饱和砂土地基应力扩散效应的离心模型试验研究

沉井基础在大跨度桥梁工程中的应用已越来越广泛。在沉井基础的沉降计算中,附加应力影响范围的确定一直是重点和难点,主要涉及应力扩散起始位置、扩散角大小和附加应力影响深度3个方面。针对目前现有理论及常用规范对确定附加应力影响范围的不适用性,开展沉井基础作用下饱和砂土应力扩散效应的研究具有十分重要的意义。通过离心模型试验开展4组不同埋置深度条件下沉井基础的静载荷试验,确定饱和砂土地基中附加应力的影响范围,试验结果可为工程设计提供依据。

Study on Foundation Stress Dispersion Effect in Saturated Sand Based on Centrifugal Model Test

The open caisson foundation is more and more widely used in the big-span bridge engineering.In process settlement calculation,the determination of the additional stress distribution is always the focus and challenge. It mainly includes the initial position of stress dispersion,the size of diffusion angle and the influence depth of additional stress. Hence,the study of the properties of stress dispersion of the open caisson foundation is of great significance. The current approach given in the codes and the existing theory cannot be used for the open caisson foundations subjected to vertical loads under some limit conditions. To deal with this problem,the behaviors of settlement in saturated sand under vertical static loading are investigated based on several centrifugal model tests,and the influence scope of additional stress in saturated sand is determined. The test results may provide some references for engineering practices.