“Liquid Limit (LL)” in the field of geological engineering, refers to the upper limit of the “plastic state.” This is a separation of the plastic phase and viscous liquid phase when measuring soil consistency. Mathematically, it is the water content (basing on the percent of dry weight), at which two sections of a soil sample (which are separate by a specific distance), minutely contact each other. However, they do not flow together when upon a sharp blow laboratory test.
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…
Control Panel in a Methane Mitigation System Control Panel of a Methane Mitigation System: A methane mitigation control panel is the brain behind the active mitigation system. In accordance with the Los Angeles Department of Building and Safety (LADBS) Methane Code, Ordinance Number 175790, a control panel synchronizes methane alarm units with sensors and the…
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.
Translational Slide Landslide Translational Slide: In the seismology branch of geology, a translational slide is a type of landslide movement that occurs predominantly along a planar surface. Alternatively, this movement can occur along gently undulating surfaces. For instance, the Palona Schist metamorphic bedrock on the eastern embankment of the former St. Francis Dam comprises an…
Thrust Fault Thrust Fault: In the field of geology, a thrust fault is a reverse fault in which the fault plane dipping angle is less than 45 degrees. Thrust faults are dip-slip faults, and can also be listric faults. For instance, the fault underlying the western embankment of the historical St. Francis Dam in Saugus,…
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…
