702EXCAVATION FOR STRUCTURES

- 453 - SECTION 702 -- EXCAVATION FOR STRUCTURES

702.01Description

may require excavation as part of their construction, and this excavation is distinguished from the roadway excavati on specified in Section 200. This work shall consist of all excavation for the following:

in the contract.

excavation limits shown in the contract. It shall include all necessary bailing, draining, pumping, sheathing, and the construction of cofferdams or temporary cribs and their subsequent removal. The work shall also include backfilling, compacting, and the disposal of any excess material obtained from such excavation.

standards.

702.02Material Requirements

Subsection 1033.02, Paragraphs 1., 2., and 3. or 6. and the requirements in Tables 1033.02A, 1033.03A or 1033.06 will be acc eptable. "Clay lump" and "mortar-making" proper ties do not apply.

702.03Construction Methods

contain the structure an d its forms and provide access to set, strike, and inspect the work (18 inch (450 mm) la teral spacing is generally adequate access).

excavation.

below the base of the excavation until after the concrete has been placed and set for at least 5 hours.

Excavation for Structures

- 454 - (3) If water percolates through the base of the excavation in spite of dewatering efforts, then:

the bottom of the excavation. This will be considered extra work.

cofferdam's walls. Such seepage shall not be justification for the placement of a watertight seal course except as noted in Paragraph 1.b.(3) of this Subsection.

established for the bottom of the excavation, the excavation shall be continued to a width and depth desig nated by the Engineer. The unsuitable material shall be disposed as directed by the Engineer. The additional volumes excavated shall be replaced with compacted approved granular material, crushed rock or crushed concrete meeting the gradation requirements of Subsection 702.02 pa ragraph 2. The material shall be compacted to optimal stiffness as defined by a deflection target value established by the Engineer.

founded on horizontal surfaces cut at least 6 inches (150 mm) into the rock.

with the rock.

the contract.

stratum, then the excavation shall be continued until rock which will furnish the required support is found.

(1 m) above, or if a satisfactory foundation is not found within 2 feet (600 mm) below the elevation shown in the contract, the work shall be suspended.

resumes.

Unit before concrete is placed.

(1 m) wider than the width of the pipe.

this Subsection.

diameter, including recesses for connections, shall be required for all pipe with a diameter greater than 2 feet (600 mm). Bedding shall include shaping the trench to not less than 10% of the total culvert height. .03

- 455 - b. Pipe and Pipe-Arch Culverts constructed on rock:

bottom of a culvert excavation, the ro ck shall be excavated to not less than 6 inches (150 mm) below the lower surf ace of the culvert and replaced with proper bedding material.

shall be excavated, disposed as directed by the Engineer, and replaced with compacted approved granular material, crushed rock or crushed concrete meeting the gradation requi rements of Subsection 702.02 paragraph 2.; the material shall be compacted to optimal stiffness as defined by a deflection target value established by the Engineer.

following requirements:

(150 mm) thick.

defined by a deflection target value established by the Engineer .

the concrete develops a compressive strength of at least 70% of the design compressive strength.

progress concurrently on all sides.

the top of berm elevation until the superstructure is in place.

from drain or weep holes and any other structure before backfilling.

area shall be drained or pumped until dry. Saturated unstable material shall be removed from the base.

produce a dry area, an approved granul ar material shall be deposited to an elevation above the water level.

material before obtaining borrow.

away or other erosion until the contra ct is complete and accepted by the Engineer.

subsequent surface or base course, wh ich includes the area directly below the pavement section of the bridge ap proach slab, shall be constructed in

Excavation for Structures

- 456 - accordance with the requirements of Subsection 205.03 for Class III embankment and meet the compacti on criteria in Table 702.01. Table 702.01 Structure Backfill Requirements Depth Below Moisture Requirements Soil Type Finish Grade Minimum Maximum Silt-Clay Upper 40 in (1 m) Opt. -3% Opt. +3% Silt-Clay Depths > 40 in (1 m) ** Opt. +2% Granular All Depths ** ** ** Moisture content as necessa ry to obtain stiffness.

other organic matter shall not be used.

than 12 inches (300 mm) in diameter if all voids between the large stones are filled with compacted soil.

compaction shall not be used.

