富水区大型钢板桩围堰施工技术

结合钢板桩围堰在某铁路桥施工中的应用,针对施工现场河道冲刷层厚、其下有2~3 m厚硬塑状黏土层的特点,为避免河床表面松散粉沙地质层受水流冲刷对施工造成影响,以及节约使用封底混凝土的原则,将钢板桩超长处理,达到围堰内清淤,不进行水下封底,直接抽干围堰内水后,浇筑20 cm厚混凝土垫层就可施工下道工序的目的,加快了工期,节省了资源,保证了质量。

Construction Technology of Large-scale Steel Sheet-Pile Cofferdam in Water-rich Region

This paper was base on an example of steel sheet-pile cofferdam used in the construction of a certain railway bridge. The construction site was characterized by a thick river channel erosion layer which is followed below by a layer of 2 m to 3 m thick hard plastic clay. In order to protect the construction from negative influence caused by water current scouring the loose mealy sand stratum of river bed surface,also in order to save bottom-sealing concrete,the steel sheet piles were made into extra-long ones longer than being designed. As a result,the aim was reached: after dredging within the cofferdam,the water within the cofferdam was able to be directly pumped out without having to do underwater bottom-sealing,only followed by casting a 20 cm thick concrete cushion for the next work procedure. It can be seen that this construction technology has helped to shorten construction time,save resource and ensure construction quality.