Research On Vibration Response Analysis And Control Technology Of High-rise Building Next To Subway Tunnels

With the gradual encryption of the subway network,there are more and more buildings along the subway tunnel.It is not uncommon for the buildings next to subway tunnels to exceed the standard.Understanding the vibration propagation law of adjacent buildings caused by subway operation and adopting effective vibration control measures are of great significance for building green subway and promoting urban prosperity.The impact of the subway environment vibration must be fully considered.Therefore,a high-rise building in the Beijing area close to the subway tunnel is taken as the research object.Based on the finite element and wheel-rail coupling dynamics theory,combined with the on-site vibration test,the vibration propagation law and vibration control technology of the adjacent subway tunnel buildings are studied.The content and conclusions are as follows:(1)Summarized the research status of the vibration problems of adjaeent buildings caused by train operation in subway tunnels at home and abroad.Explained the evaluation index and standard of building vibration.The specification standards and evaluation procedures used were determined.(2)A full-section vibration test was carried out on a high-rise building of a nearby subway tunnel in Beijing.The test found that the main vibration energy distribution band in the central position of the house is wider than the corner;the vertical vibration acceleration level of the house is 1.2dB?5dB larger than the comer.The vibration energy of each floor is mainly distributed at 40Hz?80Hz.The vibration of the building does not change monotonously with the change of the floor,but there is a certain fluctuation,which has no obvious relationship with the height of the floor.The maximum vibration level of each floor is within 40Hz?63Hz,which is about 62dB?74.4dB.The vertical vibration level of each floor is significantly larger than the transverse vibration level.(3)Based on the establishment of the wheel-rail coupled dynamics model to obtain the wheel-rail force,a finite element model of orbit-tunnel-soil-building is established.Using the wheel-rail force as the excitation input,the vibration response of the building caused by the subway operation is calculated,and the correctness of the model is verified by comparison with the measured data.(4)Based on the finite element model,the influence of parameters such as tunnel depth,distance between building and tunnel,floor thickness and number of building layers on building vibration is analyzed.Compared with the buried depth of 4.2m tunnel,the maximum Z vibration level in the building is reduced by 7.3dB?11.9dB when the buried depth is 25m.When the tunnel depth is 10m,the ground surface has a vibration amplification area within the range of 18m?25m from the center of the tunnel.When the building is located in the amplification area,the vibration level of each floor increases by 1dB?3dB.Compared with the thickness of 0.15m floor,the maximum Z vibration level in the building is reduced by 2.2dB-8.2dB when the thickness is 0.3m.Buildings with different floors have vibration amplification on the top floor.As the number of floors increases,the overall vibration level of the building decreases,but the phenomenon of several vibration peaks and valleys appearing in the building floor becomes more and more obvious.(5)The finite element model is used to study the vibration reduction effect of continuous barrier and building foundation vibration reduction.The depth of the hollow trench exceeds the depth of the bottom of the tunnel to have a good dancing effect,and the width has little effect on the effect.When the barrier depth reaches the tunnel floor,the vibration reduction effect of the empty trench is the best,and the vibration reduction effect of the foam filled trench in most floors is better than that of the lightweight aggregate concrete filled trench.Building foundation vibration reduction measures did not affect the main frequency range of building vibration.The attenuation amplitude of different floors is between 15.7dB and 19.9dB,and the damping percentage is between 22% and 28.5%.