闽南地区水泥土工程特性实验

为研究闽南地区常见土体制作的水泥土的工程特性,将淤泥、粉质黏土和粉砂分别与一定量的水泥浆混合制备水泥土试样,测定水泥土重度、强度、压缩模量、应力-应变及渗透系数。结果表明:三种土体制备的水泥土重度比原状土提高1%～7%,水泥土搅拌桩形成的复合地基不会对下部土体产生过大的附加应力和附加沉降。当水泥掺量由5%增大至20%时,淤泥、粉质黏土和粉砂制备的水泥土强度依次增大,增大幅度为原状土的1～2倍;水泥弹性模量也增大,与水泥掺量近似指数关系;渗透系数减小。当荷载较小时,水泥土应力-应变近似直线关系,当荷载超过了极限强度时,水泥土进入塑性变形阶段,破坏时存在残余应变。水泥土龄期由28 d增至60 d,其强度增长12%～36%。该研究为水泥土工程提供了基础数据。

Engineering properties test of cement-soil at south of Fujian province

This paper is an effort to investigate the properties of three common kinds of cement-soil by adding a certain amount of cement to mud,silt clay and silt sand common at South of Fujian Province,respectively,to make the cement-soil samples and measure the engineering properties of cement-soil.The result shows that cement-soil made from mud,silt clay,and silt sand has the gravity 1%～7% higher than does original soil,thus preventing cement mixing pile from producing excessive additional stress and additional settlement.A 5% to 20% increases in cement content trigger the increases in strength of cement-soil made from mud,silt clay and silt sand them,with the range going 1～2 times as much as the original soil.The elastic modulus of cement-soil increases with cement content,with exponent relationship,while the permeability coefficient decreases.A smaller load gives rises to approximate linear relationship in the stress-strain of cement-soil.The load greater than the ultimate strength results in the cement-soil’s entering into plastic deformation stage,leaving residual strain due to destruction.A 28 d to 60 d increase in cement soil age shows a 12% to 36% increase in its strength.The study could provide the basic data for the cement-soil engineering.