Showing papers by "Rodrigo Salgado published in 2018"

Effects of Interface Roughness, Particle Geometry, and Gradation on the Sand–Steel Interface Friction Angle

Abstract: Determination of interface shear strength is crucial in the design of many geotechnical structures. To study the effect of interface roughness, particle geometry (size and shape), and sand ...

Effect of Surface Roughness on the Shaft Resistance of Displacement Model Piles in Sand

Abstract: This paper presents the results of tensile load tests performed with instrumented model piles with different surface roughnesses jacked into sand samples in a half-circular calibration cham...

Physical Modeling of Cone Penetration in Layered Sand

Abstract: This paper presents the results of cone penetration tests performed in layered, uniformly graded silica sand samples prepared inside a calibration chamber specifically designed for digital ...

Quality assurance and quality control of subgrade compaction using the dynamic cone penetrometer

Abstract: The Dynamic Cone Penetrometer (DCP) is a device that is used in the construction industry for the assessment of in situ soil compaction quality. Over the past few decades, numerous correlations have been developed between the DCP test results and soil strength and stiffness parameters. This paper proposes a comprehensive set of criteria and recommendations for quality control (QC) of compacted subgrade that take into account the inherent statistical variability of DCP test results. For the development of the QC criteria, a new statistical methodology is used to extract representative test values from the raw field DCP test data. In order to use the proposed QC criteria, soils are first classified into two broad categories (fine-grained and coarse-grained) depending on their fabric and response to compaction efforts. Test results indicate that (i) for fine-grained soils, the DCP test values have good correlation with the plasticity index (PI), which is indicative of the type and amount of clay cont...

Short-Term Setup of Jacked Piles in a Calibration Chamber

Abstract: The time-dependent increase in axial resistance (setup) of jacked or driven piles in sand is still not well understood, and its quantification remains a challenge. In this paper, a series o...

Pile Driving Analysis for Pile Design and Quality Assurance

Abstract: Dynamic measurements are often used to predict the capacity of a pile in the form of (a) pile driving formulae that relate the pile set per blow to the capacity of the pile or (b) analytical methods such as the Case method that predict the pile capacity from the accelerations and strains measured at the pile head. However, accurate prediction of pile capacity remains a challenge due to the complex response of piles during driving, prevailing uncertainties in the response of piles under static loading conditions post driving, and uncertainties stemming from simplifi cations made in the development of existing formulae. For this study, a fully integrated pile driving control system (PDCS) prototype was developed that collects, processes, and analyzes dynamic data. To develop pile driving formulae, advanced and realistic soil models that explicitly consider important parameters, such as soil and pile variability, were used to accurately simulate the hammer-pile-soil system during driving and to predict the capacity of piles under static loading conditions after driving. The integrated PDCS collects dynamic data through sensors and modules during pile driving operations. The system conforms to all requirements specifi ed in the pertinent ASTM standard (ASTM D4945). The PDCS uses wireless signals for the transmission of data collected in a PC located at a suitable distance from the driving operation. The PDCS can estimate the capacity of a single pile using existing dynamic methods, e.g ., the Case method, or through the pile driving formulae developed at Purdue University.