水泥土渗透性的室内试验研究

针对水泥土的渗透性问题,首先对比实施标准养护和海水养护条件下水泥土的渗透试验及微型贯入试验,研究水泥土的强度与渗透性的关系及劣化对水泥土渗透性的影响;其次,将制备好的水泥土试样不经养护立即实施渗透试验,模拟研究场地形成的水泥土的渗透性随时间的变化规律。试验结果表明,标准养护条件下,水泥掺量越大,龄期越长,水泥土强度越高,相应地渗透系数越小。但是,水泥土的渗透系数随龄期所产生的强度变化不大。海水养护条件下,由于水泥土发生劣化,导致水泥土的渗透性随龄期呈显著增大的趋势,说明劣化使水泥土强度降低的同时,也导致其渗透性增大。水泥土劣化滞后于海水渗透。场地形成的水泥土的渗透性随水泥掺量增大而减小。水泥土渗透性随时间呈现减小的趋势,前期渗透性减小较快,之后渗透性基本趋于稳定。

Experimental Study on Permeability of Cement-treated Soil

By comparing the results of permeability tests and micro-cone penetration tests of cement-treated soil under standard and seawater curing conditions, relationship between its strength and permeability was studied. The relationship between its permeability and detdrioration was also studied. Then, in order to simulate and study the permeability variation with time of site formed cement-treated soil, permeability tests were immediately car- ried out on the newly-prepared soil samples without curing process. The experiment results showed that under standard curing conditions, with the increasing of cement mixing ratio and curing time, the strength of cement- treated soil increased, too, while its permeability decreased. However, with the increasing of curing time, its permeability decreased insignificantly. Under seawater curing conditions, seawater submersion led to significant deterioration of cement-treated soil, so with the increasing of curing time, its permeability increased, too. This indicates that deterioration could cause its strength to decrease and its permeability to increase. Its deterioration lagged behind its permeability variation under seawater curing conditions. With the increasing of cement mixing ratio, the permeability of site-formed cement-treated soil decreased, while with the increasing of permeation time, its permeability decreased. And during the early days, its permeability decreased rapidly, but soon stabi- lized.