How do you prepare geotechnical reports for civil engineering design?

Another aspect is to do a preliminary evaluation of involved risks, because the site investigation should be planned accordingly. For example, if there is a risk of slope stability in the area, the location and depth of some of the boreholes need to be adjusted. Many times this brings up the need to extend the investigation area well outside the construction area. Also, if it looks like, deep foundations may be necessary, it is important to know the depth of the bedrock, so that a desicion can be made on whether end bearing or floating piles will be needed, because this will have an important effect on the financial burden of the deep f?undation.

It's better to split the investigation campaign into multiple phases as the project proceeds so we can get an accurate picture of the site with respect to the project itself. For example starting with an exploratory investigations with wide grid after that the following investigations.

I have found it helpful to begin with a desktop study to locate published geologic, soil and topographic data for the area of interest. In addition, specific research to determine GeoHazards that might be relevant to the study area should be conducted. Determine if there is available data from previous geotechnical studies for similar projects in your geologic setting. Then perform a detailed site reconnaissance (using GPS and overlain geologic/geotechnical maps along with the proposed limits of development) to identify access issues, plan the exploration locations, types of exploration and equipment required.

In-situ tests do not measure any particular parameter directly. In general, some form of constitutive model is assumed in this property evaluation. It is, therefore, necessary to know certain properties of the soil before a rational interpretation can be made, and this always requires some laboratory testing. Everything cannot be entirely anchored to in-situ tests and iteration between laboratory testing on high-quality samples and in-situ testing is necessary.

The swell potential of over consolidated overburden and/or bedrock that has under optimum moisture content is important to characterize in the lab. The swell potential is an important consideration for selecting the correct foundation type. Also, the proper treatment of the subgrade underlying proposed flatwork should be addressed. Distress of both foundation elements and flatwork founded in areas of swelling soils and/or bedrock can be costly to mitigate. Proper design specific to site drainage is also an important consideration.

It is important to know if there are areas that might be in sinkhole areas, then the thickness and RQD are extremely important.

It might also look into the impacts on any surrounding environment and what changes in the proposed development will mitigate possible impacts

One thing not fully mentioned in the planning sections is full understanding on the structure to be placed on the ground that is being investigated. With this understanding one can actually have 50% of the report complete before one leaves the site.

Also the need to note every physical detail relevant to the structural integrity of the proposed structure in the report is crucial. This includes cracks on existing walls or buildings around the site for the proposed structure and any likelihood of inundation either from water bodies around or precipitation.