摘要
针对地铁宽基坑施工变形过大的问题,基于北京上清桥站基坑工程,采用数值模拟、现场实测分析和概率统计的方法研究围护墙变形过大原因及概率分布特征。结果表明:支撑的拆除是造成基坑围护结构变形过大原因。基坑围护墙水平变形模式呈“抛物形”,拆除钢支撑和施作主体结构期间,大部分测点超过变形控制值,基坑由安全进入危险状态。δ_(hm)/H_(e)概率密度较大区间为[0.05,0.15],可将样本均值0.13%作为该基坑指示值,判断基坑随开挖围护结构最大变形值。H_(hm)/H_(e)概率分布较大区间为[0.6,1.0],H_(hm)/H_(e)的分布符合正态分布函数,拟合函数的样本均值为0.71,标准差为0.12,确定了围护墙最大水平位移和最大水平位移位置的概率分布特征。
Aiming at the problem of excessive deformation in the construction of a subway wide foundation pit,based on the foundation pit project of Beijing Shangqing Bridge Station,numerical simulation,field measurement analysis and probability statistics were used to study the cause of excessive deformation of the retaining wall and its probability distribution characteristics.The research results show that the dismantling of supports is the cause of excessive deformation of the retaining structure of the foundation pit.The horizontal deformation mode of the retaining wall of the foundation pit is“parabolic”.During the removal of the steel support and the construction of the main structure,most of the measurement points exceed the deformation control value,and the foundation pit enters a dangerous state from safety.The larger interval of the probability density of δ_(hm)/H_(e) is[0.05,0.15],and the sample average value of 0.13%can be used as the indication value of the foundation pit to judge the maximum deformation value of the excavation of the foundation pit.The larger interval of the probability distribution of H_(hm)/H_(e) is[0.6,1.0].The distribution of H_(hm)/H_(e) conforms to the normal distribution function.The sample mean value of the fitting function is 0.71 and the standard deviation is 0.12.Determine the probability distribution characteristics of the maximum horizontal displacement and the maximum horizontal displacement position of the retaining wall.
作者
董凯
孔恒
郭飞
张旭
徐煌华
DONG Kai;KONG Heng;GUO Fei;ZHANG Xu;XU Huang-hua(Beijing Municipal Construction Group Co., Ltd., Beijing 100048, China;School of Civil Engineering, Inner Mongolia University of Science and Technology, Baotou 014010, China)
出处
《科学技术与工程》
北大核心
2022年第2期683-691,共9页
Science Technology and Engineering
基金
国家自然科学基金(51868062)
内蒙古自治区自然科学基金(2019LH05007,2020BS05031)。
关键词
北京地铁
宽基坑
围护结构
水平变形
概率分布
Beijing subway
wide foundation pit
retaining structure
horizontal deformation
probability distribution
