Experimental Study On Engineering And Mechanical Properties Of Polymer Gobi Soil

The shortage of water resources is the key factor that restricts the rapid development of Xinjiang’s economy and society.The uneven distribution of water resources and the mismatch between water resources and social and economic development are becoming more and more obvious,which hinders the rapid development of Xinjiang.Inter-basin water transfer is an effective means to solve the problem of uneven spatial distribution of water resources in Xinjiang,effectively alleviating the shortage of water resources in the economic belt of the North Slope of Tianshan and the Eastern Region of Xinjiang.The two schemes of trans-basin water transfer,pipeline water transfer and open channel water transfer,are usually adopted.The cost of pipeline water transfer is high,the flow of water transfer is low,and the follow-up maintenance and management is inconvenient.But open channel water conveyance has its own problems,because of the large amount of engineering and long route,it usually spans many areas,and the engineering geological conditions and climatic conditions are complicated and changeable,so it is easy to be influenced by the salt frost heaving and the bad geological conditions.As a result of uneven settlement,freeze-thaw and other causes of cracking and other problems,further cause large-scale destruction of the channel.In order to solve these problems,a semi-flexible and semi-rigid cementitious composite material of high polymer Gobi soil is proposed,which integrates the physical and mechanical properties of cement concrete and Tarmac,it has the rigidity characteristic of high strength close to that of cement concrete and the flexibility characteristic of good Tarmac deformation.On the basis of satisfying the basic mechanical properties of the material,it also has better resistance to deformation and impermeability.The utility model can improve the durability of the open channel water conveyance channel,reduce the frost-heaving and cracking problem of the open channel water conveyance channel,reduce the daily maintenance management difficulty and the maintenance cost,and realize the green and sustainable utilization of the building materials.However,as a new type of GEL mixture material,there are still some problems in physical and mechanical properties and durability of the special geo-climatic environment in Xinjiang.On the basis of summarizing the research progress of Gobi soil,such as its strengthening property,durability and constitutive relation,this paper takes Gobi soil as a new cementitious material,the basic properties of polymer and Gobi soil,the optimization of their mixture ratio,the mechanical properties,deformation properties,high and low temperature properties,anti-erosion properties and anti-permeability properties of the mixed materials were studied.The main research contents and results are as follows:(1)Selection of high polymer and analysis of its basic properties.High Polymer Gobi soil is a new type of cementitious materials,and the properties of high polymer are the key factors that affect the properties of high polymer Gobi soil.In this paper,three kinds of two-component polyurethane materials were selected,and the related mechanical properties were studied and analyzed.(2)Optimization of mixture ratio of high polymer Gobi soil.In order to improve the utilization ratio of the material,the maximum particle size of the aggregate in Gobi soil was determined to be 20 mm,the coarse aggregate was divided into 3 grades from 2.5 mm to 20 mm,and the fine aggregate was divided into 5 grades from 0.075 mm to 2.5 mm according to the classification of aggregate in Tarmac,from 6% to 21%(interval3%),six different contents of polymer were selected,and the related physical and mechanical properties were studied.Based on the maximum density theory and the inclusion margin theory,the range of the mixture ratio of Gobi soil with high polymer is established.(3)Study on mechanical properties of Gobi soil with high polymer at different temperatures.The physical and mechanical properties of High Polymer Gobi soil under high and low temperature were studied based on the optimized ratio of high polymer Gobi soil.A series of researches and analyses on high temperature rheology,strength and low temperature tensile and bending properties were carried out to verify the high and low temperature properties of Gobi soil.The Strength Change Law of High Polymer Gobi soil under high and low temperature environment was put forward.(4)Study on durability of High Polymer Gobi soil.The physical and mechanical properties of High Polymer Gobi soil under salt solution erosion and different freeze-thaw cycles were studied,and the durability of high polymer Gobi soil was analyzed.The durability life prediction model of Gobi soil under freeze-thaw cycles and salt solution erosion was established.The life prediction model of Gobi soil was established based on the durability test and the winner single-variable stochastic process.That is,under the existing experimental conditions,the life of High Polymer Gobi soil is about 12.5 years.(5)Study on constitutive model of High Polymer Gobi soil.The static triaxial test of Gobi soil with different polymer content was carried out.Based on the triaxial test data,the applicability of the Polymer Gobi soil to the existing constitutive model is verified,and a stress-strain constitutive model which is suitable for the polymer Gobi soil without assumption is developed,and carried on the data verification analysis.The results show that the new constitutive model developed for High Polymer Gobi soil has excellent applicability and reliability.