DIVISION 4100 SITEWORK

Size: px
Start display at page:

Download "DIVISION 4100 SITEWORK"

Transcription

1 DIVISION 4100 SITEWORK SECTION 4115 EARTHWORK PART 1 - GENERAL 1.01 SCOPE This section covers the grading and compaction of excavations, embankments, structural foundations, and planted areas REFERENCES A. KDOT Standard Specification: 1. Section 205 Excavation and Embankment for Highways B. ASTM: 1. D698 Standard Test Methods for Laboratory Compaction Characteristics of Soil Using Standard Effort 2. D1557 Standard Test Methods for Laboratory Compaction Characteristics of Soil Using Modified Effort 3. D2487 Standard Practice for Classification of Soils for Engineering Purposes 4. D4253 Standard Test Methods for Maximum Index Density and Unit Weight of Soils Using a Vibratory Table 5. D4254 Standard Test Methods for Minimum Index Density and Unit Weight of Soils and Calculation of Relative Density 6. D4318 Standard Test Methods for Liquid Limit, Plastic Limit, and Plasticity Index of Soils 1.03 SUBMITTALS A. Test Reports: 1. Proctor Analysis. 2. In-Place Density. 3. Atterberg Limits. 4. Any other geotechnical report as required to assist in the evaluation of the suitability of materials to be used in the construction of public infrastructure DEFINITIONS A. Grading: Grading shall mean the performance of all excavation, embankment, and backfill operations in connection with the construction of all improvements. B. Excavation: Excavation shall consist of the removal of materials from the construction area to the lines and grades shown on the plans. 1. Unclassified Excavation: Unclassified excavation is defined as the grading, excavation, hauling, removal, and disposal of all material encountered regardless of its Division 4100 Sitework

2 nature, including rock and weathered shale unless defined as rock excavation. All material excavated shall be considered unclassified unless the Construction Documents state otherwise. 2. Rock Excavation: Rock excavation is defined as the removal of sandstone, limestone, non-weathered shale, or other similar materials, that in the opinion of the Engineer, require the means of blasting, ramming, or drilling to be removed. C. Embankment or Backfill: Embankment or backfill is defined as the placing and compacting of suitable material in the construction area to the lines and grades shown on the plans. 1. Unsuitable Soil Material: Unsuitable material shall be defined as any material not approved to be used for fill material or embankment. This includes but is not limited to frozen material, organic material, top soil, rubbish, and rock. A material with high insitu moisture content shall not constitute an unsuitable material. 2. Suitable Soil Material: Suitable material shall be entirely imperishable with that portion passing the No. 40 Sieve, having a liquid limit not exceeding forty (40), and a plastic index not exceeding twenty-five (25), when tested in accordance with ASTM D4318. D. Borrow: Borrow shall be defined as approved material excavated from an area outside of the construction limits and required for embankment construction. E. Waste: Waste shall be defined as the excavated material in excess of that required for grading, building backfill, or the embankment... F. Structures: Structures as used in this Section refer to bridges (including foundations and abutments), culverts (including headwalls and wingwalls), basins, storm and/or sanitary sewer structures, retaining walls, and similar improvements GENERAL A. Maintaining Drainage: The Contractor shall be responsible for maintaining positive and sufficient drainage at all times during the grading operations. Soft spots that develop during grading operations resulting from, in the opinion of the Engineer, the failure of the Contractor to maintain proper drainage shall be removed. The area shall then be backfilled with suitable material and compacted to obtain the required density. No additional payment shall be made to the Contractor for this work. B. Permits: Prior to commencing any grading operations, the Contractor is responsible for obtaining all necessary local, state and federal permits. Refer to Section 4105 Temporary Erosion and Sediment Control for permit and Shawnee Municipal Code requirements governing land disturbance activities. C. Damage Prevention: The Contractor is responsible for protecting private facilities. When private facilities are disturbed or damaged by the work, the Contractor shall make necessary arrangements for repairs to the facilities. PART 2 - PRODUCTS 2.01 EQUIPMENT Equipment for compaction of fine grained soils shall be a sheepsfoot roller with minimum two hundred (200) psi bearing pressure. Equipment for compaction of granular materials shall be either a pneumatic-tired roller or a smooth-faced steel roller. The pneumatic-tired roller shall be of sufficient weight to provide a minimum bearing pressure of two hundred twenty-five (225) Division 4100 Sitework

