Geotechnical Baseline Reports for Underground Construction Guidelines and Practices

For many years, several forms of interpretive geotechnical reports have been incorporated into the Contract Documents for underground construction projects. Based on recent feedback obtained at three different industry-wide forums, it is now recommended that the Geotechnical Baseline Reports (GBR) be the interpretive report included in the Contract Documents. Its primary purpose is to establish a contractual statement of the geotechnical conditions anticipated to be encountered during underground and subsurface construction. This guideline and practice manual is intended to serve as a reference for preparers and users of GBR, and to inform owners of the importance of the contents of the GBR as related to the allocation of financial risk. In order to do this, it provides a checklist of items to consider when preparing the GBR, recommendations for the content and wording, and presents examples of problematic and improved practice in stating baselines.