Abstract:

Kizil grottoes are mainly digged on the precipice of sandstone in Kuqa of Xinjiang autonomous region, which is the middle route of Tibetan Buddhism being brought into China. Due to long-term weathering and active earthquake, collapses of grottoes have occurred frequently in recent years, detrimental to the value of cultural relics and safety of tourists. In order to explore the mechanism of reinforcing Kizil sandstone by PS (potassium silicate) solution, we first conducted XRD(X-ray diffraction) mineral analysis of sandstones, and then designed PS solutions of different concentrations to strengthen the sandstone respectively. We measured the variations of quality, volume, wave velocity in the presence of PS solutions of different concentrations, and compared the changes of sandstone’s microstructure to research the mechanism and regularity of reinforcement. Results show that the reinforcement effect is obvious, and PS solution of 20% concentration has the best effect; as the PS solution gradually solidifies, wave velocity increases by a large margin; PS plays a cementation role among particles, which enhances the compressive strength of sandstone.

Key words: sandstone, Kizil grottoes, PS solution, reinforcement, mechanical strength, wave velocity