Terzaghi

Karl Terzaghi (1883–1963) was an Austrian-American civil engineer widely regarded as the founder of modern soil mechanics and geotechnical engineering. His work established key principles for analyzing the behavior of soils under load and laid the groundwork for reliable foundation design.

Terzaghi's most influential contributions include the effective stress principle, which posits that soil strength and deformation depend on the difference between the total stress carried by the soil and the pore water pressure within it (often written as sigma' = sigma - u). He also developed the theory of consolidation, deriving the one-dimensional consolidation equation and methods for predicting settlements and dissipation of pore pressure in saturated soils. In the area of bearing capacity, his theoretical framework provided a systematic approach to determining the maximum load a soil can safely support.

Throughout his career, Terzaghi bridged theory and practice. He conducted experimental work, supervised researchers, and authored foundational texts that shaped design practice for foundations, tunnels, earth dams, and earth-retaining structures. He held academic positions in Europe and the United States and helped establish geotechnical engineering as a distinct discipline, contributing to the growth of research institutes and professional societies.

Terzaghi's influence extends beyond his own writings; the field he helped create continues to rely on the effective-stress concept, consolidation theory, and rigorous experimental methods to analyze soil behavior under complex loading.