摘要
考虑到实际工程中土体非均质以及软土地区基坑开挖过程中土体稳定性的特点,将极限分析上限方法应用于非均质软土基坑抗隆起稳定分析计算中,讨论了极限分析方法的适用性问题。选用Prandtl机构建立了非均质软土地区基坑抗隆起稳定分析的运动许可速度场,根据速度场推导了极限分析上限方法的计算公式。讨论了该方法中土体强度、基坑宽度、支护墙体入土深度、基岩埋置深度等因素对坑底抗隆起稳定的影响。通过几个工程的计算与对比,验证了该方法的适用性和优越性。
The hetergeneity of soil is a common phenomenon in geotechnical engineering. In view of the characteristic of the soil stability during excavation in soft clay, an upper-bouod limit analysis method is used to solve the problem of basal stability in heterogeneous soft soil. The applicability of the upper-bound method is discussed to ensure that it obeys the requirements of the limit analysis theorems. Prandtl mode of the beating capacity of foundation is then adopted to construct a kinematically admissible velocity field for the upper-bound method, Based on the kinematically admissible velocity field, the calculation formulas for the basal stability in heterogeneous soft soil are established. With the proposed formulas, the effect of the soil strength, the width of foundation pit, the depth of retaining wall and the location of the hard stratum on the stability coefficient are discussed. The basal stability of several cases is studied and the calculated safety factors are compared with those obtained by other methods. The comparison demonstrates the applicability of the upper-bound method used in this paper.
出处
《岩土力学》
EI
CAS
CSCD
北大核心
2008年第10期2719-2724,共6页
Rock and Soil Mechanics
基金
上海市重大科技攻关项目子课题(No.04dz12001)
关键词
极限分析上限法
软土
基坑支护
抗隆起稳定性
upper-bound theorem of limit analysis
soft clay
braced excavation
basal stability against upheaval
