206.01 Description
This work consists of constructing, maintaining, and removing a detour within the prescribed corridor and as specified in the contract.
206.02 Reserved
206.03 Construction
206.03.1 General
Construct the detour to the lines and grades shown in the contract and cross sections. Provide surfacing materials and thicknesses as specified in the contract. Remove and stockpile topsoil within areas of the detour that require excavation prior to detour grading operations. Complete detour grading operations in accordance with Section 203. In wetland or riparian areas as shown in the contract, cut shrubs impacted by temporary detour construction flush with the ground, do not grub. Use geotextile, or other approved separation, between the natural ground and temporary detour fill to provide minimal disturbance to the existing ground.
206.03.2 Design
Construct the temporary detour within the R/W or permit area and to the lines and grades shown in the contract and cross sections or as approved by the Project Manager. Surface the detour as indicated in the contract. The method required for conveyance of a waterway is not included in the Preconstruction authorizations and permits issued by resource and regulatory agencies. Prior to commencing any work on the detour, determine a preferred method of conveyance and submit this with the Contractor’s temporary facilities joint application. The submittal will be forwarded to the appropriate resource and regulatory agencies for review and approval.
A.Culverts. If used, furnish culverts of the size and length shown in the contract. Provide adequate bulkheads at the approach fills to prevent fill materials from entering the waterway. Place culverts in accordance with Section 603 .
B.Structures. If a bridge is chosen as means for conveyance of the waterway, provide a minimum waterway opening of sufficient size to accommodate the 2-year flood event, spanning the active channels with 1-foot (305 mm) minimum freeboard. Construct all temporary bents in a manner that the current remains un-deflected. Provide adequate bulkheads at the approach fills to prevent fill materials from entering the waterway. Provide the detour bridge with a width greater than or equal to that of the existing bridge, with a design live load capacity of HL-93 loading, for LRFD designs, or AASHTO HS-20 (MS-18), for ASD and LFD designs. Provide a rail system with blunt end protection at all bridge ends. Ensure the approach rail system meets either NCHRP 350 or MASH crash test requirements in accordance with Table 206-1 . Ensure the bridge rail can resist railing design forces as specified in the AASHTO LRFD (Table A13.2-1) for the design speed in accordance with Table 206-1. 206 – DETOURS 2020 EDITION V5.1 206-2 TABLE 206-1 DETOUR BRIDGE DESIGN Design Speed Bridge Rail Approach Rail Elements ≤ 30 mph TL-1 TL-1 > 30 mph – 45 mph TL-1 TL-2 > 45 mph TL-2 TL-3
206.03.3 Submittals
A.Bridge. Submit the design and calculations of the working drawings for the proposed detour bridge stamped and signed by a professional engineer licensed to practice in the State of Montana. Show the following in the drawings:
1.Bridge length and width.
2.Location of all bents.
3.Clear water opening.
4.Bulkheads and method of construction.
5.Details of the bridge rail.
B.Culverts. When culverts are not shown in the contract, submit a copy of the design for the proposed pipe which must show the following:
1.Pipe size and length.
2.Location.
3.Minimum fill cover. The Department has 20 business days to review the submittals. Approval of the detour is contingent upon meeting the requirements of this provision and those of the resource and regulatory agencies with jurisdictional authority.
206.03.4 Maintenance
Maintain the detour in accordance with Subsection 104.05 to provide the traveling public with a safe and smooth riding surface. Provide a satisfactory surface similar or better to that which existed on the PTW prior to beginning construction. Repair all damage to the detour and the PTW connections immediately and at no additional cost to the Department. This includes, but is not limited to, damage from washouts, chuckholes, soft spots, guardrail damage, or debris on the roadway. Failure to maintain the detour in a manner that provides the traveling public with a safe and smooth riding surface is cause for the Project Manager to stop work until corrective actions take place. All costs associated with the delay are the Contractor’s responsibility.
206.03.5 Removal
Remove the detour only after the mainline work has been completed and approved by the Project Manager. Fill areas excavated for detour construction and incorporate the material removed from the detour into the mainline embankment. Grade the location impacted by the detour to approximately match its original contours. Place salvaged topsoil over the disturbed area and seed as specified in the contract.
206.04 Method of Measurement
Detour - Construct, Maintain, and Remove will be measured as a lump sum quantity in accordance with Section 109 . Materials, labor, and equipment needed to construct, maintain, and remove the detour are considered incidental to this item of work and will not be measured for payment. No additional measurements will be made for finish grade control or traffic control devices associated with detour construction. Traffic control devices used to maintain traffic after 2020 EDITION V5.1 DETOURS – 206 206-3 detour construction is complete will be measured under the traffic control bid item specified in the contract.
206.05 Basis of Payment
Payment for the completed and accepted quantities is made under the following: Pay Item Pay Unit Detour - Construct, Maintain, and Remove Lump Sum Include all materials, labor, and equipment needed to construct, maintain, and remove the detour in the lump sum bid for Detour - Construct, Maintain, and Remove. Traffic control devices required to construct the detour are considered incidental and will not be paid separately. Traffic control devices required for operation of the detour will be paid under the traffic control item specified in the contract.
Referenced in this section
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Source: Standard Specifications for Road and Bridge Construction, 2020 (v5.1) Edition. Pages 173–176 of 611. View official source ↗