钢圆筒围堰变形及应力试验研究-水利工程专业论文.docxVIP

摘 要 万方数据 深水基础工程已经成为制约当代桥梁施工技术发展的关键因素，钢套箱围 堰施工由于具备防水性及整体性好等诸多优点，得到了广泛的应用和发展。但 是由于施工技术的限制,使得钢套箱围堰具有拼接以及拆除过程较为复杂，工期 较长的缺点。特别是跨海大桥等大型项目，需要采用围堰施工的桥墩数量多， 很容易造成工期延长以及围堰数量的增加，造成施工成本大大增长。 随着施工技术的进步，振动锤组的应用成功，使得钢圆筒结构能够在较短 的时间内完成打设、拔除作业。采用大直径钢圆筒作为围堰可省去传统钢套箱 围堰的拼接拆除工作，大大缩短施工时间，同时使钢圆筒的周转次数得到增加， 降低了钢结构的的消耗量。钢圆筒围堰施工工艺在某工程中得到了广泛应用， 并取得了良好的经济效益。本课题以该工程为依托展开了钢圆筒结构振动下沉 可行性及钢圆筒围堰结构应力的试验研究。 钢圆筒围堰需要承受打设、拔除期间振动锤产生的荷载，施工期需承受水 压力及土压力的作用。本文在归纳汇总钢管桩振动下沉计算方法的基础上提出 了钢圆筒振动下沉计算方法。并认为在目前理论尚不完善的情况下，需要采用 多种经验公式对钢圆筒振动下沉可行性进行分析，同时认为准确获得钢圆筒所 承受的极限静土阻力也是进行钢圆筒振动下沉可行性分析的关键因素。本文还 对钢圆筒围堰支撑结构进行了应力监测及分析，通过测试得到了钢圆筒围堰内 部支撑结构的应力状态。并利用有限元模型对钢圆筒围堰在水流力作用下的受 力状态进行计算分析，得到钢圆筒支撑钢管首层的变形最大，随着深度的增加， 支撑钢管的变形逐渐减小，还得到了钢圆筒筒壁和钢圆筒内支撑钢管的应力分 析结果。 关键词：钢圆筒；围堰施工；振动下沉；有限元；应力状态 Abstract Deep foundation engineering has proved to be the key factor which imposes restrictions on the development of the modern bridge construction technology. The construction of steel boxed cofferdam, with numerous advantages such as waterproof and integral function, has been widely applied and developed. However, due to the limitation of construction technology, the steel boxed cofferdam has some defects including a complicated process of splicing and dismantling as well as a long project schedule. In particular, some large projects such as cross-sea bridges require a large number of bridge pier cofferdam construction, it tends to cause the extension of schedule and the increasing number of cofferdam construction, which result in an increasing cost of the project. With the progress of construction technology and the application of vibratory hammer group success, the setting and urethral operation of steel cylinder structure can be completed in a relatively short period. On behalf of the traditional steel boxed cofferdam, application of the large diameter steel cylinders will remit the process of splicing and dismantling. It will greatly shorten the construction time, accelerating the turning frequency of the steel cylinder and decreasing the consumption of