Study On Elevated Temperature Sintering Treatment Of Silty Soil In Dalian Area

Silty soil layers exists in many coastal areas or along the rivers in china, due to the high compressibility, rich natural water content and strong liquidity, silty soil is very easy to cause the settlement of foundation or fracture, deflection and necking down of pile foundation in the construction process.Engineering accident, property damage and personal injury will be appear. Therefore, the silty soil layers must be improved in the process of construction.Main mineral and chemical composition of silty soil include kaolinite, Illite, montmorillonite, SiO2, Al2O3 and Fe2O3, the composition above result in the property of fire resistance and sintering of the silty soil. A series of physical and chemical reactions at elevated temperature enhance the compressive strength of the silty soil. Therefore, in this thesis, the elevated temperature sintering process of silty soil is invested. The change regulations of compressive strength of the silty soil after elevated temperature sintered with hydrolysis are studied according to site conditions. The main research contents of this thesis are as follows:(1) Geotechnical tests of silty soil in Dalian Donggang distict were carried out in order to study the basic physical properties of the soil, and obtain the particle size distribution, water content and void ratio of the soil. In the end, the soil was identified as silty soil.(2) The elevated temperature sintering process of the silty soil shows that the elevated temperature sintering can greatly improve the compressive strength of the silty soil. The compressive strength of the silty soil after elevated temperature sintered shows different change regulations along different combination of sintering temperature and time.(3) Scanning electron microscopy and X-ray diffraction experiments were used on the silty soil which is in natural state and after temperature sintered. The microscopic changes of the silty soil was analyzed to study the mechanism of compressive strength variation.(4) Hydrolysis experiment of elevated temperature sintered silty soil was carried out in view of the site condition with rich water. It shows that the compressive strength of the silty soil with hydrolysis was decreased in various degrees. Through the analytical result of the compressive strength variation of the silty soil with different hydrolysis time, the suitable sintering temperature and time combination for construction application were botained.