Work on Phase 3 of the Low Battery Seawall Repair will commence April 12thth. The anticipated duration of construction is eighteen months. The map below outlines detours that should be expected throughout Phase 2.
Below is a list of recent highlights from the current phase of the project.
Continuing the site Demo
Continue Grout and Casings on Section 2
Begin Micro-Piles on Section 1
Coring- Using a cylindrical saw (similar to a hole saw , but many times larger) to cut vertical holes in the existing concrete wall in order to insert steel casing pipes and later micro-piles.
Micro-piles- Consisting of three components:
A steel casing pipe about 20' long goes into the cores
Steel rods are then inserted in the casing and drilled to design depth.
During the drilling process, high-strength grout is injected through the hollow rod to fill the annular space in the casing and encapsulates the rod below the casing.
The Low Battery was constructed as part of a large land reclamation project undertaken in two phases: The first section (1909 to 1911) extended from Tradd Street to King Street. The second phase (1917 to 1919) extended from King Street to the "Turn" at the intersection with East Battery Street. The concrete wall of the Low Battery was constructed on a timber deck supported by timber pilings. The seaward face of the Low Battery is skirted with concrete panels attached to timber sheeting and batter piles. The repair of the "Turn" is the first phase of the overall seawall repair project and has been completed.
A "Seawall Evaluation and Study" prepared by Cummings and McCrady evaluated the condition of the Low Battery wall in 2004 and presented potential repair methods and an estimate of probable cost. In May 2015, the consulting firm Johnson, Mirmiran and Thompson (JMT) began the surveying work necessary to accurately collect data needed for the assessment and design of the seawall. A new City initiative was introduced during the design phase that requires new City projects with a design life of 50 plus years to account for an anticipated sea level rise of 2.5 feet. This requirement, along with the need to reconstruct the sidewalk to meet the Americans with Disabilities Act (ADA) guidelines for accessibility, has led to changes in the design approach.
Phase One, which included repairs of the seawall from Tradd St. to Ashley Ave., was conducted from December 2019 to January 2021 . Micropiles were first installed to support the new wall and elevated promenade. Then, demolition and repairs of the old seawall were conducted in 100' sections to assure minimum exposure in the event of a storm or high tide.
While the wall removal/concrete work proceeded, the existing water main was replaced. This included removing and replacing existing lead pipe services connections. The sanitary sewer was installed and all sewer and laterals were replaced, tested and put into service. Over 1,000 feet of new storm drain was installed along with four water quality units, the addition of a new outfall, and the improvement of the Tradd outfall. This significantly increases the drainage of Murray Boulevard as well as providing better conveyance for the Ashley and Tradd drainage systems.
Granite curb, traffic table granite edging and cobblestones, and traffic delineator cobblestones were installed and the existing gas line under the residential sidewalk was removed and replaced. A new 4’ sidewalk was added next to the wall and the residential sidewalk was removed and replaced. Work began at the Ashley parklet with the addition of bluestone pavers and park benches. Stone edging was added along the length of the wall, new lights were installed in the median, and new palm trees were planted.
Work on Phase 2 of the Low Battery Seawall Repair will commence February 15th and is anticipated to continue for one year. Work on the seawall will continue from the end of Phase 1 to just before Limehouse St., about 1,100'.
Work on Phase 3 of the Low Battery Seawall Repair will commence April 12th and is anticipated to continue for eighteen months. Work on the seawall will continue from the end of Phase 2 to just before King St., about 1,800'. Due to the length of the project, the contractor may elect to "segment" the project to make it more manageable and less disruptive to the neighborhood.