Experimental Research On Permeability Characteristic Of Cement Soil Under Corrosion-Stress-Temperature Coupling Action

Cement soil is a kind of high permeability material which is due to its good impermeability, frost resistance and strength, and is widely used in anti-seepage wall, foundation pit seepage control project, the anti-seepage curtain, slope or subgrade reinforcement. In the coastal areas of China, most of the cement soil is directly related to the sea water environment, so that the strength and permeability of the cement soil are affected and even destroyed. Due to the corrosion effect of the seawater, the safety of the use of the cement soil should not only be paiedattention, but also the impact of the mix of seawater on the cement soil when it is in the construction production. Since the cement soil in the actual engineering is involved in the coupling of stress and fluid in three directions, the study of the influence of seawater environment on the mechanical properties and permeability of cement soil under the condition of the three axis stress provides technical parameters and guidance for the design and application of cement soil, and is of great significance in engineering. In this paper, based on the analysis of the influence of domestic and foreign on the strength and permeability of cement soil with thecorrosionenvironment, the effects of the stress of the clean water environment and seawater environment, cement content and temperature on the mechanical properties and permeability of cement soil are summarized and analyzed through laboratory simulation experiments. Major research works as follow:Firstly, the three kinds of cement content are 12%、16%、20%, the cement soil is mixed with clean water and seawater respectively. and made a total of 42 groups of 126 specimens, the specimens are placed in clean water and sea water conservation to the same period 90 days.Secondly, the mechanical properties and permeability of the cement soil samples with different cement content are obtained by the triaxial compression test and penetration test in three axial compression tests.Finally, according to the experimental data, the effects and change rules of the cement content in the clean water environment and seawater environment, the stress and temperature on the shear strength, the internal friction angle, the cohesion and the permeability coefficient of the cement soil are analyzed. The regression curves of cement soil permeability coefficient under different conditions are obtained.The results show that the three axial compression stress strain curves of cement soil are generally softened, with the increase of confining pressure or the decrease of the cement content, the ductility of the specimens is significantly increased. With the increase of cement content, the cohesion and internal friction angle of cement soil increases. With the increase of temperature, the permeability coefficient of cement soil increases gradually. The seawater has a corrosive effect on the cement soil, the strength of the cement soil in seawater environment, the cohesion and the internal friction angle are gradually reduced, but the permeability coefficient increases gradually. Under the condition of the clean water or seawater environment, the permeability coefficient of cement soil decreases and then increases gradually, which shows the trend of U type in the seepage stress field.