Research On Vibration And Sound Response And Vibration Reduction Measures Of Neighboring Buildings Induced By The Shijiazhuang Metro

The metro provides excellent convenience for people’s travel and work,but it also causes lots of vibration and noise problems.The ground vibration and the vibration and noise response of the nearby buildings caused by the metro operation endanger the residents’ physical and mental health,affect people’s normal life,and also have negative impact on the structural safety of buildings.Therefore,in order to better control and solve the vibration and noise problems caused by the metro operation,ensure the physical and mental health of residents along the route,and reduce the impact on the surrounding environment.It is necessary to analyze the characteristics of the vibration and noise response caused by the metro operation,study the mechanism of the metro vibration propagation,and propose reasonable vibration and noise reduction solutions.Following are the main tasks completed in this thesis:(1)This thesis summarizes the existing common vibration control standards and noise control standards in China,collates the common vibration evaluation indexes and noise evaluation indexes,and provide the definition and calculation methods of relevant indexes.(2)By using a joint simulation of finite element software and multi-body dynamics software,create the coupled train-track-flexible substructure model,derive the train moving load.Based on the real engineering specifications of the Shijiazhuang metro,the finite element software was used to create the prediction model for soil and building vibration.The prediction approach for indoor secondary noise was determined to be the formula presented by Kurzweil.To confirm the accuracy of the prediction method,the vibration and noise prediction findings were compared with the actual measurement data.(3)The ground vibration response as well as the vibration and noise response of nearby buildings induced by the metro operation are all studied using the time domain,frequency domain,and one-third octave.The findings indicate that the surface pick-up point’s vibration response is primarily concentrated between 30 and 80 Hz.The middle and high frequency vibration of the floor center pick-up point clearly degrades as the floor rises.The indoor vibration of a frame building is,for the purposes of this article,essentially less than that of a brick and mortar construction.The internal vibration of the building essentially tends to decrease as the distance between it and the tunnel’s center line increases.(4)Different vibration reduction measures are modeled and calculated.The effects of vibration reduction fasteners,steel spring floating plate track,empty trenches,and filled trenches are all examined.For empty trenches,considerations like depth,width,and relative position are examined.For filled trenches,considerations like the impact of polyurethane rigid foam filling material and concrete material are discussed.The findings indicate that the steel spring floating plate track has the best vibration reduction impact and that indoor frequency division may reduce vibration levels to a maximum of 9.34 d B to 15.99 d B.The depth of the hollow trench has a higher influence on the vibration reduction effect,particularly when the depth of the hollow trench equals the depth of the vibration source.Polyurethane rigid foam filling material has a greater impact on vibration reduction than concrete.This thesis evaluates several contributing factors and serves as a guide for creating a program to reduce vibration and noise.