33_0523-GSBE-Trenchless_Installation_of_Utilities-02.07.25.pdf

KCAB-CVG-Cargo Village Sanitary Sewer Hebron, KY Gresham Smith Project No.: 47153.02

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SECTION 33 0523

TRENCHLESS INSTALLATION OF UTILITIES

PART 1 - GENERAL

1.1SUMMARY

A. The work to be performed hereunder consists of trenchless construction methods for the installation of utilities as shown on the Drawings or as identified in these specifications.

B. Work includes excavation of boring and receiving pits (if required), installation of casing pipe (if required), installation of carrier pipe, and backfill requirements.

1.2 DEFINITIONS

A. Methods of Trenchless Installation:

1. Bore and Jack (auger boring): A trenchless method that utilizes a rotating cutting head and augers to excavate material along a predetermined alignment. The excavation, generally 6 inches ahead of the casing pipe being jacked simultaneously, occurs by an auger placed within the encasement. The spoil material is removed through the open end of the casing pipe. Pipe diameter range: 12” thru 48”;

maximum distance: 300 feet.

2. Directional Drilling: A trenchless method that consists of a multi-stage process to excavate and install a pipeline. A pilot bore is drilled along the predetermined alignment. Drilling fluid is usually injected to minimize friction and prevent collapse of the bore hole. Typically, a radio signal from a transmitter located in the drill bit head indicates depth and alignment. The initial pilot bore can be adjusted by means of hydraulics until it reaches the termination point. The pilot bore is then replaced by a reaming device and pulled back through the initial bore alignment. The pipe material is attached to the reaming device and is pulled into the ground during the back reaming process. Pipe diameter range: 4” thru 72”;

maximum distance: 2,000 feet.

3. Microtunneling: A trenchless method similar to the bore and jack method with the exception that it is remotely controlled. The guidance system provides control of the steering head. Stability to the excavation face is provided by applying mechanical or fluid pressure to counterbalance earth and hydrostatic pressures. Pipe diameter range: 12” thru 180”; maximum distance: unlimited.

4. Pipe Ramming: A trenchless method using a pneumatic ramming tool to push a casing pipe through subsurface material, usually soil. The process effectively swallows the subsurface material into the interior of an open-ended casing pipe and is later removed by pneumatic or auger means. Pipe diameter range: 4” thru 80”; maximum distance: 200 feet.

5. Tunneling: A trenchless method requiring hand mining or drilling equipment, such as a tunnel boring machine (TBM), to excavate a predetermined alignment. Liner plates are installed as support for the open area. Tunnel diameter range: 48” thru 192”; maximum distance: unlimited.

6. Pipe Bursting: A trenchless method used to replace and upsize existing utilities. The method requires that the utility be temporarily abandoned to conduct work. A cutting head is pulled through the existing pipeline effectively displacing the fragments of the pipeline into the surrounding soil while simultaneously pulling a new pipeline into place behind it. Pipe diameter range: 4” thru 54”; maximum distance: pressure pipe – fitting to fitting; gravity pipe – structure to structure.

B. Carrier Pipe: Utility pipe in excess of 2-inches in diameter.

C. Service Pipes: Utility pipe ranging in diameter from 3/4-inch to 2-inch.

1.3 SUBMITTALS

A. Product Data:

1. Carrier pipe.

2. Casing pipe.

3. Casing spacers.

4. End seals.

5. Liner plates.

6. Tunnel liner grout.

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7. Casing and tunnel pipe filler material.

8. Backfill for abandoned casings and tunnels.

9. Utility identification sign.

B. The Contractor shall prepare a schedule for the Work and submit it to the Engineer for approval. The schedule shall include all major tasks to be performed including the following:

1. Equipment mobilization and setup.

2. Pipe assembly.

3. Pilot hole drilling (Directional Drilling).

4. Pre-reaming (Directional Drilling).

5. Pre-testing and pigging pipe before installation.

6. Pipe pulling (Directional Drilling).

7. Testing and pigging pipe after reinstallation.

8. Restoration and demobilization.

1.4 QUALITY ASSURANCE

A. The Contractor shall have a representative who is thoroughly knowledgeable of the equipment, boring, and jurisdictional Agency procedures present at the job site during the entire installation and available to address immediate concerns and emergency operations.

