Pressuremeter Testing Along Interstate 10 in Tucson, Arizona

Abstract

In arid to semi-arid regions alluvial soil deposits can range from collapse-susceptible, variably cemented to indurated. In these soils, reliable estimation of soil properties based on penetration resistance indicators such as N-values from Standard Penetration Tests (SPTs) is difficult. Varying content of gravels and cobbles provides additional complexity. In such conditions, sample recovery from SPTs is limited and refusal N-values occur. This paper presents a database of 74 pressuremeter tests along portions of Interstate 10 (I10) through Tucson, Arizona, where soil conditions noted above were encountered. The results are used to evaluate the subsurface stratigraphy. Estimated side and base resistance for drilled shafts are presented and compared with recommendations by the American Association of State Highway and Transportation Officials (AASHTO) and the Federal Highway Administration (FHWA). Comparisons of estimated side and base resistances from pressuremeter tests with those from a large-scale load test are presented. Evaluation of the collapse potential of soils using pressuremeter tests is also discussed and the results compared with collapse potential based on 1-D laboratory tests.