Long-Span Arch Bridge Seismic Assessment With Time-Frequency Hybrid Analysis

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Solution Overview

Problem

Existing methods for probabilistic seismic resistance assessment of long-span arch bridges face high computational costs and inefficiencies due to the need for extensive numerical integration and repetitive time-history analysis, especially when dealing with non-stationary seismic excitation.

Innovation Solution

A time-frequency hybrid computation method using spectral decomposition and modal superposition techniques to derive an explicit closed-form expression for non-stationary seismic response, allowing rapid computation of seismic response samples through orthogonal random variables and piecewise interpolation of time-frequency modulation functions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If frequency domain methods (evolutionary spectrum method or virtual excitation method) are used for probabilistic seismic response analysis, then the method can handle non-stationary seismic excitation, but extensive numerical integration is required resulting in high computational cost

Engineering Contradiction:

Improveability to handle non-stationary seismic excitationVSAvoidcomputational cost

Core Design Contradiction:

Adaptability or versatilityVSUse of energy by stationary object

Solution Approach 1:

The patent replaces traditional frequency domain methods with a time-frequency hybrid computation method. It uses spectral decomposition to represent seismic excitation in the frequency domain, then applies modal superposition to transform the problem into the time domain, avoiding extensive numerical integration while maintaining the ability to handle non-stationary excitation

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent segments the seismic response analysis into modal components through modal decomposition. By representing the structural response as a superposition of individual mode responses, each mode can be computed independently and efficiently, then combined to obtain the total response, significantly reducing computational cost

Inventive Principle:

Principle #1Segmentation

2Ease of operation

If time domain methods (explicit time domain method or Monte Carlo simulation method) are used for probabilistic seismic response analysis, then the computation process is straightforward, but a large number of seismic acceleration samples must be analyzed repetitively resulting in low computational efficiency

Engineering Contradiction:

Improvestraightforward computation processVSAvoidcomputational efficiency

Core Design Contradiction:

Ease of operationVSProductivity

Solution Approach 1:

The patent performs preliminary spectral decomposition of the seismic excitation before time-history analysis. By pre-processing the excitation into orthogonal random variables and deterministic basis functions, the subsequent time-domain computation for each sample becomes much faster, as it only requires evaluating closed-form modal response expressions rather than performing full dynamic integration

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent substitutes traditional repetitive time-history integration with a hybrid approach that uses spectral representation in the frequency domain combined with modal superposition in the time domain. This allows efficient computation of multiple response samples through closed-form expressions, dramatically improving computational efficiency while maintaining ease of operation

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Speed

If traditional dynamic time-history analysis is used focusing on single seismic acceleration sample, then the computation is fast for one sample, but results depend on specific excitation selection making it difficult to reflect probabilistic properties

Engineering Contradiction:

Improvecomputation speed for single sampleVSAvoidability to reflect probabilistic properties

Core Design Contradiction:

SpeedVSReliability

Solution Approach 1:

The patent changes the parameter representation of seismic excitation from deterministic time-history signals to spectral parameters (power spectral density, evolutionary spectrum). By representing excitation in terms of frequency-domain parameters and using orthogonal random variables, the method efficiently captures the probabilistic characteristics of seismic motion, allowing reliable statistical analysis while maintaining computational efficiency

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentUS12462073B2Method for probabilistic assessment of seismic resistance of long-span arch bridge based on time-frequency hybrid computation

Publication Date: 2025.11.04 SICHUAN HIGHWAY & BRIDGE CONSTRUCTION GROUP CO LTD

AI summary

A method for probabilistic assessment of seismic resistance of long-span arch bridge based on time-frequency hybrid computation includes: S1, parameter acquisition; S2, modeling; S3, model preprocessing; S4, piecewise interpolation of a time-frequency modulation function; S5, response expression derivation; and S6, probabilistic assessment of seismic resistance. By integrating spectral decomposition technology, a modal superposition method, and piecewise interpolation technology for time-frequency modulation functions, an explicit response expression of a long-span arch bridge structure is derived under conditions of arbitrary time-frequency modulated seismic excitation, which greatly saves the computational cost of probabilistic analysis of the non-stationary seismic response of the large arch bridge structure, and achieves efficient probabilistic assessment of the seismic resistance of the arch bridge structure.