boulders or other detached stones each having a volume of 1⁄2 cubic yard or more as determined by physical measurements or visually by the Engineer.

203.04 Unclassified Excavation. Unclassified excavation shall consist of the excavation and disposal of all materials of whatever character encountered in the work.

203.05 Muck Excavation. Muck excavation shall consist of the removal and disposal of deposits of saturated or unsaturated mixtures of soils and organic matter not suitable for foundation material regardless of moisture content. 203.06 Borrow. Borrow shall consist of approved material required for the construction of embankments or for other portions of the work, and shall be obtained from approved sources, designated as follows:

(a) Borrow, case 1.—Borrow, Case 1 will consist of material obtained in accordance with Subsection 106.02(a)(1), Type A, except that the Contractor shall be required to use the sources shown on the plans or specified in the special provisions.

(b) Borrow, case 2.-Borrow, Case 2 will consist of material obtained in accordance with Subsection 106.02 (b).

(c) Selected borrow, for topping.—Where provided on the plans and in the bid schedule the top portions of the roadbed in both cuts and embankments, as indicated, shall consist of selected borrow for topping, selected from Case 1 or Case 2 borrow sources. The topping material shall be of such gradation that all particles will pass a sieve with 3-inch square openings and not more than 15 percent will pass a No. 200 sieve, as determined by AASHO T11. The portion of the material passing a No. 40 sieve shall have a plasticity index of not more than 6 as determined by AASHO T 90 and a liquid limit of not more than 30 as determined by AASHO T89.

(d) General.—The Contractor shall notify the Engineer sufficiently in advance of opening any borrow areas so that cross section elevations and measurements of the ground surface after stripping may be taken, and the borrow material can be tested before being used. Sufficient time for testing the borrow shall be allowed.

Construction Requirements

203.07 General. The excavation and embankments for the roadway, intersections, and entrances shall be finished to reasonably smooth and uniform surfaces. No materials shall be wasted without permission of the Engineer. Excavation operations shall be conducted so that material outside of the limits of slopes will not be disturbed. Prior to beginning ex

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cavation, grading, and embankment operations in any area, all necessary clearing and grubbing in that area shall have been performed in accordance with Section 201-Clearing and Grubbing.

Unless otherwise specified, material classified as rock shall be excavated to a minimum depth of 6 inches below subgrade within the limits of the roadbed, and the excavation backfilled with material designated on the plans or approved by the Engineer. Care shall be taken that undrained pockets shall not be left in the surface of the rock.

When presplitting is specified in the contract or when the contractor elects to use the presplitting method, he shall furnish to the Engineer, prior to starting drilling operations for presplitting, a plan showing the proposed position of all drill holes relative to the roadway stations, grades, lines and slopes, depth of drilling, type of explosives to be used, loading pattern and sequence of firing. The drilling and blasting plan is for record purposes only and will not absolve the Contractor of his responsibility for using proper drilling and blasting procedures.

The drill holes may be 22 to 3 inches in diameter and may be spaced approximately 12 to 3 feet apart depending on the material encountered.

The maximum depth of holes drilled shall be 25 feet plus one half the distance between holes. The presplitting operations shall be completed prior to any other blasting within 50 feet of the longitudinal (station) limits within which all presplitting has been accomplished, or as otherwise approved by the Engineer.

The explosive shall be 40-percent extra strength dynamite or other approved explosives that will produce equally satisfactory results. Fertilizer type explosives may be used only upon written permission of the Engineer. The size and spacing of the individual charges may be varied to suit subsurface conditions encountered during construction.

All primary blasting holes shall be drilled not less than 3 feet from the presplit face or at a wider interval, if necessary, to avoid overbreakage.

Unless otherwise provided in the special provisions, the cost of presplitting will be considered incidental to roadway excavation and no direct payment will be allowed for this operation.

Where the plans show the top portion of the roadbed to be selected topping, all unsuitable material shall be excavated to the depth necessary for placement of the selected topping to the required compacted thickness.

Borrow material shall not be placed until after the readily accessible roadway excavation has been placed in the fill

unless otherwise permitted or directed by the Engineer. If the Contractor places more borrow than is required and thereby causes a waste of excavation, the amount of such waste will be deducted from the borrow volume as measured in the borrow area. All borrow areas shall be bladed and left in such shape as to permit accurate measurements after excavation has been completed. The Contractor shall not excavate beyond the dimensions and elevations established, and no material shall be removed prior to the staking out and cross-sectioning of the site. The finished borrow areas shall be approximately true to line and grade established and specified and shall be finished, as prescribed in Section 106.02 (c). When necessary to remove fencing, the fencing shall be replaced in at least as good condition as it was originally. The Contractor shall be responsible for the confinement of livestock when a portion of the fence is removed.

Obliteration of old roadways shall be done in accordance with section 209. Removal of portland cement pavement and base course will be paid for under section 202.

Ditches shall include side ditches and gutters, channel changes, irrigation ditches, inlet and outlet ditches, toe ditches, furrow ditches, and such other ditches as may be designated on the plans or staked by the Engineer.

