地震荷载下龙门石窟围岩变形破坏机制的数值模拟

Numerical Simulation of the Mechanism of Seismic Deformation and Damage of Country Rock of the Longmen Grottoes

以洛阳龙门石窟为研究对象,阐述了地震荷载下洞窟围岩损伤的影响因素;采用动力有限元法,从地震动的不同工程特性、不同输入方向等方面入手,分析研究了不同地震作用下洞窟围岩的位移、速度和应力动态变化特征,并指出了围岩内振动位移、速度最大值以及应力集中出现的地方,对有无裂隙两种情况下围岩的位移、速度和应力值进行了对比。最后,根据岩体强度和莫尔—库仑破裂准则,分析了围岩在不同地震作用下可能出现的拉性、压性以及剪性破坏,为石窟文物地震安全评估及防灾对策研究提供了依据。

We list the main influencing factors causing the failure of the country rock of the Longmen Grottoes in Luoyang City,Henan Province.Using finite element method,and aiming at the engineering characteristics,input directions,etc of the ground motion,we study the dynamic displacement,velocity,and stress variation of the country rock under different seismic loads and determine the locations where the maximum displacement,maximum velocity and stress concentration appear.Then,we compare the displacement,velocity,and stress of the country rock which has fractures with the ones of the courtry ROCRwhich has no fractures.On the basis of the Mohr-Coulomb Failure Criterion,we study the possibility of failure of the country rock,which serves as a reference for the assessment of seismic stability and the protection of culture relics of the Grottoes.