密度对砂土基质吸力的影响研究

目前主要是依据土-水特征曲线及含水量来确定基质吸力，而忽略了土体密度对基质吸力的影响，这不论从理论上，还是从应用方面都是不完善的。为此，笔者选取霸桥砂土，进行了大量不同密度、不同含水量土样的基质吸力测试。经过对实验资料的分析研究，得到了三种密度下的基质吸力随含水量的变化关系式，并进一步得到了既考虑土体密度，又考虑含水量的基质吸力表述关系式，最后经水分迁移试验，验证了密度对水分迁移进程的影响。研究结果表明：基质吸力随密度的变化是明显的，含水量越低，这一趋势越明显。在含水量相同的情况下，当砂土从疏松状态逐级变密时，吸力值先后经历变小、变大、又变小的过程，笔者对造成这一现象的原因作了初步分析。

Influence of density on matrix suction of sandy soil

At present, according to the soil-water retention curve, the matrix suction of soil is mainly obtained by moisture content, which neglects the influence of density on matrix suction. This is imperfect both in theory and in application. Taking the Baqiao Bridge sandy soil for sample, the matrix suction of sandy soil with various densities and moisture contents is tested. After analyzing the test data, the relation between the matrix suction and moisture content in three kinds of densities is got, and taking the density and moisture content both into account, the formula is obtained to determine the matrix suction. The one-dimensional moisture migration test verifies the influence of density on moisture migration. Then this paper finds the changing law that the matrix suction changes obviously with density especially in low moisture content. And with the same moisture content, if the density is gradually added, the value of matrix suction first is lowered, then added and finally lowered, this phenomenon is probed into in this paper.