B. Provide a record of the advancement of the casing or carrier pipe. The log shall indicate the distance traveled and depth below existing grade over the entire length at 5-foot intervals.

C. Conduct survey of finished work to ensure alignment of casing or carrier pipe is within specified tolerances.

D. Provide compaction testing of backfills and embankment, if required, as part of the field quality control for the carrier pipe being constructed. Assure that at least one compaction test site occurs at each pit.

E. Do not remove failed casing, liner plate, or carrier pipe from bore or tunnel alignment. Upon unsuccessful installation of casing or carrier pipe backfill pipe or tunnel per the requirements of Part 2.

F. Provide three copies of complete record drawings for each utility pipeline crossing. Drawings shall include plan view and profile view.

1.5 DELIVERY, STORAGE AND HANDLING

A. Deliver pipe, casing, and accessories to jobsite in accordance with Division 01 Section "Product Requirements".

B. Accessory items shall be in manufacturer’s original, unopened packaging. Store and protect materials in accordance with Division 01 Section "Product Requirements" and manufacturer`s recommendations.

PART 2 -PRODUCTS

2.1 CARRIER PIPE

A. The carrier pipe within the casing pipe shall be used to convey water, sewage, or other medium.

B. Refer to Division 33 Sections "Sanitary Sewers (Gravity)” for acceptable materials. Refer to project Drawings for material type identification.

2.2 SERVICE PIPE

A. The service pipe within the casing pipe shall be used to convey sewage.

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2.3 CASING PIPE FOR UTILITY PIPELINES

A. The casing pipe or encasement shall be used for structural integrity of the installation and protection of the carrier pipe. In all instances the casing pipe shall have a minimum nominal diameter 4 inches larger than the greatest outside diameter of the carrier pipe, including the pipe bells. The casing pipe shall meet the requirements of the American Railway Engineering and Maintenance of Way Association’s Specifications for Pipelines Conveying Flammable and Non-Flammable Substances, current edition.

B. The casing pipe material shall be as noted on the Drawings and as approved by the Agency having jurisdiction over the area being crossed.

C. The casing pipe shall be new, welded or seamless steel pipe per ASTM A139, Grade B; ASTM A252, Grade 2; or ASTM A53, Grade B. The steel casing pipe shall have a minimum yield strength of 35,000 psi and shall have a minimum wall thickness as shown in the following table:

Casing Pipe Nominal Diameter (in)

Under Roadway Wall Thickness (in)

15 0.250 24 0.312

D. When the steel casing pipe is installed without the benefit of a protective coating, the wall thickness should be increased to the nearest standard size, which is a minimum of 0.063 inches greater than the thickness indicated in the Table.

E. For directional drilling applications, and as approved by the agency having jurisdiction, the casing pipe may utilize new, welded or seamless high density polyethylene pipe (HDPE) type DR 11 per ASTM D3350-02.

2.4 CASING PIPE FOR UTILITY SERVICES

A. The casing pipe shall be used for structural integrity of the installation and protection of the carrier pipe.

B. Utility service casing pipe material shall be new Schedule 40 PVC unless otherwise indicated on the Drawings.

2.5 CASING SPACERS

A. Casing spacers/isolators shall be installed on any carrier pipe passing through a casing pipe or tunnel. They are designed to support and protect the carrier pipe, and electrically isolate the carrier pipe from the casing pipe. Casing spacers are not required when HDPE carrier pipe is used in directional drilling applications that utilize HDPE casing pipe. Casing spacers are not required for service pipe installations.

B. Band: shall be constructed of minimum 14 gage 304 stainless, two segment.

C. Risers: shall be constructed of minimum 10 gage high grade 304 stainless steel. Risers shall be sized to position the carrier pipe in the casing, support all loads and provide proper contact for the isolation function.

D. Liner: the casing spacers/isolators shall have a flexible PVC liner of 0.09 inch thickness with a Durometer "A" 85-90 hardness and a minimum 58,000 volt dielectric strength.

