San Diego Community College District: Rock-hard soil leads to rock-solid solution as Bomel Construction completes Miramar College parking structure
San Diego Community College District: Rock-hard soil leads to rock-solid solution as Bomel Construction completes Miramar College parking structure
SAN DIEGO, March 12, 2018––There’s no substitute for experience. And when it comes to design-build parking structures, Irvine, Calif.-based Bomel Construction has lots of it, decades to be exact.
A thorough understanding of the many methods to successfully design and build a garage within a customer’s budget and schedule earned Bomel Construction the contract to erect and complete a parking structure at fast-growing Miramar College in San Diego.
Moreover, Bomel’s ingenuity in the planning of the 499-stall, design-build project was so sharp that it blew away the competition. Unlike other bidders, whose plan required a high-volume excavation, Bomel and design-build partners Choate Parking Consultants (architect) and Coffman Engineers (structural engineer) had a faster and less costly solution.
“The other bidders took the Request for Proposal literally, which said there needed to be a first and second level with entrances on each,” said Adam Perrington, Bomel’s project manager.
Saving time and money
“Because of the 18 feet of elevation change across the site, we did not propose a flat slab on grade,” Perrington explained. “We simply followed the natural slope of the formational material, so the garage would ramp up from the south to the north. This simple scheme would require only a partial first level and a second level that extends above the first. This method reduced the need to do a tremendous amount of excavation, which the other bidders were proposing. It saved time and money, and convinced the district that we were far and away the best team for the new parking structure.”
Knowing the territory
Having worked on other buildings at Miramar College during the last several years, Perrington had a firm grasp of the density of the local terrain, Linda Vista Formation in geological terms, and how important it would be to limit the amount of excavation.
“In our previous projects at Miramar, classrooms A and B, and the math and science project in 2010, we had an excavator with a 15,000-lb. breaker and it literally was not putting a dent into the subgrade,” he explained. “At first, we had a single long shank or ripper at the end of the excavator and it would only create dust leaving a shallow two-inch indent in the ground. We typically do not come across hard soil like this in the San Diego area.
“In the end, we used a bucket with tiger teeth, so instead of using one point and trying to pressure our way through the soil, we just kept hitting it with 16 hardened steel tips and it broke up the dirt like a chisel on ice. After we changed the plan of attack, the equipment started eating right through it.”
A similar scenario greeted Bomel’s crews when it was time to excavate for the parking structure after workers demolished three modular classroom buildings, finished grading and prepping the site pad and relocating 18 feet of utilities.
“There were rocks everywhere,” noted Emerson Flint, project manager at Choate Parking Consultants.
Perrington said “nature’s concrete” is the best term to describe the stubborn sandstone and conglomerate underneath the 120-acre college campus.
“Our grader was able to use a drum cutter to dig the footings which saved a lot of time and frustration,” he explained. “It ate through the formational material a lot faster than what would have happened with a breaker. It also broke down some of the cobble stones to an acceptable size.”
Faster finish
Bomel started construction on what Miramar College calls the G4 parking structure last March and finished in December, at least three months faster than what it would have taken the other project bidders. The rapid construction schedule not only saved the college money but allowed the parking structure to open nearly two months before the start of the spring semester.
The garage, which requires parking permits, opened December 4 on the southeast side of campus. G4 has 48 marked stalls for staff, nine disabled parking spots and 442 student-parking stalls. It is accessed by Gold Coast Drive from South Campus Drive and by Miramar College Driveway and Hillery Drive from North Campus Drive.
In addition to Perrington, the Bomel project team included Jim Sheffield, project superintendent; Manuel Mendoza, formwork superintendent; and Angela Byan, assistant project engineer.
“Bomel did very well,” Flint said. “They always do a great job on the finishes.”
The parking garage is the first one that Bomel completed at Miramar College. Bomel has built two other garages at two other district campuses.
The last decade has been a transformational period for the San Diego Community College District as it nears the completion of Propositions S and N, a $1.555 billion construction bond program. The capital investment plan has greatly modernized the built and natural environment at Miramar College, Mesa College and San Diego City College, and seven campuses of San Diego Continuing Education. As the second largest of California’s 72 community college districts, the San Diego Community College District serves approximately 100,000 students annually.
Satisfied customer
District architect Lance Lareau enjoyed his latest experience with Bomel Construction.
“Bomel really knows how to build parking structures,” he said. “Everybody on the project was talking about the great progress being made. Bomel gets it done on time or ahead of time. The parking structure looks great.”
ABOUT BOMEL CONSTRUCTION: Established in 1970, Irvine, Calif.-based Bomel Construction Co. Inc. is widely regarded as the dean of design-build parking structure construction in the West and one of the largest concrete contractors in the United States. It placed 117th on Engineering News-Record’s ranking of the largest specialty contractors in 2017 in the U.S. In addition to its award-winning parking structure portfolio, Bomel is a one-stop source for all concrete construction needs. The company maintains a highly skilled staff for its structural, architectural and site concrete divisions. Bomel works directly for property owners, developers and general contractors. Its work includes a wide range of projects built at well-known casino-resorts, shopping malls, office buildings, mass transit centers, airports, universities and community colleges.