Trenchless Technology & Subsurface Construction

Chapter 3

Impact Moling & Pipe Ramming Method

Introduction

Impact moling is a trenchless installation method for placement of small diameter pipes, ducts and cables, in which percussion or hammering action of a pneumatic piercing tool is used to create the bore by compacting and displacing the soil rather than removing it. The method typically is non-steerable, although steerable systems have reached the market in recent years.

When properly designed, impact moling is the simplest and the least expensive trenchless technology installation method. It is the most widely used trenchless installation method. Utility companies throughout the world widely use this technique for installation of service connections to gas, water and sewer mains, usually under sidewalks, driveways and other short crossings under 150 feet. General advantages of impact moling are low operational and reinstatement costs, relative simplicity in operating, minimal or no excavation beyond the necessary connection pits or termination points for the installed product, and minimal public disruption. Support equipment is limited to a small air compressor, and perhaps a small backhoe or trencher to open and reinstate the connection/termination pits.....................for more details