geomechanics

Geomechanics is the science concerned with the mechanical behavior of earth materials under applied loads. It encompasses soil mechanics, rock mechanics, and geotechnical engineering, and focuses on how soils, rocks, and sediments deform, fail, and interact with structures and fluids. Its central goal is to understand stress, strain, stiffness, strength, and stability in natural and engineered earth systems, under conditions such as gravity, tectonic stresses, moisture changes, temperature, and time.

The material basis includes soils and rocks, with properties such as density, porosity, permeability, shear strength, stiffness, and compressibility. Key concepts include effective stress, constitutive models, and coupled processes like poroelasticity and thermo-hydro-mechanical-chemical interactions. Common analytical tools include laboratory tests (triaxial compression, oedometer, direct shear), field measurements, and numerical methods (finite element, finite difference, discrete element).

Common failure criteria include the Mohr-Coulomb criterion for soils and the Hoek-Brown criterion for rock masses, though many problems employ more advanced or site-specific models. Geomechanics also relies on in-situ stress estimation, pore pressure assessment, and time-dependent behavior such as consolidation and creep.

Applications cover civil engineering, mining, petroleum engineering, and environmental science. In civil engineering, geomechanics informs foundations, slopes, tunnels, and embankments; in mining and tunneling, it predicts rock bursts and instability; in petroleum engineering, it addresses wellbore stability, reservoir compaction, and hydraulic fracturing; in environmental contexts, it supports subsurface storage and containment projects.

The field is interdisciplinary, integrating geology, earth science, mechanical engineering, and computational modeling, and continues to develop through advances in experimental methods and numerical simulation.