Professor Ning Lu from Department of Civil Engineering of Colorado School Of Mines visits Institute of Rock and Soil Mechanics on April 7. He delivers an academic report with the title Intrinsic Relationship Between Soil Water Retention Curve and Suction Stress Characteristic Curve. Researcher WEI Changfu from State Key Laboratory of Geomechanics and Geotechnical Engineering hosts the academic meeting.

Professor Lu introduces key theories and experimental progresses in mechanics of unsaturated soil in recent years; he puts forward the concept of Suction Stress and Suction Stress Characteristic Curve. Lu points out the intrinsic relationship between soil water retention curve (SWCC) and suction stress characteristic curve (SSCC), he believes that suction stress is the internal stress of soil mass, it includes all the possible physical and chemical mechanism that contribute to intergranular stress and effective stress. The concept of suction stress expands the effective stress expression of Bishop; this innovative research achievement unites the theory of saturated soil and unsaturated soil.

Professor Lu introduces the latest experiment method in curve test at the end of his report. He shows new rapid measuring instrument for testing SWCC. The theories and methods put forward by Professor Lu are applied in many key projects. Researchers from IRSM have a heated discussion with Professor Lu about related topics after his report.

Professor Ning Lu graduated from Department of Civil Engineering of Colorado School Of Mines with his Doctor’s degree in 1991; he is a famous expert in unsaturated soil mechanics and hydraulics. Professor Lu has long been engaged in the monitoring, analysis and prediction of unsaturated soil mechanics, and coupled seepage-stress and shallow landslide. Lu develops rapid measuring instrument for SWCC and permeability coefficient, the instrument shortens the coefficient measuring time and promotes the development of unsaturated soil mechanics and hydraulics. He cooperated with USGS in applying unsaturated soil mechanics theory to the monitoring and prediction of shallow landslide. The Chinese version of Unsaturated Soil Mechanics written by Lu is published by Higher Education Press. With his outstanding achievements, Professor Ning Lu wins Normal Medal and J. James Croes Medal in 2007 abd 2010.