摘要
以北京地铁10号线某车站工程为例,采用有限元差分程序FLAC3D建立车站工程的三维数值模型,模拟分析洞桩法施工中隧道围岩位移的发展规律,并提出相应的控制措施。结果表明:地铁车站地表沉降与水平位移具有明显的阶段性;在超前支护与小导洞开挖的施工阶段1,地表沉降占总沉降的比例为36%,围岩塑性区向洞周蔓延并逐渐贯通,可采用合理的超前支护措施加固围岩;在拱部土体开挖与结构施作的施工阶段3,地表沉降占总沉降的比例为49%,并引发多次应力传递途径的转换,可通过缩短开挖进尺或设置横向支撑等措施控制。数值计算与现场监测结果基本吻合,验证了数值模型的正确性。
Taking a station project of Beijing Metro IAne 10 as example, the development laws of tunnel surrounding rock displacement induced by PBA construction method were analyzed using 3D numerical model established by finite element/difference program FLACsD, and the corresponding control measures were put forward. The results show that station surface subsidence and horizontal displacement are obvi- ously periodic. The surface subsidence is 36~ of the total during construction stage one when advance sup- port constructed and small pilot tunnel excavated. The plastic zone of surrounding rock spreads around and gradually through the tunnel, and reasonable advance support should be adopted to strengthen surrounding rock. During construction stage three when arch soil mass excavated and structure constructed, the surface subsidence is 49~ of the total. The transfer path of stress is changed many times, which can be controlled by such measures as shortening excavation footage or setting up lateral support, etc. Numerical calculation agrees well with field monitoring results, which has proved the correctness of the numerical model.
出处
《中国铁道科学》
EI
CAS
CSCD
北大核心
2013年第6期61-65,共5页
China Railway Science
基金
国家杰出青年科学基金资助项目(51108020)
关键词
地铁车站
洞桩法
地表沉降
水平位移
围岩塑性区
Metro station
PBA method
Surface subsidence
Horizontal displacement
Plastic zone of surrounding rock
