- Company: Ghilotti Bros., Inc.
- Industry: Transportation
- Location: San Francisco, California
- Expected Completion Date: April 1, 2015
- Project Website
This $30Mil Golden Gate Bridge Median Barrier Project is essentially a mechanical “zipper” that changes lane layout 2 times daily to keep traffic flowing smoothly. The Golden Gate Bridge has six traffic lanes along its single deck lane configuration that now can be adjusted to accommodate traffic conditions without reserving an unused center lane or using pylons to separate lanes. It consists of 3,200 12-inch wide x 32-inch high median units linked together to form a semi-rigid barrier. Each steel-wrapped concrete-filled unit weighs 1,500 pounds. It takes a 30-ton, 58-foot long barrier transfer machine to shift the new barrier. Each machine is equipped with an S-shaped channel running the length of its undercarriage. As the truck moves past/over a barrier unit, the segment is lifted up and moved to the other side before being set in place. Replacing the the old pylon system with this new concrete barrier will prevent head on collisions on the bridge. The scope of work included roadwork & modifications to accommodate the installation of moveable median barrier spanning the 1.7 mile bridge. Demolition of four toll booths, the toll plaza canopy, the toll islands; construction of new toll booths, including island & canopy; seismic retrofit of the toll booths and canopy structure; removal and installation of crash cushions; removal of a concrete median barrier; removal and reconstruction of the median pavement; modifications to the existing and installation of new drainage facilities; cold planing; HMA pavement & HMA dike construction; striping and pavement delineation; installation of roadside signs; installation of metal beam guardrail; demolition and installation of electrical facilities of transportation operations systems; construction of traffic control and traffic control for the weekend closure. The scheduled 52 hour bridge shutdown, started at midnight on Friday, 01-09-2015 to 4:00 am Monday, 01-12-2015. 12 hours ahead of schedule, but remained closed per scheduled shutdown. This gave the team extra time for removal of pylon holes and added retro reflective markings on barriers so they would be more visible at night for drivers.
What impact does this project have on America?
This project included demolition of the original Golden Gate Bridge toll booths. The original Art Deco design & aesthetic features were preserved in the new toll plaza including reusing the original Toll Plaza clock. The installation of the median barrier has helped to improve traffic flow as well as public road safety. “The safety implications of (the barrier) are obvious,” said Kary Witt, bridge manager. “We think it would be very difficult to imagine a scenario of a head-on collision with a physical separation of the two directions of travel.” The barrier is 12-inch–wide, 32-inch-high barrier made of high-density concrete clad in steel and tightly pinned together to form a semi-rigid structure. The barrier is made of more than 800 blocks that weigh 1,500 pounds each.
The Golden Gate Bridge is the most photographed bridge in the world. The weekend closure for this project was the longest closure since the bridge opened on May 27, 1937. On that day, the bridge was not open to vehicles – it was pedestrians, cyclists, tap dancers and roller skaters who first crossed the bridge.
What interesting obstacles or unusual circumstances did you overcome to complete the project?
Traffic management was the biggest obstacle for all involved in this project. Extended scope of project included a long-term connector phase to the Doyle Drive Project (Presidio Parkway) assuring a continuous traffic alignment and clear transition while both projects were under construction. This was accomplished via meticulous striping alignment on both projects to avoid potential driver confusion and accidents. Various modes of transportation had to be managed for cyclists, pedestrians, motorists as well as keeping the bridge fully operational during the entire project (other than the 52 hour closure). This included keeping toll booths open and operational during their demolition, maintaining heavy commuter traffic flow and working with the Contractors & Municipalities to ensure consistent flow of both the Golden Gate Bridge Median Barrier Project and the adjacent Doyle Drive Project, which were occurring simultaneously.
What dangers and risks did you encounter, and describe any extraordinary methods used to keep workers safe?
The most substantial challenge on this project was traffic management for vehicles, workers, pedestrians and cyclists. The Golden Gate Bridge’s total monthly traffic crossing is 2.5 million vehicles; the comprehensive traffic management plan created by Ghilotti Bros., Inc. for this project achieved its goal of ZERO accidents or incidents during construction. Our commitment to make safety our number one priority begins with our President Mike Ghilotti’s full participation and support in all aspects of our program on a weekly basis as a member of our Corporate Safety Committee, which includes our Corporate Safety Director, VP of Construction, VP of Operations, HR Director and employees including craftspeople and field supervisors. The committee reviews weekly safety-related reports, policy and discusses opportunities for improvement with the purpose of fostering a corporate culture of safety. The following controls are in place: Full-time Safety Director with two (2) additional support staff; Written Health and Safety Plan and Injury & Illness Prevention Plan. Maintain a drug and alcohol policy, which includes pre-hire, post-accident and random drug testing; Crews conduct Job Safety Analysis (JSA) daily including site safety huddles used to recognize, discuss, plan and overcome site specific safety issues identified; Utilize peer review and oversight by our insurance company for regular and unannounced site inspections to augment our own internal monitoring; Continuously train our supervisors to maintain a safe jobsite. Supervisors are trained in CPR, first aid for emergency care and certified with an OSHA 10-hour construction safety course; Conduct Job Hazard Analyses (JHA’s) in our project In-House Planning Meetings to identify, plan and engineer solutions to potential jobsite hazards; Hold six (6) safety-specific company wide meetings annually. Every employee, regardless of their role in the company, is expected to attend. Traffic management had multiple municipality traffic management requirements from both Caltrans as well as the Golden Gate Bridge Highway & Transportation District. This included bicycle/pedestrian traffic handling. GBI introduced several modifications of the traffic control & traffic handling plans that were made based on the field experience of GBI crew members. Prior to every shift, safety meetings were held to go over the day/nights work with the crews. This included overview, traffic management and work plans. These plans described each step of the operation and how the work was to be executed in great detail. Advanced planning flushed out any potential issues that may have arisen. A procedure to control traffic over the bridge during the weekend closure was put into practice. This required all buses to stop at points just north and south of the bridge and await authorization prior to crossing. This ensured the safety of GBI and Lindsay/Statewide crew members as they worked during the closure.
How did you leverage new technologies to work faster and reduce waste?
Pavement and concrete from the demolition portion of the project was re-purposed into other construction materials. The main focus of this project was safety, which had to be meticulously developed by GBI. For the job teams as well as public safety. A comprehensive traffic management plan was designed by GBI management and staff assigned to this project. A separate management plan was developed for each phase of the job. GBI coordinated these efforts with The National Park Service, Cal Trans, County of Marin, County of San Francisco, local fire and police departments, Golden Gate Transportation Authority as well as all municipalities and contractors at the adjacent Doyle Park Drive Project. This included managing bicyclist, pedestrians (even during closure), heavy commute hours, keeping toll booths open and operation during the demolition of them, as well as traffic flow between both Golden Gate Median Barrier Project and Doyle Drive Project. Ghilotti Bros., Inc. performed all QC/QA (Quality Control / Quality Assurance) on this project (e.g.: torque testing on bolts, GG Bridge paint inspection, rapid set Lean Concrete Base tested @ plant & on-site at pour for compressive strength) to ensure that all areas of construction and materials met or beat minimum requirements. Despite the hours and hours devoted to developing and executing the safety plans, this project was finished on time and with ZERO injuries or incidents.