Specs - Pilot Tube Guidance

8/10/2019 Specs - Pilot Tube Guidance

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TECHNICAL SPECIFICATIONS WW-483RR

DIVISION 02: SITE WORK

02446: PILOT TUBE GUIDANCE

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PART 1 - GENERAL

1.1 DESCRIPTION

A. The work specified in this Section consists of installing a retrievable pilot tube forinstallation of the carrier pipe to the line and grade shown on the Plans to serve as

line and grade control for the installation of a casing by pipe ramming methods.

B. Related work specified elsewhere:

1. Section 02431, Cellular Grout Backfill.

2. Section 02444, Shaft Excavation.

3. Section 02445, Installation of Carrier Pipe in Casing.

4. Section 02447, Casing Installed by Pipe Ramming.

5. Section 02448, Geotechnical Instrumentation and Monitoring for PipeRamming.

6. Section 02155, Ground Improvement with Water-Activated Grout.

7. Section 14000, Steel Casing

C. Definitions:

1.

Refer to Section 02447.

1.2 SYSTEM DESCRIPTION

A. Design Criteria:

1. Complete pilot tube probes at the four quadrants shown in the conceptual step-

by-step procedure presented in the drawings. Probes to be at the line and grade

shown on the plans. Retrieve the pilot tube after each probe is completed.

2. Install pilot tube to line and grade shown on the plans along the central axis of

the casing.

3. Line and grade tolerance:

a. Line: One-half inch tolerance

b. Grade: One-half inch tolerance


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c. Installation of the carrier pipe to the specified line and grade withminimal backfill as specified in Section 02445

d. Installation of the carrier pipe without reverse grades or ponding of

water in the carrier pipe invert.

4. Install seals on shaft walls where the pilot tube penetrates Ramming and

Receiving shaft walls.

5. The wall seals shall be capable of resisting a hydrostatic pressure of 15 psi.

1.3 SUBMITTALS

A. General: Submit in accordance with Section 01300

B. Pilot Tube Qualifications:

1. Pilot Tube Contractor Qualifications

2. Pilot Tube Superintendent

3. Pilot Tube Operator

C. Drawings:

1. Provide shop drawings and calculations for construction of ramming and

receiving shafts to launch and receive the pilot tube in accordance with shoringdesign as specified in Section 02444. Furnish details on the preparation and

placement of the shaft invert.

2. Provide shop drawings showing details of the wall seal. Shop drawings shall

also provide details on how the wall seal will be secured to the shaft wall toprovided sealed ingress and egress points for the pilot tube.

3. Provide shop drawings showing the pilot tube equipment layout in the piperamming shaft.

4. Provide shop drawings and engineering calculations for the pilot tube reaction

system.

D. Traffic control plan: Submit in accordance with Section 01570.

E. Pilot Tube installation work plans

1. Provide a work plan outlining the construction sequence for installation of the

pilot tube probes prior to installing the pilot tube for line and grade control.


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2. Provide a work plan outlining the construction sequence for installation of thepilot tube for line and grade control.

3. Provide the equipment manufacturers literature and drawings for the system to

be used.

4. Provide descriptions of the projects on which the system has been successfully

used including names, addresses, and telephone numbers of the owners

representatives for these projects, as well as the length, diameter, and pipematerial used and the soil type and groundwater conditions as defined by SPT

N-Value, and groundwater levels.

F. Records and reports

1. Provide as-built information for the pilot tube.

2.

Prepare and submit survey notes, records, and shift reports including rates of

advance, line and grade deviations, steering adjustments, and jacking forces

required to advance the pilot tube.

G. Contingency plans

1. Submit a contingency plan that includes a method statement for removal of

obstructions in the path of the pilot tube. Prepare and submit a plan for

emergency rescue shaft construction before the start of work. Obtain theowners and all other approvals from agencies having jurisdiction before

starting work on rescue shafts.

H. Lubrication

1. Submit lubrication plan and lubricant formulation.

I. Safety:

1. Submit a safety plan for the pilot tube construction. The contractor's safety

plan will not be reviewed and will only be noted as received.

2. Submit an Injury and Illness Prevention Plan in accordance with CalOSHA

requirements. The contractor's IIPP will not be reviewed and will only be

noted as being received.

