for Highway Construction Page 163 of 71 5 SECTION 209 – SMALL DITCHES
209.01 Description.
Construct small ditches, which the Department defines as having an average volume of less than 0.2 cubic yard per foot of ditch.
209.02 Materials.
Not specified.
209.03 Construction Requirements.
Construct small ditches as specified. If a typical small ditch section is not specified, construct small ditches by sidecasting the excavated material. Conduct the work in a manner to minimize interruption to irrigation water flows and make suitabl e arrangements with irrigation users to minimize claims for damage to crops or interruption to farming operations. Construct dikes first when they are needed to construct ditches across low ground or as directed. Use approved impervious material for the di kes. Place material in horizontal layers and compact each layer to 90 percent of the maximum dry density, as specified in 205.03.G, and then construct a small ditch in the top of the dike. Direct irrigation water, if available, into dike ditches for testing and approval before acceptance by the Engineer.
209.04 Method of Measurement.
The Engineer will measure acceptably completed work by the foot along the centerline and profile of the completed ditch. The Engineer will measure dikes and cuts constructed to carry small ditches as specified in 205.04.
209.05 Basis of Payment .
The Department will pay for acceptable quantities at the contract unit pr ices as follows: Pay Item Pay Unit Small Ditches .......................................................................................... FT for Highway Construction Page 164 of 71 5 SECTION 210 – STRUCTURE EXCAVATION AND COMPACTING BACKFILL
210.01 Description.
Excavate and dispose of materials required for the construction of structures , unless otherwise specified as structural excavation. Include necessary drainage, pumping, bailing, sheeting, shoring, and the construction and removal of cribs and cofferdams. Remove old structures or parts as required. Place and compact backf ill material as compacting backfill. Include sloping and cleaning up the sites.
210.02 Materials.
Provide materials as specified in: Granular Borrow ...................................................................................................................... 205.02 Controlled Density Fill .............................................................................................................. 522.02 Aggregate for Untreated Base ................................................................................................. 703.04 Aggregate for Granular Subbase ............................................................................................. 703.11
210.03 Construction Requirements.
A.Gene ral. Remove and dispose of unsuitable foundation material below the designed elevation as directed. Use suitable surplus excavated material in the construction of embankments. Replace material removed below the designed elevation with approved material. Sheet and brace trenches if necessary. Do not remove sheeting or bracing until backfill has progressed enough to prevent damage to pipelines or structures . Remove sheeting and bracing used in supporting structure excavation. Where rock, hardpan, or other unyielding material is encountered and a yielding material is required, remove the unyielding material below the grade specified and backfill as directed. Do not begin structure construction or backfill placement until the foundation has been approved. Do not use frozen material as backfill, and do not place backfill on snow -covered or frozen surfaces. Place backfill consisting of suitable material in 8- inch maximum, uncompacted layers and compact to Class A compaction as specified in 205.03.G. For backfill material placed within 3 feet of a concrete structure or retaining wal l, uniformly distribute the backfill material in layers of no more than 8 inches and compact with lightweight compacting equipment having an impact force of 1,000 to 3,000 pounds. Compact the backfill to the density r equirements for Class A compaction as specified in 205.03.G, before successive layers are placed. For backfill material determined by the Engineer as too granular to test, apply at least 5 overlapping compacting equipment passes per 8-inch lift or less. Compact backfill in areas not within a roadway prism, or special backfill around pipe underdrains not requiring a higher degree of compaction for some other purpose, to approximately the same density as the adjacent undisturbed soil or gravel. Perform compaction by any effective means.
Source: Idaho Standard Specifications for Highway Construction, 2023 Edition. Pages 199–199 of 768.