Cone Penetration Tests at the NGES-Texas A&M University: Clay Site

Abstract

The cone penetration test (CPT) is one of the most widely used tools for many applications in geotechnical engineering. Recognizing the importance of the CPT in geotechnical engineering, field-testing programs were conducted at five of the National Geotechnical Experimentation Sites (NGES) with funding from the Federal Highway Administration. The objective was to provide the NGES users with a CPT database with cone penetrometers of different sizes and functions. The availability of well-docwnented CPT tests to NGES users will help in developing and validating new methods for a wide range of geotechnical applications. In this paper, analyses of cone and piezocone penetration tests conducted at the NGES at Texas A&M University-clay site are presented. One novel test conducted at this site is the continuous intrusion miniature cone penetration test using the 2-cm 2 miniature penetrometer. The cone penetration tests were used to classify the soil and identify its -stratigraphy using different methods of interpretation. The probabilistic region estimation and fuzzy methods showed refined soil classification and quantified the different soil constituents (clay, silt, and sand) with depth. The 2-cm 2 miniature cone penetrometer detected finer soil stratification compared to the 10-cm 2 standard cone penetrometer. The CPT and piezocone penetration test (PCPT) results were used to evaluate soil properties such as the undrained shear strength and the overconsolidation ratio and results showed agreement with conventional test results.