盾构隧道下穿铁路股道及火车站站房的影响分析

Influence Analysis of Subway Shield Tunneling on Existing Track and Railway Station Building

通过对南宁地铁1、2号线盾构隧道下穿铁路股道及火车站站房现场的调查、了解,依据各自的环境条件分别建立二维、三维数值模型,选取适当的单元类型进行模拟计算。发现采用洞内注浆加固配合地面加固的方式可使股道最大沉降减小18.9 mm,且使沉降槽缩小60 m。对火车站站房下的隧道采用洞内加固可保证影响区范围内的最大桩基沉降差约4.5 mm,远小于过规范规定的允许值。这就确保了盾构隧道下穿南宁火车站站房及铁路股道的安全,为今后类似工程的数值模拟分析提供经验。

Through the research and analysis of field investigation for shield tunnel of Nanning Metro Line #1 and#2 which are underneath track and train station, based on two-dimensional and three-dimensional numerical mod-els established under each corresponding environmental condition and stimulations of appropriate unit type, thisstudy finds out that the usage of both inside grouting reinforcement and the outside ground reinforcement can helpto reduce the maximum track settlement by 18.9 mm and the settling tank by 60 m. The maximum differential set-tlement of pile foundation can be controlled in scope of 4.5 mm for affected area by using grouting reinforcement tobuild the tunnel which is underneath the train station. It is far less than the permissible value required by regula-tions. It ensures the safety of shield tunnel passing through under Nanning train station and train track. Moreover,it provides valuable experience for numerical simulation of similar projects in the future.