Att_06-_Horizontal_Drilling_Specifications_0001.pdf

140P8421Q0109- Sidewalk Replacement Attachment 06- Horizontal Drilling Specifications

STANDARD SPECIFICATIONS

SECTION 330522

HORIZONTAL DIRECTIONAL DRILLING

PART 1 GENERAL

1.1 DESCRIPTION

A. Section includes requirements for Horizontal Directional Drilling (HDD) of High-Density Polyethylene (HDPE) pipe.

1.2 PROJECT CONDITIONS

A. Complete HDD so as not to interfere with, interrupt, or endanger surface and activity thereon.

B. Do not use HDD in rock stratum or subsoil consisting of boulders and underground obstructions that impede the process.

C. Comply with applicable ordinances, codes, statutes, rules, and regulations of State of California, applicable County building codes, and applicable regulations of Federal Government, OSHA 29CFR 1926, and applicable criteria of ANSI A10.16-1995 (R2001), “Safety Requirements for Tunnels, Shafts, and Caissons.”

PART 2 PRODUCTS

2.1 MATERIALS

A. Pipe.

a. ASTM F2160, Standard Specification for Solid Wall High Density Polyethylene

(HDPE) Conduit Based on Controlled Outside Diameter (OD)

b. NRTL listed meeting UL 651B

c. Schedule 80

d. Red or gray in color

e. Smooth interior and exterior surfaces

f. With the following marked on the outside:

i. Manufacturers name

ii. Conduit size

iii. Conduit type

iv. NRTL certification mark

g. HDPE Joints:

i. Use butt fusion joining technique for joining pipe segments installed by

HDD.

ii. When joining HDPE pipe at ends of directional drilling runs fusion bond to adjacent pipe section.

iii. Use butt fusion, socket fusion, or electrofusion coupling joining technique.

iv. Mechanical Couplings are not permitted for joining of directional drilled pipe sections.

B. Drilling Fluid.

a. Bentonite drilling mud compatible with the environment.

b. Waste oil or environmentally non-compatible polymers cannot be part of composition.

C. Detection Wire: TW, THW, THWN, or HMWPE insulated copper, 10 gage or thicker wire.

PART 3 EXECUTION

3.1 PREPARATION

A. Provide equipment to guard against electrocution and an alarm system on drilling equipment capable of detecting electrical current as it approaches electric lines.

3.2 OPERATION

A. General.

a. Determine drilling length and equipment pull strength for type of soil encountered.

b. Provide method to control line and grade.

i. Provide and maintain instrumentation that accurately locates pilot hole.

ii. Drill pilot hole along path following Drawings to these tolerances:

1. Vertical alignment plus or minus 0.5 foot. Vertical path of the pilot hole must not establish new high points.

2. Horizontal alignment plus or minus 1.0 foot.

iii. Include electronic monitoring of horizontal and vertical drilling head location. Obtain accuracy range within 1 inch of actual position of pipeline. Record position readings at maximum of 10-foot intervals.

iv. At completion of pilot hole drilling, furnish Contract Manager tabulations of horizontal and vertical alignment.

c. If water is encountered.

i. Provide and maintain dewatering system of sufficient capacity to remove water.

ii. Keep excavation free of water until backfill operation is in progress.

iii. Perform dewatering in such a manner that removal of soils particles are held to a minimum.

iv. Dewater into sediment trap

d. Maintain close observation to detect settlement or displacement of surface and adjacent facilities.

i. Notify Contract Officer and applicable agency immediately if settlement or displacement is detected.

ii. Maintain safe conditions and prevent damage.

B. Drilling Operation.

a. Drilling Fluids.

i. Maintain drilling fluid in bore hole to increase stability of surrounding soil and reduce drag on pulled pipe.

ii. Dispose of drilling fluid and other spoils at location following laws, ordinances, rules, and regulations of local jurisdiction.

iii. Transport excess fluids and other spoils to disposal site.

iv. Minimize drilling fluid at locations other than entry and exit points.

Immediately clean up any drilling fluids that inadvertently surface.

v. Provide clean water for drilling.

b. Pilot Hole Drilling.

i. Angle entry hole so that curvature of pilot hole does not exceed allowable bending radius of HDPE pipe.

ii. Be able to make a turn of up to 90 degrees and maintain a curvature not to exceed allowable bending radius of HDPE pipe.

iii. Alignment Adjustment and Restarts.

1. Follow pipeline alignment on Drawings within tolerances specified herein. Before adjustments, notify Contract Manager for approval.

2. Notify Contract Manager when forward motion of operation is stopped by an obstruction.

a. Abandon in place with drilling fluid, unless Contract

Manager directs otherwise.

b. Attempt a second installation at approved location or excavate at the point of difficulty and install the HDPE pipe by trench method

3. Exercise caution including, but not limited to, drilling downholes (test pits) to observe drill stems or reamer assembly to clear other existing utilities at locations following Drawings.

4. Keep the number of boring pits to a minimum, no closer than following distances.