Experimental Study On The Stress And Deformation Of Steel Cylinder

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 steel structure. The technology of steel cylinder cofferdam has been widely applied in some projects and makes considerable economic benefits. Based on the project, this paper launched an experimental research on the feasibility of a steel cylinder structure vibration sinking and the study of steel cylinder cofferdam structure stress.The cofferdam of steel cylinder needs to bear the load of vibrating hammer in the process of driving and removing; in addition, the water pressure and earth pressure should also be taken into consideration. Basing on the calculating methodology of steel pipe pile vibration subsidence, this paper will propose the calculating methodology of steel cylinder vibration subsidence. Moreover, due to the limitation of the current theory, a variety of empirical formula should be employed to analyze the feasibility of steel cylinder vibration sinking. Meanwhile, it is supposed that the resistance of a steel cylinder on the earth should also be attached great importance in analyzing the feasibility of the static steel cylinder vibration sinking. This paper also intends to monitor and analyze the supporting structure of steel cylinder cofferdam; the stress state of the internal support structure is investigated through measurement. Additionally, with the application of the finite element model, the stress of the steel cylinder cofferdam is investigated under the action of water flow force. On the basis of the above research, the conclusion can be drawn that the first layer of the steel cylinder which supports steel tube deformed with the largest ratio, the deformation of the supporting steel tube decreases gradually with increasing depth. What's more, the stress analysis of the steel cylinder wall and the supportive steel pipe of cylinder are conducted.