Introduction to geological engineering

Welcome to Introduction to Geological Engineering

Geological engineering is the engineering science of applying engineering principles to the study of geological materials as part of the engineering design of facilities including roads, tunnels, and mines especially as related to minerals and mineral products. Some see it as a merging of the disciplines of geology and engineering and material science, but, while it includes aspects of all, it has several specializations unique to the field.

Geological engineers are particularly prized in the field of mining, including the fields of mine development, exploration, and operation. Geological engineers conduct slope stability analysis, and design remediations for unstable slopes including landslides for mining concerns and civil engineering projects. They are involved in both civil and mining tunneling projects. Some geological engineers choose to specialize instead on geotechnical or environmental aspects of the field.

Information

Geologic Hazards and Adverse Geologic Conditions

Typical geologic hazards or other adverse conditions evaluated by an engineering geologist include:

• fault rupture on seismically active faults ;
• seismic and earthquake hazards (ground shaking, liquefaction, lurching,lateral spreading, tsunami and seiche events);
• landslide, mudflow, rock fall and avalanche hazards ;
• unstable slopes and slope stability;
• erosion;
• slaking and heave of geologic formations;
• ground subsidence (such as due to ground water withdrawal, sinkhole collapse, cave collapse, decomposition of organic soils, and tectonic movement);
• volcanic hazards (volcanic eruptions, hot springs, pyroclastic flows, debris flows, debris avalanche, gas emissions, volcanic earthquakes);
• non-rippable or marginally rippable rock requiring heavy ripping or blasting;
• weak and collapsible soils;
• shallow ground water/seepage; and
• other types of geologic constraints.

An engineering geologist or geophysicist may be called upon to evaluate the excavatability (i.e. rippability) of earth (rock) materials to assess the need for pre-blasting during earthwork construction, as well as associated impacts due to vibration during blasting on projects.

Methods and Reporting

The methods used by engineering geologists in their studies include

• geologic field mapping of geologic structures, geologic formations, soil units and hazards;
• the review of geologic literature, geologic maps, geotechnical reports, engineering plans, environmental reports, stereoscopic aerial photographs, remote sensing data, Global Positioning System (GPS) data, topographic maps and satellite imagery;
• the excavation, sampling and logging of earth/rock materials in drilled borings, backhoe test pits and trenches, fault trenching, and bulldozer pits;
• geophysical surveys (such as seismic refraction traverses, resistivity surveys, ground penetrating radar (GPR) surveys, magnetometer surveys, electromagnetic surveys, high-resolution sub-bottom profiling, and other geophysical methods); and
• other methods.

The field work is typically culminated in analysis of the data and the preparation of an engineering geologic report, geotechnical report, fault hazard or seismic hazard report, geophysical report, ground water resource report or hydrogeologic report. The engineering geologic report is often prepared in conjunction with a geotechnical report, but commonly provide geotechnical analysis and design recommendations independent of a geotechnical report. An engineering geologic report describes the objectives, methodology, references cited, tests performed, findings and recommendations for development. Engineering geologists also provide geologic data on topograpic maps, aerial photographs, geologic maps, Geographic Information System (GIS) maps, or other map bases.