高分子固化剂改良砂土的渗透特性试验研究

Study on the Permeability Characteristics of Sand Reinforced with Polymer Soil Stabilizers

对高分子固化剂改良后的砂土进行常水头渗透试验和变水头渗透试验,研究高分子固化剂浓度、养护时间以及砂土干密度对砂土渗透特性的影响,并结合试验结果与扫描电镜深入分析了高分子固化剂改良砂土的机理。研究结果表明:固化剂浓度、养护时间和砂土干密度对改良后砂土的渗透特性有显著影响。随固化剂浓度、养护时间和干密度增加,砂土的出水时间变长,渗透系数快速降低,相对渗透阻力系数急速变大;固化剂浓度和养护时间对改良砂土渗透特性影响最为显著的范围分别为1%~5%和养护3~12 h;高分子固化剂在砂粒之间形成高分子膜包裹、连接砂粒,填充砂土空隙,减小砂土空隙,进而降低砂土渗透特性。

The constant head permeability test and variable head permeability tests were carried on polymer reinforced sand to study the influence of polymer concentration,density and curing time on the permeability of reinforced sand. The reinforcement mechanism of polymer was analyzed in depth with the test results and SEM. The results show that the polymer concentration,curing time and density have a significant influence on the permeability of the reinforced sand. With the polymer concentration,density and curing time increasing,the initial time of outflow water become longer,the permeability coefficient decreases rapidly,and relative permeability resistance coefficient of the sand increases rapidly. The most significant effects of the polymer concentration and curing time on the permeability of the reinforced sand are 1%-5% and 3~12 h. The polymer membrane in the sand forms a stable structure through wrapping and connecting sand particles,so as to enhance the bond strength between sand particles,and reduce the void ratio,thereby improving the permeability of sand.