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SECTION 02720 – ADDENDUM 2

PIPE BURSTING SEWER REPLACEMENT

PART 1 - GENERAL

1.01 DESCRIPTION

A. This Specification shall cover the rehabilitation of existing sanitary sewers using the GRUNDOBURST (static pipe bursting) and/or GRUNDOCRACK (pneumatic/percussive pipe bursting) systems, or approved equal, in accordance with the Contract Documents and the Contractor’s approved Pipe Bursting Work Plan. Pipe bursting is a system by which the bursting unit (and, where required, a splitting/cutting assembly) splits the existing pipe while simultaneously installing a new High Density Polyethylene Pipe of the same size or larger size pipe where the old pipe existed. Existing sewer service connections shall then be reconnected. Television inspection of the polyethylene pipe is required to complete the installation in accordance with the Contract Documents. Both static and pneumatic pipe bursting methods are permitted. When the pneumatic/percussive method is used, the pneumatic tool shall be used in conjunction with a constant-tension hydraulic winch sized for the proposed tool, host pipe, and upsizing requirements, as specified in the approved Pipe Bursting Work Plan. In no case shall the constant tension on the winch exceed 20 tons.

1.02 QUALIFICATIONS

A. The Contractor shall be in business under its current name for a minimum of five (5) years, and shall be certified by the manufacturer of the proposed pipe bursting system that such company is a fully trained user of the pipe bursting system.

B. The Pipe Bursting Contractor shall have successfully installed a minimum of fifty thousand (50,000) feet of conduit within the United States using the Pipe Bursting equipment and material of the type that meets the requirements stated within these specifications. At least one (1) Pipe bursting project shall have been completed at least one (1) year prior to the date of this contract.

C. The Project Superintendent and the Pipe Bursting Machine Operator are required to have at least three (3) years and two (2) years of pipe bursting experience respectively, using the similar type of equipment required for this project.

D. Polyethylene pipe jointing shall be performed by personnel trained in the use of butt-fusion equipment and recommended methods for new pipe connections. Personnel directly involved with installation of the new pipe shall receive training in the proper methods for handling and installing the

02720-2 polyethylene pipe. Training shall be performed by qualified representatives.

1.03 SUBMITTALS

A. Submit the following:

1. Shop drawings, catalog data, and manufacturer’s technical data showing complete information on material composition, physical properties, and dimensions of new pipe and fittings. Include manufacturer’s recommendations for handling, storage, and repair of pipe and fittings damaged.

2. Pipe Bursting Work Plan (method of construction and restoration of existing sewer service connections). This shall include:

a. Detail drawings and written descriptions of the entire construction procedure to install pipe, bypass sewage flow and reconnection of sewer service connections. Include the proposed pipe bursting method (static or pneumatic/percussive), manufacturer/model of major equipment (bursting/splitting head, pulling system/rods or winch system), pit locations/layout, and any proposed use of lubricant.

b. Certification of workmen training for installing pipe.

c. Television inspection reports and videos made prior to pipe bursting and after new pipe installation.

d. Engineer review of the Work Plan is for conformance only and does not relieve the Contractor of responsibility for means, methods, techniques, sequences, procedures, or safety.

1.04 DELIVERY, STORAGE, AND HANDLING

A. Transport, handle, and store pipe and fittings as recommended by manufacturer.

B. If new pipe and fittings become damaged before or during installation, it shall be repaired as recommended by the manufacturer or replaced as required by the Engineer at the Contractor’s expense, before proceeding further.

C. Deliver, store and handle other materials as required to prevent damage.

1.05 METHODS FOR NEW PIPE INSTALLATION

A. The methods approved for rehabilitation of existing sanitary sewers by pipe bursting and installation of new polyethylene pipe are T.T. Technologies GRUNDOBURST (static) and GRUNDOCRACK (pneumatic/percussive)

02720-3 systems, (800-533-2078), or approved equal, subject to approval of the Contractor’s Pipe Bursting Work Plan submitted under Article 1.03.

1.06 MATERIALS

A. Polyethylene Plastic Pipe shall be high-density polyethylene pipe and meet the applicable requirements of ASTM F714 Polyethylene (PE) Plastic Pipe (SDR-PR) Based on Outside Diameter (DIPS OD series), ASTM D1248, ASTM D3350.

B. Sizes of the insertions to be used shall be such to renew the sewer to its original or greater flow capacity.

C. All pipes shall be made of virgin material. No rework except that obtained from the manufacturers own production of the same formulation shall be used.

D. The pipe shall be homogenous throughout and shall be free of visible cracks, holes, foreign material, blisters, or other deleterious faults.

E. Dimension Ratios: The minimum wall thickness of the polyethylene pipe shall meet the following:

Depth of Cover (Feet) Minimum SDR of Pipe

1. 0 – 16.0 19

2. > 16.0 17

F. Material designation shall be PE4710 with UV Stabilizer of 2% to 3% carbon black in accordance with ASTM D-1603.

1.07 TESTS

A. Tests for compliance with this specification shall be made as specified herein and in accordance with the applicable ASTM Specification. A certificate with this specification shall be furnished, upon request, by the manufacturer for all material furnished under this specification.