E. Runners: the runners shall be of high pressure molded Glass Reinforced Polymer with a minimum compressive strength of 18,000 psi, 2 inch in width and a minimum of 8 inches long. Polyethylene runners are not acceptable. The runners shall be attached to the band or riser by welded stainless steel studs and lock nuts which shall be recessed far below the wearing surface on the runner. The recess shall be filled with a corrosion inhibiting filler.

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F. Hardware: the band sections shall be bolted together with 304 stainless steel studs, nuts and washers.

Hardware shall be 5/16-inch for pipes up to 42-inch diameter and 3/8-inch for carrier pipes 42-inch and larger.

2.6 END SEALS

A. End seals shall be used to effectively seal the casing pipe to the carrier pipe at each end of the casing pipe prior to backfilling. End seals are not required for service pipe installations.

B. Material: shall be made of 1/8-inch-thick synthetic rubber and use stainless steel bands and clamps to secure each end to the casing and carrier pipes.

2.7 LINER PLATES

A. The tunnel liner plate shall be of structural quality, hot-rolled, carbon-steel sheets or plates in conformance with ASTM A1011. The steel liner plate shall have a minimum thickness of 12 gage.

B. The tunnel liner plate submittal should specify either smooth or corrugated, number of flanges, exterior coating, and width of plate.

2.8 TUNNEL LINER GROUT

A. Cement grout shall consist of a uniform mixture of 1:6 (cement:sand). Completely fill all voids using a pumping system. The compressive strength at 28 days shall be a 100 psi, minimum.

2.9 CASING AND TUNNEL PIPE FILLER

A. The space between the casing pipe and carrier pipe should not be filled completely to avoid transfer of earth and live loads from the casing to the carrier pipe.

B. Material: fill sand, flowable mortar, or controlled low strength material. Refer to tables for approximate quantities.

C. Compressive strength at 28 days: 100 psi to 200 psi.

TABLE OF QUANTITIES FOR FLOWABLE MORTAR

Material Type Quantity per cubic yard Cement 100 lbs Fly ash 300 lbs

Fine aggregate 2,600 lbs

2.10 BACKFILL FOR ABANDONED CASINGS AND TUNNELS

A. The space between the casing pipe and carrier pipe should be filled completely to avoid settlement of casing due to earth and live loads.

B. Material: 3,000 psi minimum Portland cement concrete, flowable mortar, or controlled low strength material.

Refer to tables for approximate quantities.

C. Compressive strength at 28 days: 100 psi to 200 psi.

D. Compressive strength at 28 days 50 psi.

TABLE OF QUANTITIES FOR CONTROLLED LOW STRENGTH MATERIAL

Material Type Quantity per cubic yard

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Cement 50 lbs Fly ash 250 lbs

Fine aggregate 2,910 lbs

2.11 UTILITY IDENTIFICATION SIGN

A. Provide a utility identification sign for each end of a casing pipe or tunnel. Provide additional signs as shown on the Drawings.

B. Post: The post shall be constructed of composite material and have dimensions of 66" h x 4" w. The marker post shall be pigmented throughout based upon the utility type.

1. Sewer – Green

C. Sign: The post shall have a sign affixed to it. The sign shall be constructed of powder coated steel. The overall dimension of the sign shall be 6-inches by 6-inches. The following information shall be engraved upon the sign:

1. Warning Sewer Crossing

2. Contact: DeAlice Moore-Webb

3. Phone: (859) 767-3151

D. The marker and sign shall be guaranteed in quality for 15 years against deterioration and discoloring.

PART 3 -EXECUTION

3.1 SCOPE OF WORK

A. The Contractor shall select a method of trenchless installation which is appropriate for anticipated subsurface conditions; will allow the pipe to be installed to the desired line and grade as specified; and will prevent heaving or settlement of the ground surface or damage to nearby facilities.

B. All borings and tunnels shall be accomplished by one of the specified and approved trenchless installation methods; and shall meet the size, line, and grade shown on the Drawings.

