摘要
云南某机场高填方边坡具有原地基及基岩地形起伏大、红黏土软弱层分布广、填筑体厚度大等特点,其最大填方厚度约为70m,最大垂直高差约为46m。本文采用不同的数值法对高填方边坡稳定性进行计算分析,并与传统极限平衡法计算结果进行对比,结果表明:原地基初始地应力和填筑等施工工序对数值法稳定性分析结果影响显著,对于高填方边坡采用数值法分析更能反映边坡实际应力场特征,对于复杂高填方边坡采取数值方法进行稳定性验算是非常必要的。针对本工程的极限平衡法分析中,不同算法之间存在较为一致的相对安全系数大小关系:瑞典条分法<简化Janbu法<简化Bishop法≈Morgenstern-Price法≈Sarma法。极限平衡法(简化Bishop法)所得安全系数结果与应力分析法(SAM)较为接近,相差小于5%;但明显大于强度折减法(SRM),约为前者的1.08~1.22倍,数值法稳定性分析结果相比极限平衡法有一定的安全储备。通过强度折减法中剪应变增量云图得到的滑动面与极限平衡法、应力分析法搜索得到的临界圆弧滑动面位置基本吻合。
The high fill slope of an airport in Yunnan has the characteristics of large topographic fluctuation of in-situ foundation and bedrock,wide distribution of red clay layer and large thickness.The maximum filling thickness is about 70 m and the maximum in difference vertical height is about 46 m.In this paper,the stability of high fill slope was calculated and analyzed by different numerical methods,and compared with the calculation results of traditional limit equilibrium method.The results show that the initial in-situ stress of in-situ foundation and filling and other construction processes have a significant impact on the stability analysis results of numerical method.For the high fill slope,the numerical method can better reflect the actual stress field characteristics of the slope,which proves that it is very necessary to adopt the numerical method for the stability check of the complex high fill slope.In the limit equilibrium method,there is a relatively consistent relationship between the relative safety factors of each algorithm:Fellenious method<simplified Janbu method<simplified Bishop method≈Morgenstern-Price method≈Sarma method.The safety factor obtained by the limit equilibrium method is close to the stress analysis method(SAM),and the difference is less than 5%.But it is significantly greater than the strength reduction method(SRM),about 1.08-1.22 times of the former.The sliding surface obtained from the incremental cloud map of shear strain in the strength reduction method is basically consistent with the position of the critical circular sliding surface obtained by the limit equilibrium method and the stress limit equilibrium method.
作者
王萌
WANG Meng(East China Architectural Design&Research Institute Co.,Ltd.,Shanghai 200011,China)
出处
《地基处理》
2022年第S01期65-71,共7页
Journal of Ground Improvement
关键词
高填方边坡
稳定性分析
数值法
应力分析法
强度折减法
极限平衡法
high fill slope
stability analysis
numerical method
stress analysis method
strength reduction method
limit equilibrium method
作者简介
王萌(1991—),男,河北邯郸人,博士,工程师。主要从事地基处理与基础工程方面的工作。E-mail:wangm1028@126.com。
