地下水浮力对地下建筑结构安全的影响

为研究地下水浮力对地下建筑结构产生的损伤特征和机理，通过一典型工程实例的结构变形和裂缝原因分析，并结合有限元程序对结构变形和变形后刚度变化的模拟计算，对地下水浮力作用下造成的结构变形机理，混凝土梁、柱、墙裂缝特征，以及对结构安全的影响进行研究。研究结果表明：当地下水浮力超出地下建筑自身重量，地下建筑在浮力作用下产生隆起变形和整体上移的趋势，而在周边挡墙处该上移趋势受土体约束，致使各柱、墙竖向变形不一致，导致结构构件开裂甚至局部破坏。损伤后的结构刚度大大降低。结构的总体损伤程度与平面尺寸相关，并受平面短边尺寸的控制，且结构构件损伤呈现周边大于中部的特征。

Effect of Underground Water on Safety of Underground Structure

In order to study the damage characteristics and mechanism of underground water on underground structure. factors of structure deformation and cracks based on a case study had been investigated. Meanwhile, finite element method had been used to simulate the deformation and decrease of stiffness. And structure deformation mechanism had been investigated, together with cracks characteristics and the effect on the structure's safety. It was found that the underground structure would be swollen up and floated as the float was larger than the structure's weight. And the uptrend of boundary retaining wall was restrained by soil, which made vertical displacements in columns and concrete walls different and resulted in structure cracks and the decrease of structural stiffness. The general structural damage was depended on the plan size and controlled by the short side. And the damage was more serious in central than that in boundary.