Efficient Longitudinal Seismic Fragility Assessment of a Multispan Continuous Steel Bridge on Liquefiable Soils
Efficient Longitudinal Seismic Fragility Assessment of a Multispan Continuous Steel Bridge on Liquefiable Soils
复制标题
DOI：
10.1061/(asce)be.1943-5592.0000131
复制
发表时间：
2011
影响因子：
3.6
通讯作者：
Bayram Aygün Aygün-Bayram-Aygün-Aygün-2123231221;L. Dueñas-Osorio;J. Padgett;R. DesRoches
中科院分区：
文献类型：
--
作者：
Bayram Aygün Aygün-Bayram-Aygün-Aygün-2123231221;L. Dueñas-Osorio;J. Padgett;R. DesRoches
美国老化公路桥梁的失效可能性增加，并且在极端事件中更容易损坏，因此有必要开发有效的可靠性评估工具，以优先考虑维护和修复干预措施。当考虑地震灾害下土壤液化等复杂现象时，可靠性通信工具变得更加重要。目前，通过脆性曲线广泛使用两种方法来估计土壤破坏条件下的桥梁可靠性：液化乘数和全尺寸二维或三维桥梁-土壤-基础模型。本文提供了一种计算经济且充分的方法，将具有二维土壤域和一维 p-y 弹簧组的三维桥梁系统的非线性有限元模型链接到耦合的桥梁-土壤-基础 CBSF 系统中。在统计抽样方案中使用美国中部和东部典型的多跨连续钢梁桥以及异质可液化土壤剖面来说明土壤破坏和不确定性传播对 CBSF 系统组件脆弱性的影响。一般来说，摇臂轴承、桩、路堤土壤的脆弱性以及脱落的可能性随着液化而增加，而经常监测的部件（例如立柱）的脆弱性取决于可液化沙子上覆盖的土壤类型。这种对土壤破坏的响应依赖性支持可靠性评估框架的使用，该框架通过依赖简化但可接受的岩土工程方法来捕获复杂的土壤液化效应，从而对区域应用有效。
The increased failure potential of aging U.S. highway bridges and their susceptibility to damage during extreme events necessitates the development of efficient reliability assessment tools to prioritize maintenance and rehabilitation interventions. Reliability communication tools become even more important when considering complex phenomena such as soil liquefaction under seismic hazards. Currently, two approaches are widely used for bridge reliability estimation under soil failure conditions via fragility curves: liquefaction multipliers and full-scale two- or three-dimensional bridge-soil-foundation models. This paper offers a computationally economical yet adequate approach that links nonlinear finite-element models of a three-dimensional bridge system with a two-dimensional soil domain and a one-dimensional set of p-y springs into a coupled bridge-soil-foundation CBSF system. A multispan continuous steel girder bridge typical of the central and eastern United States along with heterogeneous liquefiable soil profiles is used within a statistical sampling scheme to illustrate the effects of soil failure and uncertainty propagation on the fragility of CBSF system components. In general, the fragility of rocker bearings, piles, embankment soil, and the probability of unseating increases with liquefaction, while that of commonly monitored components, such as columns, depends on the type of soil overlying the liquefiable sands. This component response depen- dence on soil failure supports the use of reliability assessment frameworks that are efficient for regional applications by relying on simplified but accepted geotechnical methods to capture complex soil liquefaction effects.