Anti-vibration Evaluation Of Ancient Brick Masonry Building Based On Probability Reliability Analysis

Ancient architecture is the crystallization of Chinese ancient architecture and art,inheriting a long history and culture,and is an important historical heritage of China.In recent years,under the rapid development of China’s economy,Many railway lines have been developed vertically and horizontally in China,rail traffic network throughout the train often shuttle between the city,some even close to the building pass.Therefore,the micro-vibration protection of ancient buildings has received more and more attention.However,with the passing of time,the performance of ancient building structure has changed greatly,and its material parameters may decrease greatly,and this change is random and uncertain.At present,there are few researches on micro-vibration of ancient buildings based on probabilistic reliability at home and abroad.Therefore,this paper studies the damage and fatigue life of ancient brick masonry buildings based on probability reliability theory,which provides a new technical means for anti-vibration evaluation of ancient brick masonry buildings,and has certain engineering application value.The main research contents include:1.The damage index(DI)of ancient brick masonry buildings against micro-vibration is proposed,and three kinds of structural damage of different degrees are defined based on the damage index.DI(27)15% is defined as minor damage;15%(27)DI(27)25% is defined as moderate injury;DI(29)25% is defined as severe injury.2.In this paper,small wild goose pagoda in Xi ’an is selected as the representative of ancient brick masonry buildings,and the randomness of material parameters of small wild goose pagoda is studied and the appropriate probability distribution function is selected.Monte Carlo method is used to sample random variables to provide sample space for probability analysis of damage indicators.3.ABAQUS software was used to establish the coupling model of brick masonry ancient building and foundation soil,and the results of numerical simulation were compared with the actual measurement results,which verified the correctness and effectiveness of the coupling model of brick masonry ancient building and foundation soil.4.This paper studies the acceleration response and stress change of ancient brick masonry building under high-speed train load,and compares the dynamic response change of small wild goose pagoda in different directions,different floors and frequency domain.It is observed that the vibration wave caused by train load is slowly transmitted upward along the small wild goose pagoda.As the number of layers increases,the transmitted vibration wave decreases,and so do the acceleration and stress.The vertical acceleration response of ancient building structures is the largest and the vertical vibration wave propagates the fastest and takes longer time.Through analysis,it is found that the propagation speed of stress is much faster than that of acceleration.5.The damage index and damage stress of small wild goose pagoda were calculated,and the residual fatigue life of the structure was predicted by the linear fatigue damage accumulation theory of brick masonry,and the influence of Young’s modulus on the damage index and stress of small wild goose pagoda was analyzed.The probability of small vibration of small wild goose pagoda under high speed train load is estimated by probability analysis of damage index.