All material excavated from ditches shall be disposed of as provided herein.

Ditches shall conform to the slope, grade, and shape of the required cross section, with no projections of roots, stumps, rock, or similar matter. The Contractor shall maintain and keep open and free from leaves, sticks, and other debris all ditches dug by him until final acceptance of the work.

Furrow ditches shall be formed by plowing a continuous furrow along the line staked by the Engineer. Methods other than plowing may be used if acceptable to the Engineer. The ditches shall be cleaned out by hand shovel work, by ditcher, or by some other suitable method, throwing all loose material on the downhill side so that the bottom of the finished ditch shall be approximately 18 inches below the crest of the loose material piled on the downhill side. Hand finish will not be required, but the flow lines shall be in satisfactory shape to provide drainage without overflow.

During the construction of the roadway, the roadbed shall be maintained in such condition that it will be well drained at all times. Side ditches or gutters emptying from cuts to embankments or otherwise shall be so constructed as to avoid damage to embankments by erosion.

When provided for on the plans or in the special provisions, suitable topsoil encountered in excavation and on areas

where embankment is to be placed shall be removed to such extent and to such depth as the Engineer may direct, except removal to a depth of less than 6 inches will not be required. The removed topsoil shall be transported and deposited in storage piles at locations designated by the Engineer. The topsoil shall be completely removed to the required depth from any designated area prior to the beginning of regular excavation or embankment work in the area and shall be kept separate from other excavated materials.

Where excavation to the finished graded section results in a subgrade or slopes of unsuitable soil, the Engineer may require the Contractor to remove the unsuitable materials and backfill to the finished graded section with approved material. The Contractor shall conduct his operations in such a way that the Engineer can take the necessary crosssectional measurements before the backfill is placed.

The Engineer will designate as unsuitable those soils that cannot be properly compacted in embankments. All unsuitable material shall be disposed of as directed.

When the location of unsuitable soil is shown on the plans, the removal and replacement shall be as shown.

Excavation which requires more than one handling prior to final placement, including loamy top soil to be stockpiled and reserved for later use in the work, will be paid for at the contract unit price for unclassified excavation, rock excavation, common excavation, or muck excavation, as the case may be, for each handling approved by the Engineer or may be paid for as another item of work for the second handling when so specified.

203.08 Embankment Construction. Embankment construction shall consist of constructing roadway embankments, including preparation of the areas upon which they are to be placed; the construction of dikes within or adjacent to the roadway; the placing and compacting of approved material within roadway areas where unsuitable material has been removed; and the placing and compacting of embankment material in holes, pits, and other depressions within the roadway area. Only approved materials shall be used in the construction of embankments and backfills. Embankments and backfills shall contain no muck, frozen material, roots, sod, or other deleterious matter.

203.09 Construction Methods. Rocks, broken concrete, or other solid, bulky materials shall not be placed in embankment areas where piling is to be placed or driven.

When embankment is to be placed and compacted on hillsides, or when new embankment is to be compacted against existing embankments, or when embankment is built part width at a time, the existing slopes that are steeper than

2:1 when measured at right angles to the roadway shall be continuously benched over those areas where it is required as the work is brought up in layers. Benching widths will be subject to the Engineer's approval to obtain sufficient width to permit operation of placement and compaction equipment. Each horizontal cut shall begin at the intersection of the original ground and the vertical sides of the previous cuts. Material thus excavated shall be compacted along with the embankment material in conformance to the plan cross sections.

Where embankment is to be placed and compacted and end dumping is permitted, the slopes of the original ground or embankment shall be deeply plowed or cut into before starting end dumping.

Unless shown otherwise on the plans or special provisions, where an embankment of less than 4 feet below subgrade is to be made, all sod and vegetable matter shall be removed from the surface upon which the embankment is to be placed, and the cleared surface shall be completely broken up by plowing, scarifying, or stepping to a minimum depth of 6 inches, except as provided in subsection 201.03. This area shall then be compacted as provided in subsection 203.10. Sod not required to be removed shall be thoroughly disc harrowed or scarified before construction of embankment. Wherever a compacted road surface containing granular materials lies within 3 feet of the subgrade, such old road surface shall be scarified to a depth of at least 6 inches whenever directed by the Engineer. This scarified material shall then be compacted as provided in subsection 203.10.

If embankment can be deposited on one side only of abutments, wing walls, piers or culvert headwalls, care shall be taken that the area immediately adjacent to the structure is not compacted to the extent that it will cause overturning of, or excessive pressure against the structure. When noted on the plans, the fill adjacent to the end bent of a bridge shall not be placed higher than the bottom of the backwall of the bent until the superstructure is in place. When embankment is to be placed on both sides of a concrete wall or box type structure, operations shall be so conducted that the embankment is always at approximately the same elevation on both sides of the structure.

Unless otherwise required in the special provisions, excavation areas and borrow pits may be prewatered before excavating the material. When prewatering is used, the areas to be excavated shall be moistened to the full depth, from the surface to the bottom of the excavation. The water shall be controlled so that the excavated material will contain the proper moisture to permit compaction to the specified