第34卷第4期 2017年7月
土木工程与管理学报 Journal of Civil Engineering and Management
Vol.34 No.4 July 2017
降雨入渗条件下抗滑桩加固边坡稳定性分析
郭震山，赵建斌，赵紫阳
（山西省交通科学研究院黄土地区公路建设与养护技术交通行业重点实验室，山西太原030006）
摘要：采用有限差分软件FLAC3D内置FISH语言编制相关程序，将边坡非饱和区渗透系数和基质吸力随饱和度的变化关系嵌人到数值计算中，实现了降雨入渗条件下边坡非饱和渗流过程的模拟，结合基于Fredlund双应力状态变量理论的强度折减法，进一步实现了非饱和边坡的稳定性分析。基于某典型抗滑桩加固边坡算例建立数值计算模型，研究了降雨入渗对边坡孔隙水压力分布及边坡稳定性的影响，并对降雨强度、基质吸力及桩顶约束形式对边坡稳定性的影响进行了参数分析。研究结果表明：降雨人渗条件下，随降雨历时增加，湿润锋线不断向坡体内部推进，基质吸力明显减小，边坡安全系数显著降低；边坡安全系数随降雨强度增大而减小，当降雨强度超过土体饱和渗透系数后，边坡安全系数随降雨强度变化不大，并趋于稳定；基质吸力对边坡稳定影响显著，考虑基质吸力时边坡安全系数明显提高；在桩顶设置预应力锚索可使桩身位移明显减小，边坡安全系数提高。
关键词：降雨入渗；非饱和渗流；数值分析；抗滑桩；边坡稳定性
中图分类号：U213.1+52.1
文献标识码：A文章编号：2095-0985(2017)04-0047-06
Stability Analysis of the SlopeReinforced with Anti-slide Pile
UndertheConditionofRainfallInfiltration GUO Zhen-shan，ZHAO Jian-bin，ZHAOZi-yang
(Key Laboratory of Highway Construction and Maintenance Technology in Loess Region,
Shanxi Transportation Research Institute,Taiyuan 030006，China)
Abstract: The values of permeability coefficient and matrix suction varying with the degree of saturation in unsaturated area of the slope were embedded into the numerical calculation, aiming at simulating the unsaturated seepage of the slope under the condition of rainfall infiltration, by using the FISH language built-in the finite difference program FLAC3D. Then the stability analysis of the unsaturated slope was realized combining with the strength reduction method based on the theory of two stress state variables proposed by Fredlund. A numerical model was established based on a typical anti-slide pile reinforced slope and the effect of rainfall infiltration on the distribution of pore pressure and slope stability was analyzed. Parametric analysis of the rainfall intensity, matric suction, and constraint type of the pile head was also presented. The results show that the infiltration front moves deeper into the slope and both the matric suction and slope safety factor decrease significantly with the increase of rainfall duration. The slope safety factor decreases with the increase of rainfall intensity. However, the slope safety factor tending to be stable and small variation is observed when the rainfall intensity is greater than the saturated infiltration coefficient of the soil. The matric suction has significant influence on the slope stability and the slope safety factor increases obviously when the matric suction is considered. The pile displacement decreases and the slope safety factor increases by setting prestressed anchor cable at the pile head.
Key words: rainfall infltration; unsaturated seepage; numerical analysis; anti-slide pile; slope sta-
bility
收稿日期：2016-07-05修回日期：2016-09-11
作者简介：郭震山（1990-），男，河南南阳人，助理工程师，硕士，研究方向为岩土工程（Email：guozhenshan@hust.edu.cn）基金项面：方数据交通建设科技项目（15-2-08）