387 1. Suitable random material with material sized up to three ( 3) inches with no more than 20% retained on the 1 -½ sieve (40mm),
2.Crushed aggregate, or
3.Controlled low strength material. This method of backfilling and compacting shall be followed until the top of the trench is reached. 604.8.3 -Backfill Testing: The quality control testing and acceptance of CLSM shall be in accordance with Section 219. Class B concrete shall be in accordance with Section 601, except that the job site and A -bar testin g are waived. The quality control testing and acceptance for compaction of the random backfill material shall be in accordance with applicable sections of 207 and 716, granular material according to section 716, and crushed aggregate according to section 717, with the following exception: Testing will be conducted on both sides of the pipe and testing within a lot may include tests on both sides of the pipe. For pipe installations in an embankment where existing tests are on file for the adjacent emb ankment material, the target percentage of dry density for the pipe backfill will be equal to the average of the X values for the tests in the adjacent lots of embankment material or a minimum value of 95, whichever is greater. For embankments where no te sts are on file, the target percentage of dry density will be 95. A lot shall have five
5.density tests performed for quality control. For pipes less than sixty ( 60) inches in diameter, a lot will normally consist of the quantity of backfill required for each 75 linear feet of pipe installed. For pipes sixty ( 60) inches in diameter and larger, a lot will normally consist of not more than 5 lifts of backfill. For pipe with lifts of backfill placed for the full length of the pipe, a sublot will normal ly consist of a lift of backfill placed on both sides for the full length of the pipe. For pipes that are backfilled in segments, a sublot will normally consist of a lift of backfill placed on both sides for the length of each segment of pipe backfilled. Backfill placed outside embankments and roadbed is to be compacted to or better than the average total dry density for the existing soil. An average total dry density will be determined from representative density tests conducted for each existing soil. Quality control testing will normally consist of one test per 100 linear feet of pipe installed, and lot evaluations are not required. The moisture tolerance is not applicable. 604.9 -FIELD PAVING : The Contracto r may pave with Portland cement concrete or use shotcrete. If practicable, such paving shall be delayed until completion of the fill over the structure. Before the placing of the paving, the surface of the plates shall be cleaned. The Portland cement co ncrete or shotcrete, mesh reinforcement, fastening of mesh, and paving dimensions shall be as specified and the minimum thickness over the crest of the corrugations shall be 1 -½ inches. Concrete used shall have a design 28 -day compressive strength of 3,000 psi (equivalent to Class B in 601.3); concrete may be hand mixed and shall be handled and placed as directed by the Engineer. After initial set has taken place, the paving shall be flo oded or kept moist by sprinkling for three days. Liquid membrane -forming compound, conforming to subsection 707.9 may be used for curing at a minimum application rate of one gallon per 150 square feet of concrete surface. Other methods of curing may be u sed if approved by the Engineer. Field paving with shotcrete shall conform to Section 623. When paving with shotcrete, the exposed surface shall be brought to a uniform surface by screeding or troweling. After completion of the shotcrete paving, the reb ound material shall be cleaned from the culvert above the paved 388 surface. Shotcrete shall be cured by (a) covering with burlap mats and keeping them wet for at least seven days after placing, (b) flooding for a period of at least seven days or, (c) applyin g liquid membrane curing compound, conforming to 707.9, at a minimum rate of one gallon per 150 per feet of shotcrete surface for each application. Shotcrete cured by membrane forming compound shall receive two applications; the second application shall b e made after the first application has set. Other methods of curing may be used if approved by the Engineer. After the completion of the fill over the pipe, any gaps which develop between the plates and the concrete or shotcrete paving shall be filled by pouring heated asphalt material complying with requirements of subsection 713.3. Prior to using Portland cement concrete or shotcrete for paving culverts with coatings containing aluminum, the aluminum -concrete contact area shall be coated with commercia lly- available paint.
604.10 Remove and Relay Pipe :
When specified, the Contractor shall remove, salvage, clean, safely store, and relay existing culverts. The construction requirements in this Section shall apply equally in the case of remove and relay pipe. The Contractor shall restore or replace, any pipe designated for reuse that incurs damage or destruction through faulty handling or storage. All pipes salvaged for relaying shall be cleane d of all foreign material prior to reinstallation.
604.11 Jacking Pipe :
Jacking or tunneling may be designated on the Plans or may be permitted if written approval is obtained. Culverts to be jacked shall be rei nforced concrete pipe. The strength of pipe designated in the Contract will be designated as required for vertical load only. Additional reinforcement or strength of pipe required to withstand jacking pressure shall be determined and furnished by the Con tractor without additional cost to the Division. Variation from theoretical alignment and grade at the time of completion of jacking placement shall not exceed 0.2 feet for each twenty ( 20) feet of pipe so placed. An approach trench shall be constructed on the side from which jacking operations shall take place. The end of the approach trench away from the jacking face shall be cut perpendicular to the axis of the jacking operation to provide bearing surface for the back stop and the jack blocking. The length of the approach trench shall be such that the distance between the jack blocking and the face of the bore shall be equal to five ( 5) feet plus the length of the individual pipe sections. The jacking face shall be a minimum of three ( 3) feet above t he top of the pipe; the face shall be cut vertically and shall be shored to prevent raveling and slipping. A sump shall be constructed in one corner of the trench to provide drainage. The back stop shall be constructed of heavy timbers or steel rails cap able of withstanding the jacking force. In the event the site of jacking operations is such that an approach trench cannot be constructed, the jack blocking shall be constructed to carry the reaction of the jack to the ground. This may be accomplished by means of timber, steel, or concrete vertical back stops set into the ground with the tops supported by diagonal members bearing against an embedded anchorage. Directly opposite the approach trench, an exit trench shall be constructed to line and grade. The exit trench shall be constructed in the same manner as the approach trench except that no back wall is necessary. Jacks shall be of sufficient capacity to overcome soil resistance to the jacking operation and shall be operated in pairs. As a guide, c apacity of jacks for concrete pipe shall be a minimum of 50 tons each. For large pipe, more than one pair of jacks may be required. Small track jacks may be used to start the pipe.
Source: West Virginia Standard Specifications for Road and Bridge Construction, 2023 Edition. Pages 407–408 of 1,006.