摘要
采用有限元强度折减法对单排桩、桩间距为4 m的抗滑桩在不同设桩位置加固滑坡进行数值模拟,研究发现不同的桩位影响滑坡的稳定安全系数、滑动面的位置和形状。桩位不同决定了是桩后土体还是桩前土体滑落。桩位选择的一个重要原则是加固后滑坡体的稳定安全系数必须大于设计要求的安全系数,否则就会出现桩端越顶破坏或桩前土体滑落。斜坡在同一稳定安全系数下,桩位不同时抗滑桩所受的滑坡推力、桩的内力(剪力、弯矩)和桩的挠度不同。抗滑桩位于斜坡中部时,桩身长度较长,推力和内力大,是不合理的桩位;但桩身挠度大,提供的桩前抗力也大。按常规方法与按有限元法计算桩前无土体的悬臂桩桩上推力是相近的。把桩视作埋入滑坡体中的梁单元,按有限元法算出的推力比较小,因为它已经充分考虑了桩前土体的抗力。
The slope stabilized by single-row piles is simulated by nonlinear finite element method with shear strength reduction. The piles are laid out at variant sites on the slope surface, whose spacing is four meters each. Conclusions are made that factor of stability, the location and shape of the slide surface vary as pile location varies. Pile location variable determines whether slide comes from anterior surface of the pile or from posterior surface. One critical principle for the option of pile location is that the factor of stability on landslide control is greater than the factor of safety to meet with design expects, else slide will originate from pile head or from anterior surface of the pile. Under the same factor of stability, the lateral force, internal forces such as shear force, moment and deflection of the pile vary with pile location variable. The length of the pile is longest and the lateral force is largest when the pile location is in the middle of the slope, so it is not desirable location for the pile. But the deflection and resisting force responded are largest. The lateral forces on the normal method and the method of finite element are equal for the pile that there is no soil mass in the front of pile. The lateral force is reduced when the pile as beam element is located in the body of landslide, because resisting forces supplied by the soil mass in front of the pile are taken into account.
出处
《岩土力学》
EI
CAS
CSCD
北大核心
2006年第6期950-954,共5页
Rock and Soil Mechanics
基金
国家973项目资助(No.2002CB412708)
关键词
抗滑桩
滑坡治理
有限元极限分析
桩土相互作用
anti-slide piles
landslide control
limit analysis with finite elements
interaction of piles with soil
作者简介
雷文杰，男，1974年生，博士研究生，主要从事边坡加固、渗流的理论和数值研究。Email：leiwenjie@163．com
