215EXCAVATION FOR BRIDGES

132

o L = Length of footing shown on contract plans (feet {meters}); o W = Width of footing shown on contract plans (feet {meters}); o D = Final approved elevation of the bottom of the footing (feet {meters}); o B = Average elevation of the mud line or groundline (river bottom) at the cofferdam (feet {meters}); o Ve = Volume of excavation for which payment will be made (cubic yards {cubic meters}). o Ve = L x W x ( B - D ) / 27 {Ve = L x W x ( B - D )}

a seal concrete footing, depending on the details of construction selected by the contractor. No direct payment will be made for any excavation outside of the footing plan dimensions shown on the contract plans.

Each accepted Cofferdams or Sheeting and Shoring unit will be measured for payment as a lump sum unit. A unit shall consist of all piers, bents, and abutments on a specific bridge which are not designated by the plans for Item 503-B, Cofferdam and Pumping. Partial payments will be allowed on monthly estimates in accordance with Subarticle 215.05(a)2.

215.05Basis of Payment

Payment for the yardage of Unclassified Bridge Excavation as provided above shall be payment in full for the furnishing of all materials, equipment, tools, labor, pumping, bailing, drainage, sealing crevices, backfilling (including foundation backfill), compacting, disposal of excavated material, and for all incidentals necessary to complete the work in accordance with the plans and these specifications. If a footing is lowered below the elevation shown on the plans, adjustments in the unit price for all of the Unclassified Bridge Excavation of the footing involved will be made as follows: Depth Lowered Below Plan Elevation Bid Price Plus 0 to 3 feet {1 m} 0% Over 3 feet {1 m} to 6 feet {2 m} 50% Over 6 feet {2 m} to 10 feet {3 m} 75% Over 10 feet {3 m} 100% For stepped footings, the above adjustments will be computed separately for each step.

Payment for a lump sum unit of Cofferdams or Sheeting and Shoring as provided above shall be payment in full for the furnishing of all materials, equipment, tools, and labor necessary to complete the construction of the specified piers, bents, and abutments and the removal and disposal of any cofferdams or other temporary construction used in the prosecution of the work. Payment for each accepted Cofferdams or Sheeting and Shoring unit will be made at the contract lump sum price bid for each unit, complete in place. Partial payments will be made on monthly estimates based on the percentage of the total work performed on each unit as estimated by the Engineer. In making this estimate each pier or bent considered as part of a unit will be given an equal percentage of the total unit. Upon completion of the foundation above ground line at a particular pier or bent, that percentage of the total unit may be paid. No consideration will be given for additional compensation for this item when footing elevations are lowered less than 10 feet {3 m}, such being considered incidental to the work. If elevations are lowered 10 feet {3 m} or more, consideration will be given for additional costs caused by the revised elevations in accordance with Article 109.04.

215-A Unclassified Bridge Excavation - per cubic yard { cubic meter} 215-B Cofferdams or Sheeting and Shoring, * , ** - per lump sum * Station Number, Bridge Number, Ramp Number, etc. ** Lane, if applicable. SPECIAL PROTECTION FOR ROCK SLOPES 133

SPECIAL PROTECTION FOR ROCK SLOPES

217.01Description

This Section shall cover the work of providing special treatments to rock slopes for protection against excessive weathering, popouts, and other detrimental conditions which may endanger the highway roadbed. In general, the following methods, used as directed by the Engineer, shall be applied to exposed rock surfaces or rock surfaces exposed by the construction:

bounded by joints or cracks that might prove unstable by bolting them to more solid sections of rock.

soft unsatisfactory material and the resealing of the seams with a durable cap of concrete.

of rock berms with an asphalt surface to prevent excessive wear or weathering of soft, unstable rock.

blanket layer of concrete over an area of broken or loose boulders and/or unstable rock to prevent fallouts from erosion and weathering. Special attention is directed to the fact that the items of work provided under this section are estimated and cannot be accurately determined until the work is exposed; therefore, only the amounts actually used will be measured for payment and no claims will be considered for extra compensation due to overruns or underruns of the items covered by this Section.

