Bus Maintenance and Operations Base

Ninyo & Moore was retained to provide geotechnical consulting services for the design of a new Bus Maintenance and Operations Base facility. The proposed facility is designed to handle 250 bus vehicles, including 50 articulated buses. The proposed facility includes a 70,000 square foot, two-story maintenance building, a 12,000 square foot, single-story operations building, a engine rebuild shop, a vacuum shop, a brake check area, a bus wash and cleaning facility, and a revenue collection office. In addition, the project includes asphalt paved parking area for 425 automobiles and concrete-paved parking area for 280 buses. Our geotechnical services included a review of geologic and historical background information; drilling, sampling, and logging of 23 small-diameter borings; logging of six Cone Penetrometer tests; performance of laboratory tests to evaluate soil characteristics; geologic and engineering analyses; and preparation of a written report presenting our findings and geotechnical recommendations for the design and construction of the proposed structure. Geotechnical analyses performed for this project included an evaluation of the seismic design parameters, liquefaction potential, lateral spread, and settlement potential. We also provided geotechnical recommendations for ground improvements, structured foundations, site grading, asphalt concrete and portland cement concrete pavements, and soil corrosivity. Specific challenges associated with this project included the potential liquefaction hazard and groundwater table due to the location of the site adjacent to the Santa Ana River. Following the submittal of our geotechnical design report, we performed a pilot test program for the proposed stone column ground improvements at the site.