刘中宪,孟思博,张妤,乔云帆,陈龙伟. 2024. 考虑建筑群-沉积盆地动力相互作用的建筑群震害评估方法. 地震学报,46(1):129−143. DOI: 10.11939/jass.20220130
引用本文: 刘中宪,孟思博,张妤,乔云帆,陈龙伟. 2024. 考虑建筑群-沉积盆地动力相互作用的建筑群震害评估方法. 地震学报,46(1):129−143. DOI: 10.11939/jass.20220130
Liu Z X,Meng S B,Zhang Y,Qiao Y F,Chen L W. 2024. Earthquake damage assessment for building group considering dynamic interaction between buildings and sedimentary basin. Acta Seismologica Sinica46(1):129−143. DOI: 10.11939/jass.20220130
Citation: Liu Z X,Meng S B,Zhang Y,Qiao Y F,Chen L W. 2024. Earthquake damage assessment for building group considering dynamic interaction between buildings and sedimentary basin. Acta Seismologica Sinica46(1):129−143. DOI: 10.11939/jass.20220130

考虑建筑群-沉积盆地动力相互作用的建筑群震害评估方法

Earthquake damage assessment for building group considering dynamic interaction between buildings and sedimentary basin

  • 摘要: 我国大量城镇位于沉积盆地,沉积盆地对地震动具有显著的幅值放大和持时增长效应,同时沉积盆地与建筑群间的动力相互作用将导致地震动空间重分布。针对此问题,本文提出了一种考虑建筑群-沉积盆地动力相互作用的建筑群震害评估方法:首先,以剪切层模型、弯剪耦合模型等简化力学模型模拟建筑结构,计算建筑群-沉积盆地动力相互作用,获得建筑群的基础顶面地震动;然后,基于精细化有限元模型分析典型单体建筑的地震易损性;最后,结合所求建筑群基础顶面地震动、易损性曲线进行建筑群震害评估。结果表明:采用简化力学模型、精细化有限元模型模拟建筑结构时,上部建筑对基础顶面地震动的影响具有等效性,因此所建方法适用于考虑建筑群-沉积盆地动力相互作用的建筑群震害评估;建筑群-沉积盆地动力相互作用主要导致盆地内地表地震动峰值降低,但局部位置会在盆地效应基础上产生附加放大效应;建筑群-沉积盆地动力相互作用导致不同地表点地震动加速度反应谱峰值相差3倍,同时放大邻近建筑出现相同等级震害的概率差异,所分析算例中,在是否考虑建筑群-沉积盆地动力相互作用的情况下,邻近四栋相同框架结构发生中等损坏的概率范围分别为66%—92%和87%—93%,此结果与实际震害中建筑结构交替破坏的现象一致。

     

    Abstract: Building clusters as “scatterers” and “secondary sources” will change the seismic wave propagation in the site under earthquakes. Seismic damage investigation results of the 1976 Friuli earthquake and the 1985 Mexico earthquake revealed that the building damages had the spatial distribution of alternating destruction. Additionally, many cities and towns in China are located in sedimentary basins. Sedimentary basins have significant amplitude-amplifying and duration-increasing effects on ground motion. The dynamic interaction between the sedimentary basin and buildings leads to spatial redistribution and significant spatial variation of ground motions. Thus, this paper proposes a framework for earthquake damage assessment of buildings considering the dynamic interaction between buildings and the sedimentary basin. Firstly, simplified mechanical models including the shear layer model and flexural-shear model are used to simulate building structures; and the dynamic interaction between buildings and the sedimentary basin is calculated to obtain the ground motions on the top surface of the building foundations. Then, the seismic vulnerability of a typical single building is analyzed based on a refined finite element model with fiber-beam and layered shell elements. Finally, combined with the ground motions of foundations and vulnerability curves of buildings, earthquake damage assessment of buildings is realized rapidly. The results show that the influence of the superstructures on ground motions on the top of the foundations is equivalent when the simplified mechanical model and the refined finite element model are used to simulate building structures. The proposed method is suitable for earthquake damage assessment of building groups considering the dynamic interaction between buildings and basins. However, there are significant differences in solving the seismic response of building clusters using simple mechanical models and refined finite element models. Therefore, it is necessary to comprehensively consider the size of building clusters, and the importance and complexity of buildings in urban areas in seismic damage assessment. A multi-scale method is suitable. The dynamic interaction between buildings and basins mainly reduces the peak value of the surface ground motion in the basin, however, the local location will produce additional amplification based on the basin effect. The interaction between the buildings and the basin causes a three-time difference in the peak values of the acceleration response spectrum at different surface locations. At the same time, the difference in the probability of earthquake damage of the same level in neighboring buildings is magnified. In the analyzed example, when the interaction of building group and basin is considered or not considered, the medium damage probability ranges of the same four adjacent buildings are 66%−92% and 87%−93%, respectively, which is consistent with the earthquake damage phenomenon of building structures in the previous earthquakes. The proposed method takes the failure probability of building structures as the assessment index, which can be solved through seismic vulnerability analysis of individual building structures or directly extracted from the seismic vulnerability database. Compared with dynamic time-history analysis results of building clusters, this index is more suitable for predicting unfavorable locations or buildings before earthquakes, especially for communities with relatively unitary building-types. The failure probability of the entire community can be obtained by combining the seismic vulnerability of typical building structures with the peak ground acceleration at the building foundations.

     

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