土木与环境工程学报（中英文）2021，Vol.43Issue(1)：54-63,10.DOI:10.11835/j.issn.2096-6717.2020.170
考虑空间变异性的基坑降水支护开挖引起地面沉降的可靠度评估
Reliability assessment of excavation-induced ground surface settlement with groundwater drawdown considering spatial variability
摘要
Abstract
For braced excavations in deep deposits of soft clays or residual soils,the ground surface settlement behind the excavation is correlated with the extent of basal heave as well as the wall deflections and is also affected by the magnitude of the groundwater drawdown behind the retaining system.Reliability analysis based on a recently developed simplified logarithm regression model for estimation of the maximum ground surface settlement is presented.The first-order reliability method implemented with a variance reduction technique while considering soil spatial variability is employed to investigate the probability that certain ground surface settlement threshold is exceeded.This paper presents the effects of spatial averaging and the influence of several key design parameters including the stiffness of the wall system,the magnitude of the threshold ground surface settlement,the coefficient of variation of the soil properties,and the magnitude of the groundwater drawdown on the ground surface settlement.It is concluded that soil spatial variability results in a higher probability of failure (i.e.,a lower reliability index),without considering it would result in an unreliable design.A larger characteristic length results in a lower probability of failure and a higher reliability index.When the spatial variability of both the cu/σ'v and E50/cu are considered,the influence onβis more significant.关键词
地面沉降/基坑支护开挖/降水/空间变异性/方差缩减Key words
ground surface settlement/braced excavation/groundwater drawdown/spatial reliability/variance reduction分类
建筑与水利引用本文复制引用
章润红,GOH Anthony,周廷强,仉文岗..考虑空间变异性的基坑降水支护开挖引起地面沉降的可靠度评估[J].土木与环境工程学报（中英文）,2021,43(1):54-63,10.基金项目
National Natural Science Foundation of China (No.52078086) （No.52078086）
Program of Distinguished Young Scholars, Natural Science Foundation of Chongqing,China(No.cstc 2020jcyj-jq0087) （No.cstc 2020jcyj-jq0087）
Chongqing Construction Science and Technology Plan Project (No.2019-0045). （No.2019-0045）
