Research On The Strength Property And The Engineering Application Of The Cement-Lime-loess

Collapsible loess is one of the most widely ranged zonal soils in our country. It covers nearly 60% of the total area of loess in China, which mainly distributes in the middle and downstream of Yellow River. These years, civil engineering has developed rapidly in large scales in the middle and western area. Because of the higher and higher demand of the engineering, the collapsibility of collapsible loess must be efficacious and economic eliminated, and the bearing capacity of it must be improved. Lime is a kind of low-priced construction material, using lime-loess cushion and lime-loess compaction pile to treat collapsible loess foundations can gain good technology economy effect. But, since the early strength of lime-loess is low, the using of lime-loess was limited. As a kind of important construction material, cement can quickly form in air or water. The strength of cement-lime-loess is higher and higher when more and more cement is added in it. The engineering application and the study on lime-loess and cement-lime-loess are still far behind other branches of the homogeneous subject even though rapid progress has taken place in this area.The significance of the study on cement-lime-loess is great in both theory and engineering practice.Through a large number of unconfined compression tests and triaxial compression tests, the strength and other property of cement-lime-loess was analyzed. Some laws about the strength and rigidity property of cement-lime-loess with different cement content, water content, around pressure and time are developed. A formula, which is used to forecast the strength of cement-lime-loess and another relation formula, which is between the strength and the rigidity of cement-lime-loess, are put forward. All these results have value significance and can be referred to engineering practice.In engineering the bearing capacity of lime-soil compaction pile and cement soil compacting pile are calculated by the strength of pile material now. The bearing capacity of composite foundation is calculated by averaging the bearing capacity of soil and pile according to their area.How the load is transmitted in the pile is not considered and the economic pile length can't be calculated by this easy measure. According to the strength property and stress-strain curve of cement-lime-loess, through researching how the load are transmitted in different rigidity cement-lime-loess piles, a rational design measure, which can calculate the bearing capacity, settlement and economic pile length of cement-lime-loess pile composite foundation is developed. These calculations have practice value and theory significance to the using of lime-soil pile and cement-lime-loess pile composite foundation in engineering.