Polyethylene plastic pipe and fittings may be rejected for failure to meet any requirements of this Specification.

PART 2 - EQUIPMENT

2.01 The pipe bursting tool shall be designed and manufactured to force its way through existing pipe materials by fragmenting the pipe and compressing the old pipe sections into the surrounding soil as it progresses. The bursting unit shall be static or pneumatic/percussive, as proposed in the approved Pipe Bursting Work Plan.

Equipment selection and operation shall be consistent with the pipe bursting system manufacturer’s written recommendations and generally accepted industry guidance (e.g., PPI and IPBA). The pipe bursting system shall generate sufficient force to burst or split (as applicable), compact/displace the existing pipeline, and install the new pipe as required. See manufacturer’s specifications for what size tool should

02720-4 be used in what diameter of pipe, as well as parameters of what size tool for percentage of upsize allowed.

2.02 The pipe bursting tool shall be pulled through the sewer using a winch/cable system for pneumatic/percussive bursting, or rigid pulling rods for static bursting/splitting, as proposed in the approved Pipe Bursting Work Plan. The bursting unit shall pull the polyethylene pipe with it as it moves forward. The bursting head shall incorporate a shield/expander to prevent collapse of the hole ahead of the PE pipe insertion. The pipe bursting unit shall be remotely controlled.

2.03 The pipe bursting tool shall be static or pneumatic/percussive, as proposed in the approved Pipe Bursting Work Plan. The bursting action of the tool shall increase the external dimensions sufficiently, causing breakage or longitudinal splitting of the pipe, as applicable, at the same time expanding the surrounding ground. This action shall not only break the pipe but also create the void into which the burster advances, enabling forward progress. At the same time the polyethylene pipe, directly attached to the sleeve on the rear of the burster, shall also move forward.

2.04 BURSTING/PULLING OPERATION

A. Pneumatic/Percussive Pipe Bursting: The bursting tool shall be pneumatically driven and advanced by percussive action. When a cable/winch system is used, a constant-tension hydraulic winch shall be provided to assist advancement and maintain directional stability, as specified in the approved Pipe Bursting Work Plan.

B. Static Pipe Bursting / Splitting: The bursting or splitting head shall be pulled through the existing pipe by a hydraulic pulling unit using rigid pulling rods, as specified in the approved Pipe Bursting Work Plan.

2.05 WINCH UNIT (WHEN A CABLE/WINCH SYSTEM IS USED)

A. When a cable/winch pulling system is used, a constant-tension hydraulic winch shall be provided as specified in the approved Pipe Bursting Work Plan. The winch tension shall maintain directional stability and alignment of the bursting tool/head within the host pipe.

B. The winch shall be hydraulically operated providing a constant tension throughout the operation. The winch shall be of the constant tension type but shall be fitted with a direct reading load gauge to measure the winching load.

C. The winch must automatically maintain a constant tension at a set tonnage reading.

D. The constant tension winch shall supply sufficient cable in one continuous length so that the pull may be continuous between approved winching points.

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E. The winch, cable and cable drum must be provided with safety cage and supports so that it may be operated safely without injury to persons or property.

F. The Contractor shall provide a system of guide pulleys and bracing at each manhole to minimize cable contact with the existing sewer between manholes.

G. The supports to the trench shoring in the insertion pit shall remain completely separate from the pulling system support frame and shall be so designed that neither the pipe nor the winch cable shall be in contact with them.

2.06 SEWER SERVICE CONNECTIONS

A. All sewer service connections shall be identified and located prior to the pipe insertion to expedite reconnection. Upon commencement, pipe insertion shall be continuous and without interruption from one manhole to another, except as approved by the Engineer and/or his representative. Upon completion of insertion of the new pipe, the Contractor shall expedite the reconnection of services so as to minimize any inconvenience to the customers.

B. Sewer service connections shall be connected to the new pipe by mechanical and/or electrofusion methods compatible with the new sewer pipe. Once the saddle is secured in place, a hole shall be drilled full inside diameter of the saddle outlet in the new pipe.

1. Mechanical saddles shall be made of polyethylene pipe compound that meets the requirements of ASTM D1248, Class C, have stainless steel straps and fasteners, neoprene gasket and backup plate. Mechanical saddles shall be Strap-On-Saddle Type as manufactured by Driscopipe (1-800-527-0662) or approved equal.

2. Inserta-Tee Connection by Fowler Manufacturing (503) 357-2110 shall also be allowed to be used. Also allowed would be a Unicore Plastic Fusion System (705) 876-6400 that uses butt fusion to connect the tee or a prefabricated polyethylene saddle or equivalent to the sewer pipe material.