C. Contractor shall notify the Owner 48 hours prior to start of trenchless activities.

D. Locate, mark, and protect existing utilities and facilities in the work area.

E. Trenchless installation of utilities will not be classified by material. If rock is encountered, no additional payment for drilling in rock will be made. Unit price shall include all necessary labor, materials, and equipment necessary to complete the work.

F. Upon unsuccessful installation of casing or carrier pipe based on tolerances stated herein, backfill said pipe or tunnel per the requirements of Part 2 of this Section.

G. Verify suitability of excavated materials for reuse as backfill. Remove and stockpile topsoil for subsequent reuse. Do not mix topsoil with other excavated materials. Remove rock, rubbish, debris, and unsuitable materials. Excavate the minimum size pits necessary to safely and properly perform the work.

H. Clean up all affected sites and restore all areas to pre-construction or better condition.

3.2 ACCEPTABLE TRENCHLESS INSTALLATION METHODS

A. Bore and Jack (Auger Boring):

1. Excavate a suitable sized pit to accommodate the equipment. Provide adequate walkway and workspace on each side of the auger and jacking equipment. The contractor shall furnish and install trench shoring or bracing in compliance with OSHA standards.

2. Provide continuous pressure to the face of the excavation to balance groundwater and earth pressures.

https://www.google.com/search?q=CVG&sca_esv=6c5b8bb7f034a1cd&sxsrf=AHTn8zqRcg4uMvlqSwXLT7j91RfhAcCPQg%3A1738937369553&source=hp&ei=GRSmZ9rJH_newN4P6KW7uAU&iflsig=ACkRmUkAAAAAZ6YiKQvQfik0fUOY9XCjr3kZLGL8GPRG&ved=0ahUKEwiausnB3rGLAxV5L9AFHejSDlcQ4dUDCBk&uact=5&oq=CVG&gs_lp=Egdnd3Mtd2l6IgNDVkcyBBAjGCcyChAjGIAEGCcYigUyBBAjGCcyDhAuGIAEGLEDGMcBGK8BMggQABiABBixAzIFEAAYgAQyCxAAGIAEGLEDGIMBMgsQLhiABBjHARivATIFEAAYgAQyBRAAGIAESKYEUABY7AFwAHgAkAEAmAG_AaAB-AOqAQMwLjO4AQPIAQD4AQGYAgOgAo8EwgITEC4YgAQYxwEYJxiKBRiOBRivAcICERAuGIAEGLEDGNEDGIMBGMcBwgIOEC4YgAQYsQMY0QMYxwHCAgUQLhiABMICDhAuGIAEGMcBGI4FGK8BmAMAkgcDMC4zoAftMg&sclient=gws-wiz

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3. The carrier pipe shall be furnished by the Contractor. Jack the steel casing pipe into place as the boring proceeds. Ensure that the end of casing is true. Completely weld sections of pipe to provide watertight joints.

4. Upon acceptance of the casing, install the carrier pipe in the casing by jacking it through the casing. If necessary to achieve proper line and grade on the carrier pipe, use blocking material to offset any minor variations in the alignment of the casing. Spacers shall be installed 1 foot from each end of each pipe joint and at the midpoint of each pipe joint. The carrier pipe shall be restrained by the spacer within the casing.

5. Both ends of casing pipe shall be sealed with synthetic rubber end seals with stainless steel band and clamps.

6. Tolerances:

a. Bore accuracy shall be within ±1% (both horizontally and vertically) of the total borehole length.

b. The borehole shall follow the design centerline of the pipe profile and alignment described on the

Drawings. At no point in the bore will the combined radii in the plan and profile exceed the allowable minimum radius of the pipeline manufacturer.

B. Directional Drilling:

1. Drilling unit shall be equipped with an electrical strike safety package and shall be tested upon setup of the job.

2. Drill a pilot bore with the designed tolerances for radius requirements. The pilot bore shall be monitored using instrumentation which will accurately locate the pilot bore positions in the X, Y, and Z axes relative to the ground surface.

