State Route 22 Widening

The Orange County Transportation Authority (OCTA) and Caltrans constructed improvements to the Garden Grove Freeway (SR-22) in Orange County. These improvements include the widening of the freeway and the construction of HOV lanes.  This project was the first Design-Build project on an active Caltrans right-of-way. Group Delta Consultants provided geotechnical engineering services for the Program Management Team of the Design-Build RFP.

Project Highlights:

• 33 Bridge Preliminary Foundation Reports
• More than 10 miles of walls
• Oversight of Design Build Contractor submittals
• Performed Quality Assurance Testing during construction

The Garden Grove Freeway (SR-22) HOV Lane Design Build Project was selected as the 'Project of the Year' by the Orange County Section of the American Society of Civil Engineers (ASCE).

West County Connectors

The Orange County Transportation Authority (OCTA), in partnership with the California Department of Transportation (Caltrans), started final design on the West County Connectors project. The project traverses the cities of Garden Grove, Westminster, Seal Beach, Los Alamitos and the community of Rossmoor. It was initiated to link high occupancy vehicle (HOV) lanes/carpool lanes on the San Diego Freeway (I-405) with those on the Garden Grove Freeway (SR-22) and San Gabriel Freeway (I-605) to create a seamless HOV connection amongst the three freeways.

Group Delta Consultants prepared foundation reports for replacement of 2 existing bridges and for a new 5-span HOV Connector bridge. Due to high seismic demand and poor soil conditions, bridge design included 4 foot diameter Cast in Steel Shell (CISS) pile foundations to depths of up to 100 feet, and included design of a load testing program. Other bridge foundations included steel H-piles and prestressed concrete piles.

To address long term settlement and low bearing capacity, we prepared 3 foundation reports recommending the use of lightweight cellular concrete fill in lieu of costly ground improvements and long settlement waiting periods for thousands of feet of Pre-cast Lightweight (PCLW) Fill Retaining Walls.

Construction of these improvements is scheduled to begin in 2010 and be completed by 2013.

Ocean Blvd / Terminal Island Interchange

The Ocean Boulevard/Terminal Island Interchange project was constructed to ease congestion and improve air quality by eliminating two Terminal Island traffic signals. Ocean Boulevard was raised nearly 35 feet to eliminate the two signals so that east-west traffic can travel non-stop between the Gerald Desmond Bridge and Navy Way.

The project consisted of elevating Ocean Boulevard above existing grades to facilitate grade separations at Henry Ford Avenue and Terminal Island Freeway at the Port. More than 8800 feet of Mechanically Stabilized Embankment (MSE) Walls up to 35 feet in height retain most of the new roadway fill embankment. The two grade separations were accomplished with two single-span bridge structures supported on driven steel H-piles. Group Delta Consultants provided geotechnical design level services including performing a comprehensive geotechnical investigation and developing recommendations for the design of the roadway and bridges. We also provided engineering support during construction.

The Ocean Boulevard/Terminal Island Interchange project was awarded the 2007 "Project Achievement Award" for Infrastructure Projects with a Constructed Value less than 50 million by the Construction Management Association of America (CMAA).

State Route 210, Segment 11

The State Route 210, Segment 11 project is located at the interchange of State Route 210 and I-215. The project involved the construction of a new mile of freeway with six to eight mix-flow lanes, two to four HOV lanes and access ramps mainly on fill embankment, construction of new bridges and interchange connectors, MSE walls, tieback walls and soundwalls, and widening of existing roads and bridges and other street improvements including a new storm drain. The proposed alignment was located about 1 to 2.5 km from the San Jacinto Fault and 4 to 8 km from the San Andreas Fault which could generate maximum credible earthquake magnitude of 7.5 to 8.0, respectively with peak ground acceleration of up to 0.7g at the site. Based on the results of our fault-rupture investigation, about 8-inch fault displacement (both vertical and horizontal) was recommended for the design of structures in the interchange area. Group Delta Consultants provided a comprehensive geotechnical design report (GDR) for the roadways and structure foundation reports (SFRs) for the bridges and associated MSE walls and tieback walls in accordance with Caltrans' guideline.

State Route 56

The SR-56 project in San Diego comprised of 5.7 miles of a 4 lane freeway and adjoining bicycle path. The project had four overpasses, three underpasses, eight bridges, and associated retaining and sound walls.

Group Delta Consultants performed more than 250 test borings and test pits to evaluate site geology and soil conditions, especially at locations of proposed structures. We investigated variable geologic conditions, ranging from metavolcanic rock to Eocene age soft rock, to unconsolidated overburden deposits. A number of landslides were identified and investigated along the alignment. Further activity included engineering analyses to develop geotechnical recommendations for alignment grading, landslide treatment, cut and fill slope stability, pavement design, culverts, and foundation support for walls and bridges. We provided comprehensive geotechnical design reports (GDRs) prepared in accordance with Caltrans’ guidelines for both the Middle Segment and the Black Mountain Road Segment. Structure Foundation Reports (SFRs) were prepared for four Black Mountain Road Segment bridges and overpasses, and for nine bridges and overpasses for the Middle Segment.

Noteworthy Achievement

One of the challenges on this project was that environmental concerns restricted any drilling activity after a certain date. To complete our field investigation we successfully completed three months of drilling in a single month by using double crews and weekend work.