分层土中水泥土围护结构抗倾覆验算方法的改进  

Improved method for calculating anti-overturning safety factor of cement-soil retaining wall in layered soil

作　　者：李卫超[1] 熊巨华[1] 杨敏[1] 

机构地区：[1]同济大学地下建筑与工程系岩土及地下工程教育部重点实验室,上海200092

出　　处：《岩土力学》2011年第8期2435-2440,共6页Rock and Soil Mechanics

基　　金：国家科技支撑计划(No.2008BAJ06B04-1)

摘　　要：推导了分层土中水泥土围护结构抗倾覆稳定系数计算公式,提出了改进的计算方法,研究了土层分层结构对水泥土围护结构抗倾覆稳定系数的影响。土层上软下硬时,水泥土围护结构抗倾覆稳定系数分别随着墙体宽度与入土深度的增加而增加。土层上硬下软时,增加墙体宽度对于提高抗倾覆稳定系数具有较好的效果,而增加墙体入土深度对于提高抗倾覆稳定系数作用不大,因为分层土中,水泥土围护结构抗倾覆稳定性主要依靠下部土体的被动土压力来维持,即抗倾覆稳定性主要受下层土体强度的影响。如将分层土参数按厚度加权平均取值后作为均匀土对待,对上软下硬土层,该方法计算的抗倾覆稳定系数比分层方法得到的小,偏于保守;而对上硬下软土层,该方法计算的抗倾覆稳定系数比分层方法得到的大,存在安全隐患。改进方法与常规计算方法对比表明,其计算结果更为安全合理。An improved anti-overturning safety factor calculation method of the cement-soil retaining wall in layered soil is presented. Based on the improved method, the influence of different soil structures on the anti-overturning safety factor is analyzed. When the soft soil is over the hard soil the anti-overturning safety factor increases with increasing of the width and the embedded depth of the wall respectively. Similarly the anti-overturning safety factor also increases with increasing of the width of the wall but has less change with increasing of the embedded depth of the wall when the hard soil is over the soft soil. The reason for that is the anti-overturning safety of the cement-soil retaining wall relies mainly on the passive earth pressure; that is to say, the anti-overturning safety factor is influenced by the lower soil＇s strength mainly. If treating the layered soil parameters according to the thickness weighted as the homogeneous soil, the anti-overturning safety factor is smaller which inclines to conservative when the soft soil is over the hard soil. Unlike that the anti-overturning safety factor is bigger which has the security risk when the hard soil is over the soft soil. Compared with the conventional calculation method, the improved method presents a more reasonable and safe result.

关 键 词：分层土 水泥土围护结构 倾覆稳定验算 改进算法 

分 类 号：TU432[建筑科学—岩土工程]