基于响应面法的连续刚构地震可靠度分析

Seismic reliability analysis of rigid frame bridge based on response surface method

地震可靠度是桥梁抗震研究中的重要问题。基于随机分析的响应面理论和规范反应谱法,提出了一种分析具有随机结构参数的桥梁地震可靠度的方法,研究了结构的破坏准则及其极限状态方程,计算了高墩大跨连续刚构桥在地震激励下设计基准期内的动力可靠度。分析时考虑了结构参数和场地土的随机性,分别计算了连续刚构在多遇地震、设防地震和罕遇地震作用下的失效概率,得到了结构在设计基准期内,"三水准设防标准"条件下的地震可靠度。结果表明,该桥设计满足抗震规范要求。

Seismic reliability is very important to the seismic design and the study of the bridge. Based on the theory of the response surface of random vibration and response spectrum method, an algorithm for the seismic reliability analysis of the structures with random parameters is proposed. The structural failure criteria and the equations under their limit states are studied and the dynamic reliabilitiy of the high-pier and long-span rigid frame subjected to seismic excitation in its design basic period is computed. The random of the structure parameters and the site condition of this bridge is taken into account when it＇ s failure seismic reliability is computed for the low-level earthquake, design earthquake and high-level earthquake respectively. According to the ＂three-level seismic fortification criteri- on＂ in the code for seismic design of bridge, the seismic reliabilitiy of the bridge is calculated in their design basic period. The conclusion shows that the design of this bridge meets the demands of the seismic code.