Abstract: A systematic study was conducted to explore the mechanism of pile-anchor supporting for high slopes of highway road cuttings, taking the landslide treatment of a road cutting slope in Dengjia Village, Yunnan Province as an example. Through on-site geological survey and multivariate data analysis, the engineering geological conditions and causes of the landslide were identified. FLAC3D numerical simulation was used to study the stability of the high slope without support, and two schemes of retaining walls and pile-anchor supporting were compared and analyzed. Taking a scheme with the prestress being 400 kN, the pile spacing being 4m and the pile diameter being 1m as a basic one, the influence rule of pile-anchor parameters on the stress performance of pile-anchors and slope safety factors in high slopes of road cuttings was analyzed through single factor analysis method. The research results show that, although the retaining wall can effectively prevent slip at the bottom of the slope, its stability effect on the middle and upper parts of the slope is not good. The pile-anchor supporting structure has a good reinforcement effect on the whole landslide body. The displacement of the pile exhibits a characteristic of "being large in the upper part and approaching 0 in the lower part", whose shear force and bending moments have multiple extreme points, and most of them appear above the sliding surface. With the increase of pile diameter or the decrease of pile spacing, the safety factor of slope increases. On the other hand, the prestress of anchor cable has little effect on the safety factor of slope.

Key words: highway engineering; geotechnical engineering; pile-anchor supporting mechanism; FLAC3D; high cutting slope; support scheme

摘要： 为探明公路路堑高边坡桩锚支护机理，以云南邓家村某路堑边坡的滑坡处治为例展开了系统的研究。通过现场地质调查及多元数据分析，查明了滑坡工程地质条件及成因；采用FLAC3D数值模拟研究了无支护下高边坡的稳定性，对比分析了挡土墙和桩锚支护2种方案；以预应力为400 kN、桩间距为4 m、桩直径为1 m为基本方案，通过单因素分析法分析了路堑高边坡中桩锚参数对桩锚受力性能和边坡安全系数的影响规律。研究结果表明：挡土墙虽然可以有效阻止边坡底部的滑移，但其对坡体中部和上部的稳固效果不佳；桩锚支护结构对整个滑坡体都有一个良好的加固作用，桩的位移呈现“上部大而下部趋于0”的特点，其受到的剪力、弯矩存在多个极值点，并且大多数存在于滑动面上方；随着桩直径的增大或者桩间距的减小，边坡安全系数增加，而锚索预应力对安全系数的影响很小。

关键词: 道路工程；岩土工程；桩锚支护机理；FLAC3D；路堑高边坡；支护方案