At the invitation of Institute of Rock and Soil Mechanics(IRSM), Professor Nasser Khalili from The University of New South Wales(UNSW) visits IRSM on November 16, he also makes an academic report with the topic On the Mechanics of Unsaturated Soils.

Professor  Khalili has long been engaged in the research of the theory, testing and numerical value of Unsaturated Soils, he has high academic level and rich engineering experience. With his long-term deep research on the effective stress theory of unsaturated soils, Professor  Khalili puts forward the unsaturated soil effective stress formula expressed by suction; he has also done the effective verification of the formula.

Professor Khalili introduces the development of important behavior characteristics and effective stress theories of unsaturated soils, he stresses that the study on effective stress is the most basic and important one in the research of unsaturated soils, it is the base of studies on other characteristics of unsaturated soils. Starting from the effective stress principle of saturated soil, Professor  Khalili elaborates on the current effective stress theory of unsaturated soils, he points out the main defects of the current effective stress theory. Through the summary and analysis on a large number of testing phenomena, Professor  Khalili puts forward the effective stress of unsaturated soils, he then continues his research by using unsaturated soil constitutive model based on the effective stress.

After the report, participants of the meeting have an exchange of their research direction with Professor Khalili. To strengthen the cooperation on the theory research of unsaturated soils, Professor Khalili also invites researchers from IRSM to have an academic visit to Australia.