Study On Seismic Response Of Metro Station Based On High-order Doubly Asymptotic Transmitting Boundary

The metro staion may have serious damage under seismic load according to the survey.And it is necessary to systematically study on the seismic performance of metro station.Developed from modified scale boundary finite element method and continued fraction solution,high-order doubly asymptotic transmitting boundary(DATB)is an effective approach to simulate the unbounded domain,possessing high accuracy and good efficiency.The objective of this paper is to construct layered soil – metro station coupled model by incorporating the high-order DATB with the finite element method and applys it to the study on seismic response of metro station under layered soil.The main contents and results are summarized as follows:1.The layered soil – metro station coupled model is developed by incorporating the highorder DATB and the finite element method.The coupled model is numerically implemented in the ABAQUS finite element software and used for analysis of layered soil-metro station interaction under dynamic load.Numerical experiments demonstrate the high efficiency and accuracy of the coupled model,showing the fitness for long-time seismic response analysis.Therefore,it is believed that the coupled model could be further developed for engineering.2.Applying the layered soil – metro station coupled model,numerical analysis on the damage of the Dakai station is conducted.And the damage mechanism of the Dakai station is comprehensively analyzed based on the displacement response as well as internal force response.Numerical results show that the coupled model could basically restore the damage history of the Dakai station,demonstrating the reasonableness of the coupled model.Besides,the insufficient capacity of the middle column mainly caused the damage of the station,which corresponds to the existing research results.3.A layered soil – metro station coupled model is built for the seismic response analysis of large-span non-column metro station buried in a typical stratum condition,that is “upper soft and lower hard” stratum.And the comparison with the Chineses Standards and shaking table test are carried on.Numerical examples demonstrate that this type of metro station could meet the requirement of the Standard under Richter magnitude scale of seven.Moreover,compared with the shaking table test,the coupled model can basically capture the seismic characteristic of the large-span non-column metro station under “upper soft and lower hard” stratum,manifesting the fitness for engineering practice.4.Based on the large-span non-column metro station from Chapter 4,the factors of layered soil affecting the seismic response of the metro station,that is,the different location of the layer interface and the buried depth of the metro station,are studied.The comparions among different conditions are conducted.The results show that the location of layer interface has a great impact on the seismic response of the metro station.Besides,when the metro station is totally buried in the soft soils,the deeper the station buried,the more serious damage in the structure appearing.