On Trench Construction of Diaphragm Wall in Medium-Coarse Sand: Slurry Composition and Construction Optimization

Abstract

On basis of the slurry preparation of diaphragm wall construction in Jinshan Metro Station in Fuzhou, firstly, laboratory tests are conducted to obtain 3D characteristic figures which exhibit the effects of silt soil and bentonite content on slurry properties including density, viscosity and water loss. Furthermore, influence of slurry density, viscosity on filter cake forming process under different slurry pressure is analyzed through laboratory tests. The test results indicate that: the 3D characteristic figures can give a variety of slurry proportion combinations of specific density, viscosity and water loss. The final unit water filtration first drops then starts to increase as slurry density increases. As for viscosity and slurry pressure, the final unit water filtration decreases as viscosity increases and it increases as slurry pressure increases. In addition, the influence of viscosity on final unit water filtration is less than that of density. Finally, optimization of trench construction is proposed based on filter cake formation time obtaining from the test results and construction conditions.