基于塑性铰性能的高桩码头地震损伤分析

Seismic damage analysis of pile supported wharf based on plastic hinge performance

以高桩码头为研究对象,从塑性铰性能角度对码头的损伤特性进行分析,并根据2个实际码头结构建立模型,通过有限元软件SAP2000对结构的24种工况进行Pushover分析,研究码头结构在不同等级地震下的损伤情况,建立了基于塑性铰的码头损伤等级和位移延性损伤指数之间的对应关系。结果表明:不同烈度地震下,码头的破坏形式主要为桩基塑性铰的产生和桩顶发生一定侧向位移,上部结构从开始到最终破坏并未出现塑性铰;高烈度罕遇地震作用下,纵向的码头桩基塑性铰发展程度和位移延性损伤指数均大于横向的各对应指标,表明码头纵向刚度较小,更容易发生破坏;通过码头桩基塑性铰的性能将码头在地震作用下的损伤分为基本完好、轻微破坏、中等破坏、严重破坏、倒塌5个等级,其对应的位移延性损伤指数分别为0~0.1、0.1~0.35、0.35~0.6、0.6~0.8、>0.8。

Taking the pile supported wharf as research object,we analyze the damage characteristics of the wharf by plastic hinge performance,and establish the models according to the two actual wharf structures. Through the pushover analysis of 24 kinds of working conditions,we apply the finite element software SAP2000 to study the damage characteristics of the wharf structure under different earthquake degrees, and establish the corresponding relationship between the damage degrees and the displacement ductile damage index. The results show that under different intensity earthquake,the main failure forms of wharf are mainly due to the plastic hinge of pile foundation and the lateral displacement of pile top, there are no plastic hinge appeared on the upper structure from the beginning to the final failure; under high intensity earthquake, the development degree of plastic hinge and displacement ductility damage index of the longitudinal direction of the wharf are larger than those of the transverse direction,which indicate that the longitudinal stiffness of the wharf is smaller and the damage is more likely to occur.The seismic damage of the wharf is divided into five degrees through the plastic hinge properties of the pile,which include basically intact,slight damage,medium damage,serious damage and collapse,and the corresponding displacement ductility damage indexes are 0 ~ 0. 1,0. 1 ~ 0. 35,0. 35 ~ 0. 6,0. 6 ~ 0. 8, 0. 8.