Trench Dam Trench Dam: Per the Los Angeles Department of Building and Safety (LADBS) Methane Code, Ordinance Number 175790, a trench dam is part of a methane mitigation system. A trench dam is essentially a subsurface barrier that exists within a furrow or ditch, that is adjacent to the foundation of a building in a…

Well Graded Soil Well Graded: In the soil classification process of geology, well graded soil represents a sedimentary soil sample that fully displays all of the possible grain sizes for that soil classification, in accordance with the Unified Soil Classification System (USCS). For example, a well graded sand (SW) comprises fine, medium, and coarse grains…

Mesosphere Mesosphere: The mesosphere of a terrestrial planet is the third member of the atmosphere. On Earth, the mesosphere starts atop the stratosphere at approximately 50 kilometers above mean sea level and terminates roughly 85 kilometers above mean sea level. The mesosphere is where most meteors burn to determination. Like the stratosphere, the air in…

Direct Shear Test A Direct Shear Test is a geotechnical engineering laboratory procedure that measures the shear strength value of a soil sample.

Cation Cation: In the fields of chemistry and geochemistry, a cation is a positively charged ion. The oppositely charged ion is an anion.