Nonlinear Finite Element Analysis Of Box Shaped Inverted Siphon In South To North Water Diversion Project

The south-to-north water diversion project catches attention of the universal because it is another super construction benefited to all of the people after the Three Gorges hydroelectric power station.The south-to-north water diversion project is now completed and enable the operation,which not only effectively alleviates the pressure of the lack of water resource in north China and benefits the local people along the way,but also is the scenery line of China from the south to the north.As a kind of three-dimensional and crossing water diversion project,large inverted siphon structure is widely used in the south-to-north water diversion project which is mainly existed in the type of channel,river inverted siphon.Some are still buried in a certain depth to ensure that it can operate safely when encountering dynamic load and accidental load in the future,which is related to the national stability.Inverted siphon is made of several kinds of composite concrete.Therefore,it is meaningful to simulate the nonlinear finite element analysis of inverted siphon box structure,so that it can ensure the stability and safety of the structure.Inverted siphon is a thin-walled water diversion project structure and the majority are buried in the ground,which has a extinguishing difference from other materials in material nonlinearity if we consider the loads of other construction.The Inverted siphon is relatively easier to produce larger internal force,deformation and form unbalanced moment and different degrees of cracks,so as to threaten the stability of inverted siphon structure,greatly increases the bearing of the structure,shorten the service life and reduce the durability.The paper establish a monolithic steel concrete model using functional analysis software ANSYS,under the background of inverted siphon structure of the middle route of south-to-north water diversion project.There are 5 possible working conditions of the channel and 2 working conditions of the surrounding soil needed to analysis by building model.When analyzing the structure of the pipe body,the upper soil is simplified to uniformly distributed loading on the structure roof to discuss the stress and deformation of the pipe and the surrounding soil according to the nonlinear theory.The main contents and conclusions of this paper are as follows:(1)Introduce the basic theory of finite element,the constitutive model and failure criterion of reinforced concrete and the treatment of reinforcing steel bar while building the model in the finite analysis.(2)According to the condition of the pipe and the achievements,five kinds of operating condition are getting from the research.Maximum tensile value and compressive resistance value of each part of the pipe structure is within the range of specification requests.The position and the the size of the crack of the pipe structure is available giving you a feasible suggestions to avoid the crack appearance.Getting that the most unfavorable condition of the structure appears during the completing working condition and maintenance working condition(side hole maintenance,middle hole maintenance).(3)The results of the modified scheme and the analysis results of the original design scheme have obtained that the span too large is unfavorable to the structure stability,the structure produces greater tensile stress,the chamfering produces larger compressive stress,and the cracks in the multi region make the structure produce vertical cracks in multiple regions,and the depth of the cracks increases.Therefore,this kind of situation should be avoided when designing the plan,so as to avoid large span and large load.