Research On Vibration Reduction Performance Of Underground Space With Steel Spring Floating Slab Structure Under Moving Load

With the rapid development of urban transportation,urban complexes have begun to emerge,and multi-functional complexes in which municipal roads and buildings are closely connected have been developed.Vehicle loads in the city directly act on the buildings,and the vibrations generated inside the buildings are widely concerned.The steel spring floating plate vibration damping system is widely used in the field of rail transportation,with a mature design and construction system,but the research and application in the field of urban municipal transportation is still in its infancy.This paper relies on the demonstration project of the steel spring floating plate vibration damping road above the underground space of the Panyu Wanbo Business Center in Guangzhou City,which is the first domestic application of steel spring floating plates to the field of municipal transportation.At the meantime,a series of studies have been conducted on the vibration performance of the vibration road and the underground space.The main research contents are as follows:(1)According to the actual engineering parameters,three-dimensional finite element models of steel spring floating plates,underground spaces and the overall structure were designed,and modal analysis was carried out separately to obtain the natural frequencies and vibration modes of the three structures.The results show that the fundamental frequency of the steel spring floating plate is 8.033 Hz,the fundamental frequency of the underground space is 19.493 Hz,and the fundamental frequency of the overall structure is 10.223 Hz.The steel spring floating plate can reduce the fundamental frequency of underground space.From the vibration pattern diagram,the first five-stage overall structure vibration mainly occurs in the steel spring floating plate vibration-damped road section,the vibration shape is similar to the steel spring floating plate model,and the sixth-order overall structure vibration mainly occurs in the underground space,the shape of the roof is similar to the underground space.(2)A dynamic analysis of the vehicle load model was carried out,extracted the acceleration responses of three key reference points and subjected to frequency spectrum analysis and octave analysis to study the vertical propagation of vibration in the model.Among them,the maximum reduction of vibration insertion loss is 53.67 d B,and the maximum reduction range is 93%;the maximum transmission loss of the acceleration stage is 35.65 d B,and the maximum reduction range is 90.84%.(3)A live sports car vibration test was conducted above the underground space of Wanbo Business Center to obtain the measured acceleration response of the reference point of the corresponding key part of the structure and pass the frequency spectrum analysis.Besides,the vibration effect of moving load on the underground space structure of the steel spring floating plate was evaluated by the Z vibration level and the A sound level.The results show that the vibration attenuation of the steel spring floating plate to the moving load reached 35.27% and 19.07%.Both of them meet the limit requirements.(4)Comparing the numerical simulation and the field measurement of the vibration damping effect of the steel spring floating plate by from insertion loss and vibration acceleration level transmission loss.It is found that the overall simulated value is slightly smaller and more stable than the measured value.The error is large at low frequencies,but the gap narrows as the frequency increases;by comparing the Z vibration level and the A sound level of the two,the effect of numerical simulation and field measured vehicle moving load on the vibration of the underground space after the installation of steel spring floating plates was evaluated it shows that both of them meet the limit requirements.