The book addresses fundamental issues faced by experimentalists, modelers and engineers interested in different physical, mechanical and transport aspects of biological tissues and chemically active geological materials, mainly clays and shales. The focus is on the couplings between electro-chemical and mechanical aspects involved in swelling and chemical consolidation. Emphasis is laid on the influence of these phenomena on mechanical properties and on transport properties.Applications in geo-environmental and geotechnical technologies, including nuclear and hazardous waste isolation, oil recovery, engineering geology, are addressed directly or implied. Control of long term effects of surgery and mechanical performance of prostheses may benefit from the modeling of irreversibilities that are of utmost importance in geological materials. Conversely, understanding the self-regulation mechanisms of biological tissues may be helpful in the design of efficient engineering materials.