室内试验循环冻融条件下,对克孜尔石窟的砂岩加入不同质量百分比和不同浓度的PS(Potassium Silicate,硅酸钾)溶液进行加固,测量冻融后砂岩试样的质量、体积、波速以及抗压强度,得出PS溶液的较优加固浓度以及质量百分比。结果表明:质量百分比为25%的PS溶液加固效果最好。其原因是质量百分比过低会导致砂岩黏聚力不够;当百分比过高,颗粒之间将不能直接接触,摩擦力降低,黏聚力较差。PS溶液浓度为20%时,其质量、体积、波速和抗压强度损失率最小,浓度越高,加固效果越强。

Through laboratory test under cyclic freezing and thawing, the sandstone of Kizil grottoes was reinforced by potassium silicate solution of different mass percentages and concentrations. The volume, mass, wave velocity and compressive strength of reinforced sandstone samples after freezing and thawing were measured, and the optimal concentration and mass percentage of potassium silicate solution were obtained. Results showed that potassium silicate solution of 25% mass percentage has the best strengthening effect because low mass percentage would result in inadequate cohesion whereas high mass percentage would lead to low friction and cohesion with no direct contact between particles. Higher concentration of potassium silicate solution leads to better strengthening effect. The loss of volume, mass, wave velocity and compressive strength of sandstone reinforced by potassium silicate solution of 20% concentration is the smallest.