Abstract：Engineering geomechanics is a subject aiming at investigating generalized deformation and failure processes of geological body for engineering problems. Due to geological body inherent characteristics of discontinuity，inhomogeneity，coupled fluid-solid and unknown initial state，key scientific issues in engineering geomechanics are how to judge current state of geological body，how to describe mechanical properties of geological body，and how to simulate the evolution from continuous to discontinuous failure process. Researches in the area of engineering geomechanics should take geology as the foundation，take mechanics as the analytical tool，and its aim should face engineering. The engineering problems to be solved include investigating the geometrical and mechanical properties of geological body，developing the analytical method for geological body stability，and providing the design basis for geological engineering as well as the prediction and forecast scheme. Whether model experiments or simulation results of experiment can answer engineering questions is determined by the extent to identification of geological conditions. But experimental studies can be recognized as a powerful tool to verify the results of numerical simulation；and geological investigation and spot survey are indispensable parts in engineering geomechanics. The mechanical classification of geological body embodies the underlying role of geology，and is able to quantitatively represent the geological environments. The construction of mechanical models，which meets engineering requirement，needs to consider rock masses with discontinuity，rock and soil aggregates as well as the interaction between flow in fractured rock and rock masses. The extraction of measurement parameters，development of approaches to obtain these parameters，and research on relevant test devices require the participation of geomechanics. While present mechanical models are improved or new models are developed，more attention should be paid to the verification and application of new methods.
