Introduction to Utility Pipe Construction

Question 1

Open-Cut Method of Pipe Insulation

Answer 1

The conventional method for construction, replacement, and renewal of underground utilities.

Question 2

In open-cut construction, the construction effort is
concentrated on such activities as:

Answer 2

• Managing the traffic flow through detour roads,
• Trench excavation and shoring,
• Shielding or sloping,
• Dewatering (if needed),
• Backfilling and compaction operations
• Reinstatement of the surface.

Question 3

Open-Cut Method Pipe - Disadvantages

Answer 3

• Only a small part of the construction effort focused on the final product, which is the pipe installation itself.
• In some cases, the double handling of the soil may amount to 70 percent of the total cost of the project.
• High social costs:
  Traffic disruptions, noise, and dust
• Negative impacts to the environment
• Safety hazards of trenching
• Damage to trees and tree roots,
• Reduction in service life of pavement
• Possible damage to existing utilities and structures
• Pipe deflection in flexible pipes due to soil prism overburden
  on top

Question 4

Trenchless Technology

Answer 4

A process for construction, renewal, and replacement of
underground pipelines and utilities with minimal surface
and subsurface disruptions

Question 5

Trenchless Technology Benefits

Answer 5

*More opportunities for direct installation of pipelines and ducts with welded and fused or bell and spigot and retrained joints so,
* Reducing possibilities of leaks and joint misalignments and settlements.
* More accurate
*Due to arching effects of soil in trenchless technology
installations the loads on the pipe are considerably less
and more uniformly distributed around the pipe surface,
resulting in minimum pipe deflections

Question 6

What is the difference between Trenchless Technology & Open-Cut Cost

Answer 6

Trenchless:
* The amount of excavation, backfilling, compaction, and
pavement replacement is significantly reduced.
* The costliest item is the pipe installation usually
estimated on a linear foot basis,
Open-cut:
* Excavation, backfilling, pavement replacement, and
shielding or shoring are the major cost items and are
estimated on a cubic yard
or square foot basis.