Rotational Slide (Slump) Definition Rotational Slide (Slump):  A rotational slide is a type of landslide movement that occurs in a turning moment, about a pivot point that is above the center of gravity. This is typically due to an increased normal force on a slope, as well as a reduced cohesion factor of the soil…

Passive Methane Mitigation Passive Methane Mitigation: Passive systems refer to the non-mechanical and non-electric components of the methane mitigation process. These components remove the vapor intrusion risks of methane soil gas migration into buildings atop Los Angeles Methane Zones and Methane Buffer Zones. In fact, methane testing results typically indicate the necessity for a passive…

Rigidity Definition Rigidity – In geotechnical engineering and engineering geology, rigidity represents the ratio of the shear stress and the amount of angular rotation that it produces, within a rock sample.

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…

Intrusive Rocks In the volcanology branch of geology, intrusive rocks are igneous rocks that form and crystallize under the Earth’s ground surfaces, within other geologic formations. In fact, intrusive rocks form by the process of magma shooting through pre-existing sedimentary, igneous or metamorphic rocks. For instance, a pegmatite dyke or a batholith. On the other…