近断层地震动参数对不同年代古木结构地震响应的影响

Effects of Near-fault Ground Motion Parameters on the Seismic Response of Ancient Wood Structures

基于ANSYS和ABAQUS软件建立古木结构有限元模型,将ANSYS模态分析结果和ABAQUS计算结果进行对比分析,验证建模方法的正确性,在此基础上采用ANSYS建立3种不同年代的古木结构模型。将通过人工拟合形成不同断层参数的近断层上下盘地震动作用于古木结构有限元模型,进行了时程分析,讨论不同震级、剪切波速、断层倾角以及上界埋置深度等不同的近断层地震动因素对古木结构动力响应的影响。结果表明,在相同的场地距离情况下,随着作用于古木结构近断层上下盘地震动的震级越大、土体剪切波速越小、上界埋置深度越小,结构的基底剪力逐渐增大,顶层位移越来越大,且上下盘效应越明显。同时随着距今建造时间的增长,古木结构的基底剪力逐渐减小,顶层位移随之增大。

Based on ANSYS and ABAQUS software,the finite element model of ancient wood structure is established,and the results of ANSYS modal analysis and ABAQUS calculation are compared and analyzed to verify the correctness of the modeling method.On this basis,three ancient wood architecture models of different ages were established.Using artificial fitting to form the ground motion of a near-fault with different fault parameters is applied on ancient wood structures.Time history analysis is carried out,discuss the influence of site factors,such as magnitude,shear wave velocity,fault dip angle,and the upper buried depth,on the dynamic response of the ancient timber structure.The results show that in the case of the same site distance,with the earthquake maginitude,the smaller shear wave velocity of the soil and the smaller depth of the upper boundary,the base shear of the structure and the displacement of the top layer are lager,and the upper and lower disk effect is more obvious.At the same time,with the increase of build time,the base shear of the ancient wood buildings gradually decreases,and the displacement of the top layer reases.