Page 77 - Trenchless Technology Piping Installation and Inspection

• Surface Conditions
• What is the topography?
• What are the surface features?
• What and where are the existing utilities located?
• What and where are the sensitive areas within the project site?
• What historical data is available for the project site?
• Is the existing pipeline under a road, lake, or river? What are accessibility
issues?
• Subsurface Conditions
• What are the general soil types, locations, and in-situ conditions?
• What is the potential for the presence of rocks, cobbles, or boulders?
• Is groundwater present? If yes, what is its depth?
• What is the soil’s corrosion potential?
• What is the soil’s settlement potential?
• Existing Pipeline Conditions
• What is the external condition of the existing pipe?
• What is the potential for the presence of external voids around the existing
pipe?
• What are the internal conditions of the pipe?
• What is the condition of existing manholes/on-line structures?
• Where are bends, fittings, valves, service connections, concrete encasements,
casing pipes, and other factors specific to the existing pipe located? Does
existing pipe have repair sleeves installed?
• Determination of the New Pipe Service Requirements
• What flow capacity is required?
• What length of pipe is under consideration?
• What is the corrosion potential?
• What are the structural requirements?
• Constructability and Site Limitations
• What safety issues need to be considered?
• What type of access into the existing pipe is available?
• What are the surface impacts of the construction techniques?
• What are the easement needs of the construction techniques?
• What impacts will groundwater have?
• What are the scheduling limitations and constraints?
• Will bypass pumping and flow control be required during the construction?
• What is the impact of other utilities?
• Strengths and Limitations of Potential Renewal/Replacement Methods
• Are the proposed material and method a proven technology with available
competent contractors?
• What is the availability of the technology?
• What is the anticipated service life?
• What are the potential method’s maintenance requirements?
• What are the initial and long-term costs?
• How well does the potential solution satisfy the identified service
requirements?
• What level of quality assurance/quality control is available?
TABLE 2.1 Pipeline Renewal/Replacement Parameters

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