盾构隧道施工引起的土体损失率取值及分布研究

Selection and distribution of ground loss ratio induced by shield tunnel construction

收集了杭州市庆春路过江盾构隧道施工引起的地面沉降实测数据,提出了施工阶段地面沉降值的取值办法。结合北京、上海、南京、广州、武汉、天津、深圳地区盾构法隧道施工引起的土体损失率实测值,对71个实测数据进行了统计分析。结果表明:土体损失率分布在0.20%～3.01%,其中95.77%的实测数据分布在0.20%～2.0%,43.66%的实测数据集中在0.5%～1.0%;黏性土地区土体损失率在0.20%～2.0%。土体损失率主要与施工水平、土质条件和隧道轴线埋深有关。随着隧道轴线埋深增大,土体损失率基本呈减小趋势,当埋深大于25 m后该趋势比较明显,两者关系可近似采用幂函数拟合。

The observed data of surface settlement caused by construction of Qingchun Road River-Crossing Tunnel in Hangzhou are collected, and a method to select surface settlement values during the construction stage is put forward. Based on the data of ground loss ratio induced by shield tunnel construction in Beijing, Shanghai, Nanjing, Guangzhou, Wuhan, Tianjin and Shenzhen, seventy-one groups of data are statistically analyzed. The results show that the ground loss ratio ranges from 0.2% to 3.01%. About 95.77% of the ground loss ratio is 0.20%~2.0%, and about 43.66% of the ground loss ratio is 0.5% -1% The ground loss ratio is 0.20%-2.0% for the cohesive soil area. The ground loss ratio is dependent on the construction level, soil properties and buried depth of the tunnel. With the increase of the tunnel buried depth, the ＂ground loss ratio overall decreases, especially when the buried depth is more than 25 m. The relationship between the ground loss ratio and the tunnel buried depth can be approximately expressed by power functions.