to or from designated areas outside the roadway limits; such as Case 1 borrow pits, disposal areas, etc.; will be measured along the shortest route determined by the Engineer to be feasible and satisfactory unless otherwise provided.

If the contractor chooses to haul material over some other route, and such other route is longer, the computation for payment shall be based on the overhaul distance measured along the route designated by the Engineer.

When the bid schedule contains a pay item for overhaul on a station-yard basis, the number of station-yards of overhaul to be paid for shall be the number of cubic yards of overhauled material multiplied by the overhaul distance in stations. The unit "station-yard" is the amount of hauling required to move one cubic yard a distance of 100 feet beyond the free-haul distance.

When the bid schedule contains a pay item for overhaul on a cubic yard or ton mile basis, the number of cubic yard miles or ton miles of overhaul to be paid for shall be the number of cubic yards or tons, as applicable, of overhauled material multiplied by the overhaul distance in miles. The unit “cubic yard mile" is the amount of hauling required to move one cubic yard a distance of one mile beyond the free-haul distance. The unit "ton mile", is the amount of hauling required to move one ton a distance of one mile beyond the free-haul distance.

Basis of Payment

205.03 The quantities, determined a provided above, shall be paid for at the contract unit price per unit of measurement, for the particular pay item listed below that is shown in the bid schedule, which price and payment shall be full compensation for all labor, equipment, tools and incidentals necessary to complete the work prescribed in this section.

Payment will not be made for overhaul of Borrow, Case 2, foundation fill, bedding material and material removed in the rounding of cut slopes when rounding is a separate pay item. When the bid schedule does not show estimated quantities for "overhaul" from the pay item list below, overhaul will not be paid for directly, but will be considered as a subsidiary obligation of the Contractor under other contract items.

206.01 This work shall consist of the necessary excavating for foundations of bridges, culverts, underdrains, and other structures not otherwise provided for in the specifications. Except as otherwise provided for pipe culverts, the backfilling of completed structures and the disposal of all excavated material shall be in accordance with these specifications and in reasonably close conformity with the plans or as established by the Engineer.

This work shall include necessary diverting of live streams, bailing, pumping, draining, sheeting, bracing, and the necessary construction of cribs and cofferdams, and furnishing the materials therefor, and the subsequent removal of cribs and cofferdams and the placing of all necessary backfill.

This work shall also include the furnishing and placing of approved foundation fill material to replace unsuitable material encountered below the foundation elevation of structures. No allowance will be made for classification of different types of material encountered.

Construction Requirements

206.02 Clearing and Grubbing. Prior to starting excavation operations in any area all necessary clearing and grubbing in that area shall have been performed in accordance with Section 201.

206.03 Excavation:

(a) General, all structures.-The Contractor shall notify the Engineer sufficiently in advance of the beginning of any excavation so that cross-sectional elevations and measurements may be taken of the undisturbed ground. The natural ground adjacent to the structure shall not be disturbed without permission of the Engineer.

Trenches or foundation pits for structures or structures footings shall be excavated to the lines and grades or elevations shown on the plans or as staked by the Engineer. They shall be of sufficient size to permit the placing of structures or structure footings of the full width and length shown. The elevations of the bottoms of footings, as shown on the plans, shall be considered as approximate only and the Engineer may order, in writing, such changes in dimensions or elevations of footings as may be deemed necessary, to secure a satisfactory foundation.

Boulders, logs, and any other objectionable material encountered in excavation shall be removed.

After each excavation is completed, the Contractor shall notify the Engineer to that effect, and no footing, bedding material or pipe culvert shall be placed until the Engineer has approved the depth of excavation and the character of the foundation material.

(b) Structures other than pipe culverts.—All rock or other hard foundation material shall be cleaned of all loose material and cut to a firm surface, either level, stepped, or serrated as directed by the Engineer. All seams or crevices shall be cleaned and grouted. All loose and disintegrated rock and thin strata shall be removed. When the footing is to rest on material other than rock, excavation to final grade shall not be made until just before the footing is to be placed. When the foundation material is soft or mucky or otherwise unsuitable, as determined by the Engineer, the Contractor shall remove the unsuitable material and backfill with approved granular material. This foundation fill shall be placed and compacted in 6-inch layers up to the foundation elevation.

When foundation piles are used, the excavation of each pit shall be completed before the piles are driven and any placing of foundation fill shall be done after the piles are driven. After the driving is completed all loose and displaced material shall be removed, leaving a smooth, solid bed to receive the footing.