1.4 QUALITY ASSURANCE

A. Reference Standards: (NOT USED)

B. Perform the pilot tube installation using qualified firms and personnel as specified

herein.


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C. Qualifications:

1. Pilot tube contractor

a.

Contractor must have completed at least five pilot tube projects in thelast three years on project lengths equal to or greater than 80% of thelongest drive anticipated for this project. At least one of the five projects

must have been completed within one year prior to the date of this

project. Provide experience record.

2. Superintendent

a. Minimum of five trenchless projects in the last five years.

b. Minimum of two projects where a pilot tube was set to line and grade.

Provide experience record.

3. Operator

a. Minimum of five years experience installing pilot tubes.

b. Minimum of five projects of demonstrated experience installing a pilot

tube to line and grade.

c. Of the five projects, at least three projects shall demonstrate drive

lengths that are at least 80% of the longest planned drive on this project.

D.

Acceptance Criteria:

1. Pilot tube installed to the design line and grade within allowable tolerances.

E. Preconstruction Meeting:

1. Hold a meeting, a minimum of two weeks prior to beginning the work

specified herein. The superintendent and operator shall be present at the

meeting. Meeting can be combined with meeting specified in Section 02447.

2. Review and discuss the following items:

a.

Scope of work to be performed.

b. Anticipated geotechnical conditions

c. Construction methods and constraints overview.

d. Equipment operating parameters.


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e. Safety procedures.

f. Quality Control procedures and Quality Assurance requirements.

g.

Reporting requirements.

h. Other issues as may be raised by either party.

F. Training: (NOT USED)

G. Testing: (NOT USED)

1.5 JOB CONDITIONS

A. Refer to Section 02447 and to the Geotechnical Data Report.

1.6

SEQUENCING AND SCHEDULING (NOT USED)

1.7 PRODUCT DELIVERY, STORAGE AND HANDLING (NOT USED)

1.8 WARRANTY (NOT USED)

PART 2 - PRODUCTS

2.1 MATERIALS

A. Lubricants, if used, shall consist of the following:

1.

High yield sodium montmorillonite bentonite, when used.

2. Water shall be furnished by the contractor from a potable water source.

3. All water shall be tested for ph and treated with soda ash, or approvedequal, to adjust the ph of the water as required in the accepted mix

design(s).

4. Groundwater shall be checked at each shaft for salinity and the lubricant

formulation adjusted based upon the results.

5.

Bentonite, polymers, and additives shall be NSF/ANSI Standard 060 orequal for clean water testing except for soda ash and salt water compatibleadditives.

2.2 EQUIPMENT

A. Pilot tube equipment shall be used to complete test probes and to install the pilottube between shafts.


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B. The pilot tube equipment shall be as specified herein and manufactured by:

6. Pilot tube manufacturer shall have produced at least 20 similar systemsover the last 10 years.

7. Pilot tube system shall have completed projects of at least 90% of thelongest drive on this project.

8. Pilot tube system shall have operated in groundwater with a minimum of 8

psi.

9. The pilot tube shall be inserted into the ground by displacement methods

and not excavation.

2.3 SOURCE QUALITY CONTROL (NOT USED)

PART 3 - EXECUTION

3.1 GENERAL REQUIREMENTS

A. Do not begin pilot tube installation until the following conditions have been met:

1. Submittals have been made, reviewed, and accepted.

2. Pre-construction surveys have been completed and the results aresubmitted.

3.

Design and construct shafts in accordance with Section 02444, asapplicable.

B. Pilot tube probes or line and grade installation on any single drive shall not

commence until:

1. Ramming and receiving shaft excavation and support provisions have been

completed in accordance with section 02444.

2. Breakout ground improvement provisions have been completed in

accordance with Sections 02444 and 02155.

3.

Furnish all necessary equipment, power, water, and utilities for the work,including pipe lubricant mixing and pumping, and other associated workconsistent with the method of construction.

3.2 CONTROL OF LINE AND GRADE

A. The owner will establish the baselines and benchmarks indicated on the plans.


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B. Contractor shall check the baselines and benchmarks at the beginning of thecontract period and report any error or discrepancy.

