic damage states of each building story, reflecting both shear and flexural deformations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the damage probability matrix method is used for seismic damage analysis, then the analysis can be performed with available seismic data, but the method is only suitable for areas with abundant seismic damage data and is hard to generalize to diverse building structures
Solution Approach 1:
The patent transforms the seismic damage analysis from using static probability matrices to dynamic nonlinear time-history analysis. By changing the analysis parameters to include time-domain properties of ground motions (acceleration, velocity, displacement time histories) and structural response parameters (inter-story drift, shear force, bending moment), the method achieves both high accuracy and broad applicability to diverse building structures.
Solution Approach 2:
The patent replaces the statistical probability-based damage assessment system with a physics-based nonlinear dynamic analysis system. By substituting the mechanical response analysis that directly simulates the dynamic interaction between ground motion and building structures, the method eliminates the limitation of requiring abundant historical seismic damage data while maintaining high prediction accuracy.
2Reliability
If the capacity spectrum method is used for seismic damage analysis, then the analysis can be performed with limited seismic data, but the method cannot easily represent the influence of the time-domain properties of ground motions to the structures
Solution Approach 1:
The patent segments the complex time-history analysis into manageable components: (1) acquiring ground motion time-history data, (2) establishing simplified building models (multiple mass shear series or multiple mass shear-flexural parallel models), (3) performing nonlinear dynamic analysis for each building, and (4) aggregating results for city-scale assessment. This segmentation makes the time-domain analysis feasible for large-scale urban buildings.
Solution Approach 2:
The patent applies different modeling approaches (multiple mass shear series model vs. multiple mass shear-flexural parallel model) based on the specific characteristics of each building, such as structural type, building height, and number of stories. This localized modeling strategy accurately captures the time-domain response of each building while managing overall computational complexity.
3Measurement precision
If detailed nonlinear time-history analysis is performed for each building in a city, then accurate seismic response prediction is achieved, but the computational time and resources required become prohibitively large
Solution Approach 1:
The patent performs preliminary actions by pre-establishing the building models with appropriate simplifications (multiple mass shear series or multiple mass shear-flexural parallel models) before the actual time-history analysis. By pre-defining the model characteristics, mass matrices, and stiffness matrices, the subsequent nonlinear dynamic analysis can be executed more efficiently, reducing computational time while maintaining accuracy.
Solution Approach 2:
The patent applies partial action by using simplified building models that capture the essential dynamic characteristics without modeling every detail of the actual structures. The multiple mass shear series model and multiple mass shear-flexural parallel model represent the most critical aspects of building response to seismic ground motions, providing sufficient accuracy for city-scale assessment without the excessive computational burden of full detailed models.
Data Source
AI summary
A method and device for city-scale nonlinear time-history analysis. The method comprises: acquiring building data; obtaining a model type corresponding to the building data according to the building data; establishing a multiple mass shear series model or a multiple mass shear-flexural parallel model corresponding to the building data according to the model type corresponding to the building data; performing nonlinear history analysis according to time history data of ground motion acceleration from each building through the multiple mass shear series model or the multiple mass shear-flexural parallel model, to obtain a nonlinear history analysis result; obtaining a seismic damage state and an analysis result of each story of each building according to the nonlinear history analysis result.