水溶性聚合物强化砂土剪切强度及机理研究

针对加大砂土强度的问题，采用水溶性聚合物对其进行改良，对不同砂土干密度、固化剂含量及养护时间的改良砂土进行了直接剪切试验，并对其黏聚力及内摩擦角进行分析。结果表明：水溶性聚合物改良的砂土剪切强度得到一定程度地提高，这是由于水溶性聚合物加固砂土试样，形成包裹颗粒并相互联系的弹性黏膜，从而增加了土体强度；当养护时间一定时，改良砂土的剪切强度随着固化剂含量增加而上升，试样黏聚力最高可达183.52 kPa；当固化剂含量一定时，改良砂土的剪切强度随着养护时间增加而增加，试样黏聚力最高可达200.19 kPa；剪切强度的大小与固化剂含量、养护时间、试样干密度大小呈正相关。水溶性聚合物溶液在砂土中形成的弹性黏膜包裹砂粒，填充砂土空隙，进而增强土颗粒间的相互作用，改善砂土的工程特性。

Experimental Study on Direct Shear Test of Sand Reinforced by Water-soluble Polymer

In order to increase the strength of sand, water-soluble polymer was used to improve it. The direct shear test was carried out on the improved sand with different dry density, curing agent content and curing time, and the cohesion and internal friction Angle were analyzed. The results show that the shear strength of sand improved by water-soluble polymer is improved to a certain extent, which is due to the fact that water-soluble polymer strengthens sand samples and forms elastic mucosa wrapped with particles and connected with each other, thus increasing the strength of soil. When the curing time is constant, the shear strength of the improved sand increases with the increase of curing agent content. The maximum cohesion of the sample can reach 183.52 kPa. When the curing agent content is constant, the shear strength of the improved sand increases with the increase of curing time. The maximum cohesion of the sample can reach 200.19 kPa. The shear strength is positively correlated with curing agent content, curing time and dry density of the sample. Elastic mucosa formed by water-soluble polymer solution in sand wraps sand particles and fills sand voids, thus enhancing interaction between soil particles and improving engineering properties of sand.