Preparation And Engineering Simulation Of Light Soil Mixed With Waste Rubber Particles

With the development of urbanization strategy in China,a variety of backfill projects are increasing.The traditional rolling compaction method has many limitations,such as large operation space,long construction period and large number of construction personnel,which are abandoned by more and more backfill projects.At the same time,the urbanization development strategy has also brought a surprising amount of solid waste.Every year,all kinds of construction,road and bridge projects will produce hundreds of millions of tons of construction waste in the construction process,of which construction waste accounts for about 40%;the rise of the automobile industry also makes the number of waste rubber tires surge.The accumulation of these solid wastes will cause a series of hazards such as occupying limited land resources and polluting the environment.In order to solve the above problems,this paper uses construction residue and waste rubber tires to prepare rubber light soil.The physical and mechanical properties,fluidity and frost resistance of rubber mixed lightweight soil were studied from two aspects of macro performance test and micro analysis.The early mechanical strength of rubber light soil was improved by surface modification of rubber and adding materials.On this basis,the finite element analysis of post construction settlement of rubber light soil bridge abutment back filling project is carried out.The main conclusions are as follows:(1)Adding 0-60%rubber,the apparent density of rubber light soil can be controlled in the range of 2020kg/m~3-1550kg/m~3.Rubber will reduce the fluidity,and its impact on mechanical properties is mainly strength reduction and toughness increase.The mechanical strength of rubber light soil can meet the standard requirements.Rubber can improve the frost resistance.After 15 freeze-thaw cycles,the mass loss rate can be controlled within 10%,and the strength loss almost can not exceed 15%.(2)The corrosion effect of NaOH can increase the surface roughness of rubber and reduce the fluidity of mixing.8%NaOH has the best effect and less fluidity loss.Compared with rubber surface modification,the optimization method of adding fly ash activator is more simple and effective.Among them,the excitation effect of single sodium sulfate and compound sodium sulfate+quicklime is the best.The 28d compressive strength of the sample with 2%sodium sulfate can reach 3.0MPa,and the 28d compressive strength of the sample with 4%sodium sulfate+lime can reach 3.1Mpa.(3)In the ABAQUS simulation,the maximum vertical settlement of light rubber soil is only 8.404mm.Based on the theoretical simulation results,the engineering performance of rubber light soil is good.