Design Methane Concentration: In accordance with the Los Angeles Department of Building and Safety Methane Code, Ordinance Number 175790, a Design Methane Concentration is the highest recorded concentration of methane soil gas detected during the course of methane testing on a property. The Design Methane Concentration is what defines the level of methane mitigation applicable to a subject site.
What is a Concrete Gravity Dam? A Concrete Gravity Dam is also known as “Gravity Arch Dam,” and is a freshwater-retaining concrete structure that has a wider footing (base) than the top-section. The purpose of a Concrete Gravity Dam is to maintain a low center of gravity, in order to avoid collapsing in the event…
Asthenosphere Asthenosphere: The asthenosphere underlies the lithosphere. The Asthenosphere comprises the upper mantle, where isostatic adjustments are made, and where magma is generated. It is also in this part of the earth, where seismic waves strongly attenuate.
Lumber Moisture Content Grade Lumber moisture grading is a manufacturer-provided value of moisture content, for consumers and contractors to use. There are five (5) lumber moisture content designations (S-GRN, S-DRY, KD, MC 15, and HT). Lumber Moisture Grading Lumber grade “S-GRN” stands for “surface green,” which means it is not dry, and has a moisture…
Seismic Moment Seismic Moment: In the seismology branch of geology, seismic moment represents a measure of the size of an earthquake, depending on the area of rupture, the rigidity of the rock, and the amount of slip from faulting.
Sedimentary Rock Definition In geology, the term “Sedimentary Rock” refers to the classification of rock that is the result of the gradual consolidation and deposition of loose particles of other rock classifications (igneous or metamorphic). Alternatively, sedimentary rocks can also form by the accumulation and precipitation of other natural chemical solutions in a depositional environment….
Retaining Wall Retaining Wall: A structure that provides the support needed to hold (in place) a mass of earth, preventing it from moving downhill. Retaining walls are relatively rigid structures comprising footings and a drainage system, in order to retain the soils between two different elevations. Updated May 25, 2020. Construction & Design A lot…
