Frequently Asked Questions
Engineers and Geologists are licensed in the State of California by the Board of Professional Engineers, Land Surveyors, and Geologists (BPELSG). Other states have similar licensing boards. A minimum of 5 years professional work experience, passing several licensing examinations, and requisite college degrees in engineering or earth science are required. Upon achieving licensing, a geologist can further specialize in hydrogeology, engineering geology, and/or geophysics. An engineer can further specialize in geotechnical engineering, structural engineering, and/or traffic engineering.
Our key personnel are licensed as:
- Professional Geologists
- Engineering Geologists
- Civil Engineers
- Geotechnical Engineers
In general, foundations are the most critical and costly element of a building or structure. Anytime the potential for ground deformation is suspected, a geotechnical engineer and/or a geologist should be consulted.
Common geologic and/or geotechnical indicators of potential adverse subsurface conditions include parallel ground cracks, leaning retaining walls, cracks in building walls, uneven floors, offset door frames, etc. Additionally, ponded water or erosion could lead to ground movement or deformation. A geotechnical or geologic evaluation could be needed in areas identified within a geologic hazard zone for landsliding, liquefaction, and/or fault rupture.
An engineering geologic report presents an analysis of the geologic setting and local geologic factors that influence a site. These evaluations are tailored to assessing how the soil and/or rock came to exist under a site and whether that material will remain in place. It is intended to assess geologic hazards such as landslides and fault related ground deformation. Generally speaking, if specific geologic hazards are potentially present on or near the subject site, an engineering geologic evaluation would be required by the local reviewing agency (i.e. town, city, or county).
A geotechnical engineering report is focused on the association between a structure's foundation and the soil or rock material strength characteristics that influence the performance of the foundation. The geotechnical engineering report typically follows an engineering geologic assessment.
As duly licensed engineering geologists and geotechnical engineers, we offer both types of evaluations and often conduct both assessments in a single standalone report, which generally provides better value to clients than standalone, independent assessments.
Preparing a geotechnical or engineering geologic study report typically consists of three main phases:
- Literature/map review and field exploration
- Laboratory testing, engineering/geologic analysis, and calculations
- Drafting and report preparation
A reconnaissance level evaluation for real estate transactions or initial assessments generally entail document review, site reconnaissance, and documentation. Reconnaissance level evaluations typically can be completed within two weeks. More detailed studies typically take 6 to 8 weeks after the fieldwork is completed. Complex geologic and geotechnical evaluations could take several months to complete.
The cost of a study is dependent upon numerous variables and geologic conditions that can make the cost vary substantially from one site to the next. A very rough cost approximation for a reconnaissance level evaluation would be in the range of $2,500 to $4,500. A non-complicated geologic or geotechnical evaluation would typically range between $6,000 - $12,000. Complex geologic and geotechnical evaluations could exceed $20,000.
The geotechnical engineer or engineering geologist should be involved in the plan development and construction phases of the project.
During the planning phase, the consultant would collaborate with the design team, respond to peer review comments, and review project plans and specifications for conformance with design recommendations.
During construction, the consultant would observe the pertinent aspects of the construction to assess whether the actual subsurface conditions remain consistent with the interpretations made as part of the study and to observe construction for conformance with design recommendations.
A geotechnical and/or engineering geologic report is developed by interpolating and extrapolating between points of observation (typically boring or pits). Interpretations drawn from those points of observation are an initial assessment and the actual site conditions can differ. Because earth materials can vary substantially over short distances, validation of the interpretations are essential and can only be accomplished during the construction process.
Observations during construction add value to the project by:
1) Documenting whether the intent of the recommendations are being implemented
2) Allowing the geologist/geotechnical engineer to make additional recommendations should the actual subsurface conditions vary from those anticipated
A reasonable budget estimate for construction observation services is about 5% of the construction cost for the respective geotechnical elements (foundations, retaining walls, drainage systems, etc) associated with the project and roughly 10% of the earthwork or grading construction cost. These are only rough approximations and actual costs will range substantially based upon the means and methods of construction, site conditions, and adherence to the intent of the geologic and/or geotechnical recommendations.