高原长大公路隧道通风竖井衬砌及中隔墙施工技术

Construction Technology for Lining and Separation Wall of Ventilation Shaft of Long Highway Tunnel on High Plateau

兰临高速公路新七道梁隧道通风竖井深171.16m、井筒净直径6m,采用分段整环、自井底向井口现浇的方式施工竖井衬砌,在竖井衬砌完毕后由井底向井口方向一次性施工中隔墙,施工工序单一,施工干扰小,减少了混凝土施工缝,井身围岩渗水量小。施工方案与边掘边砌相比,效果显著,可为类似工程提供借鉴和参考。

The ventilation shaft of New Qidaoliang Tunnel on Lanzhou-Lintao expressway is 171.16 m deep and the clearance diameter of the ventilation shaft is 6 m.The lining of the ventilation shaft is constructed with in-situ-cast concrete rings installed step by step from the shaft bottom toward the shaft head.The separation wall of the ventilation shaft is constructed once-for-all from the shaft bottom toward the shaft head when the lining construction of the shaft is completed.Compared to the construction method of immediate lining during shaft excavation, the above construction method has such advantages as simple construction procedure, little construction interference, less concrete joints and little water leakage from the surrounding rock. This construction method can provide reference for similar projects in the future.