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Two parallel retaining walls were constructed from 10.4 m embedded PZ22 sheet piles in order to indirectly measure the amount of earth pressure induced during excavation. Selected sheets were instrumented in an effort to measure bending moment and deflection, whereby the induced earth pressure could be discerned. Four sheets were instrumented, each with 16 strain gages (eight gages per flange) to detect bending moment. Steel tubing was attached to four additional piles for use with an inclinometer to measure horizontal movement. The soil between the walls was excavated in five equal lifts over a ten day period until the total depth of excavation was 6.1 meters. Strain gages were continuously monitored while inclinometer readings were taken at the completion of each excavation lift. The qualitative and quantitative results of the load tests showed no mobilization of lateral earth pressure on the walls with an excavation depth of 6.1 meters.

This paper presents the results of twelve lateral load test prediction case histories that include a mixture of both piles and drilled shafts in single or group configurations. PENCEL pressuremeter tests at the load test sites were used to develop p-y curves for analysis. The load tests were simulated using the program FB-MultiPier with the PENCEL pressuremeter based p-y curves. The quality of predictions suggests that p-y curves developed from PENCEL pressuremeter tests are viable. According to these cases, there is no difference in prediction between cohesionless and cohesive soil. The response of drilled shafts was predicted better than that of piles. The response of concrete foundations overall was modeled more accurately than that of steel foundations.

The objective of this study was to investigate the shear strength of Piedmont residual soil. The test program included collecting Shelby tubes from a single boring at 1.5 m increments to a depth of 16.8 m at a research site located in Charlotte, NC. The site was positioned near the geographical center of the Southern Piedmont and represented a granitic profile at various stages of weathering. Two or three isotropically consolidated drained (CID) tests were performed from each Shelby tube. Interpretation of the test results showed an average drained cohesion intercept (c') of 26.9 kPa. The average friction angle (φ') was 26.3 degrees. ABSTRACT: The objective of this study was to investigate the shear strength of Piedmont residual soil. The test program included collecting Shelby tubes from a single boring at 1.5 m increments to a depth of 16.8 m at a research site located in Charlotte, NC. The site was positioned near the geographical center of the Southern Piedmont and represented a granitic profile at various stages of weathering. Two or three isotropically consolidated drained (CID) tests were performed from each Shelby tube. Interpretation of the test results showed an average drained cohesion intercept (c') of 26.9 kPa. The average friction angle (φ') was 26.3 degrees.

Proceedings of Geo-Frontiers 2005, held in Austin, Texas, January 24-26, 2005. Sponsored by the Geo-Institute of ASCE. This Geotechnical Special Publication contains 16 papers covering contemporary foundation engineering issues including Load and Resistance Factor Design (LRFD) and reliability-based design for deep foundations; geosynthetic reinforced pile supported embankments; practical considerations for the design of foundations; problems and improvements pertaining to the Standard Penetration Test (SPT); and mat foundations.

Finite element analysis of geotechnical materials is contingent on the proper constitutive model to represent the soil. These models often range in complexity from simple linear elastic to complex hardening and consolidation behavior. Even though many models have been derived, there is little guidance for the selection of input parameters for such models. In this study, four constitutive models are considered the Mohr-Coulomb and Hardening Soil from Plaxis and the Drucker-Prager and Sandler Dimaggio from PlasFEM. A series of six consolidated drained triaxial tests are used to verify constitutive model parameters for sand. The laboratory derived strength and stiffness parameters, the results of a parametric study, and limited guidance from the literature are assembled to provide a best estimate of inputs for four constitutive models. The of plots of the finite element simulations using each of the four models versus the actual triaxial tests show good agreement, respective to the model behavior. A summary table of the parameters details the results.