摘要
针对新建地铁隧道上穿既有隧道工程,基于新建地铁隧道开挖引起的卸荷附加应力解析解,建立既有地铁隧道结构的弹性地基梁模型,推导得到预测既有地铁隧道结构隆起变形的计算公式;采用该公式对北京地铁4号线西单站隧道上穿既有1号线隧道时引起的既有隧道结构的隆起量进行预测,分析土体基床系数及卸荷参数对既有地铁隧道结构隆起变形的影响。结果表明:计算得到的既有隧道结构隆起曲线形态为单峰,近似服从正态分布;提高地基基床系数可以明显减小既有隧道结构的隆起量;随着卸荷宽度不断增加,既有隧道隆起量不断增加,但当卸荷宽度大于30m时对既有隧道的隆起变形影响甚微;随着双矩形卸荷间距的逐渐增大,既有隧道的隆起曲线分别呈基本符合正态分布的单峰形态、中间为直线段而两侧近似服从正态分布的形态及2条正态分布曲线叠加的双峰形态。
In view of the project of newly-built metro tunnel upcrossing the existing tunnel, and based on the analytical solution to the unloading additional stress induced by the excavation of the newly-built metro tunnel, the elastic foundation beam model of the existing tunnel structure was established and the expres- sion for predicting the upheaval deformation of the existing tunnel structure was obtained. The expression was applied to predict the upheaval deformation of the tunnel structure of the existing Metro Line 1 in Bei- jing induced by the upcrossing project of Xidan Station of Metro Line 4. The influence of soil foundation coefficient and unloading parameter on the upheaval deformation of the existing metro tunnel structure was analyzed. The results show that the shape of the calculated upheaval deformation curve of the existing tunnel structure exhibits single peak and follows approximately normal distribution. The upheaval deform- ation can be reduced obviously by improving soil foundation coefficient. The upheaval deformation of the existing tunnel increases continuously with the continuous increase of the unloading width. But it has little effect on the upheaval deformation when the unloading width is greater than 30 m. The upheaval curves of the existing tunnel show different shapes with the gradual increase in the distance between the double un- loading rectangles, namely, single peak pattern follows basically normal distribution, the intermediate sec- tion is straight line and two sides are similar to normal distribution, and double peak pattern follows ap- proximately normal distribution due to the superposition of two curves.
出处
《中国铁道科学》
EI
CAS
CSCD
北大核心
2014年第6期48-54,共7页
China Railway Science
基金
内蒙古自然科学基金资助项目(2012MS0713)
内蒙古科技大学创新基金资助项目(2011NCL006)
关键词
弹性地基梁理论
地铁上穿工程
既有隧道
卸荷附加应力
隆起变形
Elastic foundation beam theory
Upcrossing project of metro
Existing tunnel
Unloading ad-ditional stress
Upheaval deformation
