Study of role of basin shape in the site–city interaction effects on the ground motion characteristics

Summary Seismic damage simulation of buildings on a regional scale is important for loss estimation and disaster mitigation of cities. However, the interaction among densely distributed buildings in a city and the site, ie, the “site‐city interaction (SCI) effects,” is often neglected in most regional simulations. Yet, many studies have found that the SCI effects are very important in regional simulations containing a large number of tall buildings and underground structures. Therefore, this work proposed a numerical coupling scheme for nonlinear time history analysis of buildings on a regional scale considering the SCI effects. In this study, multiple‐degree‐of‐freedom models are used to represent different buildings above the ground, while an open source spectral element program, SPEED, is used for simulating wave propagation in underlying soil layers. The proposed numerical scheme is firstly validated through a shaking table test. Then, a detailed discussion on the SCI effects in a 3D basin is performed. Finally, a nonlinear time history analysis of buildings on a regional scale is performed using the Tsinghua University campus in Beijing as a case study. The Tsinghua University campus case results show that the SCI effects will reduce the seismic responses of most buildings. However, some buildings will suffer much more severe damage when the SCI effects are considered, which may depend on the input motions, site characteristics, and building configurations.

Section: Case Study Of Sci Effects In a 3d Basinsupporting

confidence: 91%

Section: Case Study Of Sci Effects In a 3d Basinsupporting

confidence: 65%

Section: Case 2 and Case 3: Building Response Considering Sci Effectsmentioning

confidence: 65%

Section: Case 2 and Case 3: Building Response Considering Sci Effectsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

A numerical coupling scheme for nonlinear time history analysis of buildings on a regional scale considering site‐city interaction effects

Tian

Wang

et al. 2018

Influence of site–city interaction on the response of structures considering soil stiffness, height, and number of buildings

Norouzi

Gerami

Vahdani

et al. 2020

Simultaneous effects of soil and a number of adjacent structures sitting next to each other is perceived as the site–city interaction (SCI). To better analyze the seismic behavior of the structures, the inclusion of the SCI appears to be essential. Accordingly, the SCI is affected by a number of parameters such as soil profile, urban congestion, as well as dynamic properties of buildings and soil layers. In this study, considering four soil types according to Eurocode8 (EC8) and a series of structures in single and multiple configurations (buildings arranged in 3 × 3 and 5 × 5 groups) representing an ideal city, 3D dynamic analyses were conducted using SASSI2000 software. Then, the acceleration response of the structures placed in the middle of each configuration was compared with that of the single structures to evaluate the influence of soil properties particularly, its stiffness as well as number and height of the structures on the response of the base and top nodes of multi–degree‐of‐freedom structures incorporating the SCI effects. Based on the results, the inclusion of SCI reduced the acceleration values especially at top of the structure (7% and 15% for the bottom and top of the structure on average). In addition, as soil stiffness decreases and the number of buildings increases, the influence of SCI becomes profound. According to the complexities of the SCI, to acquire more accurate results, further parameters such as the type of seismic waves, irregularity of buildings, and faulting mechanism have to be taken into account.

Experimental and analytical study on ground motion characteristics under structure cluster disturbance

Guo

Wang

et al. 2022

Soil-structure cluster dynamic interaction (SSCI) has a significant effect on structural responses as well as ground motions for soft soil, while investigations on the latter remain limited. In this paper, four test models, including the free field model, soil-single structure model, soil-equal height structure cluster model, and soil-multiple height structure cluster model, were manufactured and investigated through large scale shaking table tests. The effect of structure numbers, layouts, structural dynamic characteristics and seismic spectrum characteristics on the ground motions was discussed. On this basis, finite element analysis and wavelet packet decomposition were employed to further investigate the evolution rule of cluster effect. The results manifested that, due to the structure cluster, the predominant period of the original free field could be elongated notably and earthquake response spectrum in the long period domain was amplified, especially under the excitation of seismic waves with abundant low-frequency components. The influence of SSCI on ground motions is chiefly reflected in the variation of site predominant period and the soil damping during the vibration. In addition, the cluster effect on ground motion presents a monotonous degressive trend with the increase of the structural spacing, and its attenuation rate is negatively correlated with structural height, while the difference in ground motion due to different structure numbers becomes insignificant with the increase of structural spacing.