摘要
地震动是个动态随机过程,而传统岩石边坡地震可靠性分析往往基于拟静力法,忽略了地震的随机性。现有基于数值分析软件的地震响应功率谱法虽可考虑地震随机特征,却相对费时费力。提出一种岩石边坡随机地震响应及动力可靠度分析方法。首先,运用虚拟激励法建立了岩石边坡随机地震响应的快速计算方法。根据响应计算结果,基于首次穿越破坏准则建立了岩石边坡动力可靠度计算方法。算例分析表明,本文随机地震响应快速计算方法简便可行,且具有较高的计算精度。本文动力可靠度计算方法低估了边坡的地震可靠性,能更真实地反映边坡在地震中的实际安全情况。地震作用下边坡可靠性受地震设防烈度、场地类别和地震时间的影响。而对于传统拟静力法,地震力仅根据设防烈度确定。因此,当对于不同的场地类别和地震时间时,本文动力可靠度计算法将更具优越性。
Seismic ground motion is a dynamic random process. However,the traditional seismic reliability analysis of rock slope is usually based on pseudo-static method,which ignores the random nature of earthquake excitation. Furthermore,the existing seismic response PSD method based on numerical analysis software considering the effects of seismic random nature is time-consuming and laborious. Therefore,this paper presents an analytical method for random seismic response and dynamic reliability of rock slope. Firstly,A fast calculation method for random seismic response of rock slope is established by pseudo excitation method and structural dynamics theory. And then,based on the calculated response results,a calculation method for dynamic degree of the reliability of rock slope under random earthquake excitation is deduced by first-excursion failure criterion. Example analysis shows that this proposed fast calculation method for random seismic response is simple and feasible,and has high computational accuracy. This proposed seismic dynamic reliability calculation method underestimates slope reliability,and can reflect the actual security situation of slope in the process of earthquake excitation. Seismic reliability of slope is influenced by seismic fortification intensity,site class and seismic time. But for the traditional pseudo-static method,seismic force can be determined only according to seismic fortification intensity. Therefore,this proposed dynamic reliability calculation method will be more practical for different types of site class and seismic time.
出处
《地下空间与工程学报》
CSCD
北大核心
2016年第S2期841-848,共8页
Chinese Journal of Underground Space and Engineering
基金
国家自然科学基金(51278217)
华中科技大学研究生创新创业基地项目(0118650010)
关键词
岩质边坡
随机地震
地震响应
动力可靠度
虚拟激励法
首次穿越破坏
rock slope
random earthquake
seismic response
dynamic reliability
pseudo excitation method
first-excursion failure
