Coral sand, as a geological material for foundation filling, is widely used for reclamation projects in coral reef areas. The coral sand is characterized by a wide grain size distribution. A series of centrifuge shaking table tests were conducted to explore the seismic response of a shallow buried underground structure in saturated coral sand and coral gravelly sand. The emphasis was placed on comparing the similarities and differences in the dynamic behavior of the underground structure at the two sites. The responses of excess pore pressure, acceleration, displacement, and dynamic soil pressure of the structure were analyzed in detail. The results indicated that the underground structure in coral sand had a significant influence on the development of excess pore pressure in the surrounding soil, but this effect was not evident in coral gravelly sand due to well-drained channels. Liquefaction was observed in the soil layer around the structure in coral sand, but it did not occur in coral gravelly sand. In coral sand, the liquefaction of the soil layer at the bottom of the structure caused a significant attenuation in the acceleration of the structure. Compared to coral gravelly sand, the acceleration response of the soil layer near the bottom of the underground structure was higher in coral sand. During the shaking, the displacement pattern of the structure in coral gravelly sand was slight subsidence-slight uplift-significant subsidence, while it exhibited a significant uplift in coral sand. The maximum dynamic soil pressure distribution on the structural sidewalls presented a trapezoidal distribution, and the dynamic soil pressure had a strong connection with the development of excess pore pressure in the surrounding soil.

中文翻译：

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基于离心机建模的珊瑚砂和珊瑚砾石砂中浅埋地下结构地震响应的比较研究


珊瑚砂作为地基填充的地质材料，广泛用于珊瑚礁地区的填海造地工程。珊瑚沙的特点是粒度分布宽。进行了一系列离心振动台试验，以探究饱和珊瑚砂和珊瑚砾石砂中浅埋地下结构的地震响应。重点是比较两个地点地下结构动态行为的异同。详细分析了结构的超孔隙压力、加速度、位移和动土压力的响应。结果表明：珊瑚砂地下结构对周围土体超孔隙压力的发展有显著影响，但由于渠道排水良好，这种影响在珊瑚砾石砂中并不明显。在珊瑚沙中观察到结构周围的土壤层液化，但在珊瑚砾石沙中没有发生液化。在珊瑚沙中，结构底部土层的液化导致结构加速度的显着衰减。与珊瑚砾石砂相比，珊瑚砂中地下结构底部附近土层的加速度响应更高。在震动过程中，结构在珊瑚砾石砂中的位移模式为轻微沉降-轻微隆起-显著沉降，而在珊瑚砂中则表现出显著的隆起。结构侧壁最大动土压力分布呈梯形分布，动土压力与周围土体超孔隙压力的发展有很强的联系。