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Sand liquefaction is one of the leading causes of severe earthquake damage. In this study, shaking table tests were carried out to investigate the dynamic interaction between the saturated sand and the irregular subway stations. In this test, a method for the preparation of a liquefiable foundation based on a flexible sensing chain combined with water sedimentation was proposed. Typical test results were interpreted, including the development and spatial distribution of pore pressure, surface subsidence, acceleration, deformation, and dynamic earth pressure. Results show that the spatial distribution of excess pore water pressure is changed by the irregular underground structure, and the liquefiable soil below the bottom plate of the structure can be divided into I, II, and III areas based on the degree of liquefication. The surface subsidence is significantly related to Arias intensity and is concentrated within the range of 5 %–95 % of the intensity. The structural floating is synchronized with the liquefaction of the saturated sand, and the uneven floating and inclination of the underground structure are remarkable, anti-flotation design of underground structures should take into account differences in section forms. During the liquefaction of saturated sand, the foundation soil has conspicuous lateral deformation, especially in the deep soil layer. The shape of the dynamic earth pressure increments turns from triangular to linear, when the foundation soil changes from non-liquefied to liquefied. Compared with the limiting values of the elastic inter-story drift ratio, the maximum inter-story drift ratio of the structure is smaller. The tensile strain responses on the columns, particularly in the lower layer, are more prominent than those at the slabs and side walls. • Shaking table model test is designed on the saturated sand-underground structure interaction system. • Dynamic interaction between irregular-section underground structures and saturated sand is researched, including the different liquefaction states for saturated sand. • A method for the preparation of a liquefiable foundation based on a flexible sensing chain combined with water sedimentation was proposed. • The liquefiable soil below the bottom plate of the structure can be divided into three areas based on the degree of liquefaction. • Differences in cross-section forms should be considered in the anti-floating design of underground structures. [ABSTRACT FROM AUTHOR]

This paper presents shaking tests conducted on a 1/30-scale utility tunnel model employing a multi-shaking table array system. The model utility tunnel-soil system was subjected to input motions simulating near-fault ground motions with and without velocity pulse. The test data were collected and analyzed including acceleration, strain and displacement of the soil bed and model tunnel responses. The soil data analysis indicated that the boundary effect of the model soil box used in the test was negligible. The observed small soil settlements confirmed that the physical and mechanical properties of the model soil did not change significantly in tests. The results also demonstrated that, in general, the transverse dynamic responses of the utility tunnel and surrounding soil under near-fault ground motion with velocity pulse were much greater than the case without velocity pulse. Therefore, the effect of velocity pulse should be considered in the design of utility tunnels. • Near-fault ground motions with and without velocity pulses were selected. • A series of scaled model tests were conducted by using a shake table array. • Transverse dynamic response of the utility tunnel model is analyzed through the test data and the result is given. [ABSTRACT FROM AUTHOR]