WorldWide Drilling Resource

WorldWide Drilling Resource ® is a proud member of this association. National Drilling Association Tel: 877-632-4748 Fax: 216-803-9900 www.nda4u.com 11 WorldWide Drilling Resource ® MARCH 2014 Importance of the Geotechnical Report by Scott Cosby The article this month will focus on the importance of a geotechnical report by examining the need for the report, geotechnical concerns, and its general contents. This article is a good com- panion to the WWDR November 2011 Geotechnical Investigation article. Essen- tially, the fieldwork and report merge for further understanding of the entire geotechnical investigation. I have definite experience in the gathering and prepa- ration of geotechnical information (e.g. drilling and lab results) for a geotechni- cal report. The geotechnical report is used to communicate the site conditions, design, and recommendations for a construc- tion project. The site conditions provide specific information on subsurface soil, rock, and water conditions. Interpretation of the site investigation information, by a geotechnical engineer, results in design and recommendations which should be presented in the geotechnical report. Without this, engineers will have to make assumptions for the design criteria of the on-site construction materials (e.g. soil and/or rock). Geotechnical concerns include: ex- pansive soils, potential for erosion, lava cap, bedrock, mudflow, soils with a high liquefaction potential, high water table, frost heave potential, etc. These could significantly increase the project costs if they are discovered during construc- tion. By deciding not to develop a geo- technical report, clients are ultimately assuming responsibility for any adverse soil conditions which may be encoun- tered. They also assume the risk for any resulting defects in the structure related to such soil conditions. While the geotechnical report con- tent may vary by project size and agency and/or firm, these reports should contain certain basic general contents, includ- ing: • Summary of all subsurface explo- ration data, including subsurface soil profile, drilling logs, laboratory or in situ test results, and groundwater information. • Interpretation and analysis of the subsurface data. • Specific engineering recommen- dations for design. • Discussion of solutions for antici- pated problems. This is a pile that was crushed when they tried to drive into the ground. Cosby cont’d on page 14.