分散性粘土的分散机理分析

Analysis of Dispersion Mechanize of A Dispersed Clay Soil

分散性粘土之所以分散,除受水的影响之外,主要是土的内在矿物成份决定的。黑龙江省南部引嫩工程的土料是蒙脱石和伊利石混合物。这二种矿物系由硅氧四面体和铝氧八面体组成晶体,晶体晶格中常发生低价阳离子置换高价阳离子现象,因而增加了晶层叠置的不规则性;同时该工程地区土壤孔隙水中PH值高,钠离子丰富,矿物吸附钠离子后,使晶体扩散双电层的斥力成为引起层片分离的主力,增大了层间距离,故而具有高度分散性。文章最后还对用石灰处理分散性粘土的工程措施作了简要介绍。

The earth used at a project diverting water from the south of Nen River in Yeilongjiang Province is a mixed soil containing bentonite and illite. The latter two are composed of silicaoxide tetrahedron and aluminiumoxide octahedron, in the crystal lattice of which the cation of higher valence beibg frequently replaced by the cation of lower valence, leading to increasing the irregularity of the crystal layers piled up. In addition, there is high PH value in the pore water and plenty of sodium ion in soil. When the mineral absorbs the sodium ion, repulsion of double electron layers becomes the dominate force resulting in seperation of the layers like platters and increasing distance between them or making the soil high dispersed. In the last part of the paper is outlined an engineering measure of improving the soil by using limes.