Field Exploration
Thorough geotechnical exploration is fundamental to the planning and design of structures. CEL has highly qualified professionals that are skilled in a wide variety of exploration techniques including: auger drilling, mud rotary drilling, rock coring, test pit excavations, cone penetrometer test (CPT) soundings, and geophysical methods. The preliminary geologic research performed prior to exploring a site is crucial in determining the most effective subsurface investigative method to utilize for a site based on the project requirements. back to list

Laboratory Testing
CEL has a full service geotechnical, construction materials, and asphalt laboratory in Oakland, California. Satellite laboratories located in Sacramento, Santa Rosa, and Modesto areas support the main laboratory. Geotechnical testing includes strength (unconfined compressive strength, direct shear), soil characterization (Atterberg limits, sieve analysis, moisture content, density), settlement/swell parameters (consolidation, swell, Expansion Index), and pavement evaluation (R-value). Specialized tri-axial shear and permeability testing can also be provided by CEL. back to list

Geologic Hazard Mitigation
CEL's geotechnical engineers utilize the geologic data, compare the client's needs, and confer with the design professionals to determine the optimal and most cost effective geotechnical alternatives for a project. Soil improvement, different foundation types, and grading options are analyzed. Methods for stabilizing existing landslides or unstable temporary cut slopes, dewatering, and reducing or eliminating liquefaction impacts, settlement potential, and expansive soils are researched. back to list

Soil Improvement
Soil improvement is sometimes a more cost effective method for mitigating adverse geologic conditions for a project. Soil improvement methods include:

• Soil treatment with lime or cement
• Reinforced soil mat with geogrid
• Surface and subsurface drainage
• Geopiers
• Overexcavation
• Deep dynamic compaction
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Geotechnical Alternatives
CEL's professional staff is capable of analyzing foundation alternatives and soil improvement methods to provide the best and most cost effective support system for projects. CEL has experience in residential structures, commercial and industrial complexes, and schools and hospitals. Foundations and retaining structures can include:

• Shallow spread footings
• Mat foundations
• Post-tension slabs
• Driven piles
• Drilled piers
• Micro-piles
• Soil cement
• Tubex piles
• Tiebacks
• Soil stabilization and buttressing
• Pressure grouted auger piers
• Reinforced earth retaining walls
• Soil nailing
• Foundation underpinning
• Reinforced earth mat
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Seismic Evaluation
Seismic design parameters are required for the design of new structures. Typically, UBC, CBC, or IBC seismic design parameters are sufficient for most projects. CEL can provide site specific seismic response spectra for OSHPD, DSA, or complicated projects requiring more detailed seismic analyses. CEL utilizes United States Geological Survey (USGS) and California Geologic Survey (CGS) methods coupled with FRisk analyses to provide a more detailed seismic evaluation of a site. back to list

Pavement Design and Maintenance
CEL provides asphalt and concrete pavement designs for highways, streets, and parking lots. Pavement recommendations in California follow Caltrans methods, whereas AASHTO design methods are utilized for the other states. These methods reflect requirements of many Highway Districts and State Transportation Departments, along with the Federal Highway Administration. Mitigation methods for unstable subgrade conditions can be provided, including utilizing geogrid and soil treatment with lime and/or cement. Pavement maintenance programs can be established for large facilities and cities. Pavement distress can be investigated and mitigation alternatives provided. back to list

Instrumentation Installation, Data Collection, and Analysis
CEL has state-of-the-art equipment to measure slope movement, movement of structures, and groundwater levels. Inclinometers measure slope movement in a casing installed in the earth. Tiltmeters measure the tilt of structures to determine movement of the structure. Piezometers measure water levels in the ground. CEL is capable of installing inclinometer casing, tilt plates, and piezometer casing. Automation of the instruments can be provided. Data is collected and analyzed by CEL's geotechnical engineers and geologists. back to list

Forensics and Distressed Structures
CEL's Geotechnical Division evaluates distressed structures to determine if soil conditions have caused distress to the structures. CEL Consulting evaluates distress to construction elements such as reinforced concrete, masonry, and structural steel. CEL's Geotechnical Division in concert with CEL Consulting can provide detailed evaluations for distress to structures, including residences, large buildings, multi-story structures, pipelines, and towers. back to list

Construction Monitoring
Construction monitoring services are required to ensure the recommendations contained in the geotechnical report are implemented during construction. These services include testing engineered fill for building pads, utility trenches, retaining wall backfill, and pavement areas. CEL provides observation during shallow foundation excavation, pier drilling, pile driving, soil improvement, tieback wall installation, and other foundation construction. CEL's Geotechnical Division and CEL construction inspection and testing group can provide full service construction monitoring services for projects. back to list