Study of the lateral pressure of fresh concrete as related to the design of drilled shafts.

A series of tests were conducted to determine the effect of the consistency of concrete, as measured by the slump test, on the lateral pressure of concrete. Testing conditions simulated the construction of drilled shafts as practiced by the Texas State Department of Highways and Public Transportation. The tests showed that increasing the slump of the concrete increased the maximum pressure and the length of shaft which was under hydrostatic conditions. Pulling the tremie increased the lateral pressure by variable amounts in an unpredictable manner. The increased pressure against the sides of an excavation is desirable because the axial capacity of a drilled shaft is increased.