PS溶液渗透对非饱和土的增强效应研究

特定模数硅酸钾溶液(PS)已广泛的用于我国西北干旱地区土遗址加固保护工程中,并且取得了显著的效果。但是PS对潮湿地区遗址土加固效果,目前尚缺乏成熟的理论和实验验证。本文从室内试验的资料出发,研究PS对潮湿地区土遗址非饱和土的增强效应。本次研究土样取自位于潮湿环境中的浙江杭州良渚土遗址(3000 B C.),在实验室内对高含水量(13％ ~25％)的重塑土样进行了PS渗透加固。通过研究对比加固前后重塑土样的固结特性和抗剪强度,发现 PS对潮湿地区遗址土也有一定的加固效果。加固效果随初始饱和度的不同而不同,但初始含水量达25%的土在PS作用下仍可能得到增强。经PS渗透的土样不仅提高了初始固结性能和抗剪强度,而且加固土样而且呈现出一定的弹脆性特征,呈现出塑脆性转化,表明PS渗透可能产生对土初始结构的稳固作用。这一探索研究将为扩大PS在土遗址加固保护工程的应用提供一定的理论支持。

RESEARCH ON UNSATURATED SOIL STRENGTHENING EFFECT OF PS FILTRATION

Modulated potassium silicate solution(PS)has been applied widely for the protection of heritage soil in the arid area of northwestern China and obviously succeeded.However,protection of such site soil in the moist area is remained as one of research subjects.Based on the data of laboratory tests,the strengthening effect of PS for soil with relative higher water content is presented in this paper.The soil samples taken from Liangzhu civilization site(3000 B.C.)were modulated to obtain higher water content up to 13％ ~25％ and strengthened by PS infiltration.Some important findings were revealed in the comparison of consolidation and shear strength properties for original and PS strengthened soils.The PS strengthening effect can be observed even for soil with water content as higher as 25%.The PS filtration may increase the consolidation property and shear strength,and the laboratory study revealed some important findings in plasticity-brittleness transition.The test data show,that the PS strengthening may result in the stabilization of soil structure framework and secondary support to the pores.This work should give a support to the further application of PS strengthening technology for heritage site soil.