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 methane zone or methane buffer zone. And the purpose of a trench dam is to prevent the migration of methane soil gas through any permeations of a building foundation.
Geologic Time Scale The Geologic Time Scale is an international system used by geologists to classify and identify major geologic events and formations. The geologic timescale essentially categories the earth’s entire geologic (and biologic) history, within a series of defined eons, eras, periods, epochs, and ages. Updates & Maintenance The geologic time scale is continuously…
Consistency The term “Consistency” in the fields of engineering geology and geotechnical engineering means the degree of adhesion between soil particles within a sample, that are observed to resist deformation or rupture.
Effective Size (D10) “Effective Size” (D10) is an engineering geology term. Effective Size represents a diameter that directly corresponds to the percentage, by weight, of grains that equal to 10% on the grain-size diagram. To illustrate, 10% of the soil sample particles are finer-grained, and 90% of the sample particles are coarser than the “effective…
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…
“Toe” of a Slope Definition The “toe” of a slope is essentially the bottom, or baseline section, of the soil mass comprising the slope. It is also defined as the outermost margin of displaced material during a landslide. The toe of a slope is farthest away from the head scarp.
Plat Map Definition Plat Map: A plat map provides the metes and bounds of a parcel in a large tract (to scale), as well as the legal land-use rights and limitations. Additionally, it demonstrates locations of streets and public utility easements, as well as ingress and egress easements. And sometimes plat maps provide information about…
