Heavy rainfall from storms that occurred in late June and early July of 2006 produced significant runoff and stream flow that caused slope failures along Turner Hill and Pumpkin Hollow Roads in the Town of Davenport, Delaware County, New York. Slopes varying from 30 to 60 feet in height from streambed to roadway elevation failed at four locations.
Tectonic was engaged by the Town to assess the situation, provide immediate recommendations for maintaining partial temporary traffic flow and to document the conditions and assist with developing preliminary remedial repair alternates as needed to obtain funding from the State Emergency Management Office (SEMO) and the Federal Emergency Management Agency (FEMA).
Tectonic quickly mobilized staff and performed investigation phase services consisting of a site reconnaissance, topographic surveys and geotechnical investigations followed by design development phase services consisting of review of methods proposed by FEMA for repairing each failed area, evaluation of alternate remedial repair methods which were more desirable based on constructability, long term maintenance, cost and duration of construction, and preparation of cost estimates.
Following FEMA’S issuance of approved project work plans acceptable to the Town, Tectonic prepared design drawings and specifications for contract bidding and construction. Due to the steepness of the slopes and access constraints, the slopes were stabilized using steel H-pile and precast concrete panel retaining walls with the H-piles socketed into bedrock and tied-back with rock anchors.