Orange County NC Website
Browse       Search
Proposal for Geotechnical Engineering Services <br />Orange County Board of Elections Expansion | Hillsborough, North Carolina <br />Spetmeber 19, 2025 | Terracon Proposal No. P75255087 <br /> <br /> <br /> Facilities | Environmental | Geotechnical | Materials <br />Exhibit B - Scope of Services <br />Our proposed Scope of Services consists of field exploration, laboratory testing, and <br />engineering/project delivery. These services are described in the following sections. <br />Field Exploration <br />Orange County requested the following exploration locations and depths: <br />Location <br />Designation <br />Planned Exploration Depth <br />(feet) 1 Planned Location 2 <br />B-01 and B-02 20 Building area <br />B-03 20 Loading Dock Area <br />C-01 100 Seismic CPT Sounding 3 <br />1. Locations will be advanced to the depths indicated unless auger refusal is <br />encountered prior to reaching the planned depths indicated <br />2. The planned exploration locations are shown on the attached Anticipated <br />Exploration Plan <br />3. We will extend one seismic CPT sounding to a planned depth of 100 feet or to <br />sounding refusal. CPT sounding data will be utilized for seismic site <br />classification and liquefaction analysis . <br />Exploration Layout and Elevations: We will use handheld GPS equipment to position <br />location s with an estimated horizontal accuracy of +/-5 feet . Field measurements from <br />existing site features may be utilized. If available, approximate elevations will be <br />obtained by interpolation from a site specific, surveyed topographic map , or the Orange <br />County GIS website. We can alternatively coordinate with your Project Surveyor to <br />include locations and surface elevations in project information , if so requested. <br />Subsurface Exploration Procedures: We will advance borings with track -mounted <br />equipment in general accordance with local standard procedures for standard <br />penetration tests (SPTs ) and cone penetration tests (CPTs). <br />During the SPT, four samples are obtained in the upper 10 feet of each boring and at <br />intervals of 5 feet thereafter. Soil sampling is typically performed using split -barrel <br />sampling procedures. In the split barrel sampling procedure, a standard 2 -inch outer <br />diameter split barrel sampling spoon is driven by a 140 -pound automatic hammer falling <br />30 inches. The number of blows required to advance the sampling spoon for 12 inches of <br />penetration following a 6 -inch seating interval is recorded as the Standard Pene tration <br />Test (SPT) resistance value. The SPT resistance values, also referred to as N -values, are <br />indicated on the boring logs at the test depths. The samples are placed in appropriate <br />Docusign Envelope ID: 2ECC4EBC-6A30-4243-9E7F-16636E4F3E4BDocusign Envelope ID: 752D86D7-DF31-404C-B79C-D4F81DF70B21