基于双参数法刚性抗滑桩嵌固深度可靠性设计

将计算推力桩的双参数法应用于刚性抗滑桩,建立刚性抗滑桩嵌固深度可靠度分析模型,并引入随机优化算法搜索嵌固深度范围内最小可靠度指标作为该嵌固深度下的可靠度指标,然后以目标可靠度指标指导刚性抗滑桩嵌固深度的设计.通过工程实例分析表明,在满足目标可靠度的条件下采用双参数法进行刚性抗滑桩嵌固深度可靠性设计比传统的地基系数法更为经济.由参数敏感性分析可知,刚性抗滑桩嵌固深度的确定对滑体重度及滑动面土体内摩擦角、粘聚力的敏感性较强,对嵌固段土体重度及地基系数的比例系数的敏感性较弱.因此在进行刚性抗滑桩嵌固深度设计时应重点考虑滑体重度、滑动面土体内摩擦角和粘聚力变异性的影响.

Reliability Design of the Embedded Depth of the Rigid Anti-slide Piles Based on Bi-parameter Method

An analytical model for the reliability of the embedded depth of rigid anti-slide pile was established by introducing the bi-parameter approach used in the computation of lateral loaded pile. A reliability index target was determined by searching for the minimum of reliability index at a specified embedded depth incorporating with stochastic optimization algorithm, and was used to guide the design for the embedded depth of rigid anti-slide pile. Practical case study demonstrated that it was more economical to determine the embedded depth in the bi-parameter approach than in traditional ground coefficient methods. Analysis of the parametric sensitivity indicated that the determination of the embedded depth of the rigid anti-slide pile was more sensitive to the unit weight, internal frictional angle and cohesion of sliding mass than to the gravity of the embedded length and the proportional coefficient of ground coefficient. It is suggested that more concern be given to the variation of the former three parameters when conducting the embedded depth design of rigid anti-slide pile.