Slope Load Bearing Test??? 1

[vollEngineer]

A 2-story masonry-walled building's continuous footing is installed. The footprint sits on a 20-foot fill pad of which I observed installation. On slope has been shear cut parallel to one side of the building with the crest approx 4 feet away from the footing. A 15-ft shear cut at one corner that tapers to about 5 feet 70 feet away to the other corner. (Sigh) They have begun rebuilding the slope (without benching of course). This is a silty-clayey fine to medium sand. The contractor does not want to remove any of this footing and wants to continue masonry construction. No evident cracks. I am having the footing surveyed during construction to monitor settlement.

Any other testing ideas? A&P? Is their such a thing as a load bearing test for a slope?

 

[GeoPaveTraffic]

Only time will tell, but if I understand your description correctly; sounds like trouble to me.

I don't believe any type of bearing test will help. Problems are more likely to be related to slope creep or failure and those will not start until the soil progresses from the undrained placement condition to a drained condition.

 

[vollEngineer]

I appreciate the concern. But I feel that there must be a test that will fail now if the soil beneath the footing has loosened, maybe not enough to settle yet, but under the loads of masonry and elevated deck would settle. I will do some A&P adjacent to the footings. But if anyone knows of something else that may prove the soil is too loose now for the final loads, we could keep them from having to tear out a large portion of the finished building later when it actually fails.

 

[GeoPaveTraffic]

If your concern is the imeadiate performance of the footing, just load the footing to 1.5 to 2.0 times the anticipated load while measuring the deformation; just like doing a pile load test. The tricky part is loading the footing. If you can isolate a small portion of the footing, you may be able to use water tanks or stack steel blocks on the footing. It is not easy and be careful the the weight doesn't fall over and kill someone.

 

[vollEngineer]

oh duh. <smacks forehead> a load test on the footing. this is not sarcasm. i really never thought of that. thanks for helping me see the forest.