No abstract

This paper presents an investigation into the loading response of a saturated, cohesive soil medium associated with a pile-soil system. An instrumented test pile was driven in order to determine the adequacy with which proposed theories describe the field response of a pile-soil system. The test pile was a 50-ft-long 16-in.-diameter steel pipe in which strain gages, accelerometers, and pressure transducers were installed. Field tests were performed at Beaumont, Tex., in a marine clay deposit. Stresses and accelerations developed in the pile were measured during driving. Pore water pressures were measured after driving for a period of approximately four weeks, or until the excess pore water pressure resulting from driving had dissipated, and during static load tests. Samples were taken of soil about the pile in various states of disturbance which varied with time and radial distance from the pile. Measurement of the engineering properties of these samples furnished an evaluation of the effect of different degrees of soil disturbance. Results obtained in this study indicate that soil disturbances and resulting excess pore water pressures associated with the driving of a large diameter pile are of greater magnitude and dimensional extent than previously thought. An evaluation is presented of the magnitude and general nature of the soil response to dynamic loadings of driving. Finally, results of static load tests performed approximately two and four weeks after driving furnish a measurement of ultimate bearing capacity as a function of time after driving.