307 ALASKA 2020 SECTION 610
610-1.01 D ESCRIPTION. Construct ditch lining at the locations on the Plans or as staked.
610-2.01 MATERIALS. Use stones that are sound and durable, are no larger than 8 inches in
greatest dimension, and not more than 50 percent by weight passing a 3- inch sieve, and not more than 5% passing a 1- inch sieve, as determined by ATM 304.
610-3.01 CONSTRUCTIO N REQUIREMENTS. Excavate to the dimensions shown on the Plans.
Place and spread ditch lining materials so that the finished face is reasonably uniform and conforms with the lines and slope shown on the Plans or as directed.
610-4.01 METHOD OF M EASUREMENT. See Section 109.
610-5.01 BASIS OF PA YMENT. Excavation required below normal ditch grade is subsidiary.
Payment will be made under: PAY ITEM Item Number Item Desc ription Unit 610.0001.____ Ditch Lining CY 610.0002.____ Ditch Lining TON 610.0003.____ Ditch Lining STA 610.0004.____ Ditch Lining LS 308 ALASKA 2020 SECTION 611 RIPRAP
611-1.01 DESCRIPTION . Construct riprap bank and slope protection.
611-2.01 MATERIALS. Evenly graded stones that are hard, angular, and have no more than 50
percent wear at 500 revolutions as determined by AASHTO T 96. Use stones with breadth and thickness at least 1/4 of its length. Do not use rounded boulders or cobbles on slopes steeper than 2:1. Meet the following gradation for the class specified. Percentages are by total weight, weights are for each stone:
1.Class I 0-50% weighing up to 25 pounds 0-10% weighing more than 50 pounds
2.Class II 50-100% weighing 200 pounds or more 0-15% weighing up to 25 pounds 0-10% weighing more than 400 pounds
3.Class III 50-100% weighing 700 pounds or more 0-15% weighing up to 25 pounds 0-10% weighing more than 1400 pounds
4.Class IV 50-100% weighing 2000 pounds or more 0-15% weighing up to 400 pounds 0-10% weighing more than 5400 pounds
611-3.01 CONSTRUCTIO N REQUIREMENTS. Provide a level, compact area large enough to
dump and sort typical loads of riprap at approved location(s). Dump the loads specified in this area and assist the Engineer as needed to sort and measure the stones in the load to determine if the riprap is within specifications. Provide the equipment needed to assist in this sorting. Excavate a footing trench along the toe of the slope as shown on the Plans. Place stones to the thickness , height, and length shown on the Plans, or as staked, in a well - graded mass with a minimum of voids. Fill in unacceptable voids with smaller stones. Place riprap to its full course thickness in one operation. Avoid displacing the underlying material. Do n ot place riprap in layers or use methods likely to cause segregation. Manipulate the rock sufficiently using a backhoe, rock tongs, or other suitable equipment to secure a reasonably regular surface and stability.
611-4.01 METHOD OF M EASUREMENT. See Secti on 109, by neat line volume or by weight.
611-5.01 BASIS OF PA YMENT. Excavation and backfill are subsidiary.
Payment will be made under: PAY ITEM Item Number Item Description Unit 611.0001.____ Riprap, Class ___ CY 611.0002.____ Riprap, Class ___ TON 611.0003.____ Riprap, Class ___ LS
Source: Alaska Standard Specifications for Highway Construction, 2020 Edition. Pages 335–335 of 584.