The Experimental Research Of The Cement Improved Fine Sand Filling For Da-He Raiway Subgrade Bed

The rail, which is from Da ta to He jia ta, is under construction in Dalad banner of the city Erdos, Inner Mongolia. The railway is located in the eastern territory of Erdos highland and Ku bu qi desert, and it stretches 140 kilometers, most of the line fills all kinds of forms. According to the survey of the rail, the most surface of the line distributes Quaternary system Holocene series Aeolian fine sand and fine sand by all kinds of thicknesses, has a serious lack of group B. Powder sand. The fine sand can not meet the requirements of the engineering design and the relevant uses, because of its particular composition, structure and physical condition, when they are used as the foundation soil and packing. The main performance is the compaction performance is poorer and as filler the overall stability is poor; in certain conditions it will produce liquefaction as foundation soil, it is vulnerable to break by water flowing and so on. Therefore, how to reasonably and effectively use the fine sand, the fine sand as the subgrade fillers to cut down the overall investment in engineering constructions, become a problem which we must face. According to the relevant requirements and the design material of the railway, the paper do several aspects work below:(1) The physical mechanical properties of the Aeolian sand were summarized in the paper. Focusing on the strength properties of the soil, the liquefaction of the sand, the paper gives a deeper analysis.(2) With the cement improvement and the lime improved as the key point, the paper introduces the improved soil. The paper discusses the mechanism of the cement improvement and the lime improved and their respective improved characteristics. Contrast the various methods. The paper puts forward the method of improving soil with the cement.(3) By indoor test, we do the related tests for physical characteristics of the original sand. The physical and mechanical properties of the improved soil with the cement were studied. Draw the necessity and rationality of the fine sand through the cement improvement.(4) According to the results of the experiments, do finite element numerical simulations.According to the different cement admixture and the different improved thicknesses of the base bed, comparatively analysis the stress and the strain of the subgrade engineering how to change under different conditions, get the most reasonable cement admixture and the improved thickness of cement, when the fine sand, through the cement improved, compacts the roadbed. (5) Based on the tests indoor and the finite element calculation simulation data, we can provide the theoretical guidance, the methods of construction control and the quality test of the fine sand and the fine sand through improved to fill the subgrade.