特殊条件下复合钢围堰施工技术研究

Research on Construction Technology of Composite Steel Cofferdam under Special Conditions

在已有研究基础上,针对钢板桩应用广泛但刚度较低、锁扣钢管桩刚度高但经济性差及止水难度大的特点,结合工程实例,针对围堰结构距水管过近、承台基坑较深且面积较大、河床地质结构复杂等特殊条件,对施工方案进行优化研究,创新性提出了钢管桩、钢板桩组合“8”字形围堰施工的技术。采用围堰钢管桩精确定位方法,开创性解决了围堰锁扣钢管桩间距控制难度大的问题;锁口内采用50%石粉+25%腻子粉+20%锯末+5%水泥的集配材料进行拌和填充,成功解决了钢管桩渗水问题;采用钢管桩、钢板桩接合“8”字型围堰的设计,大幅节省了钢管桩用量且克服了小间距承台围堰结构打架的难题,极大地提升了经济性与施工便捷性。该技术在东晓南路-广州南站连接线南段某工程中得到成功应用,各项指标合格率均为100%,取得了良好的经济效益,具有较好的推广与应用价值。

On the basis of existing research,in response to the widespread application of steel sheet piles with low stiffness,the high stiffness but poor economic efficiency of locking steel pipe piles,and the difficulty of water sealing,combined with engineering examples,the construction plan was optimized and studied for special conditions such as the cofferdam structure being too close to the water pipe,the foundation pit of the pier being deep and large in area,and the complex geological structure of the riverbed.Innovatively proposed the construction technology of a combination of steel pipe piles and steel plate piles for an"8"-shaped cofferdam.The use of precise positioning method for cofferdam steel pipe piles has innovatively solved the problem of difficulty in controlling the spacing between cofferdam lock buckle steel pipe piles;The lock mouth was filled with a mixture of 50%stone powder,25%putty powder,20%sawdust,and 5%cement,successfully solving the problem of water seepage in steel pipe piles;The design of using steel pipe piles and steel plate piles to join the"8"shaped cofferdam greatly saves the amount of steel pipe piles and overcomes the problem of small spacing cap cofferdam structure construction,greatly improving the economy and construction convenience.This technology has been successfully applied in a project of the southern section of the Dongxiaonan Road-Guangzhou South Station connection line,with a qualification rate of 100%for all indicators,achieving good economic benefits having good promotion and application value.