VanBoxmeer & Stranges Structural Engineers approached EBS Geostructural Inc. for the support of a proposed 32 storey tower in downtown London Ontario. VanBoxmeer &; Stranges are familiar with EBS and our design-build capabilities when it comes to micropiles and helical piles. The geotechnical report recommended driven pile or caissons to support the proposed structure. After further review the driven pile option was not feasible because of the potential for damage and disruption to existing structures and their operations in close proximity to the site. Also, the caisson option was feasible from a constructability stand point but was ruled out as the budget for the caisson installation made the project not economically viable. Further site challenges were restricted access due to a downtown location, high water table and deep deposits of sand material.

Value Engineering Using Load Test Results
Our initial design-build proposal using Chance Helical Piles based on the existing geotechnical information, structural loading and utilizing EBS’s reference guide represented an 80% cost saving over the installation of caissons. The installation of Chance Helical Piles also eliminating the logistical concerns for a restricted access site regarding drill rig equipment, removal of spoils by dump trucks, ready-mix trucks for concrete delivery and laydown areas for rebar cages over the use of caissons.

EBS Geostructural recommended to all parties that a load test program be completed on the Chance Helical Piles to yield site specific load data that we could use to finalize our design. After load testing was completed EBS’ design was revised and the required number of helical piles reduced from our initial proposal. The site specific load testing translated into an additional cost saving of 20% from our original proposal.