Long Beach International Gateway Bridge (Gerald Desmond Bridge Replacement)
Our team was part of the Gerald Desmond Bridge replacement design/build team, providing geotechnical design services for the Port of Long Beach’s (POLB’s) “iconic” cable-stayed, six-lane bridge, which will span the Back Channel in the Port of Long Beach. This bridge replacement, designed to ease traffic congestion and improve navigational safety, is budgeted at almost $700 million and being jointly procured by the Port of Long Beach and Caltrans. The bridge will replace the existing Terminal Island steel span bridge, which is at the end of its useful design life and faces critical long-term maintenance issues. Also, the old steel span bridge was not designed to manage currently roadway traffic volumes and, at 154 feet air draft, is a navigation obstruction to larger container ships that are now common at the Port.
Being that the project was under the regulatory of Caltrans, design process followed the standard Caltrans process in which a Preliminary Foundation Report (PFR) is prepared in conjunction with a Type Selection Report (TSR) for the review and approval by Caltrans of the foundation type in the case of bridge structures and earth retention systems (ERS) in the case of retaining walls. We were responsible for the design of the of the retaining structures associated with the west approach embankment; preliminary design of the retaining structures associated with the east approach embankment; design of the foundations and alternations of the existing embankment associated with the Terminal Island Freeway bridge (at the western terminus of the project area); and design of the cast-in-drilled-hole (CIDH) bridge foundations of the low level approach regions of the bridge.
What makes design/build project delivery attractive to owners is reduced cost and schedule. To reduce cost, innovations must be “unleashed” and embraced. Our California licensed Geotechnical Engineers (GEs), with our local experience, helped to build a consensus between the innovations of the international design team and the requirements and expectations Caltrans reviewers. As an example of this, the I-710 approach embankment to the north of the bridge (i.e., east approach) was entirely constructed using lightweight cellular concrete backfill to reduce settlement of underlying old fill and estuary deposits. The retaining walls required for this approach embankment were designed as Mechanically Stabilized Earth (MSE) retaining walls but the lightweight cellular concrete was used as the “backfill” material in conjunction with embankment construction.
Considerable time was spent building a consensus for seismic design to mitigate liquefaction and lateral spreading for these embankments and retaining walls over soft soils, using finite element analysis to evaluate the magnitude of wall displacement and distortion. This required both mastering state-of-the-art earthquake engineering concepts required in California, mixed with a bit of tact and diplomacy; which was delivered.
In addition to geotechnical seismic issues, there were significant geoenvironmental issues for this site. Soils and groundwater at the site were impacted with petroleum hydrocarbons and heavy metals from past local oil production and industrial facilities. Field exploration activities required the preparation of a Health and Safety Plan and a Work Plan were prepared prior to initiating subsurface explorations, which consisted of over 120 borings and 70 Cone Penetrometer Test (CPT) soundings. Soil samples were collected and tested simultaneously for both engineering properties at our Irvine in-house geotechnical laboratory, and for potentially hazardous compounds, including total petroleum hydrocarbons (TPH) carbon chain, volatile organic compounds (VOCs), polychlorinated biphenyls (PCBs), polycyclic aromatic hydrocarbons (PAHs), organochlorine pesticides (OCPs) and Title 22 metals. Soil cuttings and groundwater from borings were stored in 50-gallons drums, tested for hazardous materials, and then properly disposed of offsite. Our cross-trained staff is experienced working in urban environments where geoenvironmental issues need to be addressed simultaneously with geotechnical issues. We provide seamless geotechnical, geoenvironmental and materials testing services, safely and efficiently to reduce cost
Client
Port of Long BeachLocation
Long Beach, CACapability
Geotechnical and Geological EngineeringServices
Geotechnical EngineeringGeotechnical Engineering/Geology
Related Projects
Penn Mag Inc. approached Verdantas to provide a geotechnical evaluation for a former industrial site located at the Port of Wilmington. Their goal was business expansion in the form of a new bulk material processing facility.
