By DONALD WITTKOWSKI
There’s a whole lotta shakin’ going on in Sea Isle City.
If you don’t believe us, check out the strange-looking devices scattered along the beachfront that say, “Vibration Monitoring in Progress.”
Is this Sea Isle, or the earthquake-prone San Andreas Fault in California?
Actually, it’s earthmovers and other construction machinery – not earthquakes – that are causing the ground to shake during Sea Isle’s major beach replenishment project supervised by the U.S. Army Corps of Engineers.
Seismic Surveys LLC, one of the contractors for the project, has deployed between three and 10 vibration detectors throughout the beach replenishment work zones at any given time, depending on the location and type of ongoing construction activities.
The monitors allow the contractor to measure the level of vibrations as part of efforts to protect surrounding homes or businesses from being damaged by the beach replenishment work, Army Corps spokesman Steve Rochette said.
“The monitors do not ‘prevent’ damage, rather they allow construction personnel to know when equipment is causing vibrations that may affect neighboring structures. It is a preventative measure the contractor uses to monitor the work to cut off the potential for affecting third-party structures,” Rochette explained in an email.
Vibration detectors are periodically placed and relocated throughout the construction area so that homes and businesses within 500 feet of active beachfill work are monitored, he noted.
As the replenishment project moves to different parts of Sea Isle’s shoreline, so do the earthmovers, bulldozers and other types of heavy construction equipment that are used to spread all of the new sand around to widen the beaches. The veritable army of construction machinery causes the ground vibrations that are being monitored.
The vibration monitors aren’t that big, standing about chest high. In addition to the words “Vibration Monitoring in Progress,” they also come with the warning, “DO NOT TOUCH” written on them in all capital letters.
Each monitoring station includes a geophone sensor buried in the ground or attached to a solid structure. The sensors measure and record the level of ground vibrations coming from the construction work.
“The measured vibration levels are compared to industry standards and project-specific limits and communicate via cellular network any measurements that approach or exceed these levels,” Rochette said.
If any resident or property owner has concerns about their structure, they should contact the Army Corps of Engineers at (215) 687-9031.
Army Corps official Dan DePasquale said Monday there have been no complaints from Sea Isle property owners about damage possibly caused by the project during work in the first phase of construction in the south end of town.
“So far, so good,” DePasquale said.
Sea Isle is the last of three towns – Ocean City and Strathmere were the other two – to have their storm-damaged beaches restored by the Army Corps in partnership with the New Jersey Department of Environmental Protection in what was originally a $33.7 million project.
An extra $5 million worth of sand is being added in Sea Isle after additional federal funding became available. Mayor Leonard Desiderio said the extra sand would be enough to fill about 50 football fields 4 feet deep.
Although Sea Isle officials had originally hoped the project would be completed by the Memorial Day weekend kickoff to summer, the latest timetable for wrapping things up is mid-June, Desiderio said.
Originally, the project called for 388,000 cubic yards of beach sand in the south end of the island from about 73rd Street to Townsends Inlet at 94th Street.
However, the $5 million worth of new sand added an extra 292,000 cubic yards to the south end for a total of 680,000 cubic yards in this area.
Construction crews have completed restoring the south end and are now spreading 252,000 cubic yards of new sand on the shoreline in central and downtown Sea Isle from about 29th Street to 53rd street.
Currently, the work is focused on the beaches at 40th Street, John F. Kennedy Boulevard, 42nd Street and 43rd Street. The contractor closes off the beaches where the work is being done for safety reasons and then reopens them after construction is completed.
