This paper will discuss a challenging 4,200 foot Horizontal Directional Drill (HDD) crossing of the St. Johns River in Jacksonville, Florida, with a 42-inch steel casing pipe and 36-inch high density polyethylene pipe (HDPE) carrier pipe. The project provides a new force main for one of JEA's largest wastewater pump stations, increases system reliability and provides operational flexibility for JEA. The existing pump station force main crossing the St. Johns River is a 42-inch ductile iron pipe installed over 40 years ago. Connections to the existing pump station were configured to avoid any pump station shutdown or bypass. The entry point for the HDD crossing started in the heavily used parking lot of EverBank Field - home of the Jacksonville Jaguars. The HDD alignment traverses a number of surface and sub-surface features including a large box culvert, abandoned gantry rails and piles, a stormwater pond, piles supporting an elevated expressway, a deep bulkhead, and finally crosses under the St Johns River. The project also includes a second HDD consisting of 840 feet of 36-inch HDPE pipe installed under a large drainage culvert, other utilities and abandoned infrastructure in the stadium parking lots. The pipe for both HDDs was delivered, assembled, and staged within the stadium parking lots. While there were significant challenges during pre-design and design to find the best route through the obstacles, the hard work paid off during construction with clearly identified existing features, settlement monitoring of key structures and construction being completed in time for kickoff of the 2016 Jacksonville Jaguars NFL football season. The success of this high profile project required close and constant collaboration between the contractor, designer, driller, client, and stakeholders.
展开▼
