连拱隧道浅埋偏压段的受力和变形机制研究

 以安景高速双河口隧道为工程背景，针对连拱隧道洞口浅埋偏压段特殊的地形情况，探讨围岩在地应力和边坡滑动共同影响下的应力分布情况。为满足工程应用的需要，在监测数据分析的问题上提出对监测数据进行非线性分离的方法，并以其中的线性趋势项为依据建立围岩的应力与变形之间的映射关系，来指导隧道设计和施工，用分离出来的波动项来分析施工过程中出现的异常情况。结果表明：连拱隧道洞口浅埋偏压段受到上覆荷载和边坡滑动的共同作用，其中最危滑动面和洞口上部坡角处的围岩和支护结构受边坡滑动的剪拉作用影响最为明显，消除施工等因素影响的监测数据趋势项可以更直观地说明这一点，因此在隧道工程中如果穿越岩体最危滑动面附近的围岩时有必要考虑边坡滑动的影响。

RESEARCH ON STRESS AND DEFORMATION MECHANISMS OF SHALLOW SECTION WITH UNSYMMETRICAL LOADING OF MULTI-ARCH TUNNEL

Taking Shuanghekou tunnel of Anjing expressway as engineering background，focused on the shallow section with unsymmetrical loading of multi-arch tunnel，the stress distribution of wall-rock is discussed under the combined effect of geostress and slope sliding. In order to meet the need of practice，a nonlinear method has been proposed to decompose the monitoring data；and the function between the stress and the deformation of wall-rock is established. At the same time，the remaining fluctuations is used to analyze the abnormal phenomenon in construction. The results show that when the shallow section with unsymmetrical loading of multi-arch tunnel is in the combination action of overlying load and sliding slope，the wall-rock and supporting structure，which are located in the tail of the most dangerous sliding surface，will have the largest deformation under mixed loading of tension and shearing. It is more obviously explained by monitoring data tendency item when eliminating construction and other influencing factor. Thus，the slope sliding must be taken into account when the tunnel goes through the wall-rock close to the most dangerous sliding surface.