上中隔壁下双侧壁预锚锭工法在清华园隧道上穿地铁15号线中的应用

为研究新建隧道近距离上穿对既有地铁隧道的变形影响,以京张高铁清华园隧道上穿北京地铁15号线区间隧道为工程背景,提出一种新的施工方法:上中隔壁下双侧壁预锚锭工法,并采用数值模拟和现场实测进行验证,分析隧道施工过程中既有地铁隧道的变形规律。研究结果表明:(1)在侧导洞扩大基础内增加预应力锚索可以有效控制15号线的上浮;(2)上中隔壁下双侧壁预锚锭工法能够保证地铁15号线的安全运营。

Application of Center Diaphragm in Upper Part + Double Side Heading in Lower Part + Prestressed Anchor Cable Construction Method in Qinghuayuan Tunnel Crossing over Metro Line No. 15

In order to study the effect of new tunnel crossing over the existing subway tunnel on the deformation of the latter tunnel,based on the Tsinghuayuan Tunnel of Beijing-Zhangjiakou High-speed Railway crossing over Beijing Metro Line No.15,a new construction method which is named the center diaphragm in upper part+double side heading in lower part+prestressed anchor cable construction method is proposed.Numerical simulation and field measurement are used for verification,and the deformation law of existing subway tunnels during newly-built tunnel construction is obtained.The results show that:(1)adding pre-stressed anchor cable on the basis of enlarging side heading can effectively control the floatation of Line No.15;(2)the center diaphragm in upper part+double side heading in lower part+prestressed anchor cable construction method can ensure the safe operation of Metro Line No.15 in the construction process,and it has been successfully applied in Tsinghuayuan Tunnel crossing over Line No.15 at a short distance.