Study On Mechanical Properties Of Rubber-Sand Mixture Cored Isolation Block

In recent years,there are frequent earthquakes in the underdeveloped areas of central and Western China,and the disaster situation in the rural areas is very serious,so it is very important to study the economic and suitable isolation methods.On the other hand,with the development of China’s economy and automobile industry,cars have gradually entered thousands of households,but a large number of waste tires bring a lot of inconvenience to people.Due to the good isolation performance of the mixture of crushed particles and sand,this method can alleviate the pressure of waste rubber tires to a certain extent.In this thesis,through the combination of Rubber-Sand Mixture,hollow block and cover plate,on the premise of the shaking table test of RSMCIB,through the research on the bearing characteristics of RSMCIB,in order to get the data of RSMCIB with reasonable design parameters,lay the foundation for the subsequent application of RSMCIB engineering.The specific research contents are as follows1.The vertical bearing capacity of the RSMCIB which has completed shaking table test by the research group is tested,and its bearing characteristics are obtained.The common cement hollow brick and steel hollow block in the market are selected as the test objects.Combined with 20%,30% and 50% RSM ratio and different size and buried depth of clay brick cover plate,the combined test is carried out,and the different working conditions are obtained through graded loading test According to the load cover plate settlement displacement curve under the condition of load,combined with the test phenomenon,the test rules are summarized for different parameter changes.The analysis shows that the lateral deformation caused by the consolidation of RSM is affected by the size of the upper cover plate,the buried depth and the ratio of RSM.2.The box hollow block,box cover plate and clay brick cover plate are selected to obtain the load cover plate settlement displacement curves of integral cover plate and split cover plate in the box hollow block.Under the conditions of 20%,30% and 50% RSM ratio,different cover plate size and buried depth,the vertical bearing capacity of box cover plate and complete clay brick cover plate is better than that of side-by-side cover plate,At the same time,the ultimate bearing capacity test of the box cover plate is carried out,and the ultimate bearing capacity and failure situation of the box RSMCIB under RSM ratio of 30% and three cover plate buried depths are obtained.3.Through theoretical analysis,the bearing capacity of RSM and the settlement displacement of load cover plate are analyzed,and the influence of small size cover plate on the bearing capacity of RSM is analyzed through the bearing capacity formula of foundation,so as to understand the damage phenomenon of cover plate on RSM core under load;through the combination of compression modulus and elastic modulus of RSM,the influence of small size cover plate on the bearing capacity of RSM is analyzed The settlement of cover plate caused by RSM deformation is analyzed.The load settlement displacement theory of isolation block with rubber sand core under different cover plate size,buried depth and RSM ratio is analyzed.Combined with the theoretical analysis,a practical example is given.Under the condition of selecting cover plate size,RSM ratio and other parameters,the reasonable design height of cover plate is given according to the results of the example.Through the reasonable design of unit size,placement density,rubber sand ratio and other parameters,the bearing capacity of ordinary residential buildings can be satisfied,and good isolation effect can be achieved under the condition of reasonable design.At the same time,the cost of cushion can be controlled through the comprehensive consideration of cushion unit density,unit parameters,isolation effect and other multiple effects.4.Based on the numerical simulation of RSMCIB,the horizontal stiffness and damping ratio of composite block under quasi-static simulation test are obtained by studying the cover plate size and rubber sand thickness.The test results show that: the hysteresis curve of RSMCIB is relatively full,and the damping ratio of RSMCIB is between0.15 and 0.30.With the increase of dynamic shear strain,the damping ratio is concentrated around D=0.2,which indicates that the isolation block has good damping and energy dissipation effect,and can be applied to the isolation of low buildings on hard sites in mountainous areas.