New Harbour Wharf

 

The Harbour Authority of New Harbour hired HGC to carry out a geotechnical investigation for the proposed wharf reconstruction in New Harbour, Guysborough, NS.  The existing wharf consists of a timber block and span stem and a full cribwork “T” which is currently barricaded due to its’ deteriorated state.  The program comprised a marine based geotechnical field investigation, laboratory testing program, and preparation of two separate geotechnical reports. Prior to commencement of field activities Harbourside prepared and submitted for approval, a project specific health and safety plan for the activities to be carried out.

 

The geotechnical field investigation consisted of ten marine boreholes put down at various locations adjacent to the existing structure. The boreholes were carried out in H size casing to depths of 1.8 to 10.6 m below harbour bottom. The soils were sampled at near continuous intervals using a 50-mm OD split spoon sampler while performing standard penetration tests and 70-mm OD thin wall Shelby tubes. Bedrock was proven by core drilling in HQ size. HGC carried out field supervision of the drilling activities and managed the subcontractors required for the marine drilling program.

 

All soil samples recovered were stored in moisture tight containers and delivered with the rock core to our geotechnical laboratory in Dartmouth, Nova Scotia for final classification and testing. Laboratory testing on selected soil samples included:

  • water content determinations (ASTM D2216 Standard Test Methods for Laboratory Determination of Water Content of Soil and Rock by Mass);

  • particle-size analyses (ASTM D6913 Standard Test Method for Particle-Size Distribution of Soils Using Sieve Analysis);

  • Atterberg Limits (ASTM D4318 Standard Test Methods for Liquid Limit, Plastic Limit, and Plasticity Index of Soils); and,

  • Unconfined compressive strength rock core (ASTM D7012 Standard Test Method for Compressive Strength and Elastic Moduli of Intact Rock Core Specimens under Varying States of Stress and Temperatures).

At the client’s request, two separate reports were prepared for the Harbour Authority upon completion of the field investigation and laboratory testing program.  A factual report was prepared which provided the investigation procedures used, site description, subsurface soil description from laboratory tests, formal borehole records, laboratory report and a borehole location plan. This report presented construction and geotechnical recommendations for design of the wharf reconstruction and contained recommendations for gravity structures (Timber Cribs) with consideration given to rockfill mattress and infilling, bearing resistance, settlement estimates, and ballast and backfilling; bulk head structures (Berlin wall and steel sheet pile walls); and pile supported structures, including discussion on steel and timber piles.  The report also detailed geotechnical parameters for use in structural design and Seismic Site Classification in accordance with the National Building Code.


Client: Harbour Authority of New Harbour/Fisheries and Oceans Canada, Small Craft Harbours

Year: 2016

Role: Marine Based Geotechnical Field Investigation, Laboratory Testing Program