DEMOLISHING THE PAST, CREATING THE FUTURE
Contractor Helps to Safely Bring Down 60-Year Old Bridge
The 5th Street bridge in Yuba City, CA, spans the Feather River roughly 40 miles north of Sacramento and is a vital conduit for the region connecting Yuba City to Marysville, CA. It is one of only two bridges along a 40-mile stretch of the river, making it an essential transportation conduit.
General Contractor MCM Construction contracted with CSDA member Penhall Company, headquartered out of Irving, TX, to demolish the 300-foot span of the 5th Street bridge directly over the Feather River. The local Sacramento, CA Penhall Company team determined that wire saw cutting was the safest method to complete the project successfully and fulfill the requirements of the project permit. It would also ensure that no concrete would fall into the river below. Alternate methods were considered, including building a cofferdam to allow for the bridge to be broken out with excavators and breakers. Another method considered was to build a platform below the bridge but above the water to catch falling debris from entering the river. Ultimately, the wire saw method was chosen because it was the most cost effective and required the least amount of extra work to keep any debris from falling into the river
Using the Hilti DSW 3018-E wire saw and Husqvarna wire ranging in lengths from 100 feet to 200 feet, Penhall began cutting on the east side of the bridge and made their way across, carefully sawing through diaphragms and girders. The diaphragms were 7 feet tall and 8 inches thick, while the girders were 8 feet tall and 2 feet thick. MCM provided supports underneath the bridge to hold it in place while Penhall made their wire saw cuts.
When Penhall Company was nearly done with the wire saw cutting, MCM realized that extra supports had to be added to the middle of the bridge to ensure the safety of the workers and to minimize any negative environmental impacts. While the addition of extra supports delayed the start of slab sawing by two days, safety, as always, was the priority rather than speed
When the wire saw work was done on the first span, Penhall began slab saw cutting the 8-inch thick concrete deck. The perfect tools for the job were Husqvarna FS 4600 and FS 4800 slab saws using Husqvarna 24-inch blades. As the deck was cut into 9-foot by 7-foot sections, MCM crew members strapped each section with a bracket so it could be safely lifted to the ground by crane. The cranes included baskets covered in plastic to prevent any slurry or debris from falling into the river.
As typical on a CSDA contractor’s jobsite, safety was a paramount concern with crew members working on an open bridge hundreds of feet above a river. Penhall took the following steps to ensure the safety of their crew and everyone on the bridge:
• Meetings took place each morning before work began, including reminders to never hurry or run on the bridge deck, and for crew members to always be aware of their surroundings.
• Safety plan reminders to workers were announced up to three times each day.
• Handrails were installed around the perimeter of the deck.
• Anchor holes were installed on the deck every 10 feet for tie-off points.
• Employees were harnessed and tied off during set up.
• Red danger tape was tied to each section of the handrail.
• “Danger” was painted in red on the deck and delineators with red danger tape seven feet from the edge around the entire perimeter.
• Penhall crews were constantly monitored by a Superintendent.
• Attention was paid to keeping hoses and cords in the center of the bridge and never tangled.
• Crews worked in teams of two to ensure that if a fall occurred, rescue procedures could be executed immediately.
• A boom lift was in place for rescue in the event of a fall.
• Saw operators were always aware of the location of brackets and hoses to avoid tripping hazards.
• Sufficient drinking water was supplied for the crew each day
Penhall Company finished the demolition within 30 days. Over the course of the job, they made 33 diaphragm cuts and 24 girder cuts with the wire saw. Slab saws were used to cut 90 sections of 8-inch thick deck into 9-foot by 7-foot pieces to allow for crane removal. The sections of bridge that were not over the water were demolished by MCM with excavators.
Brandon Rowland of Penhall Company commented, “We completed our scope of work on time and allowed the general contractor to alleviate concerns with removing pieces of the bridge from the river. Our crew did an awesome job and we’re proud to be a trusted partner that can be counted on to perform this type of intricate concrete cutting.” He continued “Penhall Company was chosen by MCM Construction because of our years of experience and expertise with wire saw and slab saw cutting. Due to the intricate cuts necessary for MCM to fly the pieces of the bridge down to the ground via crane, they needed a company that left no margin for error. We formed a great partnership and exceeded expectations.” CSDA contractors are chosen for complicated, intricate and challenging jobs time and time again because of their experience, professionalism and dedication to getting the job done the right way the first time. This job is no exception, and the Penhall crew proved that they can handle any job that comes their way, no matter how high the expectations.
Penhall Company has been the go-to concrete services partner for a wide-range of industries since 1957. What began as a single flat saw operation has developed into an expansive offering of concrete solutions, including concrete scanning, cutting, sawing and breaking/ removal. They have specialized in concrete scanning for more than 20 years. Penhall employs expertly trained analysts that use state-of-the-art GPR equipment to find common embedded objects and other subsurface hazards that are hidden in the concrete. Penhall Company has been a member of CSDA since 1999.
CSDA Cutting Contractor
Methods Used: Wire Sawing, Slab Sawing