可回收式长护筒在桥梁深水桩施工中的应用

Application of Recyclable Long Casings in Construction of Deep-Water Piles for Bridges

摘要:

为解决桥梁深水桩基础施工中传统长护筒用钢量大、回收工期长等问题，提出一种新型可回收式长护筒及其施工方案。通过创新设计，采用特殊的连接装置，使长护筒在钻孔灌注桩施工完成后、基坑围堰搭设前能够便捷地回收，省去了传统护筒切割环节。以邵家渡大桥为例，分析其在施工中应用该形式护筒的效果。结果表明：这种护筒显著减少了钢材消耗量（减少30.5%），提高了施工效率，缩短了基坑开挖工期（节省12 d），并在汛期显著降低了阻水率，提升了排洪能力，保障了周边地区的安全。该新型可回收式长护筒在提高施工效率的同时，还具备较高的经济效益与社会价值，具有广泛的推广应用前景。

Abstract:

To address the issues of excessive steel consumption and long recovery periods associated with traditional long casing methods in deep-water pile foundation construction of bridge, a new type of recyclable long casing and its construction scheme are proposed. Through the innovative design and the use of special connection devices, the long casing can be easily recycled after the completion of the bored pile construction and before the erection of the cofferdam for foundation pit, which omit the traditional casing cutting step. Taking the Shaojiadu Bridge as an example, its effect of applying this type of casing in construction is analyzed. The study result shows this type of casing significantly reduces the steel consumption (by 30.5%), improves the construction efficiency, shortens the excavation period of foundation pit (saving 12 d), and notably decreases the water resistance during flood season, which enhances the flood discharge capacity and ensures the safety of the surrounding areas. This new type of recyclable long casing not only improves the construction efficiency, but also offers the considerable economic and social benefits with the wide prospects of promotion and application.