【摘要】 基于野外调查和室内试验建立了玉门关段汉长城结构的三维动力分析模型,其中以长城墙体结构中的夯土层、芦苇层和芦苇绳为主要研究对象。采用有限差分法计算了该段长城结构在地震动作用下的抗震性能。计算结果表明:在自重作用下,芦苇层与夯土层变形机制相互补充,芦苇绳的拉结作用明显,整个墙体变形合理;从墙体底部到顶部,地震波的高频成分减少,低频成分增加;在强震作用下,墙体芦苇层的最大应力远小于单根芦苇纤维的抗拉强度,处在比较安全的状态;采用格栅单元和锚索单元分别模拟芦苇层、芦苇绳是合理的。研究成果可为河西地区土遗址保护提供参考。更多还原

【Abstract】 Based on field investigation and lab test,three-dimensional calculation model of a wall construction for Yumenguan Han Great Walls is built,in which rammed earth layers,reed layers and reed strings of the wall construction are studied.The finite-difference method is used to analyze seismic performance of the walls construction.The results show that:(1)deformation of the reed layer and the rammed earth layer is reasonable;(2)the content of high frequency in seismic wave is decreased and low frequency is increased from the bottom of the walls to its top;(3)under strong earthquake,the maximum stress of the reed layer is far less than the tensile strength of reed fiber;(4)it is rational to use geogrid element and cable element to simulate reed layer and reed string respectively.The studied results can provide a reference for the protection of earthen ruins in the northwest of China.更多还原