Representative Projects

Union Pacific Railroad Bridge

Arroyo provided an engineering geology and geotechnical engineering study for the replacement of a 755-foot long railroad bridge over the Los Angeles River and a 282-foot bridge over the Dominguez Channel. The geotechnical investigation included the development of drilling work plans, drilling safety plans, construction of temporary diversion dikes in the river channel, soil logging, soil sampling, borehole abandonment, evaluation of nearby active faults, borehole geotechnical and geophysical testing, probabilistic seismic hazard analyses, quantitative liquefaction and settlement estimates, detailed pile design recommendations, borehole geophysical test report and foundation report.

Kanan Road Interchange

This project won the Southern California APWA Traffic Congestion Mitigation Project of the Year in 2007. Arroyo performed geotechnical investigation that included development of drilling work plans, permit acquisition, traffic control, soil and rock logging, sampling, laboratory geotechnical tests, and foundation recommendations for highway improvements consisting of removal of existing off-ramps, relocation and widening of streets, construction of bridges and relocation and construction of new on- and off-ramps.

Boeing Maintenance Facility

Arroyo performed geotechnical investigation for an aircraft driveway consisting of 1,100 lineal feet of flexible asphaltic concrete pavement to carry an empty Boeing 717 aircraft across Lakewood Boulevard. The investigation included coordination of fieldwork and clearance with the Long Beach Airport, excavating, sampling and logging of four 14-inch diameter bucket auger borings, geotechnical laboratory testing, and recommendations for pavement design in accordance with FAA rules and regulations.

SCLA Runway Improvements

Arroyo performed geotechnical investigation in accordance with FAA regulations for the proposed 2,000-foot extension of Runway 17/35 and for new pavement design and rehabilitation of Taxiway Bravo. The Runway 17/35 additions were designed to accommodate Airplane Design Group V aircraft (Boeing 747-400) with a design takeoff weight of about 870,000 pounds. The fieldwork required drilling, sampling and geologic logging of thirty-two 18-inch diameter bucket auger borings to evaluate subsurface conditions. CBR design values and pavement design recommendations, in addition to laboratory test results and engineering analyses, were included in the report.

Balcom Canyon Road Failure

The project consisted of an engineering geology and geotechnical engineering investigation of distress to Balcom Canyon Road between South Mountain and Bradley Roads. The investigation included field mapping, development of temporary bulldozer roads for drill rig and backhoe access. Fieldwork also included excavation, sampling and detailed geologic logging of 24 backhoe test pits, excavation, sampling and downhole logging of 18 bucket auger borings. Geotechnical laboratory testing was conducted, and deep-seated slope stability analyses were performed. Cross sections were developed, and recommendations for repair of the roadway and partial stabilization of the landslides were provided.

Alta Canyada Road

Arroyo performed geotechnical investigation of distress to Alta Canyada road due to the failure of an adjacent slope. The fieldwork included geologic mapping of slopes below the road surface, drilling, soil sampling, preparation of a geologic cross section, computerized slope stability analyses to determine the deep-seated factor of safety of the road surface and recommendations for stabilization.

Above Ground Water Tank

The proposed above ground water tank for a new casino was located within a State of California Alquist-Priolo Fault Zone and County of Riverside Fault Hazard Zone for the San Gorgonio Pass Fault. The investigation included a 300-foot, 11-foot deep trench to identify potential faults. Recommendations were made about mitigation strategies as required. Seismic hazard analysis included the use of FRISKSP, EQFAULT, and EQSEARCH to locate all active faults within 15 kilometers of the site. Soil profile classification, seismic coefficients, and near source factors were determined in accordance with UBC requirements.

New Sanitary Sewer System

Arroyo performed geotechnical investigation services for 89,000 lineal feet of new sanitary sewer system to replace septic tanks. The investigation consisted of 70 exploratory borings, soil sampling and logging, geotechnical laboratory testing, engineering analyses, recommendations for trench shoring, and bedding and backfill requirements.

Interstate 5 Sound Walls

Arroyo performed geotechnical investigation for proposed soundwalls along Interstate 5. The fieldwork required site inspection, clearance with homeowners (as boring locations were in their backyard), soil sampling and logging of 6 bucket auger borings using a mini rig, 2 hand dug borings, geologic cross sections, and recommendations for foundation design considering vertical and lateral load supporting capacities.

Aliso Creek Soundwall Feasibility Study

For two segments of sound walls proposed behind residential backyards and on top of slopes, Arroyo investigated surficial and global stability of the slopes as well as the foundation design. Six soil borings were performed to evaluate subsurface soil and bedrock conditions. Using the developed geologic cross sections, detailed analyses were conducted to assess the slope stability. The most economical foundation type was recommended and the foundation responses under the specified vertical and lateral loads were determined.

Parking Structure No. 2 in Park Place

For the proposed 6-story parking structure in the City of Irvine, California, with a subterranean half-level, Arroyo performed field investigation (drilling, sampling and logging of nine borings to evaluate subsurface soil conditions to a maximum depth of 70 feet), a probabilistic seismic hazard analysis to evaluate the ground motion, and engineering analyses to provide recommendations for foundation design and construction. The presence of thick compressible clayey alluvium required driven 14-inch square precast prestressed concrete piles.

Camp Conrad-Chinook

The project constructed 13 one-story cabins on the 18-acre campsite. The investigation included fieldwork, a laboratory testing program, recommendations for seismic design of proposed structures in accordance with UBC design criteria, discussions of the corrosivity and chemical attack potential of onsite soils, and recommendations for general site grading including subgrade preparation, fill placement and site drainage.

CSU Sacramento

Energy Facility

Generator