引青济秦降云顶隧洞不良地质段的处理措施

Treatment Measure for Bad Geological Section of Jiangyunding Tunnel in Qing-qin Water Transfer Project

引青济秦东西线对接工程降云顶隧洞全长3.487 km,于2006年8月3日开工,至2007年10月14日全线贯通,历时15个月。隧洞洞身穿越硬质安山岩、安山角砾岩、灰岩及石英砂岩,遇到了断层破碎带、泥化火成岩段、软弱夹层段3种类型9处不良地质段,采取了超前钻探、超前支护、短进尺、弱爆破、早封闭等手段,及时加强支护,严格进行变形监测,采用钢格栅跟进外加混凝土喷层的加强支护,后期按Ⅳ类围岩进行了混凝土全断面衬砌,结构内、外层环向钢筋由原来的16@20 cm调整为18@15 cm。混凝土衬砌完成后,对该洞段进行了回填和固结灌浆。通过以上处理措施,确保了围岩稳定和工程安全及施工安全,取得了良好效果,工程运行以来未发现任何异常。

Full length of Jiangyunding Tunnel which connects east line and west line of Qing-qin water transfer project is 3.487 km,the construction begun on August 3rd,2006,the transfixion of the whole line is on October 14th,2007,which lasts for fifteen months.The tunnel passes through hard andesite,andesitic breccia,limestone and quartz sandstone,there are 9 bad geological sections including shattered fault zone,mudding igneous segment and weak intercalated layer,treatment measures such as advance exploratory drilling,advanced support,short footage,weak blast etc have been carried out,deformation monitoring has been done also.Steel grid and concrete spray layer were adopt,full-section lining of concrete is used by the standard of Ⅳsurrounding rock,steel bars have been converted 16@20 cm into 18@15 cm.Backfilling and consolidation grouting are used after concrete lining.The treatment measures ensure the stability of surrounding rock and the safety of engineering and construction,and up until now no abnormal conditions have been discovered.