C. Use the baselines and benchmarks to furnish and maintain all reference lines and

grades for the pilot tube installation. Use these lines and grades to establish thestarting location for each probe and for setting the line and grade pilot tube.

D. Submit copies of field notes used to establish all lines and grades prior to

launching the pilot tubes from the pipe ramming shaft.

E. Control insertion of the pilot tube such that the tolerances described in this section

are met.

F. Mount the grade control equipment in a manner recommended by the equipmentmanufacturer.

G.

Verify the pilot tube is installed at the correct line and grade between the pipe

ramming and receiving shafts before continuing with installation of the casing

using pipe ramming methods.

3.3 PILOT TUBE INSTALLATION

A. Refer to drawings for a conceptual step-by-step procedure for completing the pilot

tube probes, line and grade installation, and installation of the steel casing. The

conceptual step-by-step procedure is augmented with the following:

1. Pilot tube wall seals can be pre-installed as part of the wall seal specified in

Section 02447.

2. Install the pilot tube at the line and grade established in the drawings,

incorporating any adjustments so the pilot tube exits at the desired location

and elevations within the receiving shaft.

3. Provide egress in the shaft support of the pipe ramming shaft to allow the

pilot tube to exit the shaft. Provide ingress into the receiving shaft for thepilot tube. Groundwater inflow through the egress and ingress points shall

be controlled and limited to a maximum inflow of five gallons per minute.

4.

Upon the completion of each drive verify the line and grade of the pilottube.

5. See Section 02447 and the conceptual step-by-step procedure in the

drawings for mating of the pilot tube to the casing.

6. If needed, lubricate the pilot tube as it is installed.

3.4 OBSTRUCTIONS DURING PILOT TUBE INSTALLATION


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A. When forward advance of the pilot tube is stopped by an obstruction, identify thepoint on the ground surface immediately above the obstruction. Pothole down to

the obstruction to identify the type and size of obstruction. Work with the owner

and owner's representative to identify means of removing the obstruction thus

allowing advancement of the pilot tube or pilot tube probe to the receiving shaft.

B. Allow the owner access to removed obstruction.

3.5 OPTION FOR PILOT TUBE PROBES

A. Provide unit prices to complete four pilot tube probes at each casing installation

in addition to the central axis pilot tube installed for line and grade control. Theunit prices for the pilot tube probes should be based on the following criteria:

1. Pilot tube probes would be located immediately outside each of the four

quadrants at the perimeter of the tunnel zone as shown in the drawings.

2. The pilot tube probes shall be retracted and need not penetrate the

receiving shaft wall.

3. If advance of a pilot tube is obstructed, identify the exact location of the

obstruction and retract the pilot tube clear of the obstruction. Potholedown to the obstruction to identify the type and size of obstruction. Work

with the Owner and Owner's Representative to identify means of

removing the obstruction. Upon obstruction removal, complete the pilottube probe to the receiving shaft. If other obstructions are encountered,

repeat step 3. Perform a pilot tube probe at the remaining un-probed

quadrant locations.

4. Upon completion of the four pilot tube probes, summarize the results of

the probes and submit to the Owner and Owner's representative.

5. For purposes of deriving a unit price cost, the contractor shall assume that

two obstructions will be encountered during the initial pilot tube probes.The contractor shall further assume that one obstruction will be

encountered when the pilot tube probe is restarted after an obstruction

removal.

6.

Provide unit prices for the following:

a. Four successfully completed pilot tube probes.

b. Potholing to identify the obstruction

c. Restarting a pilot tube probe after an obstruction removal

d. Stand-by rate for the pilot tube and pipe ramming systems.


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3.6 INSTRUMENTATION AND MONITORING

A. Monitor the installed instrumentation in accordance with Section 02448.

3.7 FIELD QUALITY CONTROL

B. Complete a closed loop survey of the pilot tube projection in the ramming and

receiving shafts to confirm line and grade installation of the pilot tube.

3.7 CLEAN-UP

A. Pilot tube for pipe ramming line and grade control shall remain in place until

removed as required in Section 02447.

B. After successful installation of the pilot tube, remove the pilot tube jacking and

operational equipment from the pipe ramming shaft.

END OF SECTION


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DIVISION 16: ELECTRICAL

16500: LIGHTING

16500 - 1

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Specs - Pilot Tube Guidance