PS加固对非饱和遗址土的渗透特性影响研究  

Impact of PS on permeability of unsaturated ruins clay

作　　者：李最雄[1,2] 邵明申[1] 陈锐[3] 

机构地区：[1]兰州大学土木工程与力学学院,兰州730000 [2]敦煌研究院,甘肃敦煌736200 [3]哈尔滨工业大学深圳研究生院,广东深圳518055

出　　处：《岩土力学》2011年第7期2039-2044,共6页Rock and Soil Mechanics

基　　金：国家科技支撑计划重点项目"土遗址保护关键技术研究"(No.2006BAK30B02)

摘　　要：高模数硅酸钾(简称PS)对西北干旱区的土遗址具有明显的加固效果,其加固后的土体也具有较好的渗透性。采用VJ-T非饱和土渗透仪和常规压力板仪测试了PS加固前后饱和样的渗透系数和非饱和土的土-水特征曲线(SWCC),并利用相关模型预测了非饱和土的渗透系数。结果显示,PS加固以后,在各个含水条件下的渗透性都有一定程度的提高,7%PS加固样表现非常明显。其原因是PS与土颗粒进行了非常复杂的物理化学变化,在反应中颗粒的几何形状发生变化,大量棱角弱化或消失,土颗粒磨圆度变好。同时,孔隙壁变得光滑、平直,孔隙弯曲因子减小,有效孔隙增大,这些因素导致了非饱和黏土的渗透性能有较大幅度提高。电镜测试分析了PS加固以后黏土颗粒及孔隙的变化,较好地验证了渗透性试验的结果。The high-modulus potassium silicate （PS） is used to protect the earthen ruins under add weathering condition, of which protective effect is good. The earthen ruins reinforced by PS show good permeability. VJ-T and pressure plate apparatus are used to study coefficient of permeability of saturated clay and soil-water characteristic curve （SWCC） of unsaturated clay before and after reinforcement by PS. The coefficient of permeability of unsaturated clay is predicted by correlated model. The results show coefficient of permeability increases more or less under different saturated conditions after reinforcement by PS, particularly evident in sample reinforced by 7% PS. This is because that PS changes geometric figure of these particles and the degrees of roundness to a great degree, which increases effective porosity. The reaction between PS and particle surface leads to a large pore structure to some extent and particle morphology, which leads to the increase of coefficient of permeability. SEM is used to analyse the influence of clay mineral, pore structure on coefficient of permeability of unsaturated remolded clay reacting with PS. The results can validate the permeability test well.

关 键 词：硅酸钾(PS) 非饱和土 孔隙 土-水特征曲线 渗透特性 

分 类 号：TU411[建筑科学—岩土工程]