Holland Tunnel

SJH Engineering, P.C. (SJH) successfully provided condition inspection and evaluation services for two (2) tasks under this Expert Professional Traffic Engineering ITS Services On-Call agreement. The team integrated seamlessly with other disciplines as a subconsultant to HNTB. Work involved providing data and coordinating foundation designs for sign structures at two PANYNJ tunnels. SJH performed 100% hands-on inspections of sign bridges and cantilever structures and performed efforts related to structural evaluations, recommendations, conceptual designs, details, specifications, and costs.

Holland Tunnel Replacement of ITS – Stage I

Elements included foundations, base plates, anchor bolts, support posts, mast arms, cross, sign frames, trusses, sign panels and luminaires. For post mounted signs, 100% visual and 10% hands-on inspection was performed except on signs with panels less than 10 square feet. Ultrasonic thickness measurements were taken at tubular steel poles to evaluate their remaining steel thickness. Inspection equipment included hammers, level measurement device, D-Meters, calipers, wire brushes, crack gages, binocular and digital cameras. A 35-foot bucket truck with shadow vehicle was used for the inspection. For Stage 1, conceptual drawings were produced for each sign bridge or cantilever location. For single post locations, a typical drawing may suffice. For structural design and detailing, SJH followed AASHTO LRFD Specifications for Structural Supports for Highway Signs, Luminaires and Traffic Signals. Compared to the Standard Specifications which were based on the Allowable Stress Design (ASD) method, these new LRFD Specifications are consistent with the AASHTO LRFD Bridge Design Specifications in that both are based on probability rationale and achieve consistent factors of safety with calibrated load effects and carefully adopted load and resistance factors. Wind load effects are based on latest ASCE 7-10.