隧洞塌方冒顶明挖处理施工技术

Construction Technology for Open-excavation Treatment of Tunnel Collapse and Roof Fall

在隧洞开挖支护过程中,发生塌方冒顶后,以往的处理方法一般都是大管棚注浆,塌方部位回填后采取固结灌浆处理,塌方体清除,扩挖加强支护等方法进行塌方冒顶处理。在向家坝水电站灌区北总干渠邱场分干渠水井坝上3号施工支洞塌方处理过程中,采用了明挖→明拱快速防护→二衬混凝土施工→回填处理的方法进行塌方冒顶处理,很好的处理了塌方段流塑状土体以及排水的问题,施工安全得到保证。该方法适用于浅埋隧洞发生贯穿型塌方冒顶后的处理,且塌方冒顶部位土体含水量较大,具有流动性和塑性。

In the process of tunnel excavation and support,the treatment method for collapse and roof fall is generally pipe shed grouting.Consolidation grouting treatment,removal of collapse body,expanded excavation and reinforced support are adopted to treat collapse and roof fall after backfilling.During the treatment of collapse of No.3 construction branch tunnel on the water well dam of Qiuchang branch channel of the North Main Canal in the irrigation area of Xiangjiaba Hydropower Station,the method of first open excavation,then open arch quick protection,then second lining concrete construction and finally backfilling is adopted for the treatment of collapse and roof fall.The problem of flow plastic soil and drainage in the collapse section has been well handled and the construction safety has been guaranteed.This method is suitable for treatment after penetrating collapse and roof fall of shallow tunnel,and the soil at the top of collapse has large water content,which is fluidity and plasticity.