浅谈涨壳式预应力锚杆与喷锚组合支护在取水竖井施工的应用

Application of Combined Support of Expansion Shell Prestressed Anchor and Shotcrete Anchor in Water Intake Shaft Construction

一侧高边坡大偏压、另一侧临水及岩层破碎、开挖形状不规则的深基坑施工,存在基坑稳定性控制难、基坑受力变形薄弱、库区渗水等问题。文章探索了在该种不利条件下的一种深基坑支护施工方法,采用预应力注浆锚杆与喷锚支护施工技术结合帷幕注浆施工方法,确保了基坑的受力稳定性及防渗效果。该方法不受场地条件限制,且深基坑开挖和支护同步进行,不需另设桩类支护结构以及内支撑系统,在保障基坑施工安全的前提下大幅降低了施工造价、提高了基坑开挖施工效率。

The construction of deep foundation pit with high slope and large eccentric compression on one side,water on the other side as well as broken rock and irregular excavation shape has some problems,such as difficult control of the stability of foundation pit,weak deformation of the foundation pit and water seepage in the reservoir area.This paper explores a construction method of deep foundation pit support under such unfavorable condition,which uses prestressed grouting anchor and shotcrete anchor support construction technology combined with curtain grouting construction method,to ensure the mechanical stability of the foundation pit and anti-seepage effect.This technology is not limited by the site conditions,and the deep foundation pit excavation and support are carried out simultaneously,without the need to set up another pile supporting structure and internal support system.Under the premise of ensuring the safety of the foundation pit construction,the construction cost is greatly reduced and the construction efficiency of the foundation pit is improved.