基于能量耗散的多层木结构古建筑的地震破坏评估

Earthquake Damage Assessment of Ancient Architectrue with Multi-layer Wooden Structures Based on Energy Dissipation

以西安城墙永宁门箭楼为研究对象,评估震后多层木结构古建筑的破坏程度,根据各主要耗能构件在低周水平反复荷载作用下的滞回耗能特性,计算其构件破坏总耗能;根据地震模拟振动台试验,计算不同地震工况下各耗能构件所耗散的能量,在此基础上建立主要耗能构件相应的破坏模型。对三个主要耗能部位:柱架榫卯节点、斗栱结构层和柱础进行地震破坏状态评估;引入能量分配系数建立主要耗能构件破坏状态与整体结构破坏状态之间的关系,继而得出整体结构的破坏系数以反映整体结构在不同地震作用下的破坏状态,研究结果可为多层木结构古建筑的抗震加固提供参考借鉴。

Take Embrasure watchtower of Yongning Gate of Xi＇an City Wall as a research subject,we made a reasonable assessment for the extent of damage to the ancient architecture with multilayer wooden structure after the earthquake. Based on the hysteretic energy properties of the major energy- dissipation components under low-cycle levels cyclic loading,we calculated the damage total energy consumption of the component. According to the seismic simulation shaking table test,we calculated the dissipated energy induced by each energy- dissipation component under different seismic conditions. And on the basis of it,we established the damage model of major energy- dissipation component under different seismic action. We also made the earthquake damage assessment of three major energy- dissipation parts： the column frame straight mortise tenon joint,brackets structure layer and column bases layer. Then introducing the energy distribution coefficient,we built the relationship of damage state between major energy component and overall structure to obtain destroy coefficients of the whole structure to reflect the damage state of overall structure under different earthquake. The obtained results can provide the reliable theoretical basis for the seismic reinforcement of ancient architecture with multi-layered wood structure.