Effect of the Los Angeles Soft-Story Ordinance on the post-earthquake housing recovery of impacted residential communities
Effect of the Los Angeles Soft-Story Ordinance on the post-earthquake housing recovery of impacted residential communities
复制标题
《洛杉矶软故事条例》对受影响住宅社区震后住房恢复的影响
作者：
Hua Kang;Zhengxiang Yi;H. Burton
震后恢复模型可用于量化旨在减轻建筑地震风险的政策所带来的与复原力相关的效益。本文对《洛杉矶软层条例》对居民社区震后住房恢复的影响进行了评估。考虑了位于洛杉矶五个社区的约8000栋建筑的清单。这些社区根据软层建筑的比例、人口密度以及租客和自住住宅的比例而有所不同。代表目标库存的原型建筑是基于使用谷歌街景进行的逐栋调查而开发的。在原型的发展中考虑了故事数量的变化以及软第一故事的存在和布局。利用代表每个原型的结构模型的非线性分析结果，建立了分析建筑物级别的损伤易损性曲线。基于场景的损害评估使用南加州ShakeOut场景产生的震动强度进行，并使用离散时间基于状态的随机过程模型来表示震后恢复。修订条例的量化效果因所考虑的回收指标而异。例如，整个库存的初始占用损失减少了25%。然而，如果以恢复90%入住率的时间作为恢复绩效指标，则该条例的改造可减少64%的占用率。
Post-earthquake recovery models can be used to quantify the resilience-related benefits of policies intended to mitigate building seismic risk. An assessment of the effect of the Los Angeles Soft-Story Ordinance on the post-earthquake housing recovery of residential communities is presented. An inventory of approximately 8000 buildings located in five Los Angeles neighborhoods is considered. The neighborhoods vary based on the percentage of soft-story buildings, population density and the fraction of renter- and owner-occupied residences. Archetype buildings that are representative of the target inventory are developed based on a building-by-building survey performed using Google Street View. Variations in the number of stories and presence and layout of the soft first story are considered in the development of the archetypes. Analytical building-level damage fragility curves are developed using the results from nonlinear analyses of structural models representing each archetype. A scenario-based damage assessment is performed using shaking intensities generated from the Southern California ShakeOut scenario, and a discrete-time state-based stochastic process model is used to represent post-earthquake recovery. The quantified effect of the Ordinance retrofit varied based on the considered recovery metric. For instance, the initial loss of occupancy for the entire inventory is reduced by 25%. However, if the time to restore 90% occupancy is used as the recovery performance metric, the Ordinance retrofit leads to a 64% reduction.