NASCLA Accredited Commercial General ContractorSite WorkMedium
A utility contractor is installing a new natural gas line that crosses underneath an existing paved road. To avoid disrupting traffic and minimize damage to the road surface, which method is typically preferred for this type of utility installation?
- ADirectional boring (Horizontal Directional Drilling)
- BJack and bore method
- COpen trench excavation
- DPipe bursting
Show answer & explanationAnswer & explanation
Correct answer: A. Directional boring (Horizontal Directional Drilling)
Directional boring, also known as Horizontal Directional Drilling (HDD), is a trenchless method used to install pipes, conduits, and cables under roads, rivers, and other obstacles without disturbing the surface. It's ideal for gas lines under paved roads to minimize traffic disruption and surface damage.
Why the other options are wrong
- B. Jack and bore is also a trenchless method but typically used for larger diameter pipes and often requires pit excavation on both sides, while HDD can be more flexible.
- C. Open trench excavation would require cutting and repaving the road, causing significant disruption.
- D. Pipe bursting is used for replacing existing pipelines by breaking the old pipe and pulling a new one through, not for new installations.
Directional Boring (HDD)
A trenchless technology used to install underground pipes, conduits, or cables along a pre-determined bore path, minimizing surface disruption. It's commonly used for crossings under roads, railways, and waterways.
- Trenchless method.
- Minimizes surface disruption.
- Ideal for road, river, or railway crossings.
- Used for new utility installations.
Memory trick: To cross a road, without a trench, bore it straight, no need to wrench.