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Helicals for Walkways:
The Green Alternative
by Pat Haffert
Danbro Vice President
Danbro Distributors (www.danbro.com), and our Installer Network, have probably installed more helicals for walkways than any other partnership. This conclusion is based on our longevity (25 years in the industry) and geography. The Northeast and Mid-Atlantic states are bordered by the Atlantic Ocean to the East with numerous inlets, bays, rivers, and barrier islands. Many of the major metropolitan areas within this territory are port hubs with significant reclaimed wetlands. In addition, state and local governments in the Northeast and Mid-Atlantic were early adapters to the “Environmental Sensitivity” ethic and were willing to invest in and showcase their dwindling open areas.
Helical piles have proven to be an increasingly popular choice for walkways, boardwalks, porches, stairways, observation decks, docks, and pedestrian bridges. The driving force for the use of helicals in these applications is concern for fragile ecosystems. Helical piles install gently with little disturbance to wetlands and other sensitive areas by using small, low-impact equipment. There is no soil excavation required, with minimal impact on vegetation or aquatic animals, and helicals can be installed in remote, limited-access areas. The Nature Conservancy, Appalachian Trail Commission, local, state, and federal Parks, Utilities, and Authorities have all used helical piles to support elevated structures in pristine, sensitive environments. Portable hand-held installation equipment has been used for the more remote project locations with equipment and piling segments transported by volunteers. On the other end of the spectrum, the famous Asbury Park, NJ boardwalk was able to use grouted helical micropiles while replacing a section of their boardwalk destroyed in Super Storm Sandy. Click here for Asbury Park project history
Recently, Danbro contractors have installed helicals for pedestrian bridges in public settings. Anne Arundel County’s The Preserve at Eisenhower Golf Course in Crownsville, MD decided to use the downtime afforded by the pandemic to rehab and expand their existing courses. As part of the renovations, they used helicals to support pedestrian bridges to traverse wetlands and creeks. For the boardwalk infrastructure, they chose Perma Trak, a durable, maintenance-free precast concrete boardwalk system. An historically challenging aspect of using helicals for boardwalk systems is sourcing the specially designed new construction/saddle brackets. The tolerance from the helical to the beam seat bracket to the concrete decking is tight. This is particularly true of the Perma Trak system. Perma Trak has only an ⅛” to ¼” tolerance for bracket-bolt connections and requires higher capacity piles to carry the load. The IDEAL GROUP, our supplier, came through once again and produced precision brackets in-house. The entire order was shipped direct, on one truck, instead of having to source the brackets separately from another vendor. Click here for Eisenhower project history IDEAL made a similar contribution two years ago for the PSE&G Basket Flats boardwalk on the Maurice River in southern New Jersey. Click here for PSE project history
On two public projects in Virginia, a pedestrian bridge in Fairfax and the Smith Creek Pedestrian Bridge in Clifton Forge, mobilization concerns in remote locales drove the decision to use helicals. It is true of many small jobs that mobilization for driven piles is often too costly when a limited number of piles are involved. In addition, the smaller equipment used to install helicals is better suited to forest terrains, facilitating a quicker and less costly installation. Click here for Smith Creek project history Danbro and our installing contractors have installed thousands of helicals for walkway projects in a variety of challenging, sensitive environments during the past 25 years. Until recently, most of our pedestrian walkways and bridges were made of wood or synthetic materials like Trex decking. However, as demonstrated at The Preserve at Eisenhower Golf Course and at Basket Flats, helicals can support newer boardwalk infrastructure materials with a little help from our friends at IDEAL. The aforementioned projects are just a few examples of the many public jobs that illustrate the virtues of installing helicals in verdant, open spaces. When environmental concerns call for stewards of the land to go green, the answer is to go helical! Click here for Walkways project histories