The field of engineering geology is a specialty of science of geology. Engineering geology combines aspects of both geology and soils engineering into one discipline of earth science. One of the main applications of the discipline of engineering geology is hillside construction. The responsibilities of the geologist and soils engineer include the following:
Subsurface exploration to determine type and distribution of soil and bedrock
Determination of soil and bedrock characteristics through laboratory testing
Evaluation of the geologic structure of the bedrock pertaining to slope stability, retaining wall design and pool shell design
Evaluation of gross and surficial slope stability
Identification of the recommended bearing material and establishing design values for bearing support
Surface and subsurface drainage control recommendations
Setback recommendations from ascending slopes
Foundation and shell setbacks to descending slopes
Grading recommendations
Recommendations for temporary excavations and shoring
Recommendations for construction of concrete pool decking
Groundwater Evaluation
Most governmental agencies require the signature and stamp of both a geologist
and soils engineer in order to prepared a geologic and soils engineering report
for construction in hillside areas. The area of responsibility is divided
between the geologist and soils engineer, resulting in some overlap of duties
and the requirement for coordination of efforts.
Geologist - Within the state of California, two licenses are required for
practicing in the field of engineering geology. The geologist must obtain a
license as a “Registered Geologist” and also a license as a “Certified
Engineering Geologist”. The licenses are issued through the Department of
Consumer Affairs. The geologist’s responsibilities include identification of
earth materials, determination of geologic structure, planning and execution of
the field exploration program and seismic hazard evaluation. The geologist and
soils engineer also confer on determining the proper bearing material for the
proposed structure, methods of stabilization of slopes and design
recommendations for construction.
Soils Engineer - The soils engineer can have several types of licenses.
The most common license necessary to practice soils engineering is the “Registered
Civil Engineer, R.C.E.”. Within the City of Los Angeles, this is the only
license necessary to prepare and sign soils engineering reports. The soils
engineer can also obtain a specialty license, “Geotechnical Engineer”. The soils
engineer’s responsibilities include laboratory testing of the earth materials,
engineering analysis and foundation design value assignment. The soils engineer
is also responsible for monitoring and testing the placement of compacted fill.