by James Savage
It has been nearly four years since Hurricane Sandy severely damaged many residential areas throughout NYC, including the Rockaways, Queens, Brooklyn and Staten Island. The NYC Mayor’s Office of Housing Recovery Operations and the Build it Back Program were launched to help New Yorkers repair and rebuild their homes, and bring their lives back to the pre-Sandy days.
One of the most common program options is the “Repair with Elevation,” in which a single family house is lifted above the new FEMA flood elevations, a new foundation is constructed, and the home is lowered onto the new foundation. Another popular option is the “Rebuild,” in which the original home is demolished, and a new home is constructed on an elevated foundation. The process sounds simple, however the program itself, and partnerships, is a diverse array of many moving parts. There are the NYC Housing Recovery Operations (HRO) Office, the Department of Design and Construction (DDC) and Department of Buildings (DOB) as part of the public program management and oversight.
The NYC Build it Back program hired private Construction Management firms in each of the five boroughs to oversee construction and management efforts. Many of the construction and program management firms have subcontracted the projects to General Contractors, who manage and execute all aspects of the elevations or rebuilds. The General Contractors work exclusively or hire subcontractors for different phases of the projects, which can be broken down into areas in the order of: House Lift, Original Foundation Demolition, Helical Pile Installation, New Foundation Construction, Walls Formed and Poured, House Lowered, Interior Rehabilitation, Mechanical and Electrical Hookups, and Final Site Work. The contractors participating in the NYC Build it Back program are vetted through a registration process where they must meet stringent requirements prior to being awarded work. There are also a multitude of architectural and engineering firms who completed the designs of each project, and third-party inspectors overseeing all aspects of the work and submitting required forms and paperwork to the DOB when a phase of work is completed. I have personally witnessed inspectors issuing NCR (Non-Compliance Reports) for work that was deemed unsatisfactory, and the contractor must take corrective action to have the NCR closed out.
In addition to the house lifting process as a critical aspect of the NYC Build it Back program, new foundations require a deep pile system to anchor the homes in case of a future storm surge. Helical Piles were chosen unanimously as the pile system for the NYC Build it Back program, and DANBRO has been intimately involved in educating public agencies such as the HRO, DDC, DOB and others, as well as private A/E firms, Construction Managers, General Contractors, House Lifters, Concrete and Pile Contractors and the third-party inspection agencies since the end of the storm. We have provided complimentary Engineering “Lunch and Learn” Seminars to both public and private entities heavily involved in the Build it Back program.
The advantages of helical piles are that they can be installed underneath homes in segmented sections, typically no more than 5ft – 7ft, using hydraulically powered small equipment and small crews. The helical piles do not cause vibrations or loud noises on the site, which could cause damage to surrounding properties and inconveniences in the many neighborhoods. The piles also offer compression and tension support, meaning that the home is supported based on the weight of the structure, and anchored in case the waves or wind loading in a future storm could cause the structure to uplift and move off of the foundation. According to the NYC Building Code, helical piles installed for residential homes, below certain loading criteria do not need to be load tested to verify structural capacity, which saves time and money for the project. The torque of the helical piles is measured using a certified calibrated torque measuring device, and the structural capacity of the pile is calculated and field verified by multiplying the empirical torque factor by the measured torque to obtain the pile capacity. Our most common NYC Build it Back helical pile product is the SS5 (1.5” x 1.5” solid square shaft) which has an empirical torque-to-load capacity factor of 10. The A.B. Chance Company invented this method in the early 1950’s, and today the relationship is documented in the International Building Code for Helical Piles. DANBRO’s Engineer, Steve Gencorelli, P.E., has assisted many engineers, architects and NYC Build it Back Program Managers in specifying the appropriate helical piles, including installation notes and troubleshooting projects with challenging soil characteristics. Additionally, we have aided in a creative pile design using a helical pile lead shaft, typically a 10”-12”-14” diameter helix configuration, with 14” helix extension trailer shafts to assist in generating torque and adequate pile strength in areas where the soil is weak for excessive depths. This creative solution has led to program cost savings and reduced time needed to install the helical pile foundation since the piles did not need to be installed as deep as other configurations with less helix plates.
In addition to aiding architecture and engineering professionals in the design and specification of the proper helical piles to be used for the NYC Build it Back projects, DANBRO has been working tenaciously with contractors to aid in the training, CHANCE certification and field installation using A.B. Chance helical piles. When a contractor expresses interest in becoming a Certified DANBRO helical pile installer, we work with them in setting up their pile driving equipment, recommending the appropriate Anchor Drive, Torque Monitor, Pile Tools and other equipment needed to install the piers. The next steps include education and training on helical piers, including the online CHANCE University Training course and field training. Armed with five unique products approved for helical pile installation in New York City, DANBRO has helped contractors install the SS5 (1.5” x 1.5” Solid Square Shaft) as well as our newest ICC-approved RS2875.276 (2.875” diameter hollow round shaft) helical pile. A new trend includes saving the original foundation and installing CHANCE underpinning brackets to anchor and support the original foundation. This includes driving the piles adjacent to the foundation, and underpinning the footing with a steel bracket, which is anchored using anchor bolts through the concrete. It can be a challenging work, but our Certified Installers are prepared to install any type of New York City approved helical pile and the appropriate pile cap. Construction in the NYC Build it Back program has reached new heights, with aggressive completion goals set by Mayor De Blasio. Our diverse network of Certified Installers are working throughout the 5 boroughs ensuring proper installation of quality helical products so that the rehabilitated homes are anchored for years to come.
If you would like more information regarding Helical Pier Engineering, Field Support or becoming a DANBRO Certified Installer, please visit www.DANBRO.com or our Hurricane Sandy educational website, www.MYFOUNDATIONSOLUTIONS.com. You can also reach us at email@example.com or by calling the main office, 215-271-7700.
James Savage is DANBRO’s NY Metro and Long Island Territory Manager. With over 8 years in the civil engineering and construction industry, James works with new installers, engineers and general contractors on all aspects of residential and commercial helical piers, earth retention solutions including helical tie-backs and soil screws, and support of excavation using helical soldier piers and tie-backs. Please contact James at (908) 625-1316 or James@Danbro.com.