(c) Pipe culverts.-The width of the pipe trench shall be sufficient to permit satisfactory jointing of the pipe and thorough tamping of the bedding material under and around the pipe. Where rock, hardpan, or other unyielding material is encountered, it shall be removed below the foundation grade for a depth of at least 12 inches or one-half inch for each foot of fill over the top of pipe, whichever is greater, but not to exceed three-quarters of the vertical inside diameter of the pipe. The width of the excavation shall be at least one foot greater than the horizontal outside diameter of the pipe. The excavation below grade shall be backfilled with selected fine compressible material, such as silty clay or loam, and lightly compacted in layers not over 6 inches in uncompacted depth to form a uniform but yielding foundation. Where a firm foundation is not encountered at the grade established, due to soft, spongy, or other unstable soil, such unstable soil under the pipe and for a width of at least one diameter on each side of the pipe shall be removed to the depth directed by the Engineer and replaced with approved granular foundation fill material properly compacted to provide adequate support for the pipe, unless other special construction methods are called for on the plans.

The foundation surface shall provide a firm foundation of uniform density throughout the length of the culvert and, if directed by the Engineer, shall be cambered in the direction parallel to the pipe centerline.

Where pipe culverts are to be placed in trenches excavated in embankments, the excavation of each trench shall be performed after the embankment has been constructed to a plane parallel to the proposed profile grade and to such height above the bottom of the pipe as is shown on the plans or directed by the Engineer.

206.04 Utilization of Excavated Materials. All excavated material, so far as suitable, shall be utilized as backfill or embankment. The surplus material shall be disposed of in such manner as not to obstruct the stream or otherwise impair the efficiency or appearance of the structure. No excavated material shall be deposited at any time so as to endanger the partly finished structure.

206.05 Cofferdams. Suitable and practically watertight cofferdams shall be used wherever water-bearing strata are encountered above the elevation of the bottom of the excavation. If requested, the Contractor shall submit drawings showing his proposed method of cofferdam construction, as provided under subsection 105.02.

Cofferdams or cribs for foundation construction shall, in general, be carried well below the bottoms of the footings and shall be well braced and as nearly watertight as practicable. In general, the interior dimensions of cofferdams shall be such as to give sufficient clearance for the construction of forms and the inspection of their exteriors, and to permit pumping outside of the forms. Cofferdams or cribs which are tilted or moved laterally during the process of sinking shall be righted or enlarged so as to provide the necessary clearance.

When conditions are encountered which, as determined by the Engineer, render it impracticable to dewater the foundation before placing the footing, the Engineer may require the construction of a concrete foundation seal of such dimensions as he may consider necessary, and of such thickness as to resist any possible uplift. The concrete for such seal shall be placed as shown on the plans or directed by the Engineer. The foundation shall then be dewatered and the footing placed. When weighted cribs are employed and the weight is utilized to overcome partially the hydrostatic pressure acting against the bottom of the foundation seal, special anchorage such as dowels or keys shall be provided to transfer the entire weight of the crib to the foundation seal. When a foundation seal is placed under water, the cofferdam shall be vented or ported at low water level as directed.

Cofferdams shall be constructed so as to protect green concrete against damage from sudden rising of the stream and to prevent damage to the foundation by erosion. No timber or bracing shall be left in cofferdams or cribs in such a way as to extend into substructure masonry, without written permission from the Engineer.

Any pumping that may be permitted from the interior of any foundation enclosure shall be done in such a manner as to preclude the possibility of any portion of the concrete materials being carried away. Any pumping required during the placing of concrete, or for a period of at least 24 hours thereafter, shall be done from a suitable sump located outside the concrete forms. Pumping to dewater a sealed cofferdam shall not commence until the seal has set sufficiently to withstand the hydrostatic pressure.

Unless otherwise provided, cofferdams or cribs, with all sheeting and bracing involved therewith, shall be removed by the Contractor after the completion of the substructure. Removal shall be effected in such manner as not to disturb or mar finished masonry.

206.06 Preservation of Channel. Unless otherwise permitted, no excavation shall be made outside of caissons, cribs, cofferdams, or sheet piling, and the natural stream bed adjacent to the structure shall not be disturbed without permission from the Engineer. If any excavation or dredging is made at the site of the structure before caissons, cribs, or cofferdams are sunk in place, the Contractor shall, after the foundation base is in place, backfill all such excavations to the original ground surface or stream bed with material satisfactory to the Engineer.

206.07 Backfill and Embankments for Structures Other Than Pipe Culverts. Excavated areas around structures shall be backfilled with approved freedraining granular material in horizontal layers, not over 6 inches (in depth, to the level of the original ground surface.

Each layer shall be moistened or dried as required and thoroughly compacted with mechanical tampers.

In placing backfills or embankment, the material shall be placed simultaneously insofar as possible to approximately the same elevation on both sides of an abutment, pier, or wall. If conditions require placing backfill or embankment appreciably higher on one side than on the opposite side, the additional material on the higher side shall not be placed until the masonry has been in place 14 days, or until tests made by the laboratory under the supervision of the Engineer establishes that the masonry has attained sufficient strength to withstand any pressure created by the methods used and materials placed without damage or strain beyond a safe factor.

