Investigation of numerical analysis and seismic performance of underground loess cave with traditional dwellings: Fid-Bau Portal

Investigation of numerical analysis and seismic performance of underground loess cave with traditional dwellings

Zhao, Xiangbi / Xue, Jianyang / Zhang, Fengliang / Hu, Xiaofeng / Zhang, Xin / Xu, Dan

Abstract In recent years, the dynamic characteristics and failure mechanism of earth building under earthquake action have been paid more attention to engineering. In the loess area, the seismic performance of the underground loess cave (ULC) dwelling is still poorly understood. In this paper, the seismic response of the ULC structure under seismic action was discussed by numerical simulation based on the shaking table test. The dynamic triaxial tests were carried out on the loess samples at different depths of the prototype. The dynamic characteristic parameters such as dynamic shear modulus and damping ratio of the original loess were measured, and the dynamic constitutive model was established to provide reliable calculation parameters for the numerical analysis of the seismic response of the ULC. Modeling by coupling finite element (FE) and infinite element (IE), the numerical analysis model of the ULC structure was established, and the loading input of external seismic was achieved on the artificial boundary. The accuracy of the loading input and established model was verified by an example of a 3D solid model. The experimental results were processed according to the similarity relation and then compared with the results of numerical simulation of the seismic response of ULC, such as tensile stress, acceleration response, displacement response, and reliability. To further explore the internal relationship between the seismic performance of the ULC, and the structure size, the parameter analysis of the loess cave model, was carried out. An evaluation suggestion related to the size of the structure during the safety assessment of the seismic performance of the existing loess caves is proposed.

Highlights • First time carried out the shaking table test to study seismic performance on the underground loess cave. • The dynamic constitutive model of loess by dynamic triaxial test is established for numerical simulation analysis. • Refined finite element modeling of earthquakes in underground loess cave was carried out. • The FE-IE coupling modeling was used and verified in the seismic response of ULC structure. • To study the relationship between the size and the seismic response of the ULC, parameter analysis was carried out.