When one sounding sits above the rest

Anyone sizing bridge foundations knows this. The soundings come from several campaigns, years apart, in PDF, and the first job is getting them into one plot. Then one sits above the rest, and nobody knows if it's the ground or the reduction.

One case on our Try page: the soundings for a creek bridge. Yesper put them in one compilation, shear strength against depth and top of rock. One CPT read 40% high. The earlier report had used a different Nkt. Under all but one support, 5 to 12.5 ft of weathered rock.

Which values to trust gets asked before the foundations are sized. The weathered rock turns up in the compilation, not when the rig is on site. Same for the rest of the Try page: lab data from scanned reports, a topo base from a point cloud.

Try it yourself →