Seismic Performance Levels of a Large Underground Subway Station in Different Soil Foundations

ABSTRACT

With the soil constitutive model developed for the dynamic large deformation of soft soil, a finite element model was constructed to simulate the soil–underground structure static and dynamic coupling interaction system, in which the dynamic contact between soil and underground structure and the dynamic damage of reinforced concrete were considered. The seismic performance and damage mechanism of the large underground subway station in different soil foundations were investigated and evaluated in detail. It was proven that the interaction mechanism between the soil and underground structure would change with the type of soil foundation and the peak acceleration of input ground motion, which can be evaluated by the interaction coefficient between the soils and underground structure. At the same time, some regulations on the seismic performance of underground structure in China code are already unsuitable for evaluating the seismic performance of a large underground subway station in the soft soil foundation or subjected to a strong earthquake, which should be investigate by the specialized time–history analysis method instead. In this study, five seismic performance levels were firstly defined by the inter-storey drift angle of underground structure and corresponding earthquake damage states.

KEYWORDS:

• Underground subway station
• site geotechnical condition
• seismic performance level
• dynamic soil–structure interaction
• finite element method

Acknowledgments

The authors are grateful for the research funding provided by the National Natural Science Foundation of China (NSFC, Grant Nos. 51778290, 51878266), the Natural Science Foundation of Jiangsu Province (NSFJ, Grant No. 16KJA560001), the fund for excellent post graduation student (No. SJCX18_0337) and the National Key Technologies R & D Program of China (2017YFC1500400). All statements, results, and conclusions are those of the researchers and do not necessarily reflect the views of these foundations. The authors also sincerely thank the anonymous reviewers for their insightful comments and suggestions.

Additional information

Funding

This work was supported by the National Natural Science Foundation of China [Nos. 51778290, 51878266, 51778260]; Natural Science Foundation of Jiangsu Province [No. 16KJA560001]; National Key Technologies R & D Program of China [2017YFC1500400].