石膏质岩毛细吸水特性与孔隙特征研究  

Capillary Water Imbibition and Pore Characteristics of Gypsum Rocks

作　　者：李科[1] 贾志刚[1,2] 余宏明[1] 师华鹏 

机构地区：[1]中国地质大学工程学院,武汉430074 [2]黄淮学院建筑工程学院,河南驻马店463000

出　　处：《长江科学院院报》2014年第9期79-83,共5页Journal of Changjiang River Scientific Research Institute

基　　金：国家自然科学基金项目(41272377)

摘　　要：以巴东十字垭隧道石膏质岩作为研究对象,采用一维吸水方法得到石膏质岩累计吸水量随时间的变化曲线。岩石吸水曲线可分为快速吸水段和恒速吸水段,吸水量主要集中在快速吸水段,不同试件的快速吸水时间不同。随着时间增加,各试件吸水速率逐渐减小,减小速度变慢。吸水0.4 h、吸水4 h和快速吸水段均可以采用二次函数进行曲线拟合。干湿循环后,岩石累计吸水量增加,平均吸水速率提高,前期吸水比例增大,快速吸水时间变短。利用压汞实验,根据数据分析表明石膏质岩孔隙率较低,平均最大连通孔径2.85μm,平均孔隙直径0.88μm,孔隙分选性较差。干湿循环之后孔隙最大连通孔径及平均孔径增大,分选性提高。最后根据岩石毛细吸水量和饱和吸水量,结合压汞数据提出求取毛细吸水孔径范围的一种简单方法。Curves of water absorption process of gypsum rocks are obtained by using one-dimensional water absorbing method. Gypsum rocks from Shiziya tunnel are taken as research object. The water absorption processes are divided into two stages: rapid absorption stage and constant speed stage. Water absorption is mainly concentrated in the first stage and different specimens have different absorption durations. With the increase of time,the water absorption velocity decreases and the decreasing slows down as well. Water absorption characteristic curves in 0. 4hour,4 hours and the rapid absorption stage are all polynomial. After dry-wet cycling,the accumulated water absorption volume and average absorption velocity both increase,the absorption in early stage increases,and the rapid absorption stage is shortened. Through mercury injection experiment,it is found that the maximum diameter of gypsum rock is 2. 85μm and average diameter is 0. 88μm,indicating poor degree of sorting. After wetting-drying cycles,maximum diameter and average diameter increase and the sorting improves. Finally,a simple approach to obtain the range of effective pore diameter is presented using saturated absorption,capillary water absorption and mercury injection data.

关 键 词：石膏质岩 毛细吸水 干湿循环 孔隙特征 

分 类 号：U452.11[建筑科学—桥梁与隧道工程]