A Study On Strength Of Songnen Plain Soda-saline Soil

The saline soil area in Songnen plain is one of the three large saline soil areas in northeast inland of China. It is in the first place for its large area, wide spread, fast development and deeply hazard in northeast of our country. The leading content of this saline soil is NaHCO₃ and Na₂CO₃, which belongs to inland soda-saline soil. It is not only harmful to agricultural production but also harmful to engineering construction because of its poor engineering properties. It also leads to highway distresses of the roadbed subsidence and collapse in the highway construction.For the research of soda-saline soil is much less now, in this theses based on the physical indexes, chemical properties and mechanical properties of the soil, the engineering properties and the engineering parameter are discussed. The study is valuable to the engineering design and construction in Songnen plain soda-saline soil. The main content of research as follows:â‘ On the basis of introducing classification of saline soil and its solid's characteristics, the climate of Songnen plain and survival circumstance for saline soil have been analyzed.â‘¡The basic properties of littoral Songnen plain saline soil are entirely and systematically researched, including testing physical indexes(nature density, moisture content, liquid and plastic limit graduation, particle composition), chemical properties and mineral component analyzing, basic mechanical properties(shear strength, consolidation, collapse and dilatability, CBR), hydrologic properties(the relationship between limit water content and water content, permeability) and so on.â‘¢On the basis of the study above, strength property is studied especially, The main content as follows: The relationship between shear strength and water content of Songnen plain soda-saline soil was studied with two different experimental methods. A shear strength formula was brought out based on tests and the strength parameters were given accordingly. At the same time the yield surface and the critical water content of Songnen plain soda-saline soil was proposed and the mechanism of strength variation was analyzed. The relationship between the moisture content and shear strength is studied too.â‘£The application of the research in roadbed filler improvement of Songnen plain soda-saline soil is discussed initiatively.The research solves difficult problems of the project. It is very important to fulfill the research of Songnen plain soda-saline soil. The study is valuable to the engineering design and construction in Songnen plain soda-saline soil.