DuBois & King provided an annual condition assessment of fall protection systems permanently installed at six facilities. System components inspected consisted of horizontal lifelines, tip over roof anchors, roof top anchors, shock absorbers, freestanding counterweight anchors, portable guardrail systems, and concrete bolt anchors. D&K’s structural engineers carried out field investigations and completed a letter report with annotated sketches and photographs summarizing the existing equipment, equipment condition, serviceability of the equipment and recommendations for repairs, annual inspections, and service.
Evans Road Bridge
DuBois & King designed the replacement of an existing steel stringer bridge supported on one stone and one concrete abutment. Replacement design included load determinations and development of prestressing strand configuration for the new pre-stressed, precast concrete beams. Performed calculations and cost estimates and provided preliminary and final design, and construction phase services.
High Street Slope Stabilization
A landslide occurred on a steep slope between High Street and the Otis Falls Hydro impoundment on the Souhegan River following a prolonged period of heavy rain. High Street and one private residence were threatened by the potential for continuing slope failure. DuBois & King performed final slope stabilization design to include a sheet pile retaining wall at the top of the failure scarp and stabilization of the lower slope with rock riprap. DuBois & King provided bidding assistance to the Town. Services include FEMA Grant Application, data and field investigations, geotechnical investigations, survey, wetland mapping, consultation with sheet pile contractor, utility coordination, environmental permitting, coordination with nearby landowners and oversight agencies, preparation of easement plans, and construction phase administration.
Slope Stabilization for NRCS
Under an on-call contract with the USDA Natural Resource Conservation Service, D&K conducted geotechnical engineering and design of slope stabilization measures for four projects in central and southern Vermont. D&K’s work included field investigations, slope stability analysis, preparation of engineering plans and technical specifications and engineering assistance during construction. The work included coordination with property owners, state and federal regulatory agencies, permitting and cost estimating. Projects included:
Brattleboro, VT. 35-ft-high, 250-ft-long slope that failed during T.S Irene. The solution was a heavy stone fill slope keyed into the bottom of the river.
Jamaica, VT. 24-ft-high, 85-ft-long slope that failed during T.S Irene. Solution was a concrete block toe wall keyed into the bottom of the river with a heavy stone fill slope supporting the upper portion of the slope.
US Route 4, Mendon, VT. 20-ft-high, 70-ft-long slope that failed during T.S Irene. Solution was a heavy stone fill slope keyed into the river bottom with a concrete block head wall supporting the upper portion of the slope.
Stockbridge, VT. 35-ft-high, 80-ft-long slope that failed during T.S Irene. Solution was an open concrete block toe, pinned to bedrock to provide toe resistance and aquatic habitat, and a heavy stone fill slope to provide stability to the slope.
Slope Stabilization for Vermont Highways
In the aftermath of Tropical Storm Irene, many roadways throughout the State were severely damaged due to flood waters from adjacent streams and rivers. DuBois & King was tasked with designing permanent fixes to five of these areas. They include areas along VT Route 14 in Sharon, VT Route 100B in Moretown, VT Route 100 in Granville, VT Route 125 in Hancock, and areas of VT Route 125 in Ripton. Emergency repairs were made to these areas following the storm to reopen the roadways to traffic. The current focus is to provide permanent designs to stabilize the stream embankments and provide additional protection against future storm events.
Project locations received hydrological and geomorphological reviews. Stream bank protection measures were designed for each site. Roadway drainage at project locations was analyzed and updated to meet current design standards. The Hancock location includes the installation of a new buried, 14′ x 7′ concrete box culvert to alleviate potential flooding to the roadway and an adjacent residence. All proposed designs received an environmental permitting review from the State of Vermont.
Design of new guardrail systems was included, also providing additional shoulder width in many areas to increase safety for pedestrians and bicyclists. The Sharon location included an adjustment to the vertical profile of the roadway to help alleviate a substandard geometric condition. Project locations received new pavement and signage to meet current design standards.