5-112
d.Approach embankments The earth material used for approach embankments shall have sufficient strength under the placement method specified i n the Contractor’s plans to maintain stability throughout the duration of the Special Detou r.
e.Approach Road Base Drainage The approach road base structu re shall consist of a 1 foot thick layer, minimum, of aggregate subbase course gravel, Type D or E. This layer shall be designed to support legal loads during the use of the detour. Drainage shall be designed to drain the approach area.
f.Approach Road Surface The a pproach road surface, including the shoulders, shall be paved with a 3 inch, minimum, thickness hot bituminous pavement layer, except when specified to be a gravel surface. When a gravel surface is spe cified, it shall consist of an approved gravel.
g.Design Speed The design speed of the Special Detour shall be not less than the construction area posted speed limit, or the advisory speed lim it, as applicable, unless otherwise indicated in the Contract.
510.04 Pedestrian Traffic Only The provisions of Section 510. 03 - Vehicular and
Pedestrian Traffic Not Separated, shall apply to this Section w ith the following modifications:
a.Structures shall be designed for a live load of 85 lb/ft². b. The Special Detour shall have a minimum clear width of 5 fe et or as specified in the Contract.
c.Vertical alignment and ramps shall be ADA compliant. d. Deflections due to live load shall not exceed 1/300 of the span.
510.05 Vehicular and Pedestrian Traffic Separated The provisio ns of both Section
510.03 Vehicular and Pedestrian Traffic Not Separated, and Se ction 510.04- Pedestrian
Traffic Only, shall apply to thi s Section. If vehicles and ped estrians are carried on the same structure, each shall have its own lane as specified. The pede strian lane shall be protected from vehicular traffic by being a t least 9 inches above the roa dway surface or suitably protected by means of an adequate curb at least 9 inches in hei ght above the roadway surface. No bridge rail will be required between vehicle traff ic and pedestrian traffic, unless otherwise specified, but shall be located at the exterior side of the sidewalk.
510.06 Special Detour Construction T he Special Detour, includin g temporary structures
and approaches, shall be constructed in accordance with the pla ns submitted by the Contractor. Barricades, warning s igns, lights and other traffi c control devices shall be provided in accordance with the Contract and the approved Traff ic Control Plan. The temporary structure’s deck and floor members shall be faste ned or anchored so that all contact surfaces with adjacent supporting members bear cont inuously. If timber plank decking is used, it shall be secured into timber nailer strips with screw-type nails, or securely fastened by an alternate method that will prevent the decking from loosening. 5-113 Immediate corrective action shall be taken by the Contractor to remedy any condition in the structure that results in objectionable or distractive noise le vels, or results in the decking becoming loose, when subject to traffic loads. Screw-type nails will not be required to anchor timber plank de cking for pedestrian traffic use. The approach road surface, including shoulders, whether paved o r graveled, shall be maintained in a compacted and smooth condition. The temporary s tructure travel surface shall be constructed and maintained in an acceptably smooth con dition, as determined by the Resident. Immediate corrective action shall be taken by the Co ntractor to remedy objectionable roughness of the Sp ecial Detour riding surface. Provisions shall be made for a skid resistant wearing surface t hroughout the period of time the temporary structure is open to public travel for vehic ular and pedestrian traffic. A steel grid floor may be used for vehicular traffic if installed in accordance with the design plans and these specifications. Erosion control shall be accomplished in accordance with Sectio n 656 - Temporary Soil Erosion and Water Pollution Control. When the Project has been opene d to traffic, the temporary stru cture and approaches shall be removed to, or below, the streambed, finish ground lin e or original ground line, as applicable. The approaches shall be obliterated and the distur bed areas shall be stabilized to original, or better than original, conditions. The provisions of Section 104 - General Rights and Responsibilities, shall apply.
510.07 Contractor's Responsibility The Contractor shall be res ponsible for removal of
snow from areas provided for pedestrian traffic as well as vehi cular traffic in accordance with Section 105, General Scope of Work. In addition to normal maintenance, should any part, or all, of the Special D etour be damaged or destroyed by high water, or any other cause, prior to, or after, opening t he Special Detour to traffi c, it shall be repaired or replaced by the Contractor without additional compensation.
510.08 Method of Measurement Special Detours will be paid by t he lump sum.
510.09 Basis of Payment The accepted Special Detour will be pa id for at the Contract
lump sum price which price shall be full compensation for the r espective items, as called for in the Contract, including desi gn, construction, maintenance, c omplete removal, rehabilitation and permanent stabilization including loaming, s eeding and mulching. All gravel or borrow material and excavation needed to accommodate changes in elevation between temporary structures and existing roadways shall be inc idental to this item. The lump sum price shall also incl ude the cost of furnishing and re vising, as necessary, all plans, computations and certifications, as called for in the Contract. Payment will be made as follows: 60 percent of the lump s um price will be paid when th e Special Detour is acceptable and open to traffic; anot her 20 percent of the lump sum price will be paid when
Source: Maine Standard Specifications for Road and Bridge Construction, 2020 Edition. Pages 404–405 of 817.