开挖基坑支护稳定性的双安全指标分析  

STABILITY ANALYSIS FOR SUPPORT FOUNDATION EXCAVATION BY USING DOUBLE SAFETY INDEX

作　　者：宋云连[1] 汲敏[1] 张振国[1] 冀光宏[1] 

机构地区：[1]内蒙古工业大学建筑工程学院,呼和浩特010051

出　　处：《内蒙古农业大学学报（自然科学版）》2008年第1期113-117,共5页Journal of Inner Mongolia Agricultural University(Natural Science Edition)

基　　金：教育部留学回国人员科研启动基金项目(2006-2008)

摘　　要：利用确定性安全系数法与可靠度理论,分析了开挖深度达11.3m的某工程基坑支护结构的安全系数K和可靠指标β。对于开挖非直立坡,工况1到工况4对应的K值和β值较大,从工况5开始,K值虽满足规范要求,但β值非常小,说明基坑失效概率较大,为此,从工况5开始对基坑进行加固,重新计算K和β,均有很大提高,保证了该基坑开挖的安全。本文还利用3σ原理,分析了土钉墙几个主要土性参数变异性对K和β影响的敏感度,本文结论对其他实际工程具有一定参考价值。For those project excavation foundations that intended to be dug to over 11.30 m depth, the safety factor K and reliability index β is analyzed by using the deterministic design method and the reliability design method in this paper. For the non - vertical slope digging, the value of K and β is quite large from operating condition one to four. The value of K is all qualified to the relevant regulations. But, starting from operating condition five, the value of β becomes very small though it is still in the range of required, indicating the failure probability is becoming larger. However, if the reinforced excavation project is strengthened, the value of K and β are all significantly improved after recalculation. Therefore, it secures the digging safety. Furthermore, the influence intensities of the variability of the soil - nailing wall related soil parameters to K and β are also discussed based on the principle of 3σ. The results shows the variability of soil property parameter f plays the biggest affection to safety factor K, the second is the variability of soil property c, the smallest is the.variability of soil property γ- γ plays the biggest affection to β, the second is f, the smallest is the sensitivity of soil property c. Above method of double safety factors could assure the excavatio＇s safety and has a reference value to the other project.

关 键 词：基坑 土钉墙支护 安全系数 可靠指标 敏感度 

分 类 号：TU432[建筑科学—岩土工程]