双线盾构施工管隧平行或相交时地下管线的安全判别

Safety Assessment of Underground Pipelines when Parallel to or Cross Tunnel during Shield Tunneling

为保护地下管线在盾构施工时的安全,研究双线盾构隧道施工时,邻近地下管线与隧道平行、相交工况下管线的安全性判别方法,将不易监测的管线状态转化为可见的地表沉降。管隧平行时,根据偏离系数建立管线与地表沉降关系式;管隧相交时,建立相应计算模型,提出管线与横轴的夹角、管线与横轴交点到纵轴的距离等参数,建立管线与地表沉降关系式。考虑管线连接方式,将管线分为连续管线与非连续管线,分别推导管线和隧道平行、相交时,连续管线的应变与地表沉降关系式和非连续管线的转角与地表沉降关系式。将预测值与实测值进行对比,研究结果表明:此方法具有可靠性;施工前可采用此方法对管线安全进行预测,避免事故发生。

The pipeline monitoring can not be easily carried out when the pipelines parallel to double-line shield tunnelor cross the tunnel during shield tunneling. As a result, the visible ground surface settlement monitoring is regarded asthe safety assessment factor for the shield tunneling safety. When the pipelines parallel to the tunnel, the relationalexpression between pipeline and ground surface settlement is established according to the deviation coefficient; when thepipelines cross the tunnel, the calculation model is established, and the angle between the pipelines and the horizontalaxis and the distance between the intersection of pipeline and horizontal axis and the longitudinal axis are put forward,and the relational expression between pipeline and ground surface settlement is established. The pipelines are dividedinto continuous pipelines and discontinuous ones considering connecting modes of pipelines; the relational expressionsbetween the strain of continuous pipelines and the ground surface settlement and that between the corner of discontinuouspipelines and the ground surface settlement are deduced respectively when the pipelines parallel to or cross the tunnel.Finally, comparison is made between predicted values and monitored data, and the results show that the above-mentioned safety assessment method is feasible and can be carried out before shield tunneling.