黄土地区既有隧道上方新建建筑施工影响分析

针对黄土地区大面积基坑开挖与高层建筑施工对下卧地铁隧道的不利影响,对基坑开挖与高层建筑施工进行了模拟分析,研究表明,大面积基坑开挖引起下卧隧道的隆起变形与内力变化均在可控范围之内,地铁隧道与上部建筑“结构分离”的设计思路是安全可行的,建筑物荷载能够通过转换梁与桩基础形成的转换机制有效地传递到隧道下方的地层深处,同时扩散至隧道的附加荷载在一定程度上是有利的;基坑开挖应遵循先两边后中间的开挖步序,尽量减少基坑中部区域地层应力的释放与坑底隆起,同时还应采取措施尽量减少基坑开挖初始阶段引起的地层扰动。研究结论对后续类似工程具有重要的借鉴意义与参考价值。

Analysis on the Influence of Construction of Buildings on Existing Tunnel below in Loess Area

According to the adverse effect on the metro tunnel of large-scale excavation and high-rise building construction in loess area, a simulation analysis was made of excavation and high-rise buildings construction, Studies have shown that the changes of uplift deformation and inner stress on tunnel caused by large-scale excavation are within the controllable range. So the design idea to structural separation of metro tunnel and upper construction is secure. Thus building loads can be passed to the depths of formation under tunnel inferior effectively through the conversion mechanism formed by transfer beam and pile foundation. Meanwhile, the attached loads that diffuse to the tunnel are favorable to some extent. The release of formation stress at middle regional of foundation pit and bottom heave should be avoided. Simultaneously, we also should take measures to reduce the ground disturbance caused by excavation at its initial stage. The research conclusions have an important reference meaning and value for the subsequent similar projects.