In trenchless main replacement, which installation system is used?

• A. Static bursting
• B. Pneumatic
• C. Hydraulic
• D. Open-cut

Answer: (A)

Static bursting is a trenchless installation method where a bursting head is pulled through the existing main, breaking the old pipe apart while a new pipe is drawn behind it into place. As the head advances, the old pipe is split and displaced, and the new pipe takes its place, usually with the same or a larger diameter. This approach minimizes surface disruption compared with open-cut excavation.

In contrast, pneumatic bursting uses compressed air to fracture the host pipe, and hydraulic bursting uses fluid pressure to do the same. Open-cut is not trenchless, as it requires digging a trench to install the new pipe. So, the installation system used for trenchless main replacement is static bursting.