ASCE MOP 106

Abstract

Scope: SCOPE OF THIS MOP This MOP presents HAB technology and its application to utility construction projects. Chapter 2 of this manual examines the mechanics of the HAB system, including the different components and attachments, along with recent innovations in the technology. The rest of the chapters present and discuss the different phases of a HAB project: the planning phase (Chapter 3), the geotechnical investigation process (Chapter 4), the design and preconstruction phase (Chapter 5), and the project construction phase (Chapter 6). It is always a challenge to determine the level of detail in an MOP for a technology like HAB because it is highly adaptable and is applicable over a wide range of conditions. HAB can be used to install simple, short, and unsteered casings in uniform ground. The method can also be used to install complicated long crossings in challenging ground and environments. The level of project risk typically determines the complexity. Low-risk projects are often completed with little preconstruction phase activity (planning, geotechnical exploration, and design); the assumption is that the risks will be dealt with if and when they are encountered. Risky and challenging projects typically involve extensive planning, exploration, and design prior to the construction phase. This manual is written to address the installation of a typical carrier pipe with low to moderate risks and challenges. For these projects, the owner and engineer are typically faced with a series of judgment calls on the number of preconstruction activities needed to identify the level of risk involved, the challenges, the parties’ experience, the project’s contracting mechanisms, and the associated environmental and social issues.