吸力精确控制型压力板仪的研制与应用  

Development and Application of Ceremicplate Extractor of Controlling Matric Suction Accurately

作　　者：庞维福[1] 林鸿州[2] 

机构地区：[1]陕西铁路工程职业技术学院,陕西渭南714000 [2]长安大学地质工程与测绘学院,陕西西安710054

出　　处：《岩土工程技术》2015年第5期264-270,共7页Geotechnical Engineering Technique

基　　金：国家自然科学基金青年科学基金项目(40902080);国家自然科学基金(41272283);国家自然科学基金重点项目(41130753)

摘　　要：压力板仪不仅可用于测试非饱和土的减湿曲线,还能测试其增湿曲线,对研究土壤与水分之间的物理关系具有重要意义。针对当前压力板仪的不足,提出了利用电子压力表组提高吸力控制的精度,利用电子天平与蒸发校正对照组实现了精确量测土样中水分质量的变化,建立了数据采集系统避免了人为读取数据造成的误差积累,大幅提高了土水特征曲线测定的精度。利用该设备对毛乌素砂进行了试验,并利用Van Genuchen、Gardner、Fredlund and Xing土水特征曲线函数模型对试验数据进行了拟合分析,发现这三种模型对毛乌素砂均有较好的拟合效果;通过几何作图法确定了毛乌素砂土水特征曲线减湿曲线陡降段与增湿曲线陡降段的分界点。Ceremic plate extractor is used to test not only the unsaturated soil drying curve,but also the wetting curve, which has important meaning to the study of the physical relation ship between soil and water. To improve the present ceremic plate extractor, I recommend using electronic pressure gauge to improve the accuracy of the Suction control, using electronic balance and setting evaporation-control group to realize the accurate measurement of moisture in soil sample variation, establishing a data acquisition system to avoid the error accumulate caused by testers in recording process. Mu Us sand was tested by using this device, the test data are fitted by using the Van Genuchen, Gardnera, Fredlund and Xing model. Conclusion them have better fitting effects. Determine the boundary point of the unsaturated soil wetting and drying curve of steep drop section through the geometric mapping method.

关 键 词：非饱和土 土水特征曲线 基质吸力 压力板仪 毛乌素砂 曲线拟合 

分 类 号：TU411[建筑科学—岩土工程]