3. The enlargement of the hole to accommodate the carrier pipe shall be accomplished by the ream and pull back method:

a. Prereaming: Prereaming operating shall be conducted at the discretion of horizontal drilling Contractor. All provisions of this specification relating to simultaneous reaming and pulling back operations shall also pertain to prereaming operations.

b. Pulling Loads: Contractor shall be responsible for determining safe pulling loads required for proper installation. Such loads shall be minimized as required to prevent failure of the pipeline during installation.

c. Torsional Stress: A properly sized and fully operational swivel will be installed between the reaming assembly at the end of the drill pipe, and the pipeline to restrict torsional stress from being transmitted to the pipeline.

d. Pull Section Support: The pull section shall be supported as it proceeds during pull back so that it moves freely and the pipe material is not damaged.

4. Tolerances:

a. A smoothly drilled pilot hole shall follow the design centerline of the pipe profile and alignment described on the Drawings. At no point in the bore will the combined radii in the plan and profile exceed the allowable minimum radius of the pipeline manufacturer.

b. The course of the pilot hole must stay within the given right-of-way at all points along the drilled route. Contractor shall provide and use a separate steering system employing a ground survey grid system, such as “Tru-Tracker”.

c. The Contractor shall have accurate working gages which register the tensile force being used to pull the pipeline back through the reamed borehole. It is the Contractor’s responsibility to prepare the reamed-out hole such that pulling back operations do not exceed the tensile strength of the pipe. The Contractor shall provide estimated calculations for the pulling loads and allowable loads before pull back operations begin. If during the pipeline pulling process this force exceeds 75 percent of this allowable load for the pipeline, the project inspector must be notified immediately.

Logs must be kept intact referencing all forces exerted on the pipeline during pullback.

d. The Contractor shall provide adequate supports along the stringing area to protect the pipe and allow free movement of the pipeline during pullback.

e. During pullback operations, Contractor shall monitor roller operation and use Sidebooms, if required, to assist movement of the pipe. Situations which could cause damage to the pipe material shall be corrected immediately. Damaged pipe shall be repaired to the satisfaction of the Owner or replaced by the Contractor before pulling operations resume.

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C. Microtunneling:

1. Excavate suitable sized pits to accommodate the tunneling equipment at entrance and exit of proposed microtunnel bore. The contractor shall furnish and install trench shoring or bracing in compliance with OSHA standards.

2. Excavate the tunnel using a steerable, laser guided tunnel boring machine remotely controlled and monitored from the surface by the operator at all times. Functions of the system to be monitored at the remote console shall include rate of advance, length of conduit installed, thrust force, deviation from line and grade, roll, inclination, and valve positions.

3. Excavation of tunnel shall take place within the tunneling shield. Personnel should not enter the excavation. The tunnel shield shall be full faced with the capability of supporting the face both during excavation and during shutdown. When soil conditions dictate, the tunnel shield must be capable of removing cobbles and boulders. The excavation system shall be fully capable of excavating all material that it will encounter.

4. The jacking system, including any intermediate jacks used, shall be capable of continuously monitoring the jacking pressure, the rate of advancement and the distance jacked. The equipment shall have the capability of limiting the jacking force applied to the pipe/tunnel shield so as not to exceed the maximum compressive loads allowed for the pipe. A lubrication system shall be provided that injects an approved lubricant at the rear of the tunneling shield to lower the friction developed on the exterior of the pipe during jacking.

5. The spoil can be removed from inside the pipe or casing by auger, compressed air, or water jetting.

6. Tolerances:

a. Microtunnel accuracy should be within ± 1 inch (both horizontally and vertically).

b. The borehole shall follow the design centerline of the pipe profile and alignment described on the

Drawings. At no point in the bore will the combined radii in the plan and profile exceed the allowable minimum radius of the pipeline manufacturer.

D. Pipe Ramming:

1. Excavate suitable sized pits to accommodate equipment at entrance and exit of proposed tunnel bore.

The contractor shall furnish and install trench shoring or bracing in compliance with OSHA standards.

2. Set guide rails to line and grade of proposed bore. The first section of pipe or casing shall be equipped with a steel band around the leading edge to overexcavate the bore and reduce friction on successive sections.

3. Install steel pipe casing using a pneumatic tool hammer to push the pipe or casing into the ground. The leading edge of the pipe shall be left open for most applications, allowing the soil to enter the pipe or casing. The leading edge can be closed for pipe casing diameters of 4 inches or less.

