摘要
小角度超浅埋隧道下穿铁路在施工过程中围岩变形及地表沉降对铁路运营安全有重要影响,为了保证隧道施工不影响铁路的正常运营,需对超浅埋隧道施工工法、沉降控制措施及施工安全进行分析研究。结合东胜至鄂尔多斯机场铁路隧道下穿既有包西铁路工程设计实例,运用三维有限元法对超前管棚按一次性打设和分段打设进行模拟计算,论证2种超前支护措施下隧道开挖过程中影响范围、拱顶下沉、地面沉降变化规律,确定最优施工工序及超前支护方案。研究结果表明:在这种小角度超浅埋的条件下,超前管棚一次性打设对土体扰动小,抵抗列车动荷载及对地表沉降控制效果显著,是一种非常有效的支护措施。
During the construction process of the super shallow-buried railway tunnel passing beneath the existing railway by small angle,the surrounding rock deformation and the ground surface settlement may cause a great influence on the safety of railway operation.In order to ensure that the tunnel construction does not affect the normal operation of the railway,it is indispensable to investigate the construction method,settlement control measure and construction safety of the super shallow-buried tunnel.The paper,taking the super shallow-buried railway tunnel of Dongsheng-Ordos' Airport Railway passing underneath the existing Baotou-Xi'an Railway as a design example,using three-dimensional finite element method,simulates and calculates the pipe-roof forepoling,respectively under the two conditions of being erected by wholeness method and by segment method.Further,the paper demonstrates the variation law of the influence range,vault settlement,ground settlement during the process of tunneling with the two kinds of advanced support conditions respectively,confirms the best working procedure and the scheme of advanced support.The study results show that: under the condition of super shallow-buried tunnel with a small-angle,when the pipe-roof is erected by wholeness method,the disturbance on the ground is small,and the effects on controlling train dynamic load and ground settlement are remarkable,so the pipe-roof forepoling is a very effective support measure.
出处
《铁道标准设计》
北大核心
2012年第8期80-82,共3页
Railway Standard Design
关键词
铁路隧道
超浅埋
数值模拟
下穿铁路
沉降控制
railway tunnel
super shallow-buried
numerical simulation
passing beneath railway
settlement control
