干湿循环效应对膨胀土边坡稳定性影响研究  

Impact of wetting-drying cycle effects on stability of expansive soil slopes

作　　者：周健[1,2] 徐洪钟[1] 胡文杰[1] 

机构地区：[1]南京工业大学交通学院,江苏南京210009 [2]常州市中元建设工程勘察院有限公司,江苏常州213001

出　　处：《岩土工程学报》2013年第S2期152-156,共5页Chinese Journal of Geotechnical Engineering

基　　金：国家自然科学基金项目(41072217)

摘　　要：干湿循环中土体强度变化在膨胀土边坡的稳定性分析中十分重要。通过膨胀土边坡干湿循环模型试验,直接在坡面切取各次干湿循环后的边坡土样进行直剪试验,得到其抗剪强度随边坡干湿循环进行而变化的规律。在此基础上,采用有限元强度折减法评价干湿循环状态下边坡的稳定性问题。研究结果表明:干湿循环作用导致边坡强度不断降低,其中黏聚力的下降较为明显,内摩擦角的变化较小。随着干湿循环次数的增加,边坡稳定性降低,安全系数减小。The strength change of expansive soil under wetting-drying cycles plays an important role in the slope stability analysis. Through wetting-drying cycle model tests on the expansive soil slope, direct shear tests on soil samples fetched from the slope surface after various wetting-drying cycles are performed, and it follows that the strength varies with the wetting-drying cycles. The stability of expansive soil slopes under wetting-drying cycles is simulated by means of the shear strength reduction technique in finite element analysis. The results show that the shear strength of expansive soils decreases with the increasing number of cycles, the cohesion of expansive soil decreases obviously and the friction angle keeps a stable value. Furthermore, the slope stability and safe factor decrease with the increasing number of cycles.

关 键 词：膨胀土边坡 干湿循环 强度折减 稳定性 

分 类 号：TU443[建筑科学—岩土工程]