Penn Mag’s idea was to obtain high quality steel processing waste slag from Japan, ship it to Wilmington Delaware, refine it, and sell it to local ready mic concrete plants. The refined slag can replace virgin cement. The environmental benefits of the project included reuse of a former industrial site reuse of a recycled material in lieu of a completely manufactured product.
We were able to offer additional services, beyond geotechnical engineering, to help Penn Mag complete their project including critical environmental permitting that threatened to stop the project.
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Civil Infrastructure
- Geotechnical
- Civil Engineering
- Structural Engineering
- Construction Review
Environmental Health & Safety
- Air Permitting
- HSCA Compliance
Applied Data & Technology
- Vibration Monitoring
Natural Resources & Environmental Planning
- Floodplain Permitting and FEMA
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Geotechnical and Geological Engineering | Site and Roadway Civil Engineering | Structural Engineering and Architecture
Building a new global waste material reuse business on the Delaware waterfront
Read how Verdantas helped a client build a new global waste material reuse business on the Delaware waterfront
The North County Transit District/Amtrak route is a scenic one as it travels between the surf and coastal bluffs. Beautiful for the rider, unless the train is stopped due to the coastal bluff deterioration, slope failures and landslides that occurred adjacent to the railway, and prevented the trains from passing through.
In April 2001, a 40-foot section of concrete retaining wall collapsed, a wall that had lined the top of the Del Mar Bluffs at 7th Street. The failure, which had been identified in the completed Del Mar Bluffs Geotechnical Study as one of the highest risk areas, consisted of three wall sections approximately 60 feet above the beach.
To keep trains running atop the bluffs, the North County Transit District (NCTD), which owns the tracks, declared an emergency and approved spending $1,050,000 to design both immediate and long-term repairs to the portion that gave way. In addition, funding for mid-term measures, that could cost as much as $8.2 million on other high-risk portions of the bluff, were also approved. These measures are intended to ensure that the Amtrak and Coaster trains that run along the 1.6-mile-long section will be able to do so for the next 20 years.
In response to the emergency, our experts assessed the geological conditions and provided emergency repair alternatives for local agency review. With the selection of a shear-pin stabilization method, a “fast-track” analysis, the design and review period was successfully completed within 30 days. Construction of the stabilization system, twelve 60-foot-deep shear pins with tie-backs, was then successfully completed within 45 days.
Prior to this emergency, our geotechnical report had informed the NCTD that saturation from groundwater is/was the biggest problem facing Del Mar’s bluffs. The report predicts that, without reinforcing measures along at least half of their length, the bluffs will erode another 12 feet within the next 20 years, making them even more fragile. Specifically, our report had identified the area (at 7th Street) that failed as a high-risk zone.
The railroad tracks were first built along the bluffs in 1910. Because of population growth, runoff from irrigation has increased tremendously, saturating Del Mar’s bluffs with groundwater and causing them to erode faster than they otherwise would. (Leighton’s study showed that normal rainfall in the San Diego County would dump about 10 inches on Del Mar Bluffs, but with the increased runoff, water reaching the bluffs each year is equivalent to between 100 and 200 inches of rain.)
Improvements constructed included additional shear pins, soil cement improvements, sea walls at the base of the bluffs, reinforcing the bluffs, and improving surface and sub-surface drainage, all with site aesthetics as a key element.
The selected stabilization method included additional shear pins connected at the top by a reinforced grade beam with tie backs. Where improvements are exposed they have been boulder-scaped to match the adjacent bluffs. Site stabilization also included the installation of a deep cut off subdrain which was outletted by boring through the bluff to the beach below and exiting through a boulder-scaped outlet.
Leighton has continued to provide geotechnical services since that first report, including the Thanksgiving 2019 failure.
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Geotechnical and Geological Engineering
Del Mar Bluffs
Read how geotechnical services kept the North County Transit District/Amtrak scenic route safe for riders.