scholarly journals Evaluation of Unknown Foundations of Bridges Subjected to Scour

2014 ◽  
Vol 2433 (1) ◽  
pp. 27-38 ◽  
Author(s):  
Negin Yousefpour ◽  
Zenon Medina-Cetina ◽  
Jean-Louis Briaud
Keyword(s):  
Unknown Foundations

Evaluation of Unknown Foundations Using Surface-Based Full Waveform Tomography

2016 ◽  
Vol 21 (5) ◽  
pp. 04016013 ◽  
Author(s):  
Trung Dung Nguyen ◽  
Khiem T. Tran ◽  
Michael McVay
Keyword(s):  
Full Waveform ◽  
Waveform Tomography ◽  
Unknown Foundations

scholarly journals Probabilistic Evaluation of Unknown Foundations for Scour Susceptible Bridges

2020 ◽  
Vol 25 (10) ◽  
pp. 04020074
Author(s):  
Zenon Medina-Cetina ◽  
Negin Yousefpour ◽  
Jean-Louis Briaud
Keyword(s):  
Probabilistic Evaluation ◽  
Unknown Foundations

scholarly journals Field Evaluation of Load Bearing Capacity and Embedment Depth of Existing Ballastless Plate Girder Bridge Foundations

2021 ◽  
Vol 21 (1) ◽  
pp. 225-230
Author(s):  
Hyeonwoo Yoo ◽  
Jeongho Oh ◽  
Sinwhan Ahn
Keyword(s):  
Bearing Capacity ◽  
Embedment Depth ◽  
Penetration Test ◽  
Bridge Foundations ◽  
Load Bearing Capacity ◽  
Load Bearing ◽  
Girder Bridge ◽  
Unknown Foundations ◽  
Unknown Foundation ◽  
Plate Girder

The ballastless plate girder bridge, classified as a structure type that requires an emergent replacement among domestic railway bridges, generally tends to upgrade to a ballasted track along with continuous welded rail (CWR). The axial forces of the CWR due to the temperature change need to be distributed to the bridge foundations. Because most of the existing ballastless plate girder bridges of over 50 years of age do not provide any design information, such bridge foundations are regarded as unknown foundations, and therefore, it is crucial to identify the structural adequacy and dimension. In this study, an effort was made to establish a correlation between the standard penetration test (SPT) and mid-size pneumatic cone penetration test (MPCP) to estimate the load bearing capacity of an unknown foundation. A field test was conducted to estimate the depth of the unknown foundation by employing SPT and MPCP as the source wave part. The magnitude of the shear wave was mitigated by the presence of PVC and steel pipes, such that it might be possible to identify the embedment depth of unknown foundations.

Evaluation of Unknown Bridge Foundations Using Borehole-based Nondestructive Testing Methods: A Case Study in Urban Settings

2019 ◽  
Vol 24 (2) ◽  
pp. 299-315
Author(s):  
Joseph Thomas Coe ◽  
Behnoud Kermani ◽  
Jonathan Nyquist
Keyword(s):  
Nondestructive Testing ◽  
Primary Objective ◽  
Direct Access ◽  
Bridge Foundations ◽  
Urban Settings ◽  
Borehole Radar ◽  
Minimum Estimate ◽  
Long Term Performance ◽  
Term Performance ◽  
Unknown Foundations

There are a significant number of bridges for which information regarding the foundation is missing or incomplete. It is extremely challenging to evaluate the performance of such unknown foundation bridges (UFB), particularly against scour or when their foundations are reused. For critical UFB, it is often necessary to estimate performance by developing an appropriate working model of subsurface foundation conditions. Typically, nondestructive testing (NDT) has served as the most viable alternative due to the costs and risk associated with excavation, coring, and probing. NDT can be quite difficult to perform and their results can contain significant uncertainty in highly urban settings. The primary objective of this study was therefore to compare performance of borehole NDT methods when evaluating the depth of two in-service unknown foundations (concrete-filled steel pipe piles and H-piles) in highly urban settings. The borehole magnetic, parallel seismic, borehole sonic, and borehole radar methods were implemented to determine the foundation bottom locations. Though uncertainty was present in all measurements, the borehole magnetometer and radar results proved the most conclusive. Parallel seismic testing did not yield any evidence of foundations due to issues with background noise and lack of direct access to the foundation. Likewise, borehole sonic testing was generally inconclusive due to issues with sensor directivity and attenuation. Borehole magnetometer estimated the depth to the foundation bottom as 8.6 m and 9.2 m at the two sites. Borehole radar estimates for the depth to foundation bottom compared favorably at 9.8 m and 8.0 m for the two sites. Given the borehole construction and depth to competent rock at the sites, these results for borehole magnetometer and radar were likely a minimum estimate for the location of the foundation bottoms. Such information can help evaluate long-term performance of this system as part of rehabilitation and reuse efforts.

Risk-Based Design of Bridge Scour Countermeasures

2000 ◽  
Vol 1696 (1) ◽  
pp. 229-235 ◽  
Author(s):  
David R. Pearson ◽  
J. Sterling Jones ◽  
Stuart M. Stein
Keyword(s):  
Probability Of Failure ◽  
Limited Resources ◽  
Recent Experience ◽  
Optimum Level ◽  
Bridge Scour ◽  
Decision Tool ◽  
Loss Of Life ◽  
Lost Time ◽  
National Bridge Inventory ◽  
Unknown Foundations

HYRISK was originally developed to prioritize bridges with unknown foundations to determine where to spend limited resources to investigate those bridges. It was later modified to prioritize bridges of any type for scour evaluations where there are limited resources for the evaluations each year. The model is based on information that can be read from the National Bridge Inventory and accounts for average daily traffic, detour lengths, value of lost time, risks associated with scour at various types of foundations, bridge condition, bridge geometry, and bridge age. The model can readily be modified for use as a decision tool to select various levels of countermeasures for a bridge that has already been evaluate and determined to be scour critical for some probability flood event. For that application, the model can use the determined probability of failure and does not need to rely on the assumed risks for various foundation types. The model will need to account for the risk of loss of life on the basis of recent experience. The bridge owner will provide information on the expected life of the bridge and the costs of various levels of protection. The model will determine the optimum level of protection for the bridge and the maximum expenditures that should be accepted to increase the level of protection.

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