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PART 3 - PREPARATION

3.01 BYPASSING SEWAGE

A. Bypass Pumping: The Contractor, when and where required, shall provide diversion for the pipe bursting/replacement process. The pumps and bypass lines shall be of adequate capacity and size to handle all flows.

B. The Contractor shall be responsible for continuity of sanitary sewer service to each facility connected to the section of sewer during the execution of the work.

C. If sewage backup occurs and enters buildings, the Contractor shall be responsible for clean-up, repair, property damage cost and claims.

3.02 TELEVISION INSPECTION

A. Television inspection of pipelines shall be performed by experienced personnel trained in locating breaks, obstacles and service connections by closed circuit color television. Television inspection shall include the following:

B. Video (pre) to be recorded by the Contractor and submitted to the Owner/Engineer prior to commencement of pipe bursting operations.

C. Video (post) to be recorded by the Contractor and submitted to the Owner/Engineer before final invoice.

D. Videos to remain property of the Owner; Contractor to retain second copy for his use.

E. All flows tributary to length of sewer being inspected are to be completely bypassed around the length during inspection if necessary and required by the Owner.

F. Post construction video upon completion of reconstruction of each length of sewer with the voice description, as appropriate with stationing of services indicated. Data and stationing to be on video.

G. Should any portion of the inspection videos be of inadequate quality or coverage, as determined by the Owner/Engineer, the Contractor will have the portion re-inspected and videoed at no additional expense to the Owner.

3.03 CONSTRUCTION METHOD

A. Equipment used to perform the work shall be located away from buildings so as not to create noise impact. Provide noise control measures (e.g., mufflers, enclosures, sound blankets, or other means) as required to meet local requirements.

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B. The Contractor shall install all pulleys, rollers, bumpers, alignment control devices and other equipment required to protect existing manholes, and to protect the pipe from damage during installation. Lubrication may be used as recommended by the manufacturer and as specified in the approved Pipe Bursting Work Plan. Under no circumstances will the pipe be stressed beyond its elastic limit. The pulling medium and bursting head/tool shall be maintained on line and centered within the host pipe using alignment control devices as required by the approved Pipe Bursting Work Plan.

C. The installed pipe shall be allowed to cool and relax for the manufacturer’s recommended time, but not less than four (4) hours, following installation and prior to reconnection of service lines, sealing of the annulus, or backfilling of the insertion pit. Sufficient excess length of new pipe, but not less than four (4) inches, shall be allowed to protrude into the manhole to allow for relaxation and final trimming/finishing.

D. Following the relaxation period, the annular space may be sealed. Sealing materials shall be approved by the Engineer and/or his representative and shall extend a minimum of eight (8) inches into the manhole wall, forming a smooth, uniform, watertight joint.

E. The Contractor shall be solely responsible for determining the number, location, size, and construction of all insertion/launch pits and receiving pits, including excavation support (shoring), dewatering, and surface restoration, as required to perform the Work. Proposed pit locations and details shall be identified in the approved Pipe Bursting Work Plan.

3.04 FIELD TESTING

A. After the existing sewer is completely replaced, internally inspect with television camera and video as required. The finished video shall be continuous over the entire length of the sewer between two manholes to be free from visual defects.

B. Defects which may affect the integrity or strength of the pipe in the opinion of the Engineer shall be repaired or the pipe replaced at the Contractor’s expense.

3.05 PIPE JOINING

A. The polyethylene pipe shall be assembled and joined at the site using the butt-fusion method to provide a leakproof joint. Threaded or solvent-cement joints and connections are not permitted. All equipment and procedures shall be in strict compliance with the manufacturer’s recommendations. Fusing shall be accomplished by personnel certified as fusion technicians by a manufacturer of polyethylene pipe and/or fusing equipment.

B. The butt-fused joint shall be in true alignment and shall have uniform rollback beads resulting from the use of proper temperature and pressure.

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The joint shall be allowed adequate cooling time before removal of pressure. The fused joint shall be watertight and shall have tensile strength equal to that of the pipe. All joints shall be subject to acceptance by the Engineer and/or his representative prior to insertion. All defective joints shall be cut out and replaced at no cost to the Owner. Any section of the pipe with a gash, blister, abrasion, nick, scar, or other deleterious fault greater in depth than ten percent (10%) of the wall thickness, shall not be used and must be removed from the site. However, a defective area of the pipe may be cut out and the joint fused in accordance with the procedures stated above. In addition, any section of the pipe having other defects such as concentrated ridges, discoloration, excessive spot roughness, pitting, variable wall thickness or any other defect of manufacturing or handling as determined by the Engineer and/or his representative shall be discarded and not used.

C. Terminal sections of pipe that are joined within the insertion pit shall be connected with a full circle pipe repair clamp or equal. The butt gap between pipe ends shall not exceed one-half (1/2) inch. Also, the Unicore Plastic Fusion System can be used to butt fuse the sewer pipe material.

**END OF SECTION**