Thomas and Marker Construction won a $1.5 million lawsuit against Wal-Mart on December 23, 2008 through a unanimous jury verdict and court order in Federal Court in Dayton, Ohio. The lawsuit was related to unanticipated hard bedrock “in areas and at depths not indicated in the subsurface geotechnical report furnished by Wal-Mart.” This is obviously a relatively common occurrence, but the fact that Wal-Mart refused to pay the contractor for the change of conditions is the real story.
I think big box stores like this have their own requirements/guidelines for a geotechnical investigation. Does anyone know what Wal-Mart’s requirements are like? I’m guessing that just a few borings were done, but not enough to get a complete picture of the subsurface. A seismic refraction survey might have been of some use in the particular case. I wonder if Wal-Mart will now go after their geotechnical subconsultant (or their insurance company anyway) for a portion of that $1.5 million. Source: Dayton Business Journal.
Wal-Mart made it onto GeoPrac.net a few times previously with regards to their Kilbuck Landslide issues in Pennsylvania.
Wal-Mart’s Geotechnical Investigation Specifications
As a geotechnical engineer familiar with subsurface explorations for proposed Wal-Mart Supercenters, as well as additions, I must say that Wal-Mart’s Geotechnical Investigation Specifications are thorough, especially with regards to bedrock. Under WM’s specs, a consultant must characterize the hardness and extent of rock, if encountered and anticipated to have a potential affect on earthwork activities. Furthermore, the specs indicate ‘borings that encounter refusal are considered significant. Each boring, or borings, that are terminated because of refusal are to be discussed in the body of the report and a conclusion reached regarding it’s significance. If additional investigation is warranted to reach an appropriate conclusion, expand the investigation and exploration appropriately.’
For a typical Supercenter (nearly 200,000 sf), a minimum of 15 borings to a depth of 20 feet below proposed finished floor, or 20 ft. below the existing grade, whichever is greater, are required within the footprint. Beyond the building, a grid pattern of borings, with a max. spacing of 100 feet, are required to a depth of 10 feet. Based on the past few projects I’ve been involved in with WM, the total number of borings ranged between 30 to 200.
Given WM’s guidelines, it would seem to me the responsibility for the construction difficulties experienced due to shallow bedrock falls squarely on the geotechnical consultant responsible for the study.
Specs seem pretty rigorous
Thanks for your comment Ryan. That’s exactly the kind of information I was curious about. 100-ft spacing max seems pretty tight, if the geotech firm followed the specs it makes it hard for me to imagine missing large areas of bedrock. Of course, I don’t want to badmouth another geotechnical firm, even if I don’t know their name. Perhaps there was more to this story than we think…
This is an interesting site I happened upon since it’s the same business I’m in. I’m not a Geotechnical Engineer, but it’s what my family business is. It’s our experience with box stores such as Wal Mart is that they have their “favored” labs, usually the big national firms. While their standards may be stringent with regard to the report requirements, often times the Geotechnical Engineering firm is not a local office nor do their Engineers have the local expertise of the soil conditions, and even worse they are less knowledgeable about the local area’s construction practices. These are things that big box stores fail to recognize often. My family’s firm is a locally owned and headquartered firm, also the largest in our region so the majority of our project experience is in our area. A geotechnical engineer 200-600 miles away is really doing their Client a disservice in many respects. We also provide Construction Materials Engineering and Testing, so many times we are hired to provide those services only to be asked to do a secondary analysis of the Geo report and provide a second opinion. The majority of the time we are able to save the Owner money because of less conservative recommendations, based on past experience with proven track records.