基于响应面法的硅溶胶注浆材料配比优化研究

硅溶胶注浆材料具有可注性好、凝胶时间可控、环保无毒、耐久性高等优点,但常规的硅溶胶固砂体抗压强度偏低,其推广应用受到了一定限制。本文通过单因素实验分别研究了胶凝剂种类、胶凝剂浓度、硅溶胶与胶凝剂质量比、注浆材料pH值对硅溶胶固砂体抗压强度的影响,同时通过响应面法研究了胶凝剂浓度、硅溶胶与胶凝剂质量比、注浆材料pH值交互作用对抗压强度的影响。试验结果表明:单因素对抗压强度影响的显著程度依次为胶凝剂浓度、注浆材料pH值、硅溶胶与胶凝剂质量比;双因素交互作用对抗压强度影响的显著程度依次为胶凝剂浓度和注浆材料pH值、胶凝剂浓度和硅溶胶与胶凝剂质量比、硅溶胶与胶凝剂质量比和注浆材料pH值。采用响应面法获得的硅溶胶固砂体抗压强度最优配比为胶凝剂质量浓度为7%,硅溶胶与胶凝剂质量比为7 ∶1,注浆材料pH值为7。响应面法的预测值和实测值误差较小,表明响应面法可用于硅溶胶注浆材料的配比优化。

Proportion Optimization of Silica Sol Grout Based on Response Surface Method

Silica sol grout has advantages of good groutability, controllable gelation time, non-toxicity and high durability, however the compressive strength of silica sol grouted sand is relatively low, which restricts its application. In this paper, a series of single-factor tests were carried out to examine the effects of various factors on the compressive strength of grouted sand. Those factors include the type and concentration of gel-agent, the mass ratio of silica sol to gel-agent and the pH value of grout. In addition, response surface method was used to studythe effect of the interaction of the factors including the concentration of gel-agent, the mass ratio of silica sol to gel-agent and the pH value of grout on the compressive strength of grouted sand. The experimental results demonstrate that the following factors are arranged in a descending order in terms of the influencing degree of a single factor, the concentration of gel-agent, the pH value of grout and the mass ratio of silica sol to gel-agent. Moreover, the following factors are arranged in a similar manner regarding interaction effects between two factors, interaction between gel-agent concentration and grout pH value, interaction between gel-agent concentration and the mass ratio of silica sol to gel-agent, and interaction between the mass ratio of silica sol to gel-agent and the pH value of grout. Based on response surface method, the optimized compressive strength of silica sol grouted sand can be achieved when the mass concentration of gel-agent, the mass ratio of silica sol to gel-agent and the pH value of grout are selected as 7%, 7 ∶1 and 7, respectively. The difference between predicted values of response surface method and experimental measurement is minor, suggesting that response surface method can be used to optimize the proportion of silica sol grout.