Eine Plattform für die Wissenschaft: Bauingenieurwesen, Architektur und Urbanistik
Eine Plattform für die Wissenschaft: Bauingenieurwesen, Architektur und Urbanistik
Crosshole Sonic Logging and velocity tomography imaging of drilled shaft foundations
Crosshole Sonic Logging (CSL) has come into widespread use for quality assurance of the concrete placement in concrete drilled shaft foundations, particularly when they are drilled using wet-hole drilling methods due to the risk of concrete contamination. The CSL method is used to measure the speed of sound between water-filled cast-in-place access tubes. The velocity of the sound wave which travels from source to receiver in a horizontal plane determines the presence of anomalous regions (due to water or air-filled voids or soil intrusions) and therefore the quality of the concrete. When plotted against depth, a CSL velocity log quickly defines the depth and approximate lateral location of a potential defect. For added higher resolution of shaft integrity and defects, the Crosshole Tomographic (CT) velocity imaging method is used. The CT velocity method accurately and precisely defines the size, shape, severity, depth, and location of potential defects by determining the spatial velocity distribution of shaft concrete through analysis of numerous soundwave raypaths. Although the CT process is currently slower than CSL, its two-dimensional (2D) and three-dimensional (3D) imaging results go unmatched for engineering accuracy, interpretation simplicity, and visual appeal. CSL and CT results are presented for sound and defective drilled shafts tested in research projects and real-world consulting. The methods have been successfully applied in both arenas to locate unknown and pre-existing test defects. Meaningful and valid CSL and CT data analyses and interpretation require sufficient knowledge in the history of the concrete placement, local site parameters, material properties of concrete, and the physics of the test. The CSL method has been recently standardized by the American Society of Testing and Materials (ASTM) and is described in Standard No. D 6760. When used by an experienced professional, the CSL and CT methods are an excellent tool for determining shaft integrity and finding potential areas of concern. Further, they eliminate the questions and concerns associated with a problematic concrete pour.
Crosshole Sonic Logging and velocity tomography imaging of drilled shaft foundations
Crosshole Sonic Logging (CSL) has come into widespread use for quality assurance of the concrete placement in concrete drilled shaft foundations, particularly when they are drilled using wet-hole drilling methods due to the risk of concrete contamination. The CSL method is used to measure the speed of sound between water-filled cast-in-place access tubes. The velocity of the sound wave which travels from source to receiver in a horizontal plane determines the presence of anomalous regions (due to water or air-filled voids or soil intrusions) and therefore the quality of the concrete. When plotted against depth, a CSL velocity log quickly defines the depth and approximate lateral location of a potential defect. For added higher resolution of shaft integrity and defects, the Crosshole Tomographic (CT) velocity imaging method is used. The CT velocity method accurately and precisely defines the size, shape, severity, depth, and location of potential defects by determining the spatial velocity distribution of shaft concrete through analysis of numerous soundwave raypaths. Although the CT process is currently slower than CSL, its two-dimensional (2D) and three-dimensional (3D) imaging results go unmatched for engineering accuracy, interpretation simplicity, and visual appeal. CSL and CT results are presented for sound and defective drilled shafts tested in research projects and real-world consulting. The methods have been successfully applied in both arenas to locate unknown and pre-existing test defects. Meaningful and valid CSL and CT data analyses and interpretation require sufficient knowledge in the history of the concrete placement, local site parameters, material properties of concrete, and the physics of the test. The CSL method has been recently standardized by the American Society of Testing and Materials (ASTM) and is described in Standard No. D 6760. When used by an experienced professional, the CSL and CT methods are an excellent tool for determining shaft integrity and finding potential areas of concern. Further, they eliminate the questions and concerns associated with a problematic concrete pour.
Crosshole Sonic Logging and velocity tomography imaging of drilled shaft foundations
Akustische Querbohrungserfassung und Schallgeschwindigkeits-Tomographieabbildung für die Bohrlocherstellung
Hollema, D.A. (Autor:in) / Olson, L.D. (Autor:in)
2003
9 Seiten, 10 Bilder, 2 Quellen
(Nicht paginiert)
Aufsatz (Konferenz)
Datenträger
Englisch
| British Library Conference Proceedings | 2001
Crosshole Sonic Logging of South Carolina Drilled Shafts: A Five Year Summary
| British Library Conference Proceedings | 2007