中洞法施工技术

Middle hole construction method

中洞法作为矿山法的一种,具有如下特点:安全性高,灵活性好,可操作性强,机械化程度低,出土效率高,工序间干扰较少等。北京地铁四号线石榴庄隧道工程中采用了中洞法施工技术,工程将中洞法施工划分成13个步骤,遵照“小分块、短台阶、早成环、环套环”的原则,先进行中洞施工,然后两侧洞同步采用正台阶法自上而下分部掘进成环施工,有效地控制了地面沉降,保证了施工安全。

The middle hole construction method as one of the mine construction methods, has many characteristics： high security, good flexibility, easy operation, low mechanized degree, high excavation efficiency and little working procedure disturbed and so on. The middle hole construction technology was used in Shiliuzhuang tunneling of No. 4 metro line of Beijing The middle hole construction method was divided into 13 steps in the project. According to the principle ＂small partition, short step, ringing early, linking ring＂, after the middle cell construction finished, the side cells are excavated and ringed synchronously by the terrace measure from top to bottom. The ground subsidence was effectively controlled and the construction security was guaranteed.