Crumbling Bridge Safely Removed with the Help of Diamond Saws
Bridge Spanned 13 Active Railroad Tracks in Wyoming Residential Neighborhood
As infrastructure all over the United States continues to age and deteriorate, literally crumbling away, general contractors are increasingly seeing the value and advantages of using diamond tools to help restore or safely demolish these structures without damaging surrounding structures and keeping those around the area safe.
The Clark Street Bridge in Laramie, Wyoming was being removed due to a revised roadway alignment that would shift the bridge half a mile away. The existing bridge was crumbling and there were concerns that in taking it down, debris could fall onto the active Union Pacific railroad tracks, so it was vital that all precautions be taken to control the demolition. General Contractor S&S Builders had many options for taking the bridge down; explosive demolition, jackhammering/breaking in place and fully dropping the bridge were all options. Since the 13 railroad tracks running under the bridge needed to remain in operation throughout the project, none of those methods were considered viable. Additionally, the bridge was located near a residential area, so the noise, vibration and risk of flying debris eliminated any kind of uncontrolled demolition as an option. It was determined that concrete cutting to assist in the selective structural demolition of the bridge was the best option.
S&S Builders contracted CSDA member Diamond Drilling & Sawing Company (DDSC) of Denver, Colorado to demolish the Clark Street Bridge using concrete sawing and pulverization methods. One of the most important aspects of this job was ensuring open and effective communication between the demolition contractor and the railroad representative, as cutting and other demolition tasks had to be coordinated with the railroad to ensure no trains passing underneath the bridge on any of the 13 operating tracks were in danger of being struck by falling debris.
Because of the level of existing deterioration, another concern was debris spontaneously falling from the bridge as demolition progressed, endangering not only the demolition contractor, but also any other construction personnel in the area and trains passing underneath the bridge. The contractor removed any crumbling concrete when possible prior to the demolition to prevent slips, trips, falls and flying loose debris, especially from the sidewalk that ran the length of the bridge. Any questionable areas were taped off to prevent personnel and equipment from entering the area of risk if the concrete could not be removed safely without compromising the integrity of the bridge.
Once a demolition plan with the railroad was approved, DDSC commenced work on July 1, 2018. This engineered demolition plan was required for bridge removal to maximize safety and mitigate noise, dust and debris, as well as prevent damage to the surrounding properties. Demolition began with cutting the bridge deck into sections using Husqvarna 7000 and 9900 Diesel Slab Saws and up to 36” blades to get through the bridge deck. The bridge itself measured 1,660 feet long by 36 feet wide, and the deck was cut into 14-foot by 6-foot sections for removal. Removal was handled by excavators and moved into a stockpile area for processing. After the bridge deck sections were removed, DDSC then used flame torches to cut the steel girders and a crane was brought in to remove the steel.
The steel cutting created a fire hazard around the operational railroad tracks, so a railroad-specific fire suppression plan was implemented. This plan consisted of charged water hoses and backpack pump can systems used on any area that was exposed to the flame torches prior to cutting. Proper PPE for the cutting was provided to operators, as was fall protection while working from manlifts to rig the beams for hoisting by crane.
After the steel girders were cut and removed, DDSC was tasked with pulverizing the 14 piers and abutments, then processing the concrete and removing rebar. The pulverized concrete was hauled off to a processing center for recycling.
In all, DDSC made 3,000 linear feet of saw cuts and removed 2,700 cubic yards of concrete, 600 tons of structural steel and 200 tons of reinforcing steel over a two month period. The job was completed on time and without incident or injury. Paramount to the success of this job was DDSC’s effective communication with the Union Pacific Railroad officials to coordinate the demolition schedule with the train schedule, as well as their coordination with the crane operator, Winslow Crane Service of Denver. Winslow supported the structural steel removal, which was a challenge as Laramie experiences frequent high winds and gusts. Managing and coordinating the crane work with DDSC while monitoring the weather added an additional challenge to this job.
The bridge removal project was a success, thanks to the versatility, hard work and dedication of the Diamond Drilling & Sawing Company crew. “Our ability to take on the complicated nature of this bridge with its many railroad tracks, while coordinating with the railroad and flaggers was key to the success of this job,” stated Eric Blackburn, Senior Project Manager of National Contracts for Diamond Drilling & Sawing Company. “The versatility of the entire DDSC crew is what makes us successful on these types of projects. Our highly skilled operators are proficient at all tasks this type of demolition requires,” he continued.
Once again, a CSDA contractor showcases the professionalism, versatility, flexibility and open communication that is essential for the success of projects like this. Cutting with diamond tools enables another project to be completed safely, precisely, on-time and with the highest level of professionalism.
Diamond Drilling & Sawing Company is headquartered in Denver, Colorado and is celebrating 60 years in 2019. They have been in business since 1959 and with the current ownership since 1989, and a CSDA member since 1995. Their fleet consists of approximately 50 trucks. Diamond Drilling & Sawing Company is a full service contractor for slab sawing, wall sawing, structural demolition, GPR scanning, wire sawing, core drilling and surface grinding. In addition to the Service Division, DDSC’s Airport, Bridges & Road Division specializes in larger scope cutting, rehab and demolition projects around the country; including seal repair, control joints, crack sealing, spall repair and panel replacements.