The science that applies laws and principles of physics, especially continuum and particulate mechanics and hydraulics of porous media, to solve problems encountered in civil engineering that are related to force-deformation behavior of soil and the flow of fluids through soil. Civil engineers use the term soil for a naturally occurring multiphase material consisting of gas or liquid and solid particles, whether or not the material supports plant life. The term geotechnics or geotechnical engineering refers to a subspecialty of civil engineering that combines the disciplines traditionally known as soil mechanics, soil dynamics, rock mechanics, earthwork engineering, and foundation engineering for the design or analysis of natural or constructed facilities of, in, or on rock or soil.