Remedial Grouting of Existing Embankment Dam Foundations: Lessons Learned (and Ignored)

摘要

The authors have had intimate experience in the design, construction, and evaluation of remedial grout curtains for embankment especially dams during the "heyday" of the last 20 years in North America. Their experiences - and those of other active participants in such projects - have been widely published in the technical press, and have been incorporated in recent federal guidelines. However, not all the "lessons described" in such publications have been translated as "lessons learned," and indeed many "lessons learned" have been ignored totally in certain quarters. The paper focuses on several topics which the authors feel merit particular attention in this regard, namely: drilling techniques for overburden and rock, design and testing of grout mixes, placement and sealing of standpipes and MPSP's, data management systems (DMS), refusal and closure, allowable injection pressures, joint instrumentation monitoring plan, and long-term monitoring. The authors trust that the conclusions of the paper will provide guidance to engineers about to participate in a major grouting project for the first time, and comfort to more experienced engineers faced with conflicting "opinions" from unqualified but strongly opinionated "experts."