Experimental Study On Permeability Of Three Kinds Of Improved Loess

Present in loess area, the road embankment works, drainage works, landfill engineering, and the foundations of multi-story building foundation had related to improved penetration performance. With the lime in the region as a cushion, it is hoped to play a waterproof, waterproof foundation in the loess soil cement has been used more widely, the engineering of cement generally considered stronger than waterproof loess dust, but these are all improved soil soil, in the end be more appropriate to what proportion is still not very clear, usually by adding the greater the proportion of cement or hydrated lime, waterproof performance is better. But had the general assembly affect the strength of lime (usually the largest proportion of 3:7 lime), adding a larger proportion of cement increased more when the cost, engineering more difficult to bear; In addition, few studies are more accurate permeability.This paper summarizes the research situation, the choice of lime soil, lime and fly ash loess soil, compaction test by variable head permeability test and measured in loess and loess penetration of maximum dry density coefficient. In order to get more accurate penetration data for what percentage of these territories can be as impervious material as the criterion. The results showed that: loess permeability coefficient increased with the permeation time, gradually reduce and finally stabilized. After the prime soil compaction significantly reduced permeability, and loess less than about one order of magnitude. 3:7 ratio of cement can be used as impervious material, 3:7 ratio of limestone soil and water can be separated as a short-term seepage control materials, lime and fly ash is not capable of doing; the same time, it is found 28 days in the conservation of soil improvement.The permeability coefficient after stable to 21 days in the conservation have increased permeability phenomena, this mechanism needs further study.