南京地铁稳定性优势面理论分析

以南京地铁为例,运用优势面理论分析方法,对控制城市浅埋隧道稳定性的优势断裂进行了分析。并对土体中具有规模效应的构筑物的稳定性分析发展了一套工程地质层组划分和优势层判定的分析方法。通过对南京地铁场区优势断裂和优势层的分析。确定南京－湖熟断裂和定淮门－彭楼断裂为控制场址区工程地基稳定性的场区优势断裂,并控制着鼓楼岗和小红山地铁隧道的稳定性;地铁隧道在土层中最佳持力层为O3的硬粘土层Ⅲ1,其次为Q3的软粘土层Ⅲ2。敏感层为Q3的软粘土层Ⅱ2和饱和松砂层Ⅱ4,在保证工程的稳定性和经济的可行性情况下,地铁隧道的底部标高以－5－－15m为宜。

Stability Analysis of Subway in Nanjing Using Preferred Plane Theory

Using preferred plane theory,this paper developed a new analytical method for the preferred planes which control the urban shallow tunnel stability,taking the subway in Nanjing as an example.The new analytical method categorizes the soils into different layers and determines the preferred layers for the stability analysis of buildings in the soils.The results of the study on Nanjing subway are：① the regional preferred faults of Nanjing are Nanjing-Shuhu fault and Dinghuaimen-Gulou fault which control the tunnels stability in Gulou and Xiaohongshan;②the most favorable and mechanically stable layer for Nanjing subway is Tertiary hard clay layer(Ⅲ1), the next is the Tertiary soft clay layer(III2);the most unfavorable layer for subway is Quaternary soft clay layer(II2)and loose layer(II4);③the elevation of bottom of Nanjing subway tunnels is suggested to be at -5 ~-15m..