4. Remove spoil from inside of pipe casing by auger, compressed air, or water jetting.

5. Tolerances:

a. Pipe ramming bore accuracy should be within ±5% (both horizontally and vertically) of total bore length.

b. The bore shall follow the design centerline of the pipe profile and alignment described on the Drawings. At no point in the bore will the combined radii in the plan and profile exceed the allowable minimum radius of the pipeline manufacturer.

E. Tunneling:

1. Excavate suitable sized pits to accommodate the equipment at entrance and exit of proposed tunnel bore. The contractor shall furnish and install trench shoring or bracing in compliance with OSHA standards.

2. Excavate a utility tunnel using a tunnel boring machine (TBM) and conventional methods. Excavation of tunnel shall take place within tunneling shield. Tunneling shield shall be of steel construction and sufficient length to install one complete ring of liner plates before it is advanced for the installation of the next ring of liner plates.

3. Liner plate must be constructed in-place in the tail section of the tunneling shield. Liner plate shall have tapped grout holes of minimum 2-inch diameter, spaced at approximately 3 feet along the circumference of the tunnel. The grout holes shall be spaced 4 feet longitudinally along the tunnel course.

4. Inject grout through liner plate grout holes. Grout holes shall be plugged when grouting is completed.

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5. Install utility carrier pipeline after tunnel is complete and fill remaining annular space completely with filler. Carrier pipe must be able to withstand potential earth loads transferred to the pipe after the annular space is filled with filler.

6. Tolerances:

a. Tunnel accuracy shall be within ±2.0 ft horizontally and ±1.0 ft vertically.

b. The borehole shall follow the design centerline of the pipe profile and alignment described on the

Drawings. At no point in the bore will the combined radii in the plan and profile exceed the allowable minimum radius of the pipeline manufacturer.

3.3 MANAGEMENT OF CUTTINGS AND FLUIDS

A. The approved methods of trenchless installation are to be conducted in a manner to eliminate the discharge of water, drilling mud, and cuttings to the creeks or land areas involved during the construction process.

Contractor shall immediately contain and clean-up any inadvertent returns. Contractor shall also provide equipment and procedures to maximize the recirculation or reuse of drilling mud to minimize waste disposal.

B. Disposal of drilling and cutting fluids shall be responsibility of the Contractor and shall be conducted in compliance with all relative environmental regulations, easement and workspace agreements, and permit requirements.

C. Water supply is the Contractor’s responsibility, whether purchased locally or hauled in.

D. Drilling and cutting fluids must be free of all additives that will adversely affect the environment.

E. Adequate dewatering of all excavations and tunnels is the Contractor’s responsibility unless otherwise stated.

1. Take measures to prevent surface water from entering excavation.

2. Pump surface water and groundwater from excavation or tunnel, if necessary.

3. Discharge water may not be discharged to property without written permission from property owner.

4. Excavation discharge water should not interfere with vehicular traffic and must be directed away from adjacent electrical facilities.

5. Sanitary sewers are not an acceptable option for disposal of discharge water.

6. Erosion control measures should be taken to protect the discharge location(s), if applicable.

7. Adjacent structures should be monitored for subsidence as a result of dewatering, if applicable.

3.4 CLEANUP, REPAIRS, AND RESTORATION

A. The Contractor is responsible for leaving all areas affected by his construction activities in a condition equal to or better than the condition before construction.

B. All carrier pipe beyond the end of casing pipe as well as in entry and exit pits shall be bedded and backfilled in accordance with Division 31 Section "Earthwork".

C. The Contractor shall restore area around entry and exit pits within 1 day of work completion. Fill to previous existing ground elevation and grade any areas where settlement occurs due to subsidence.

D. Install a utility identification sign above ground at each end of the casing or tunnel. If the utility has been installed without a casing or tunnel, install utility identification signs as shown on the Drawings.

©2024 GRESHAM SMITH. ALL RIGHTS RESERVED. USE SUBJECT TO ANY WRITTEN AGREEMENT WITH

GRESHAM SMITH.

END OF SECTION 33 0523