Contractor, the interior of all abutme nts and wingwalls and tie rod trenches shall be backfilled with granular backfill.

substructure and then backfilling to t he limits shown on the granular backfill detail, the Contractor may utilize ot her methods to achieve a minimum of 3 1/2 feet (1.1 m) of clear excavati on from the inside abutment and wing faces.

shall be backfilled with "Granular Backfill" from the bottom of the void to the bottom of the approach slab; and a mini mum depth of 1 foot (300 mm) of granular backfill shall be placed and compacted under the remaining approach slab section.

elevation shown in the contract. The backfilled surface shall be a smooth continuation of the surrounding ground.

abutments, wingwalls, piers adjacent to ra ilroad tracks, piers in the toe of embankment slopes, piers for grade separations, culverts, inlets, sewers, and all other structures shown in the contract.

shall be placed and compacted to an elevation matching the planned tie rod elevations. The tie rods shall then be installed and the backfilling operation continued. The contractor may trench the tie rods after the abutment and .03

- 457 - wing backfill. If the tie rods are trenc hed after the abutment and wing backfill, the tie rods shall be backfilled with granular material.

the entire embankment between the faces of the abutment walls and vertical planes 10 feet (3 m) outside and par allel to the ends of the floor.

bridges shall be compacted.

superstructure (except bridge slabs) has been placed.

near pipe and box culverts in accordance with the requirements of Subsection 205.03 for the class of em bankment and type of compaction shown in the contract.

culverts shall be backfilled carefully to insure the specified stiffness is achieved. Backfill shall be placed concurrently in equal lifts on both sides of the culvert.

immediately placed, the embankment sha ll be constructed to the elevation of the original surrounding ground surfaces or at least to the midpoint of the culvert’s vertical height (or to the elevation of the widest dimension of a pipe-arch culvert), with berm tops 2 feet (0.6 m) wide and with 1 vertical to 2 horizontal slopes away from the cu lvert. When the full embankment over a box culvert is not immediately pl aced, the embankment around the foundations shall be backfilled to at least the elevation of the original surrounding ground surfaces, but no lowe r than the top of the foundations. If necessary, additional excavation for backfill or embankment shall be required for this work.

within 15 feet of traveled way shall be ba ckfilled to 15 feet minimum from the edge of the traveled way prior to remo ving traffic control. Backfill for traffic shall be to the final grade or to the lim its shown in Figure 702.01. Additional excavation for culverts may be required.

or desirable to allow vehicles (construction or otherwise) to travel over a pipe or box culvert. The volume to be compacted adjacent to the pipe or box culvert shall be that between vertical pl anes located 5 feet (1.5 m) outside of and parallel to the neat lines of the pi pe or barrel at its maximum horizontal dimension and a 1 vertical to 6 horizontal slope to natural ground line. Compacted soil shall be placed to a depth at least 3 feet (1 m) above the top of the box or pipe and to the grade of the existing adjacent shoulder slope on extensions. The remaining length of the pipe or box culvert shall be filled in accordance to pipe culverts in 702.03 Paragraph 3.f.(3).

concrete reaches 3000 psi compressive strength, the Contractor shall complete the backfill within 10 calendar days.

Excavation for Structures

- 458 - (iv) Failure to complete the backfill within 10 calendar days shall be cause for the assessment of liquidated damages in the amount of $500 per working day until the backfil l is completed. “Completion of the backfill” shall be defined as the time when all of the required material has been placed, compacted, and shaped.

because of weather and soil conditions.

in Section 702 shall be in addition to any applicable liquidated damages assessed in accordance with Subsection 108.08.

material as approved by the Engineer.

flow of waterways except as shown in the contract.

utilized in the fill shall be removed fr om the project and disposed at an approved site.

