Seismic assessment method of bridges under near-fault earthquakes

Abstract

The invention provides a seismic assessment method of a bridge under the near fault ground motion. Whether the selected bridge type meets the requirements can be rapidly assessed, design time of primary type selection can be saved, seismic analysis and assessment of the bridge can be rapidly performed, the complex process of generating artificial seismic waves carrying the near fault characteristics by using finite elements to perform time procedure analysis can be effectively avoided without artificial generation of seismic waves, and the conformed index value of the bridge site is directly substituted to a probabilistic seismic demand model to perform simplified calculation. Besides, multiple positively correlated ground motion parameters are adopted for solution and then the comparisonresult proves that the result is reliable and effective, the accuracy is higher, the seismic performance of the bridge can be enhanced, the characteristic of constant length periodic structure of thebridge can be further met, and the method is further suitable for bridge seismic design under the near fault pulse-like ground motion, widely suitable for seismic analysis and assessment of all the components of the near fault bridge structure and rapid verification of other design methods and favorable for enhancing the accuracy of bridge seismic design analysis.

Description

technical field [0001] The invention relates to the technical field of bridge anti-seismic analysis, in particular to an anti-seismic evaluation method for bridges under the action of near-fault earthquakes. Background technique [0002] Due to the complex ground motion of earthquakes, seismic waves with different characteristics may have different effects on structures. Generally, the seismic waves can be classified according to magnitude, focal mechanism, site, epicentral distance, peak value of seismic waves (PGA, PGV, PGD), seismic wave components, effective period of seismic waves, and strong earthquakes. The collection of strong earthquake records is divided by the area where the observer is located. Since the earthquake duration, intensity, and spectrum content are all random, the difference in the selection of earthquake motions will have different effects on the calculation results. [0003] In the modern seismic analysis and structural design system, the seismic in...

AI Technical Summary

Problems solved by technology

[0005] The technical problem to be solved by the present invention lies in the need to select the bridge type and artificially simulate seismic waves in the prior art when performing bridge seismic assessment, but the steps of simulating near-fault seismic waves are complicated and difficult to match, resulting in reduced reliability of analysis conclusions and huge workload. At the same time, the strength index used in the current analysis is insufficient, resulting in inaccurate and imprecise seismic analysis and design of the bridge structure, which is prone to safety hazards and other deficiencies. A method for seismic evaluation of bridges under the action of near-fault earthquakes is provided. In order to realize the above invention Purpose, the invention provides the following technical solutions:

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