Geologic and Geotechnical Services
Typically, Coastal Geotechnical provides services for residential, commercial, and industrial projects ranging in size from small buildings or land parcels to very large structures and developments. Our clientele generally consists of homeowners, contractors, developers, architects, engineers, lawyers, governmental agencies, and insurance companies. The scope of assignment may vary from conducting a limited feasibility study to performing a comprehensive investigation including subsurface exploration, laboratory testing, detailed analyses and formulation of geotechnical recommendations.
RESIDENTIAL, COMMERCIAL, INDUSTRIAL, LAND PARCELS, LARGE STRUCTURAL DEVELOPMENTS, AND MORE
Site and Home Evaluations
Buying a home in the seismically active and landslide prone areas of Southern California can be a bit nerve racking. Our company can perform a site/home evaluation that would inform you of any potential geologic hazards that may exist. We typically perform a floor-level survey of the existing residence to give us an idea of how the house is performing, to date. We also review any and all available documents pertaining to the home/site, aerial photographs, and geologic literature. We provide you with a written report presenting our findings, and you are always welcome to gives us a call or come by our office to chat about any questions you may have.
Soil/Geologic Investigations and Foundation Engineering
We work with a large group of experienced drillers and excavators to enable us to tailor the proper investigation for your site in order to provide detailed geotechnical parameters to present to Structural Engineers and Architects for the design and construction of your site.
Geotechnical Investigations and Analysis for Landslides
We have been involved in investigations and analysis of slope failures and landslides ranging from small surficial slope failures a few feet deep to large ancient landslides causing catastrophic damage to residential and commercial structures. Review of stereoscopic aerial photographs and downhole logging of deep, large diameter borings by our geologic staff provides the necessary information that our geotechnical engineers can input into state-of-the-art computer programs to analyze whether a slope has an adequate factor-of-safety. We can also provide and install instrumentation can be utilized to determine whether landslide movement may be on-going. Based on the information gathered, a detailed analysis can be made as to what factors may have caused a slope to fail, and what appropriate mitigation measures may be taken to prevent future damage or repair existing damage.
Grading/Construction Observation and Testing
During grading, we provide qualified field technicians, experienced at working with grading contractors and certified to utilize sophisticated nuclear density testing methods as well as conventional sand-cone and drive-cylinder testing methods to provide quality control during placement of man-made fills on projects as small as a simple room addition to larger multi-lot tracts and subdivisions. We also provide the necessary inspections during construction of foundations, retaining wall subdrains, retaining wall backfill, and utility trenches as required by most city and county agencies, to confirm compliance with the design as determined by our testing and the requirements of the Architect, Engineer and city and county codes.
We can also provide the proper geotechnical parameters for the design and construction of both public and private roadways, and perform inspection and testing of the underlying soils to confirm compliance by the contractor with the design parameters and plans. We can analyze and investigate paved surfaces that have experienced distress due to failure of the subgrade soils or inadequate pavement design and /or construction and provide repair recommendations.
Fault Studies, Liquefaction Analysis, and Groundwater Studies
We have the capacity to perform detailed fault studies to determine whether an active, potentially active or inactive fault exists on or in the vicinity of your site, and provide the appropriate seismic design parameters for use by architects and structural engineers in the final design of your structure. Our up to date library provides the necessary background information on most sites throughout California, and if necessary, our experienced geologic staff can perform detailed mapping of trenches excavated for the purpose of exposing fault traces.
A form of ground movement, known as liquefaction, and is relatively common along the sandy beach areas and alluvial valleys, occurs as a result of seismic forces. Damage to a structure as a result of liquefaction can potentially be catastrophic. We can identify when and where the potential for liquefaction exists, utilize the proper site investigation and sampling techniques, and can perform detailed computer aided analysis to evaluate the risk of liquefaction and provide the proper design information to the architect or structural engineer so that the risk of damage is minimized.
Groundwater studies are performed and/or monitored by our Registered Hydrogeologist. These studies are essential to providing the necessary detailed information to investigate the sources and effects of groundwater on planned or existing improvements.
Second and Third Party Reviews
We can review another professional’s geologic/geotechnical report if you are looking for a second opinion. We are also commissioned by certain cities to perform third party reviews of geologic/geotechnical investigations in order to make sure they are in compliance with current industry standards and address appropriate issues relating to the area.
Forensic Investigations for Distressed Studies
Foundation distress can be caused by a wide variety of factors, and determining the exact case and nature of any ground movement is essential to providing the proper repair concept. To begin with, we perform an evaluation of your property, which will typically include a detailed site inspection with photographic documentation of distress, researching documents, either in our own library or at the local building department, and a manometer (floor level) survey to determine whether there are indications that adverse geotechnical conditions may be contributing to the distress and provide guidance in whether a detailed investigation is necessary.
Following the evaluation, we work with a wide variety of subcontractors to enable us to investigate problems such as foundation movement caused by heave and shrinkage of expansive soils, settlement of structures due to poorly compacted fills underlying the structure and movement related to slope movement and landslides.
After determination of the type and nature of ground movement that has caused distress to your structure and its foundations, we can provide the geotechnical guidance and recommendations to providing a long-term and cost-effective solution.