Research On Vibration Reduction By Sheet Piles For Waterworks Vibrations Generated By Elevated Railway

With the completing of a large number of high-speed railways in China,attentions have been attracted to the environmental vibration pollutions caused by the high speed train.Because of the longer path and a number of influence factors,the environmental vibration caused by the high speed train is more complex than the conventional high-speed railways on the ground.A numerical model is established for the coupled vibrations of the train,the track and the viaduct.Then the dynamic loads(forces and moments)on the pile caps of the pile foundations are obtained analytically.In what follows,a computational model is set up in ABAQUS to model the coupled vibrations of the pile foundations,the ground,the anti-vibration sheet pile and waterworks.Inputting of the dynamic loads on the pile caps to the computational model,comparisons on the vibration on the pile caps to the computational model are made.And comparisons on the vibration reduction effects are made for different designing parameters of the sheet piles,basing on which the most effective arrangement for the anti-vibration sheet pile has been suggested so that the vibration level for the waterworks is acceptable.The following works are done:1.A numerical model is established in ABAQUS for the vibrations of the foundations to analysis the parameters which influence the absorption of infinite element boundary.The parameters consist of grid size,time steps and the way of loading.Then the effect of infinite element boundary is tested in the model established for the coupled vibrations of the pile foundations,the ground.2.A numerical model is established in ABAQUS for the coupled vibrations of the pile foundations,the anti-vibration sheet pile and the ground.The boundary of the model is infinite element boundary.The model is used to analysis the effect of vibration reduction influenced by the length of piles and the space of piles.3.A numerical model is established for the coupled vibrations of the train,the track and the viaduct to simulate the actual engineering.The model is used in the way that using the periodic structure theory to analyze the dynamic response of track and bridge under the excitation of the load made by train.Then the dynamic loads transmited by the bridge pier are calculated.The dynamic loads include the horizontal,vertical and bending force.4.Based on the study above,a computational model is set up in ABAQUS to model the coupled vibrations of the pile foundations,the ground,the anti-vibration sheet pile and waterworks.After inputting of the dynamic loads on the pile caps to gain the vibration velocity response of waterworks in the model,comparisons on the vibration reduction effects are made.