702.04Method of Measurement

not a field measured quantity. The pay item is a Lump Sum.

excavation.

or with a change in the location, the payment may be recomputed. .04

- 459 - 2. Excavation for pipe culverts, headwalls, and box culverts is measured by the cubic yard (cubic meter). The quantity of excavation is computed by the Department using Figure 702.01 and the following limits described below: EXCAVATION PAYMENT LIMITS

EXCAVATION DEPTH Dia. + 38 Feet (11.5 m) 19.0 Feet or Greater (5.75 m) Dia. + 28 Feet (8.5 m) 14.0 Feet to 19.0 Feet (4.25 m to 5.75 m)

Dia. + 18.0 Feet (5.5 m) 9.0 Feet to 14.0 Feet (2.75 m to 4.25 m)

Dia. + 8 Feet (2.4

(1.25 m to 2.75 m)

Dia. 0 Feet to 4.0 Feet (0 m to 1.25 m)

Dia. + 3 Feet (0.9 m)

Figure 702.01

when shown in the contract, or the ground elevations, when a new channel section is not shown in the contract.

excavation will be as follows:

outside of and parallel to t he limits of the footings.

and parallel to the limits of the headwalls.

the pipe culverts separated by a distance equal to the nominal inside diameter of the pipe, plus 36 inches (9 00 mm), and vertical planes 18 inches (450 mm) beyond the ends of the culvert.

the pipe-arch separated by a distance equal to the maximum nominal inside clear span dimension of the pipe-arch, plus 36 inches (900 mm), and vertical planes 18 inches (450 mm) beyond the ends of the culvert.

excavation will be as follows:

the lower limits of unsuitable material removed at the direction of the Engineer.

Excavation for Structures

- 460 - (ii) Headwalls. The bottom of the headwalls.

the culvert or to the lower limits of unsuitable material removed at the direction of the Engineer.

dimensions, for the portion of the curtain or cutoff wall below the bottom of the concrete footings will also be included for payment for box culvert excavation.

deducted from the pay volumes so that a volume is only paid for once.

excavation volume required to construct new work will be deducted by subtracting the overlapping removal excavation volume from the new work excavation volume.

or the removal of a structure shall be included in the quantity of excavation for pipe culverts and headwalls or excavation for box culverts when the structure is within the limits of exca vation for the culvert or its headwalls.

structure, except for pipe or pipe-arch culverts, when the intersecting structure has a cross sectioned area of more than 16 square feet (1.5 m2) within the limits of culvert excavation as shown in Figure 702.02. DEDUCTION LIMITS

Shaded area > 16 Ft2

Deduction

Shaded area < 16 Ft2 No Deduction

Dia. + 3 Feet

Figure 702.02

horizontal allowance will be computed on the basis of Figure 702.01. The slope of trench walls shall be approxim ately 1 foot (300 mm) rise to 1 foot (300 mm) run.

requirements shown in the contrac t. The quantity of excavation will be computed on the basis of Figure 702.01. Dia. .04

- 461 - j. The limits in figures 702. 01 and 702.02 are for measurement purposes only. Any changes in the excavation limits for the Contractor’s operations or that which is necessary to meet any safety requirement will not be cause for recalculation of the established quantity.

with shoring or sheet piling, then Figure 702.01 will be superseded by the location of the shoring and the sheet piling when determining the authorized volume of excavation for culverts and pipes.

construction of embankments as descr ibed in these Specifications, the quantity to be paid for will be the volume of the material actually removed measured in cubic yards (cubic meters) in its original position.

actually removed in its original position, the quantity to be paid will be 1.4 times the volume of placed embankment (cubic yards) (cubic meters). Payment will not be made for any surplus material placed outside the specified limits.

a Pipe Culvert, Pipe-Arch Culvert, Headwall, or Box Culvert is removed and replaced, the pay volume of soil removed shall be 2 times the actual volume removed as Excavation for Pipe, Pipe-Arch, Culverts, and Headwalls.

piers and bents will be paid for as extra work.

the contract.

computed in cubic yards (cubic meters) based on the lines and grades shown in the "Granular Backfill" details. In the event that a bridge is constructed with a change in contract or with a change in the location, the payment may be re-determined.

Backfill" when the Contractor elects to use a sheet pile wall to construct the abutment substructure in lieu of excavation.

direction of the Engineer and additio nal granular backfill is required, the removal and the additional "Granular Backfill" will be paid for as "extra work."

Subsection 702.03 is measured and paid for as “Excavation for Pipe, Pipe- Arch Culverts and Headwalls” or “Excavation for Box Culverts”.

of Subsection 702.03 is paid for under the pay item for the remainder of the surrounding embankment.

structure for the backfill. The Contractor shall dry the material that exceeds the maximum moisture requirements. If the material ex ceeds the maximum moisture requirements during excavation and the volume exceeds 200 cubic yards (cubic meters), the drying of the material in excess of 200 cubic yards (Cubic meters) will be paid for as “extra work”.

