钢圆筒围堰变形及应力试验研究

发布时间：2018-05-31 08:26

本文选题：钢圆筒 + 围堰施工　；参考：《天津大学》2015年硕士论文

【摘要】：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。
[Abstract]:Deepwater foundation engineering has become a key factor restricting the development of modern bridge construction technology. The construction of steel box cofferdam has been widely used and developed because of its many advantages such as waterproofing and good integrity. However, due to the limitation of construction technology, the steel box cofferdam has the disadvantages of complicated jointing and dismantling process and long construction period. Especially for large projects such as sea crossing bridges, the number of piers that need cofferdam construction is large, which can easily lead to the extension of the construction period and the increase of the number of cofferdams, resulting in a great increase in construction costs. With the development of construction technology and the successful application of vibratory hammer, the steel cylinder structure can be set up and pulled out in a short time. Using large diameter steel cylinder as cofferdam can save the jointing and dismantling of traditional steel box cofferdam, shorten the construction time, increase the turnover times of steel cylinder, and reduce the consumption of steel structure. The construction technology of steel cylinder cofferdam has been widely used in a project, and good economic benefits have been obtained. Based on the project, the feasibility of vibration sinking of steel cylinder structure and the stress of steel cylinder cofferdam are studied. The steel cylinder cofferdam needs to bear the load caused by vibration hammer and the action of water pressure and earth pressure during construction. On the basis of summing up the calculation method of vibration subsidence of steel pipe pile, a method for calculating vibration subsidence of steel cylinder is presented in this paper. Under the condition that the theory is not perfect at present, many kinds of empirical formulas are needed to analyze the feasibility of vibration subsidence of steel cylinder. At the same time, it is considered that accurately obtaining the ultimate static soil resistance of the steel cylinder is also the key factor for the feasibility analysis of the vibration subsidence of the steel cylinder. The stress monitoring and analysis of the steel cylinder cofferdam bracing structure are also carried out, and the stress state of the steel cylinder cofferdam inner bracing structure is obtained by testing. The finite element model is used to calculate and analyze the stress state of steel cylinder cofferdam under the action of flow force. The results show that the deformation of steel cylinder braced steel tube is the largest, and the deformation of steel tube decreases gradually with the increase of depth. The stress analysis results of steel cylinder wall and steel cylinder inner braced steel pipe are also obtained.
【学位授予单位】：天津大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U445.556

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