Specialty foundation contractors are heavily reliant on geotechnical reports. These reports are created at the start of the job and are compiled by the geotechnical engineering consultant for the project design team often long before the specialty foundation contractor is onsite or known. These reports contain valuable information such as the depth of groundwater, the soil types at each depth and SPT data. Often, these reports are the only piece of data that the specialty foundation contractor can rely on to make predictions about what the ground is like. 

Overview of Geotechnical Reports

The geotechnical report is created by first recovering soil samples from the proposed job site using a core drill. These borings are done at various locations across the site. There may be a large number of borings or very few borings depending on the budget of the site investigation. The amount of borings obviously affects the potential risk of discovering unforeseen soil conditions. The soils that are recovered are then examined, tested and classified according to their UCS soil classification. The geotechnical reports also often give a recommendation of a specific foundation element to use onsite based on a variety of factors including very conservative estimates of soil strength data. The structural engineer will take these recommendations and use them to design the structural elements for the foundation. A test program may also be recommended in the report. A test program is when a sacrificial foundation element is installed and exposed to loading conditions to collect actual soil strength data. These test programs will help to determine if the soil strength assumptions in the geotechnical report are too conservative or too liberal. Once completed, geotechnical reports are distributed to potential specialty contractors and included in the contractual documents of a job.

How Specialty Contractors can Combine Geotechnical Report Data, and Historical Performance Data to Gain a Competitive Advantage

In the November/December issue of DFI the authors highlighted DOTs that were starting to require BIM (Building Information Models - basically 3D site models) as contractual documents and the role of BIM in the future of geotechnical reports. I found this interesting as I believe established specialty foundation contractors have an opportunity to utilize a combination of BIM, past project geological information and data acquisition from drilling operations to give the contractor an advantage over their competitors. Specifically, I believe that the drilling contracts should aggregate this past and future data into a single database that would help contractors estimate jobs more accurately, estimate jobs more efficiently and to aid in design consultation in preconstruction. 

How Would a Database be Built?

Specialty contractors have a few sources of past and present data that at the present moment is not being utilized as effectively as possible. Companies that have completed a large variety of projects often have a “Past Projects” file that contains information such as soils, techniques used, equipment used, job performance etc. These files are a great resource to estimate future projects from but they require people to recall past work as there is no way to quickly compare a wide variety of past work. 

Contractors also often have a variety of sensors on their drilling equipment that monitors a wide variety of parameters such as drilling times, grout takes, air pressures, crowd pressures and other data points as needed. The other data point that foundation contractors have access to is field staff observations. These personnel can verify soil types at certain depths as well as anomalies, and drill tooling/condition. This job specific data is given to the EOR to verify that the foundation element was installed correctly and then rarely used again.

My vision is simple – create a Master Model that has all of the past projects completed by a specialty contractor as points in a geographic map layout. The individual points on the map  would then link to a 3D BIM file that shows the overall foundation layout and technique used for the job. From there, the 3D model could contain a wealth of data and layers such as a layer with the original geotechnical borings and soil parameters or a layer that has the as – seen soil conditions. The model would also contain the installation parameters, the test pile results, the grout takes, the crowd pressure and any other drill data that is relevant. These models would also contain information gathered from the onsite field personnel such as tooling used/condition, schedule duration, total down time or other issues faced  These would be a one stop shop for past cost estimators.

How a Database Model would help Estimators and Design Consultants

A historical database could be easily searched and filtered to match the current project that is being estimated. A proposed project could have a geotechnical report with soils that have a very low N values. In a few seconds, an estimator could search the database for projects with soils and N values that have used the same or similar techniques. From there, the estimator has a past project with data such as cost performance, labor rates, tooling used, etc. There is clearly a use case for estimators here. 

Another way that the model could be used is in design consultations. Often, designers may choose to over design or pick a technique that is not well suited for the soil data. With the historical database, a contractor can quickly compare past jobs that may have been in similar soils and similar geographic areas but have chosen to use a different technique. The database would also have historical test pile data which could be provided to the EOR as further back up for the substitution or redesign.

Clearly there would be no shortage of value provided from a historical database. There also may even be some use from the field when choosing which tooling to use to get through certain soil layers. The main point is that there is a wide variety of information that is collected or can be collected in the specialty foundation space however the value of the data collected has not fully been maximized yet.