02 41 13.23 - Utility Line Removal.pdf

02 41 13.23 – UTILITY LINE REMOVAL

Herbert, Rowland & Grubic, Inc. 02 41 13.23 - 1 007297.0444

SECTION 02 41 13.23 – UTILITY LINE REMOVAL

PART 1 - GENERAL

1.1 SUMMARY

A. Section Includes:

1. Abandonment in place, by cutting and capping, of existing sewers, junction structures, manholes, service lines, and force mains.

2. Abandonment in place of existing sewers and force mains using flowable backfill.

1.2 SUBMITTALS

A. Section 01 33 00 - Submittal Procedures: Requirements for submittals.

B. Shop Drawings: Indicate:

1. Products.

2. Location of force main abandonment access pits.

C. Technical information for equipment and operational procedures including projected slurry injection rate, grout pressure, method of controlling grout pressure, bulkhead and vent design, and number of stages of grout application.

D. At least 15 days prior to commencing abandonment activities, submit plan for abandonment, describing proposed grouting sequence, bypass pumping requirements, and plugging in any, and other information pertinent to completion of work.

1.3 PROJECT CONDITIONS

A. Existing facilities must remain in operation through the construction period until such time as new construction is accepted and placed into operation. Conduct abandonment so utility services will not be disrupted unnecessarily.

B. Notify Engineer of discrepancies between existing conditions and Work Orders before proceeding with abandonment.

C. Storage or sale of removed items or materials on-site is not permitted.

1.4 CLOSEOUT

A. Section 01 78 39 – Project Record Documents: Requirements for Record Drawings.

B. Project Record Documents:

1. Accurately record actual locations of capped and abandoned utilities.

2. Indicate receipt and acceptance of hazardous wastes by a landfill facility licensed to accept hazardous wastes.

Herbert, Rowland & Grubic, Inc. 02 41 13.23 - 2 007297.0444

PART 2 - PRODUCTS

2.1 PLUGS

A. Grout Plugs: Cement-based dry-pack grout conforming to ASTM C1107, Grade B or C.

B. Manufactured Plug: Commercially available plug or cap specifically designed and manufactured to be used with pipe being abandoned.

2.2 FLOWABLE BACKFILL

A. Flowable Backfill: Type C, in accordance with PennDOT Publication 408, Section 220.

PART 3 - EXECUTION

3.1 PREPARATION

A. Section 01 73 00 - Execution Requirements: Requirements for installation preparation.

B. Call Pennsylvania One Call System, Inc. at 1-800-242-1776 not less than three working days before performing Work:

1. Request underground utilities to be located and marked within and surrounding construction areas.

C. The Contractor shall be responsible for removal and disposal of the liquid and solids from manholes, structures, and pipes.

3.2 DEMOLITION OF SEWER MANHOLES AND PIPELINE STRUCTURES PRIOR TO ABANDONMENT

A. Remove manhole frames and covers and castings from existing pipeline structures.

Deliver castings to Owner for future use.

B. Demolish and remove precast concrete adjustment rings and corbel section or brick and mortar corbel and chimney, or other pipeline structures, to minimum depth of 18-inches below finished grade.

C. Drain manholes and sewers prior to filling.

D. When adjacent sewer lines are not to be filled, place temporary plugs in each line connecting to manhole, in preparation for filling manhole.

E. Excavate overburden from sewers to be abandoned at locations indicated on Drawings.

Cut existing sewers, when necessary, to provide an end surface perpendicular to axis of pipe and suitable for plug to be installed. Remove sewer piping material remaining outside of segment to be abandoned.

3.3 CUTTING AND CAPPING OF MAINS

A. Do not begin cut, plug, and abandonment operations until replacement sewer has been constructed and tested and the sewer has been approved for use.

Herbert, Rowland & Grubic, Inc. 02 41 13.23 - 3 007297.0444

B. Existing Services to Be Removed or Abandoned: Locate, identify, disconnect, and seal or cap off indicated utility services serving areas to be selectively demolished.

C. Install plug and concrete thrust block and make cut at location shown on the Work Orders and/or as directed by Engineer. Plug shall be capable of withstanding pressures needed to place the flowable backfill.

3.4 PREPARATION FOR ABANDONMENT VIA FLOWABLE BACKFILL

A. Select backfill placement equipment and follow procedures with sufficient safety and care to avoid damage to existing underground utilities and structures. Operate equipment at pressure that will not distort or imperil portion of work, new or existing.

B. Perform abandonment work prior to starting backfill placement. Clean placement areas of sewers and manholes of debris that may hinder backfill placement.

C. Remove free water prior to starting backfill placement.

3.5 EQUIPMENT FOR FLOWABLE BACKFILL

A. Mix flowable backfill in automated batch plant and deliver it to site in ready-mix trucks or mix on site.

B. Use concrete or grout pumps capable of continuous delivery at planned placement rate.

3.6 INSTALLATION OF FLOWABLE BACKFILL

A. Abandon existing sewer lines, manholes, and structures by completely filling with flowable backfill.

B. Have filling operations performed by experience crews with equipment to monitor density of flowable backfill and to control pressures.

C. Clean inside surface of sewer at least 12 inches from end to achieve firm bond and seal grout plug or manufactured plug to pipe surface. Similarly, clean and prepare exterior pipe surface if manufactured cap is to be used.

D. When using grout plug, place a temporary plug or bulkhead approximately 12 inches inside pipe. Fill pipe end completely with dry-packed grout mixture.

E. When using manufactured plug or cap, install fitting as recommended by manufacturer’s instructions, to form water tight seal.

F. Place flowable backfill to fill volume between manholes. Continuously place flowable backfill from manhole to manhole with no intermediate pour points.

G. Temporarily plug sewer lines which are to remain in operation during pouring/pumping to keep lines free of flowable backfill.

Herbert, Rowland & Grubic, Inc. 02 41 13.23 - 4 007297.0444

H. Pump flowable backfill through bulkheads constructed for placement of two (2) 2-inch PVC pipes or use other suitable construction methods to contain flowable backfill in lines to be abandoned. These pipes will act as injection points or vents for placement of flowable backfill.

I. Place flowable back under pressure flow conditions into properly vented open system until flowable backfill emerges from vent pipes. Pump flowable backfill with sufficient pressure to overcome friction and fill sewer from downstream end to discharge at upstream end.

J. Backfill areas excavated, open pits, and/or holes resulting from demolition according to Section 31 23 16.13 – Trenching.

K. Rough grade and compact areas affected by demolition to maintain site grades and contours, and/or accommodate subsequent construction operations.

L. Collect and dispose of excess flowable backfill material in accordance with PADEP requirements and the Erosion and Sedimentation Pollution Control Details.

M. Continuously clean up and remove demolished materials from site. Do not allow materials to accumulate on-site.

N. Transport demolished materials off-site and legally dispose of them.

O. Do not burn or bury materials on-site; leave site in clean condition.

END OF SECTION