鹫峰山一号隧道衬砌环向施工缝破损防治技术

PREVENTION AND CONTROL TECHNOLOGY FOR DAMAGE OF LINING CIRCUMFERENTIAL CONSTRUCTION JOINT OF JIUFENGSHAN NO.1 TUNNEL

衢宁铁路(福建段)鹫峰山一号隧道为单洞单线特长隧道,受斜井选址条件影响,洞内独头掘进距离长,运输组织难度大,施工任务重,工期紧。为了减少隧道衬砌环向施工缝破损,确保隧道衬砌施工质量,分别从衬砌台车挤压、环向止水带切割混凝土、施工冷缝、止水带背后脱空等方面,对衬砌环向施工缝破损产生原因进行深入分析,通过采取台车端头软搭接、钢端模固定止水带、运用先进的混凝土浇筑工艺、施工缝V形槽等措施,有效预防了衬砌环向施工缝破损。根据施工缝环向裂缝位置、大小、有无渗漏水情况,采取相应整治方案,提出优化设计的合理化建议。

Jiufengshan No.1 tunnel of Quzhou-Ningde Railway(Fujian section)is a single tunnel,single track and extra long tunnel.Affected by the site selection conditions of inclined shaft,the single head excavation distance in the tunnel is long,the transportation organization is difficult,the construction task is heavy,and the construction period is tight.In order to reduce the damage of tunnel lining circumferential construction joint and ensure the construction quality of tunnel lining,this paper deeply analyzed the causes of the damage of lining circumferential construction joint from the aspects of lining trolley extrusion,waterstop cutting concrete,circumferential cold joint,waterstop void,and so on.The damage of lining circumferential construction joint was effectively prevented by taking measures such as soft lap at trolley end,fixing waterstop belt with steel end formwork,using advanced concrete pouring technology and V-shaped groove of construction joint.According to the location and size of circumferential cracks of construction joint and whether there is water leakage,corresponding treatment schemes are adopted,and reasonable suggestions for optimal design are put forward.