嵌固于多种地层的抗滑桩设计计算方法

A calculation method for design of the stabilizing piles embedded in various strata

在采用抗滑桩加固边坡或滑坡的工程中通常会出现桩体嵌固段位于多种地层的情况,嵌固段桩体的受力对所加固坡体的稳定性有极为重要的影响。现行规范建议采用等效地基系数法计算桩体嵌固段,其计算结果往往与实际不符。针对实际工程中常见的嵌固段地层为3种及以下地层的情况,将其分为全土型、土土岩型、土岩岩型和全岩型4类,基于侧向受荷的弹性地基梁分析模型,采用嵌固段实际各地层的弹性抗力系数,考虑桩体嵌固段在各地层界面处的内力和变形连续性,给出了这4类典型情况下抗滑桩嵌固段的内力和位移计算公式。工程实例分析表明,本文提出的计算方法与数值模拟法、桩体有限差分算法的所得结果较为接近,但本文的计算过程更为简单,更便于实际操作。

Stabilizing piles embedded in various strata are extensively used for practical slope reinforcement or landslide control.Mechanical behaviors of the fixed segment in various strata have significant influence on stability of the reinforced slope.Equivalent ground coefficient of elastic resistance is suggested to solve this problem in current specifications in China.But the corresponding calculation results are not generally consistent with the actual pile responses.the slide-resistant piles are usually embedded in four basic types of strata including the soil-soil-soil type,soil-soil-rock type,soil-rock-rock type,and rock-rock-rock type.Based on analysis model of laterally loaded beam on elastic foundation,internal forces and displacements of the fixed segment are provided respectively with considering actual ground coefficient of elastic resistance of each strata and continuity of internal forces and displacements of the pile at interfaces of adjacent strata.Analysis of some practical engineering examples show that the calculation results obtained using the proposed method are in good agreement with those computed using numerical simulation method and finite difference algorithm for the pile.In particular,the computation procedure of the proposed method is easier and more convenient for practical application than the existing methods.