PPP Notes - Reading Soils Reports

SOILS STUDIES AND REPORTS

 

READING A SOILS REPORT

 

• A geotechnical report helps the design team understand the site on which the structure is to be built.
• Most geotechnical reports contain the following information:
• Report Summary
• Project Information
• Exploration Methods
• Description of Soil and Groundwater Conditions
• Design Recommendations
• Construction Considerations
• Appendix
• Location Diagram
• Soil-boring or Test Pit Logs
• Soil Profiles
• Laboratory Test Results
• The report summary is generally one of two pages long, and provides the most salient information and recommendations of the report. 
• Use the summary as quick reference, but read the entire report for details and qualifications/limitations.
• Most reports are read within 30 minutes.
• Check and verify the project information and criteria (building height, structural loads, floor/basement levels, so on).
• The scope of the evaluation and recommendations are based on this information.
• Also, included in the report would be project information describing the building and site characteristics such as number of stories, building construction materials, foundation loadings, basement data if applicable, and grades.
• The exploration section defines how the geotechnical engineer obtained the soil information required to describe the foundation this would include number, location and depth of soil boring and tests pits, and laboratory and field-testing to be performed.
• The general soil and groundwater conditions include a general overview of the results of the geotechnical engineer’s tests.
• More detailed information is contained in the soil-boring and test pit logs, which can be reviewed when required.
• The design recommendations section is of greatest interest to the project design team, as it makes specific recommendations concerning the design of foundations, glade slab, walls, drainage requirements, and other key building components.
• Should be read together with the section on construction considerations, which identifies potential problems during construction that can be avoided or minimized by both the design team and contractor when everyone understands the challenges for the project.
• Often reports will provide a transverse section of the soil profile, combining the soil-boring information in a convenient picture.
• The section enables the reader to better understand approximately how the soil properties will vary across the site.