Backfill or embankment shall not be placed behind the walls of concrete culverts or abutments or rigid frame structures until the top slab is placed and cured. Backfill and embankment behind abutments held at the top by the superstructure, and behind the sidewalls of culverts, shall be carried up simultaneously behind opposite abutments or sidewalls.

All embankments adjacent to structures shall be constructed in horizontal layers and compacted as prescribed in subsection 203.19 except that mechanical tampers may be used for the required compaction. Special care shall be taken to prevent any wedging action against the structure and slopes bounding or within the areas to be filled shall be benched or serrated to prevent wedge action. The placing of embankment and the benching of slopes shall continue in such a manner that at all times there will be a horizontal berm of thoroughly compacted material for a distance at least equal to the height of the abutment or wall to be backfilled against except insofar as undisturbed material obtrudes upon the area. Broken rock or coarse sand and gravel shall be provided for a drainage filter at weep holes as shown on the plans.

206.08 Bedding, Backfill, and Embankment for Pipe Culverts. Bedding, backfill, and embankment for pipe culverts shall be done in accordance with section 603.

Method of Measurement

206.09 Structure Excavation. The volume of excavation to be paid for will be the number of cubic yards, measured in original position, of material acceptably excavated in conformity with the plans or as directed by the Engineer, but in no case, except as noted, will any of the following volumes be included in the measurement for payment:

(1) The volume outside of vertical planes 18 inches outside of and parallel to (a) the neat lines of footings and (b) the inside walls of pipe and pipe-arch culverts at their widest horizontal dimension.

(2) The volume of excavation for culvert end sections outside the vertical plane for culverts stipulated in (1) above.

(3) The volume outside of neat lines of underdrains as shown on the plans, and outside the limits of foundation fill as ordered by the Engineer.

(4) The volume included within the staked limits of the roadway excavation, contiguous channel changes, ditches, etc., for which payment is otherwise provided in the specification. (5) Volume of water or other liquid resulting from construction operations and which can be pumped or drained away.

(6) The volume of any excavation performed prior to the taking of elevations and measurements of the undisturbed ground.

(7) The volume of any material rehandled, except that where the plans indicate or the Engineer directs the excavation after embankment has been placed and except that when installation of pipe culverts by the imperfect trench method specified in subsection 603.09 is required, the volume of material re-excavated as directed will be included.

(8) The volume of excavation for footings ordered at a depth more than 5 feet below the lowest elevation for such footings shown on the original contract plans, unless the bid sched

ule contains a pay item for excavation ordered below the elevations shown on the plans for individual footings.

206.10 Bridge Excavation. The volume of excavation, designated on the plans or in the special provisions as "Bridge Excavation" will be measured as described below and will be kept separate for pay purposes from the excavation for all other structures.

The volume of bridge excavation to be paid shall be the vertical planes 18 inches outside of and parallel to the neat lines of the footing. These vertical planes shall constitute the vertical faces of the volume for pay quantities regardless of the excavation inside or outside of these planes.

206.11 Foundation Fill. The volume of foundation fill to be paid for will be the number of cubic yards, measured in final position, of the special granular material actually provided and placed below the foundation elevation of structures as specified, complete in place and accepted.

206.12 Shoring, Cribbing, and Related Work. Shoring, cribbing, and related work, whenever included as a pay item in the bid schedule, will be paid for at the lump sum bid price. This work shall include furnishing, constructing, maintaining, and removing any and all shoring, cribbing, cofferdams, caissons, bracing, sheeting, water control, and other operations necessary for the acceptable completion of excavation included in the work of this section, to a depth of 5 feet below the lowest elevation shown on the plans for each separable foundation structure.

Basis of Payment

206.13 The quantities, determined as provided above will be paid for at the contract unit price per unit of measurement, respectively, for each of the particular pay items listed below that is shown in the bid schedule, which prices and payment will be full compensation for the work prescribed in this section, except as follows.

(1) Any excavation for footings ordered at a depth more than 5 feet below the lowest elevation shown on the original contract plans will be paid for as provided in subsection 109.07, unless a pay item for excavation ordered below plan elevation appears in the bid schedule.

(2) Concrete will be measured and paid for as provided under Section 552 or 602.

(3) Any roadway or borrow excavation required in excess of the quantity excavated for structures will be measured and paid for as provided under Section 203.

(4) Shoring, cribbing, and related work required for excavation ordered more than 5 feet below plan elevation will be paid for in accordance with subsection 109.07. Payment will be made under:

(a) developing an adequate water supply for all items in the contract that require water

and