“Effective Stress” (σ’) is a geotechnical engineering term. Effective Stress is a function of “total stress,” and is due to the solid particles of soil. Effective stress represents an excess of stress above pore-water pressure (or neutral stress).
Effective Stress = Total Stress – Pore-Water Pressure.
Volcanology Volcanology: Volcanology is a branch of geology that focuses on the study of volcanos. In volcanology, geologists conduct field and laboratory investigations to learn about continental, coastal, and submarine volcanic activities. In fact, volcanology ties into many other branches of geology. For instance, a volcanologist may study the geochemistry of igneous rocks, such as…
Gravel Blanket in Methane Mitigation A gravel blanket is a 2-inch or 4-inch thick layer of gravel, sand, or approved material that transmits methane soil gas to the horizontal sub-slab perforated pipes and verticle vent riser of a passive methane mitigation system.
Stratosphere Stratosphere: The stratosphere of a terrestrial planet is the second-lowest member of the atmosphere. On Earth, the stratosphere starts atop the troposphere at approximately 10 kilometers above mean sea level, and terminates roughly 50 kilometers above mean sea level. In fact, geologists understand that the Earth’s ozone layer exists within the stratosphere, which absorbs…
Liquefaction Liquefaction: Liquefaction is the process by which there is: (1) a sudden and significant decrease of shear resistance in a soil sample (cohesion-less); (2) a sudden (but temporary) increase of the pore-water pressure of a substance; and (3) a solid mass of soil that is transformed into a fluid state mass. In the event…
Regression Regression: In geology, regression is the formation of a specific sequence of sedimentary and metamorphic layers, that are the result of ocean water withdrawing from the land. To illustrate, when regression occurs over millions of years, geologists find a layer of limestone, overlain by shale, and overlain again by limestone. The opposite of regression is…
Vent Riser in Methane Mitigation Vent Riser in Methane Mitigation: As per the Los Angeles Department of Building and Safety (LADBS) Methane Code, Ordinance Number 175790, a vent riser is a cast iron or ABS pipe that runs through the building walls (vertically). A vent riser is part of a methane mitigation system and has…
