Abstract Nowadays stochastic ground motion models used for the seismic analysis and design of structures take into account the soil deposit only, disregarding the presence of existing buildings nearby. However, it is well known that ground motion in urban environment is modified by the presence of buildings, mainly due to the radiation energy emitted from a vibrating structure in the soil that alters the seismic free field motion. This study is a first attempt to propose a stochastic ground motion analytical model able to take into account the influence of the urban environment. A simplified discrete model is developed so to consider the influence of the radiated wave field into the free field ground motion. Comparison in terms power spectral density functions and peak ground acceleration determined from the proposed ground motion model and those determined through conventional approaches are carried out. Numerical results clearly show the efficiency of the proposed model to capture this complex phenomenon in the stochastic seismic analysis of structures by improving the accuracy of the estimation of the peak response of above 30% . Limits of the proposed formulation are also discussed.

中文翻译：

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城市环境的随机地面运动模型

摘要 如今，用于结构抗震分​​析和设计的随机地震动模型只考虑土壤沉积，而忽略附近现有建筑物的存在。然而，众所周知，城市环境中的地面运动会因建筑物的存在而改变，这主要是由于土壤中振动结构发出的辐射能量改变了地震自由场运动。本研究首次尝试提出一种能够考虑城市环境影响的随机地震动分析模型。开发了一个简化的离散模型，以便考虑辐射波场对自由场地面运动的影响。对根据建议的地面运动模型确定的功率谱密度函数和峰值地面加速度与通过传统方法确定的那些进行了比较。数值结果清楚地表明，通过将峰值响应的估计精度提高 30% 以上，所提出的模型在结构的随机地震分析中捕捉这种复杂现象的效率。还讨论了建议配方的限制。