702.05Excavation for Structures

- 462 - 702.05 -- Basis of Payment

Abutment _____ Excavation Lump Sum (LS) Pier _____ Excavation Lump Sum (LS) Bent _____ Excavation Lump Sum (LS) Granular Backfill Cubic Yard (CY) [ C u b i c M e t e r ( m3)] Excavation for Pipe, Pipe -Arch Cubic Yard (CY) Culverts, and Headwalls [Cubic Meter (m3)] Sheet Pile Excavation Cubic Yard (CY) [ C u b i c M e t e r ( m3)] Excavation for Box Culv erts Cubic Yard (CY) [ C u b i c M e t e r ( m 3 ) ]

removing cofferdams or cribs. This work shall be considered subsidiary to the item requiring the cofferdam or crib.

Department and the Contract or at the time of receiving bids, and which, in the opinion of the Engineer, will be detr imental to the work of Excavation for Structures shall be "extra work", ex cept as noted in Subsection 104.06.

shall be considered as being subsidiary to the associated structure pay item:

allowed in Paragraph 6. of this Subsection).

contract.

material excavation calculated in Section 702.04 Para. 5.

differs from the contract because of on e or more of the following changed conditions:

(3 m). .05

- 463 - (2) A change in location, measured along the centerline of the project, of more than 10 feet (3 m).

structure, of more than 1 foot (300 mm).

significant change in excavation has resu lted from the occurrence of one or more of the conditions listed above, then the quantity of excavation need not be recomputed.

connection with the construction of pipe culverts, median inlets, and flared- end sections or other appurtenances whic h are a part of the median culvert items shown in the contract. This work shall be considered subsidiary to the items for which the contract provides that direct payment will be made.

culverts, headwalls, and box culverts will be paid at the item's contract unit price, "Excavation for Pipe or Pipe -Arch Culverts and Headwalls" and "Excavation for Box Culverts".

Subsection 702.03, Paragr aph 3.f.(3) shall be incl uded with appropriate earthwork pay item ["Excavation", "Excavation Borrow", "Excavation (Established Quantities)", or "Earth work Measured in Embankment"].

subtracted from the appropriate ea rthwork pay item, if applicable [“Excavation”, “Excavation Borrow”, “E xcavation (Establis hed Quantities)”, “Earthwork Measured in Embankment”].

Figure 702.01

Excavation for Structures

- 464 - 8. a. When compacted approved granular material, crushed rock or crushed concrete is placed for a st ructure foundation, payment will be “Granular Backfill”.

Proposal Schedule of Items and is the required backfill material to replace unsuitable material approved by the Engineer for removal, then the unit price for the replacement granular backfill shall be a negotiated unit price.

their records of unsuitable material removed and reconcile any differences.

when placed at the bottom of a foundation if the material is not required structurally and is being provided solely as a good working platform for the Contractor.

beds, the additional excavation will be measured for payment as "extra work".

excavation limits shown in the contract and removed at the direction of the Engineer will be paid as "extra work."

satisfactory foundation beds for spr ead footings are found at elevations within 36 inches (900 mm) above the elevations shown in the contract; however, when it is necessary to lo wer the elevations of these foundation beds or to remove unsuitable material as directed by the Engineer, the additional excavation will be paid for as "extra work".

- 465 - SECTION 703 -- PILES AND PILE DRIVING

703.01Description

all bearing and sheet piles. They shall be driven or placed in accordance with the requirements of these Specific ations at the locations, elevation, penetration, and bearing shown in the contract.

Before construction begins, the Contra ctor shall advise the Engineer in writing which type is to be furnished at each structure.

703.02Material Requirements

Table 703.01 Material Requirements Applicable Materials Section Reinforcing Steel ....................................................... 1020, 1023, 1024

in ASTM A 328/A 328M.

in the contract.

shall be as shown in the contract. Maximum slump for concrete used in cast- in-place piling shall be 6 inches (150 mm).

class of concrete, the Contractor shall ad vise the Engineer, in writing, of the class of concrete to be used 14 da ys before the date of beginning the concrete work.

written permission of the Engineer.

placed in accordance with the r equirements of Section 707.