高陡斜坡作用下群桩基础设计计算方法

Design and Calculation Method for Pile Group Foundation in High and Steep Slope

基于陡坡双桩柱基础探讨了陡坡群桩基础承载机理,提出了陡坡与群桩相互作用简化分析模型,得到了陡坡群桩基础的等效分析模型,即侧向受荷高承台嵌岩群桩基础分析模型;综合考虑滑坡推力与简化分析模型建立了基于结构位移法的陡坡群桩基础计算分析方法,并提出了同时考虑稳定安全与经济最优的陡坡群桩基础优化设计方法。研究结果表明:陡坡群桩基础应尽量减小承台底部至最危险滑动面的距离,嵌岩深度为4倍桩径时能满足工程要求,群桩基础至坡面的距离不小于4倍桩径要求时符合工程实际。

The bearing mechanism of pile group foundation was discussed based on the double pile column foundation. A simplified analysis model was proposed for the interaction between high and steep slope and pile group foundation. The equivalent analysis model of pile group foundation in high and steep slope was also presented. In this analysis model, the pile groups were embedded in rocks with high pile caps and load-bearing on one side. And the calculation method for pile group foundation in high and steep slope was proposed based on structure displacement method with landslide thrust and simplified analysis model considered. The optimum design method for the pile group foundation was also presented with stability and economic optimality considered. The results show that the distance between the bottom of pile cap and dangerous sliding surface should be reduced as small as possible. The rock-embedded depth of 4 times of the pile diameter （4d） can satisfy the engineering demand. When the distance between pile group foundation and slope surface is no less than 4d, it is in accord with the practical engineering.