路堑边坡桩锚支护施工过程数值分析  

Numerical Analysis of Construction Process of Pile-anchor Retaining Structure for Cutting Slope

作　　者：曾利军 程学明 赫亚楠 虢希 林宇亮[2] ZENG Lijun;CHENG Xueming;HE Yanan;GUO Xi;LIN Yuliang(China Construction Fifth Engineering Division Corp.,Ltd.,Changsha 410000,China;School of Civil Engineering,Central South University,Changsha 410000,China)

机构地区：[1]中国建筑第五工程局有限公司,长沙410000 [2]中南大学土木工程学院,长沙410000

出　　处：《路基工程》2019年第6期67-72,77,共7页Subgrade Engineering

基　　金：国家自然科学基金面上项目(51678571);中建五局土木工程有限公司技术开发委托项目(020115003G019)

摘　　要：对长沙市某桩锚支护路堑边坡的施工过程进行数值模拟,分析研究边坡开挖对周围土体变形、支护结构变形及受力的影响。结果表明:桩顶的位移先向边坡土体变形,再向坡前临空面变形;边坡开挖后坡顶的小土坡在其坡面中点高度处产生的y向位移最大;边坡开挖对坡顶的6层建筑物无太大影响;边坡土体开挖后在开挖面的中部和边缘处会出现较大的地表隆起;开挖面以上桩后各点的土压力随着开挖高度的增加出现先增大后减小的现象;第1~3排预应力锚索自由段的轴力是随开挖高度增加先减小后增大,而第4~6排预应力锚索自由段的轴力仅有增长的趋势,最终锚索的最大轴力均小于初始预应力值。Through the numerical analysis of the construction process of pile-anchor retaining structure for a cutting slope in Changsha, how the slope excavation affects the deformation of surrounding soil mass and the deformation and stress of the retaining structure were analyzed. The results show that, the displacement of pile top firstly causes the deformation of the slope soil and then the front free face;after the excavation, the small slope at the slope crest has the maximum Y-direction displacement at the midpoint along the slope height;for a 6-floor building at the slope crest, the slope excavation has minor impacts, then there arises relatively large ground heaving at the middle and edge of the excavating face;as the height of excavation increases, the earth pressure at each point behind the piles above the excavating face increases first and then decreases, and the axial force in the free section of the pre-stressed anchor cable in the first to third rows decreases first and then increases, while that in the forth to sixth rows shows rising tendency only;the maximum axial force of the anchor cable at last is smaller than the initial pre-stress value.

关 键 词：路堑边坡 桩锚支护 施工过程 FLAC3D 数值分析 

分 类 号：U417.1+2[交通运输工程—道路与铁道工程]