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I <br /> I <br /> 1 1. Descriptions of two primary control points used for the horizontal and vertical <br /> I 2 control. Primary control points will be described by reference to the project <br /> 3 alignment and the coordinate system and elevation datum utilized by the <br /> 4 project. In addition, the Contracting Agency will supply horizontal coordinates <br /> for the beginning and ending points and for each Point of Intersection (PI) onIs <br /> 6 each alignment included in the project. <br /> 7 <br /> 8 2. Horizontal coordinates for the centerline of each bridge pier. <br /> I <br /> 9 <br /> 10 3. Computed elevations at top of bridge roadway decks at one-tenth points along <br /> 11 centerline of each girder web. All form grades and other working grades shall <br /> I <br /> 12 be calculated by the Contractor. <br /> 13 <br /> 14 The Contractor shall give the Contracting Agency three weeks notification to allow <br /> I <br /> 15 <br /> 16 adequate time to provide the data outlined in Items 2 and 3 above. The Contractor <br /> shall ensure a surveying accuracy within the following tolerances: <br /> 17 <br /> I 18 Vertical Horizontal <br /> 19 1. Stationing on structures ±0.02 feet <br /> 20 2. Alignment on structures ±0.02 feet <br /> I <br /> 21 <br /> 22 3. Superstructure elevations ±0.01 feet <br /> variation from <br /> 23 plan elevation <br /> I <br /> 24 <br /> 25 4. Substructure ±0.02 feet <br /> variation from <br /> 26 Plan grades. <br /> 27 <br /> I <br /> 28 The Contracting Agency may spot-check the Contractor's surveying. These spot- <br /> 29 checks will not change the requirements for normal checking by the Contractor. <br /> 30 <br /> I 31 When staking the following items, the Contractor shall perform independent checks <br /> 32 from different secondary control to ensure that the points staked for these items are <br /> 33 within the specified survey accuracy tolerances: <br /> I <br /> 34 <br /> 35 Piles <br /> 36 Shafts <br /> I <br /> 37 <br /> 38 Footings <br /> Columns <br /> 39 <br /> 40 The Contractor shall calculate coordinates for the points associated with piles, shafts, <br /> I41 footings and columns. The Contracting Agency will verify these coordinates prior to <br /> 42 issuing approval to the Contractor for commencing with the survey work. The <br /> 43 Contracting Agency will require up to seven calendar days from the date the data is <br /> I <br /> 44 received to issuing approval. <br /> 45 <br /> 46 Contract work to be performed using contractor-provided stakes shall not begin until the <br /> I <br /> 47 stakes are approved by the Contracting Agency. Such approval shall not relieve the <br /> 48 Contractor of responsibility for the accuracy of the stakes. <br /> 49 <br /> i <br /> I 4151 STREET TO WMVD FREIGHT <br /> CORRIDOR IMPROVEMENTS <br /> FED AID#STPUL-9931(012);PW#3472 SP-21 February 10,2016 <br />