217.02Materials

All materials furnished for use under this Section shall conform to the applicable sections of

Material fabricated for use in the rock bolting operations shall conform to the following:

All slotted bolts shall be steel conforming to the requirements of ASTM A 588, Grade A.

All headed bolts shall be steel conforming to the requirements of ASTM A 588, Grade A.

All wedges shall be steel conforming to the requirements of ASTM A 588, Grade A.

All expansion shells shall conform to the requirements of ASTM A 47, Specification for Malleable Iron Castings, Grade 32510. Tapered plugs used with expansion shells shall be forged from steel conforming to the requirements of ASTM A 663 and A 675, Grade 60 to 65.

All roof plates shall be steel conforming to the requirements of ASTM A 242, Type 2, or ASTM A 588, Grade A.

217.03Construction Details

Rock bolts shall be installed at the direction of the Engineer at any point where the stability of the rock cut is questionable. When bolting is deemed desirable, it shall be done as quickly as possible. Rocks should be kept tight and not pulled back into place once it has been loosened by successive blasting or construction operations. The holes for the rock bolts shall be drilled as closely as possible to the diameter recommended by the manufacturer of the wedge or shell. SPECIAL PROTECTION FOR ROCK SLOPES 134

The diameter and length of the rock bolt to be used shall be determined by the Engineer. All installations shall be in accordance with the recommended procedure or method as given by the manufacturer of the rock bolts. When directed by the Engineer, proper tests will be made to determine what torque the rock can withstand. If the tests show that the highest torque practical is of a certain value for a particular grade of rock, then torque shall be applied to the rock bolt provided the torque does not exceed the maximum recommended by the manufacturer of the rock bolts. It is recognized that any over-application of torque will only destroy the anchorage in the rock and in due time destroy the initial tightness of the bolt. It is desired that a minimum torque of 125 foot pounds {170 N•m} be applied in all cases where the rock will withstand such pressure.

Extreme care shall be taken to keep the drill hole aligned perpendicular to the plate bearing surface. The diameter of the drill hole shall be as recommended by the manufacturer for the type of expansion unit to be used for anchorage into the rock. Expansion units shall not be used in holes larger than that for which they are designed. When slotted type rock bolts are used, the bolt with wedge shall be inserted in the hole until the wedge hits the bottom of the hole. The bolt shall then be driven into the hole with an air-percussion hammer forcing the wedge into the slotted end of the bolt, thus anchoring the bolt in the hole. The plate and nut shall then be installed on the collar end of the bolt and the nut tightened to the torque recommended by the manufacturer.

The seam designated by the Engineer for sealing shall be examined carefully during the grading operations for evidence of seepage which will require construction of weep holes in the sealing cap as well as for the best method for placing the sealing cap.

The material in the seam to be treated shall be routed out or otherwise removed to a depth at least equal to the thickness of the seam or layer to be treated or to a depth which will give firm support to the sealing material.

The clean seam shall be sealed or packed with one of the following types of concrete mixes. The method of packing or placing the sealant shall be left to the Contractor provided the method used produces the desired results and presents an acceptable appearance. Weep holes, when deemed necessary, shall be placed as directed.

Specifications.

water applied pneumatically. (Mix designed by the Contractor to produce a 28-day cylinder strength of 5000 psi {35 Mpa})

An Asphalt Surface shall be placed on areas designated by the Engineer to prevent excessive erosion from surface runoff over relatively soft and erodible materials.

The surface to receive the asphalt surfacing shall be fairly uniform, without excessive high and low spots, suitable for coverage with asphalt. The surface shall be clean and free from loose rock fragments before applying the surfacing material.

The surfacing material shall be Asphalt Cement Grade 40 or an approved equal. The bituminous material shall be applied at the rate of 1.25 gallons per square yard {5 L/m²}. The method of application shall be that of the Contractor's provided it is approved by the Engineer, and it produces the desired results and presents a pleasing appearance.