Client:   Chevron Land Development
Location:   Brea, California
Surface Area: 124 acres

La Floresta was a Chevron Land Development project in Brea, California, that comprised approximately 124 acres in what was once Unocal’s Hartley Center research facility and Manassero Farms. The site was developed primarily as a community of single family detached homes, courtyard homes, condominiums, and apartments. The project required more than 14 years to complete. Albus & Associates, Inc. (AAI), was involved from the beginning, during site characterization and feasibility studies, to final paving of the streets.

Challenges encountered and overcome during site development included demolition of the research facility, including oil processing systems, abandonment of oil wells, removal and remediation of soil impacted by oil production contaminants, protection of a live 96-inch-diameter MWD water line, and the typical daily challenges of grading the site and the construction of the residential structures and associated improvements. AAI was there every step of the way.

Grading the site required the removal of contaminated soil and surficial soil deemed unsuitable to support the proposed improvements. Removals and filling of excavations were accomplished using heavy equipment.

AAI geologists monitored and mapped removals and our field technicians monitored fill operations and performed field density testing to assure adequate compaction criteria was being met.

One of the biggest challenges was protecting an existing 96-inch-diameter MWD water line that was to have up to 5 additional feet of fill placed over it. AAI investigated the soil conditions around and under the pipe and determined that earth materials below the pipe were prone to consolidation under the weight of the additional fill. AAI designed a system that replaced up to 8 feet of existing soil over the pipe with geo-foam, reducing the weight of the existing materials over the pipe and allowing the safe placement of additional fill to design grades. The geo-foam system incorporated elements to prevent the trapping of water under the foam. The client was pleased with the outcome and a paved road into the development has been constructed over the geo-foam.

During the investigation of the old stairs the conditions of the existing wood framing and concrete pedestals were assessed. The wood framing was found to be heavily weathered and abundant areas had wood rot, especially at the ends close to, and in contact with, the slope face. Using hand-augers, the embedment depths of the concrete pedestals were determined. Other elements of the stairs were observed and evaluated for reuse.

It was determined that the concrete pedestals were adequate to support new and heavier structures, and that the rest of the stairs were too weathered or under-designed to be structurally sound, except for the concrete landings at the upper and lower terminus ends. Our recommendation to the client was for total replacement, except for the pedestals.

We prepared a stairs repair plan, designing two replacement stairs, one with an overall rise of about 29 feet, and one with a rise of about 20 feet. The surveyed locations of the upper and lower concrete landings and of the tops of the concrete pedestals were the control points for the designs. 3” x 12” urethane-sealed glue-lam beams were specified for the frame members. Short concrete block retaining walls were designed under the stairs to protect the glue-lam frame from contact with the dirt slope. Pre-cast lightweight concrete steps were specified for the stair risers, and components by Trex, a decking material company, were specified for the railings. The Trex elements are made from recycled plastic, reclaimed sawdust, and a binder material, making them eco-friendly and highly resistant to weathering. The construction plan was reviewed and approved by the City Building Department.

With an approved repair plan in hand, our company prepared contractor bid packages for the construction and solicited various local contractors to submit bids for the work. Construction bids were reviewed, and at our recommendation, Seashore Construction, Inc., of Santa Ana was awarded the contract.