中文摘要：

微型桩是一种常用边坡快速加固手段,多大面积成群布置。基于梁柱理论和弹塑性地基系数法中的P–y曲线法建立了微型桩加固边坡的水平抗力分析模型,提出了确定微型桩截面极限弯矩以及最大抗剪力的迭代分析方法;采用有限差分法推导了轴向和横向复合外力作用下微型桩内力和变位的计算公式;以最大限度发挥微型桩群横向抗力为目标,重点研究了微型桩群中微型桩横向间距和纵向间距的确定方法。在此基础上,形成了采用微型桩群加固土质边坡的设计方法,内容主要包括微型桩群布设位置的选取、微型桩选型、桩长选取、微型桩群断面设计、微型桩群平面设计以及顶梁设计等。将该方法应用于某公路路堤边坡病害加固工程设计中,监测资料表明,坡体位移在微型桩群的作用下逐渐趋于收敛,坡体病害得到了根治,从而验证了设计方法的有效性。

英文摘要：

As a kind of measure for fast slope reinforcement,micropiles are always designed as a group.An analytic model for the ultimate resistance of the micropiles is proposed based on the beam-column equation and the existing P-y curve method,and then an iterative process to find the bending moment and shear capacity of the micropile section is developed.The formulation for calculating the inner force and deflection of the micropiles using the finite difference method is derived.Special attention is paid to determine the spacing of the micropiles,aiming to get the ultimate shear capacity of micropile group.Thus a new design method of micropile group for soil slope stabilization is proposed,including choosing a location for the micropile group within the existing slope,selecting micropile cross section,estimating length of micropile,evaluating shear capacity of micropile group and calculating spacing required to provide force to stabilize the slope and design of concrete cap beams.The application of the method to an embankment slope hazard problem in Qinghai is described,and the monitoring data indicate that slope movement is effectively controlled as a result of the slope stabilization measure,which verifies the reasonability of the design method.