2026 ACEC-NH & NHDOT Technical Exchange Conference

Session 15A: Route 11 Slope Stabilization Project in Sunapee, NH 
Speaker: Curtis Morrill, NHDOT
- The NH Route 11 slope stabilization project was initiated in response to a slope failure that transpired during the storm event from July 9-13, 2023, approximately 1600-ft east of Trow Hill Road in Sunapee. Severe settlement of the eastbound lane and sloughing of the embankment for approximately 400-ft occurred, stemming from a significant rainfall event. This project is under construction and will reinforce the slope with stabilization piles, remove and replace the existing thickened pavement and embankment soils, and incorporate a temporary surcharge program to mitigate further movement and return the roadway to the pre-failure layout.

Session 15B: Dummer/Erroll Construction Phase 16304B
Speaker: Mario Giroux, NHDOT
- The D-C-E 16304B project is the 2nd out of 3 NH 16 realignment projects located along the Androscoggin River Valley from Dummer, NH north to Errol, NH. This presentation shows the steps taken during the construction phase of the NH 16 realignment project located along the southern portion of the ‘13 Mile Woods’ corridor in Cambridge, NH. This presentation will give an overview of building a road over muck and unsuitable excavations, including a narrative of the drainage installed, erosion controls used, traffic phasing and a comparison of the plan cross sections to the As-Built cross sections.