مقاله انگلیسی رایگان در مورد اثرات ته نشست روانگرای لایه لایه بر پاسخ لرزه ای ساختمان – الزویر 2018

Increasing number of underground structures are under construction in China in seismically active areas with liquefiable soil, e.g., Xuzhou and Nanjing. Severe underground structure damage in liquefiable ground has been reported in the past major earthquakes, including the 1995 Kobe earthquake [1,2] and the 2011 Tohoku earthquake [3–5], suggesting that underground structures in liquefiable ground may be vulnerable to seismic damage. Existing research on underground structures in liquefiable ground have mostly been conducted in homogeneous soil profiles, which have provided important insights into the influence of soil liquefaction on the seismic response of underground structures. Some physical model tests have been carried out, most of which with focus on upheaval caused by soil liquefaction rather than the deformation and internal forces of underground structures during shaking [6–15]. Chen et al. [16] suggested through shaking table tests that internal columns are easily damaged under strong horizontal forces on sidewalls. Zhuang et al. [17] found that lateral spreading led to large residual internal forces in underground structures. Several centrifuge model test studies on underground structures in liquefiable ground indicated that the base of pillars and the intersections of sidewalls and floors are prone to failure during shaking [18]. Numerical studies on the seismic response of underground structures in homogeneous liquefiable soil have also been carried out using elastic or elasto-plastic structure models, along with soil models of various complexity [19–26]. However, in practice, few underground structures are built in homogeneous liquefiable soil. Instead, layered soil profiles with liquefiable layers passing through parts of underground structures are much more widely encountered. For example, Subway Line 1 of Nanjing in China, from Xufuxiang Station to Nanjing Station passes through a non-uniform liquefiable area (Fig. 1, [27]). Hashash et al. [28,29] suggested that underground structures partially or entirely embedded in liquefiable soil require additional evaluation. Hence, an important question must be answered: are underground structures in layered liquefiable ground more or less susceptible to seismic damage compared with those in homogenous non-liquefiable and liquefiable ground, and why? Recent developments in numerical simulation methods provide a feasible means to investigate this problem. To appropriately model liquefiable soil and structure interaction during seismic events numerically, the plasticity of underground structures should be considered, and as importantly, constitutive models that reflect the liquefaction behavior of soil along with solid-fluid coupled formulations should be adopted. Several constitutive models have enhanced the description of cyclic behavior of sand [30–35], and can be useful in conducting dynamic analysis on underground structures in liquefiable ground.