Research On The Vibration Isolation Effect Of The New Cold Resistance Layer In Seasonally Frozen Areas

With the rapid development of transportation infrastructure construction,the environmental vibration caused by road traffic load has been paid more and more attention.The vibration caused by road vehicles propagates to the roadbed and the foundation in the form of vibrating waves,causing the vibration of subgrade soil and foundation soil,making the surrounding structures to vibrate by propagating vibration through the foundation soil to surroundings.Long term vibration leads to the decrease of the dynamic stability of soil and the settlement deformation of road,and it increases the potential safety hazard of the surrounding buildings as well.On the basis of analyzing mechanism and feasibility of XPS board and our team’s research foundation of new cold resistance layer,this paper studies the vibration isolation of new cold resistance layer(a combination of modified fly ash soils with rubber particles and XPS board)as a roadbed packing.Through the provision of new cold resistance layer,using XPS board excellent vibration isolation effect,to reduce the influence of vibration caused by traffic load on subgrade,foundation and surrounding environment.In this paper,by doing impact load laboratory test,the effects of XPS plate’s thickness,vibration intensity and freeze-thaw cycles on the vibration of soil structure and the vibration isolation effect of new cold resistance layer are analyzed,and the ABAQUS finite element software is used to simulate the laboratory test and the actual road,the specific contents are as follows:(1)In order to evaluate the vibration isolation effect of the new cold resistance layer and XPS board,three groups of comparative tests were set up to compare the vibration isolation effect of silty clay,modified soil and new cold resistance layer.(2)In order to determine the optimal thickness of the XPS board,the vibration isolation effects of the new cold resistance layer composed of XPS plates with different thicknesses were compared,and by synthesizing economic indexes,thermal insulation effect and mechanical properties,the optimum value of the XPS board thickness is determined.(3)The influence of vibration intensity on vibration of soil and vibration isolation effect of new cold resistance layer is studied by using the new cold resistance layer composed of XPS plate with the best thickness.The new cold resistance layer set up in this paper is mainly used in seasonal frozen areas,in order to simulate the real road environment of the frozen season,three kinds of soil model structures were respectively subjected to five freeze-thaw cycles,by comparing their vibration situation,the influence of the number of freeze-thaw cycles on the vibration isolation effect of the new cold resistance layer was analyzed.(4)The ABAQUS finite element software was used to simulate the laboratory test,and the simulation results were compared with the actual laboratory test results.Based on the verification of the accuracy and feasibility of the finite element simulation,the application of the new cold resistance layer in the actual road is simulated,and the vibration isolation effect in the result is evaluated.The results show that under the impact load,the new cold resistance layer and XPS plate have certain vibration isolation effect,and the vertical vibration isolation effect is obvious.Based on various control factors,5cm is the best XPS plate thickness for the new cold resistance layer.The vibration of the soil structure increases with the increase of the impact load,and the vibration isolation effect of the new cold resistance layer and the XPS plate increases at first and then gradually become stable with the increase of the impact load.In the case of less freezing and thawing cycles,the dynamic stabilities of the rubber particles modified fly ash soil and the new cold resistance layer are better than that of the silty clay.The new cold resistance layer can maintain certain vibration isolation effect during freezing and thawing cycles,and vertical vibration isolation effect is obvious.The simulation analysis of ABAQUS finite element software shows that the new cold resistance layer subgrade reduces the vibration deformation of roadbed soil and foundation soil and the influence on the surrounding environment caused by road vehicle load vibration.