Soil Sorptive Potential: Unitary Definition of Matric Potential
主讲人: Ning Lu
时间: 2019年3月25日(星期一)下午14:30
地点:泥沙馆数字报告厅
内容摘要:
In nature, soil-water interaction involves two physical mechanisms: capillarity and adsorption. As such, matric potential or the negative of matric suction should reflect both mechanisms. However, the common definition of matric potential, being the pressure difference between pore water and pore air pressure, overlooks the adsorption, leading to poor predictions on when soil water freezes, when change phase occurs between liquid and vapor, and why soil water density could be as high as 1.8 g/cm3. The adsorption can be fully captured in a new concept called soil sorptive potential, leading to a general definition of matric potential. This new definition of matric potential provides thermodynamic ways to bridge the long-standing gap between pore water pressure and soil sorptive potential, and to accurately quantify soil freezing curve (constitutive relationship between soil water content and temperature below 0oC), soil water density (soil water density as a constitutive function of soil water content), and soil water cavitation (soil water phase transition between liquid and vapor).
主讲人介绍：
Ning Lu is professor of civil and environmental engineering at Colorado School of Mines (CSM) and the director of the joint CSM/US Geological Survey Geotechnical Research Laboratory in Golden, CO. He is a recipient of the ASCE 2007 Norman Medal, of the ASCE 2010 Croes Medal, of the ASCE 2017 Ralph B. Peck Award, and of the ASCE 2017 Maurice Biot Medal, as well as a fellow of ASCE, Engineering Mechanics Institute, and Geological Society of America. His primary research interests are flow and stress laws in multiphase porous media, rainfall-induced instability of natural and engineered slopes, geologic hazards, energy storage in porous media, and subsurface nuclear waste isolation. He is the senior author of the widely used textbook Unsaturated Soil Mechanics (John Wiley and Sons, 2004) and the textbook Hillslope Hydrology and Stability (Cambridge University Press, 2013). Both books are translated into Chinese and published by The Chinese Higher Education Press.
