An investigation of correlation factors linking footing resistance on sand with cone penetration test results

Hester

Journal of Sound and Vibration

et al. 2013

113

Publication informationJournal of Sound and Vibration, 332 (25): 6685-6702Publisher Elsevier Item record/more information http://hdl.handle.net/10197/6581 Publisher's statementThis is the author's version of a work that was accepted for publication in Journal of Sound and Vibration. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Journal of Sound and Vibration (VOL 332, ISSUE 25, (2013) AbstractScour around bridge foundations is one of the leading causes of bridge failure. Up until recently, the monitoring of this phenomenon was primarily based around using underwater instrumentation to monitor the progression of scour holes as they develop around foundation systems. Vibration-based damage detection techniques have been used to detect damage in bridge beams. The application of these vibration based methods to the detection of scour has come to the fore in research in recent years. This paper examines the effect that scour has on the frequency response of a driven pile foundation system, similar to those used to support road and rail bridges. The effect of scour on the vibration characteristics of the pile is examined using laboratory and field testing. It is clear that there is a very clear reduction in the natural frequency of the pile as the severity of scour increases. It is shown that by combining state-of-the-art geotechnical techniques with relatively simple finite element modelling approaches, it is possible to accurately predict the natural frequency of the pile for a given scour depth. Therefore, the paper proposes a method that would allow the estimation of scour depth for a given observed pile frequency. Scour Monitoring: The accurate assessment and monitoring of existing structures to progressive scour has come to the fore of research in recent years [7,8]. A myriad of current technology aims to detect the existence and severity of scour around the foundation systems of existing bridge structures. Most of these technologies comprise underwater instrumentation that aim to monitor the evolution of scour holes over time. A brief summary of available instrumentation is given herein. The use of float-out devices [9] and Tethered Buried Switches [10] positioned in the soil near a bridge pier can provide a simple method of scour monitoring. These devices float out when the scour depth reaches their position and are programmed to send a remote signal to provide a warning. However, they require reinstallation upon floating out, which is a distinct disadvantage. Time Domain Reflectometry (TDR) aims to detect changes in the dielectric permittivity constants between materials that would occur at a water-sediment interface and thus has been used to detect scour [10 -12]. Devices using this method work very well at detecting the depth of scour i...

show abstract

Section: Field Testmentioning

confidence: 99%

An investigation of the changes in the natural frequency of a pile affected by scour

Hester

Journal of Sound and Vibration

et al. 2013

113

show abstract

“…The field investigation was undertaken at the University College Dublin (UCD) dense sand test bed located near Blessington, southwest of Dublin, Ireland. This test site has been developed over the past eleven years and has been used for a number of model, prototype and full scale foundation experiments [32][33][34][35]. A full description of the geotechnical properties of the site can be obtained in [5,32,36].…”

Section: Dynamic Responsementioning

confidence: 99%

A comparison of initial stiffness formulations for small-strain soil–pile dynamic Winkler modelling

Soil Dynamics and Earthquake Engineering

2016

“…The test quarry has been characterised in detail [45] and used to investigate the performance of a number of model, prototype and full scale foundation concepts over the last number of years [46][47][48][49]. A full description of the geotechnical properties of the site can be obtained in Refs.…”

Section: Experimental Pile Testsmentioning

confidence: 99%

Experimental application of FRF-based model updating approach to estimate soil mass and stiffness mobilised under pile impact tests

Soil Dynamics and Earthquake Engineering

2019