3 pounds per inch of tire width. The smooth-faced steel roller shall be eight (8) to twelve (12) tons in weight. Confined areas and backfill adjacent to structures shall be compacted with mechanical rammers or tampers. PART 3 - EXECUTION 3.01 PREPARATION A. Tolerances: Grading, excavation, and backfilling for all improvements, shall be made to the lines, grades, and cross sections indicated within the Construction Documents. Areas shall be cut or filled to within one-tenth (0.1) foot of the approved subgrade elevation B. Erosion Control: Erosion control measures shall be taken to protect downstream drainage systems from pollution, sediment or erosion caused by the grading operations. Refer to Section 4105 Temporary Erosion and Sediment Control. The Contractor shall be responsible to correct any pollution or damage caused by the grading operations EXCAVATION A. Material: The Contractor shall sort all excavated material and stockpile when necessary, so as to provide suitable material for backfill and embankments. As far as practical, all material removed by excavation shall be used in the formation of embankments as required within the Construction Documents. Debris and other unsuitable material shall be hauled to approved disposal areas The Contractor shall ensure that the material for earth embankments conforms to the material requirements as they are defined in this Section. B. Rock Encountered: Where rock, shale, or similar material is encountered under future pavement, the excavation shall extend a minimum of fifteen (15) inches below the finished subgrade for the full width of the Right-of-Way or to the depth required by the Engineer, whichever is greater. C. Top Soil: Top soil material shall be sorted and stockpiled to the extent necessary to resurface disturbed areas. Stockpiled top soil material shall be free from brush, large roots, vegetation and other materials that will be detrimental to the intended use. D. Waste: Excavation materials in excess of the amount needed to complete the grading shall be considered as waste material, which shall be removed from the site by and at the expense of the Contractor. E. Over-Excavation: Over-excavation is required when unsuitable materials, as determined by the Engineer, are found during the excavation process. The Contractor shall remove the unsuitable and/or unstable materials to a minimum depth of eighteen (18) inches or to the depth required by the Engineer, whichever is greater. The area involved shall then be backfilled with suitable material as determined by the Engineer and compacted to obtain the required density EMBANKMENT A. Surface Preparation: Embankment areas shall be cleared and grubbed as required by Section 4110 Clearing and Grubbing prior to placing the fill. Embankment subgrade shall be scarified a minimum of six (6) inches and compacted to ninety-five percent (95%) of maximum density as determined by ASTM D698. B. Benching: Where embankments, regardless of height, are placed against hillsides or existing embankments, either of which have a slope steeper than six units horizontal to one unit vertical (6:1), the existing slope shall be benched or stepped in approximately eighteen Division 4100 Sitework

4 (18) inch rises as the new fill is brought up in eight (8) inch layers or lifts. Both the material bladed out and the bottom of the area cut into, as well as the embankment material being placed, shall be compacted to the required density. Material cut out, bladed into place, and compacted shall not be measured and paid for directly but will be considered as incidental work. C. Existing Surfaces: Where embankments two (2) feet or less in depth are to be placed on areas covered by existing pavement, the existing pavement shall be removed and the cleared ground surface shall be compacted at optimum moisture to the specified density. Where embankments greater than two (2) feet in depth are to be placed on areas covered by existing pavement and pavement is to be left in place, the existing pavement shall be broken in to pieces not larger than twelve (12) inches maximum dimension, left in place, and the embankment started thereon. The existing pavement shall be free of all foreign material such as rebar, wire mesh and pavement fabric. D. Placement: Suitable material shall be placed in successive horizontal layers distributed uniformly over the full width of the embankment area. Each layer of material shall not exceed eight (8) inches maximum in thickness (loose state) and shall be compacted to not less than the required density before the next layer is placed thereon. As the compaction of each layer progresses, continuous blading or dozing will be required to level the surface and to insure uniform compaction. Embankment construction shall not be performed when material contains frost, is frozen, or is snow covered. 1. Within the ROW: In no case shall rocks, larger than three (3) inches in any dimension, be deposited within the Right-of-Way. As an exception, embankments that exceed five (5) feet in depth, may include rock greater than three (3) inches but less than twelve (12) inches in diameter, at the discretion of the Engineer. 2. Outside the ROW: In no case shall rocks, larger than three (3) inches in any dimension, be deposited within the top twelve (12) inches of an embankment. In no case shall rocks, larger than twelve (12) inches in any dimension, be placed throughout the remaining depth of the embankment. E. Compaction: The maximum density for an embankment shall be determined in accordance with ASTM D698 and within the tolerances of the optimum moisture at maximum density as determined by the Moisture Density Curve obtained for the given material. 1. Compaction of the final eighteen (18) inches of an embankment shall be at least ninety-five percent (95) of maximum density. KDOT Type AA compaction shall be used with a moisture range of KDOT MR-3-3, unless recommended in a soils report by a qualified testing laboratory and approved by the Engineer. 2. The fill area below the top eighteen (18) inches shall be KDOT Type B compaction with a moisture range of KDOT MR-90 unless more stringent compaction is recommended in a soils report by a qualified testing laboratory or required by the Engineer. All the work involved in either adding moisture to, or removing moisture from embankment materials shall be considered incidental to the completion of the grading operation. F. Compaction in Cut Sections: The soil six (6) inches below the finish subgrade line in cut sections shall be scarified, broken up, and then compacted as specified in this Section. The depth of compaction in cut sections shall be a minimum of six (6) inches. Division 4100 Sitework

