Hydro-Compaction Definition (Hydrocompaction) The term “Hydro-Compaction” or “Hydrocompaction” in engineering geology refers to the process whereby soils collapse upon saturation. Hydrocompaction can also be called “Hydro-Consolidation.”

Twinning Definition Twinning is the observed intergrowth of multiple crystals in a symmetrical fashion. This term applies to the examination of rock thin sections, in the field of optical mineralogy.

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

Total Petroleum Hydrocarbons (TPH) Total Petroleum Hydrocarbons (TPH): The term “Total Petroleum Hydrocarbons” represents the complete carbon chain of hydrocarbon compounds that originate from petroleum. In general there are three ranges of TPH: Gasoline Range Total Petroleum Hydrocarbons (TPH-g); Diesel Range Total Petroleum Hydrocarbons (TPH-d); and Oil Range Total Petroleum Hydrocarbons (TPH-o). Gasoline range TPH represents the…

Soil Creep Definition Soil Creep is a type of landslide that entails the slow and gradual movement of a soil mass (or even some loose rock) materials.

Triggered Creep In the field of geology, the term “Triggered Creep” refers to a type of creeping landslide, usually along a fault line, that is triggered by a source of seismic activity.