Stress Measurement Of Compacted Loess In Standard Compaction Process And Thermo-Physical Properties Of Compacted Loess

In recent years, with the national economic construction continuing to prosper our countries pay more and more attention to urban construction. Our country’s urbanization process speeds up unceasingly.The utilization rate of land resources has become more and more enlarged. As a result, land resources are increasingly scarce and more and more over-ground space will be depleted. Subsequently nervous problems of construction land have become increasingly prominent. Meanwhile, the deterioration of natural environment is becoming more and more serious. It means that we need to improve the natural soil conditions, so that it can meet the requirements of modern engineering construction. The application of filling engineering and development of underground space is one of effective methods to speed up China’s city construction. In loess area, the local loess is used as the filling material, which can not only save the cost of the project and speed up the construction period, but also reduce the waste and be sensible use of resources. Therefore the understanding of the relationship of earth stress and compaction, moisture content of in the compaction process of loess like soil has positive significance to correctly reveal the Loess like soil compaction mechanism, choose reasonable strike method and construction parameters Because the underground projects are generally through the city center in the city. The geology and environment have very high risks. The slightest mistake will cause serious losses. So it is necessary for us to have an accurate grasp about engineering properties of soil in the construction process of the underground space. The thermal physical properties of soil is one of the basic properties of parameter in geotechnical engineering construction.In this paper, in order to further understand the special engineering properties of Loess Filler in Shanxi, the laboratory experiment derives from part of surface soil samples(Q4) of a fill site Shanxi Linfen. The research is mainly divided into the following three aspects: one is to test the curve of compaction loess solid by the standard heavy compaction test under different compaction energy, and the maximum dry density and optimum water content are gotten undet different compaction energy of soil samples. The greater the compaction energy, the greater the maximum dry density of soil samples, the smaller the optimum water content; two is to test the stress in the process of soil compaction by the improved the standard compaction device indoor, curves of impact force and ground pressure are gotten, and the relationship between the compaction energy, water content, soil thickness and stress in soil is analyzed. Tests show that soil in a point of stress and the impact force at the bottom of the hammer increases with the increasing number of compaction and stress under the same soil layer; the soil stress decreases with the increase of the thickness of overlying soil under the same compaction energy and the same water content; three is to test thermal physical parameters of compacted loess samples,thermal conductivity and specific heat of compacted soil are obtained under different water content, dry density and void ratio. The test results show that there is a corresponding relationship between the thermal conductivity of compacted loess and compaction water content, dry density under the same compaction energy. Thermal conductivity basically reaches the maximum value in the optimum water content.But whether the size of compaction energy, the specific heat of compacted loess reaches the maximum value when water content were in 12% ~ 13%. Under the conditions of this experiment, the specific heat capacity of compacted loess content ranges from 1.218 kJ/kg·K to 1.639 kJ/kg·K.