- 622 - SECTION 717 -- CONCR ETE BOX CULVERTS
717.01 Description
1.This work shall consist of the construction of concrete box culverts. Concrete Box Culverts shall be constructed in accordance with these Specifications and in conformity with the lines, grades, dimensions, and designs shown in the contract.
717.02 Material Requirements
1.Concrete shall meet requirements of Section 1002.
2.Reinforcement shall be furnished, handled, and placed in accordance with the requirements of Section 707.
3.Crushed rock shall meet the general aggregate requirements of Section 1033.
717.03 Construction Methods
1.The Contractor shall not order box culvert materials like reinforcing steel and form lumber until the Engineer provides a field checked order list.
2.Excavation and backfilling shall be performed by the Contractor in accordance with the requirements of Section 702.
3.Concrete construction shall be performed by the Contractor in accordance with the requirements of Section 704.
4.Foundation excavations shall be as dry as practicable before concrete is placed.
a.The Contractor may elect to use crushed rock or crushed concrete as a base for the floor of the box culvert. Riprap Filter Fabric shall be placed under all rock.
b.Any unsuitable material encountered during the box culvert construction shall be excavated and removed from the site. The resulting void may be filled with crushed rock or crushed concrete as directed by the Engineer.
5.Dirt, mud, or other foreign ma terial shall not become mixed with concrete which is being placed in footings and curtain walls.
6.Fence Connections:
a.Fence connections require t hat a 3/4 inch (19 mm) diameter hole shall be cast through each wing of new or extended concrete box culverts with rises of 5 feet (1.5 m) or greater.
b.This hole shall be located 4 feet (1.2 m) above the box flowline near the end of the wing and shall be a minimum of 4 inches (100 mm) from the end and top surfaces of the wing.
7.Extensions: a. When box culverts are extended, if the existing thickness is different than the new, the new shall be adjusted by forming a variable thickness in the first 2 feet (600 mm) of the extension. Concrete Box Culverts 717.04 - 623 - 717.04 -- Method of Measurement and Basis of Payment
1.Pay Item Pay Unit Crushed Rock for Base Course Cubic Yards (CY) [ C u b i c M e t e r s ( m3)]
2.Measurement and payment for the quantities involved in the construction of concrete box culverts shall be made in accordance with the provisions in Table 717.01. Table 717.01 Measurement and Payment Requirement Section Excavation for Structures ........................... .702 Concrete Construction ................................ .704 Reinforc ement ............................................ .707
3.No payment will be made for concrete placed outside the dimensions shown in the contract.
4.The work of providing fence connection holes shall not be paid for directly but shall be considered subsid iary to the construction of the box culvert.
5.No additional compensation will be made for the additional work of forming the taper as described in Subsec tion 717.03, Paragraph 7.a. or for the concrete required.
6.Crushed Rock for Base Course shall include the crushed rock or crushed concrete, filter fabric, excavation and any additional labor or materials necessary to construct the base.
a.The limits for payment will be 6 inch depth and 18 inches outside any concrete face, including aprons. No adjustment in plan quantity will be made unless the dimensions of the box are changed. Any crushed rock or crushed concrete, fabric, or excavation outside of the limits described will be at no cost to the Department.
b.Excavation will not be paid directly but shall be considered subsidiary other items to which direct payment is made.
7.Payment is full compensation for all work described in this Section. - 624 - SECTION 718 -- CULVERT PIPE
718.01 Description
1.This work shall consist of furnishing and installing culvert pipe of the various types shown in the contract.
718.02 Material Requirements
1.The Contractor shall not order the culvert pipe until a list of sizes and lengths is furnished by the Engineer.
2.Reinforced concrete pipe shall conform to the requirements of Section 1037.
3.Corrugated metal pipe shall conform to the requirements of Sections 1035 and 1036.
4.Plastic pipe shall conform to the requirements of Section 1038. 5. Slotted pipe shall conform to the requirements shown in the contract.
6.Granular material for bedding shall conform to the requirements shown in the contract.
7.Flap gates shall conform to t he requirements of Section 1043.
718.03 Construction Methods
1.Excavation and backfilling shall be performed by the Contractor in accordance with the applicable requ irements of Section 702 and the contract.
2.The installation of Culvert Pipe shall be in accordance with Sections 701, 702, 719, 720, 721, 722, 724, 725, and 726.
3.Deflection Testing:
a.When plastic pipe is used or when corrugated metal pipe 48” (1200 mm) and larger is used, the Cont ractor shall peri odically check for pipe deflection during pipe installa tion and again not less than 30 days following completion of the roadway embankment. The internal diameter of plastic pipe shall not be reduced by more than 5% of its design diameter. The internal diameter of corrugated me tal pipe shall not be reduced by more than 7.5% of its design diameter. If t he installation does not meet these requirements, the pipe shall be remo ved and replaced at no additional cost to the Department.
b.During the required 30-day reinspection of the culverts, the Contractor must treat the culvert as a “confined space”. Appropriate safety procedures shall be followed. The Cont ractor shall provide the appropriate safety equipment.
c.Optional devices for deflection testing include electronic deflectometers, calibrated television or video cameras, or properly sized "go, no-go" mandrels. Deflection measurements can be made directly with extension rulers or tape measures at 10’ feet (3 m) increments in pipes that allow safe entry. To ensure accurate measurements, the pipe should be cleaned before testing.
d.Deflection testing will not be required on corrugated metal pipe extensions of less than 25 feet (7.6 m).
Source: Nebraska Standard Specifications for Highway Construction, 2017 Edition. Pages 656–657 of 1,048.