5 3.04 STRUCTURAL BACKFILL A. Placement: Backfill around and outside of structures shall be deposited in layers not to exceed eight (8) inches in thickness (loose state). Material shall be mechanically compacted, using hand operated tampers for earth compaction or a vibrating plate compactor for granular material. B. Timing: Backfill against cast-in-place structures shall not begin until eighty percent (80%) of the twenty-eight (28) day design strength of the concrete has been reached. Additionally, backfill shall not be placed against cast-in-place structure until the minimum required curing period has elapsed, in conformance with Section 4505 Cast in Place Concrete. C. Compaction: Earthen backfill shall be compacted to at least ninety-five percent (95%) of the maximum density at optimum moisture content as determined by ASTM D698. Compaction of structure backfill material by inundation with water will not be permitted. D. Backfill Behind Curbs and Sidewalks: Backfilling behind curbs and sidewalk shall not commence earlier than seventy-two (72) hours after curbs and sidewalks are finished but shall be completed within seven (7) days after installation unless otherwise approved by the Engineer. The material used to backfill the excavation behind curb and sidewalks shall be topsoil free of rock and debris. E. Material: Earth embankment material, as defined in this Section, shall be used for structure backfill. As an alternative to earth backfill, the Contractor may use flowable fill in conformance with Section 4125 Excavation, Trenching and Backfilling FINISHING A. Planted Areas: Topsoil shall be placed to a minimum depth of six (6) inches in all areas indicated or specified to be seeded or sodded. Immediately prior to dumping and spreading the topsoil, the graded surface shall be loosened by scarifying to a depth of six (6) inches to permit bonding of the topsoil to the underlying surface. Refer to Section 4135 Sod and Section 4130 Seed for additional requirements. B. Fine Grading: Except where other permit or utility work is in progress, the graded surface shall be free of rock, concrete, brick, rubbish and other types of unsuitable material. The graded surface shall be finished to within one-tenth (0.1) foot of the elevations, slopes, contours, and cross-sections shown within the Construction Documents, including shoulder, berm, and sidewalk spaces. Use of graders or other power equipment will be permitted for final grading and dressing of slopes, provided the result is uniform and conforming to the lines and grades shown within the Construction Documents. C. Repair: Contractor shall protect grading and repair damage from, but not limited to, erosion, wind, settlement, unauthorized excavation, unauthorized traffic, and sliding. D. Cleanup: Cleanup shall follow the work progressively and final cleanup shall follow immediately behind the finishing. The Contractor shall remove from the work site all equipment, tools, and discarded materials, and other construction items. The entire Rightof-Way or easement shall be left in a finished and neat condition. Cleanup shall be considered as incidental to the completion of the grading work. E. Settlement: The Contractor shall be responsible for all settlement of backfill, fills, and embankments that occur within two (2) years after substantial completion (initial acceptance) of the work performed under the Construction Documents. The Contractor Division 4100 Sitework

6 shall make, or cause to be made, all repairs or replacements made necessary by settlement within thirty (30) days after notice from the Engineer. PART 4 MEASUREMENT AND PAYMENT 4.01 UNCLASSIFIED EXCAVATION A. Method of Measurement: Plan Measured. B. Unit: Cubic yards or tenth part thereof. C. Payment: Payment for unclassified excavation shall be made at the Contract unit price or at the Contract Lump Sum price, whichever applies ROCK EXCAVATION A. Method of Measurement: Field Measured. B. Unit: Cubic yards or tenth part thereof. No measurement will be made for rock over-break in excess of twelve (12) inches below the subgrade elevation. C. Payment: Payment for rock excavation shall be made at the Contract unit price or at the Contract Lump Sum price, whichever applies EARTH EXCAVATION A. Method of Measurement: Plan Measured. B. Unit: Cubic yards or tenth part thereof. No measurement will be made for embankment performed in rock over-break areas, where the over-break is in excess of twelve (12) inches below the subgrade elevation. C. Payment: Payment for earth excavation shall be made at the Contract unit price or at the Contract Lump Sum price, whichever applies EMBANKMENT A. Method of Measurement: Plan Measured. B. Unit: Cubic yards or tenth part thereof. C. Payment: Payment for embankment shall be made at the Contract unit price or at the Contract Lump Sum price, whichever applies OVER EXCAVATION A. Method of Measurement: Field Measured. B. Unit: Cubic yards or tenth part thereof. C. Payment: Payment for over excavation shall be made at the Contract unit price or at the Contract Lump Sum price, whichever applies. Backfill of over excavated areas shall be subsidiary to this pay item. END OF SECTION Division 4100 Sitework