Composite Cushion Of Combination Blocks And Short Piles-rubber Sand Mixture Experimental Study On Seismic Isolation

In recent decades,many earthquakes occurred in our country,the seismic effect of low-rise buildings in township areas is very poor,and the damage is particularly serious.Nowadays,China has developed rapidly in the research and development of shock isolation and their engineering applications.However,the current shock isolation are either expensive or complex in structure,which makes it difficult to be widely used in township areas.Therefore,it is of great practical significance to study low-cost seismic isolation methods.A large number of experts have studied and found that,on the one hand,with the rapid development of the automobile industry,tire discards are increasing,causing environmental pollution,waste of resources and other issues;on the other hand,rubber sand mixture made by mixing rubber particles and sand obtained from mechanical crushing of waste tires has a good energy isolation and shock isolation effect,and has a good research field in improving the performance of potential base shock isolation.Therefore,through shaking table device,this paper carries out experimental research on the vibration isolation effect of composite blocks and short piles.The main contents are as follows:(1)This paper introduces the research background,research status,application status and research significance of rubber sand mixture.(2)When the peak value of input acceleration is less than 8 m/s~2,the isolation effect of 30%rubber sand isolation layer is better than that of50%rubber sand isolation layer;When the peak value of input acceleration is greater than 8m/s~2,the isolation effect of 50%rubber sand isolation layer is better than that of 30%rubber sand isolation layer,but when the peak value of input acceleration is greater than 8m/s~2,the isolation effect of 50%rubber sand isolation layer is better than that of30%rubber sand isolation layer.They are similar.(3)The width and buried depth of the cover plate are systematically studied,and the influence of two different widths and three different buried depths of the cover plate on the vibration isolation performance of the rubber sand mixture and composite block is studied.The research shows that the isolation effect of the damping layer with the cover plate width of 75mm is better than that of the isolation layer with the cover plate width of 115mm;The influence of the cover depth on the isolation effect of the damping layer is greatly affected by the loading frequency.When the loading frequency is 1Hz,the influence of the cover depth on the isolation effect is not obvious.When the loading frequency is 2Hz,the greater the cover depth is,the better the isolation effect is.(4)The shaking table was covered with rubber sand mixture,and the effects of no pile,small pile bedding and small pile staggered on the damping effect of the damping layer were compared.The results show that When the vertical load is 20kN,the shock isolation effect of the shock isolation layer corresponding to the pile-free layer is the best,followed by the short pile laying down,and the short pile staggering is the smallest;when the vertical load is 40kN and 60kN,the shock isolation effect of the short pile laying down is the best,followed by the short pile staggering,and the pile-free layer is the smallest.(5)When the vertical load is 20kN,40kN and 60kN,the isolation effect of large piles is better than that of small piles.With the increase of peak value of input acceleration,the isolation coefficient of the isolation layer under the small pile and the large pile pavement decreases,and the isolation effect of the large pile pavement is better than that of the small pile pavement.(6)This paper summarizes the research results and the deficiencies of the experiment,and makes a prospect for the future research.