Geotechnical Data Report Requirements
The purpose of a Geotechnical Data Report (GDR) is to provide enough information to adequately reduce the risk to the design-build proposers, to have sufficient information to provide a responsive proposal, and to provide consistent information from which all proposers can develop their concepts and costs. The scope of this GDR is preliminary and provides a basis for conceptual designs and future geotechnical investigations.
The GDRs should contain neither interpolation of the information nor design recommendations. Rather, GDRs present the raw data and laboratory results. However, when geotechnical hazards (potential instability, excessive settlement, lateral squeeze, rock fall, mine subsidence, scour, etc.) are known, they should be listed. The GDR should point out past coal mining, gas wells, quarriable stone, and append other background information when pertinent. Provide a brief discussion of the subsurface investigative sampling and testing procedures used and any deviation from our standards. Include a brief discussion of the laboratory testing methods used. The GDR should present geologic structure including strike and dip of strata in the project area.
Potential problems documented in the GDR may require further investigation by the proposers to help manage their risk. When significant geotechnical risks such as landslides and rockfalls are present, acceptable remedial measures may be prescribed in the GDR.
At the minimum, the report appendix should have the following: boring plan, boring logs, color core photos, laboratory test sheets, and background geotechnical data that is readily available.
For small bridges, the WVDOH prefers an 8.5”x11” letter style report and the above appended information. For larger bridges, roadway reports, or projects with more complexity, a 11”x17” format is preferred.
Geotechnical data reports are not required to be sealed by a registered engineer. However, the GDR will be performed under the supervision of a practicing geotechnical engineering in the state of West Virginia.