Specifications for Rock Mass Grouting

During the last decade or so, there have been significant and well-documented advances in rock fissure grouting. This has arisen principally because of the technical challenges faced when conducting major remedial grouting operations under high head conditions. Many specifications, particularly those of the USACE, have kept pace with the technological advances and are compatible and consistent with them. However, the authors find that, especially on privately-owned grouting projects, specifications can be most kindly described as traditional, to the extent that they do not encourage, or indeed permit, the more recent innovations. The purpose of the paper is to provide clear guidance on the critical technical elements of specification writing for such projects. The paper therefore covers aspects relating to drilling, flushing, water testing, grouting and automated monitoring and control. It also describes materials, grout formulation principles, and methods of in situ verification. Equally importantly the issues of measurement and payment are addressed. It is the hope of the authors that this guidance will encourage the use of Best Value contractor procurements, and help mitigate against contractual disputes. 12 pp., 8 references.