Study On Engineering Properties And Engineering Classification Of Inland Saline Soil

In view of insufficient study on engineering characteristics of saline soil and salt heaving mechanism, the paper makes a start with the study on engineering characteristics of saline soil, aiming mainly at revealing rules and serving projects, introducing a systematic study on engineering characteristics, salt heaving characteristics, melt sinking rules, mechanics characteristics and engineering classification of fine granulated saline soil and coarse granulated saline soil under different conditions by combining the practice and theory of saline soil application for highway engineering in China today, on the basis of data retrieval, collection, analysis and reduction, using the research methods such as field observation, large-scale model test, centrifugal model test and GDS triaxial test in the ways of system test, qualitative analysis and quantitative computation.It is the first time to take multifunctional triaxiality system (GDS) as test platform to conduct strength property test of saline soil under different soil groups with different water content and salinity, and the (σ1-σ3)-ε1 relation curve of saline soil with different water content and salinity, the rules of volumetric changing with axial strain (ε1), the relation between ultimate strength and initial water content, and the relation between salinity and confining pressure are analyzed, thus the stress-strain relation of salty soil under different water content and salinity conditions is established systematically. Representative natural saline soil is selected for water and salt migration test after different freeze-thaw cycles, and the water and salt migration rules and character analysis of natural saline soil are researched in terms of soil groups after different freeze-thaw cycles. To prepare sulfate and chlorate saline soil samples in typical area and simulate natural drop in temperature and groundwater recharge by applying the developed open-system's large-scale model test, and therefore, to research engineering characteristics of natural saline soil in subzones, and analyze salt heaving characteristics of natural sulfate and chlorate saline soil during different frost thawing periods, and engineering evaluation as well. Based on actuality of study on engineering characteristics of coarse granulated saline soil, it is the first time to use homogeneous design theory and prepare different fine grain-size filling materials, salinities and water contents, simulating natural temperature drop in winter with large-scale model test, and deepen the research on salt heaving characteristics of coarse granulated salty soil at five aspects of soil, water, salt, temperature and mechanics by means of statistical software. Centrifugal model test on melt sinking characteristics of sulfate and chlorate salty soil is conducted systematically for the first time, and the rule and mechanism of saline soil melt sinks are advanced, and the melt-sinking deformation behavior of different saline soil types under different conditions of water content and salinity is described systematically with comparative analysis of laboratory melt sinking test result with uniline or dual line. The preparation particle diameter of coarse grained saline soil are advanced though statistical analysis of particle composition in typical region and research on preparation particle diameter of coarse grained saline soil, and analysis on relation between soil water extract and salt content. The test method of soluble salt for saline soil are optimized. With large-scale investigation and observation on highway distress characteristics in typical saline soil area, to summarize and analyze systematically highway distress characteristics and genesis in typical saline soil area. With field survey, laboratory engineering characteristic test and site test, and based on the analysis and summary of saline soil classification data at home and abroad as well as production practice of highway construction in saline soil area, it is the first time to establish systematically a comprehensive system of saline soil highway engineering classification with indicators of soil group, salinity, water content and temperature which exert influence on saline soil engineering properties.Research papers has important theoretical and practical application value to improve the relevant norms of order and guide in Saline Soil Area road construction.