scholarly journals Bridge Deck Load Testing Using Sensors and Optical Survey Equipment

2012 ◽  
Vol 2012 ◽  
pp. 1-11 ◽  
Author(s):  
Hubo Cai ◽  
Osama Abudayyeh ◽  
Ikhlas Abdel-Qader ◽  
Upul Attanayake ◽  
Joseph Barbera ◽  
...  
Keyword(s):  
Sensor Network ◽  
Structural Integrity ◽  
Structural Response ◽  
Lessons Learned ◽  
Load Test ◽  
Load Testing ◽  
Deck Panels ◽  
Test Study ◽  
Deflection Analysis

Bridges are under various loads and environmental impacts that cause them to lose their structural integrity. A significant number of bridges in US are either structurally deficient or functionally obsolete, requiring immediate attention. Nondestructive load testing is an effective approach to measure the structural response of a bridge under various loading conditions and to determine its structural integrity. This paper presents a load-test study that evaluated the response of a prefabricated bridge with full-depth precast deck panels in Michigan. This load-test program integrates optical surveying systems, a sensor network embedded in bridge decks, and surface deflection analysis. Its major contribution lies in the exploration of an embedded sensor network that was installed initially for long-term bridge monitoring in bridge load testing. Among a number of lessons learned, it is concluded that embedded sensor network has a great potential of providing an efficient and accurate approach for obtaining real-time equivalent static stresses under varying loading scenarios.

scholarly journals Stop Criteria for Proof Load Tests Verified with Field and Laboratory Testing of the Ruytenschildt Bridge

2018 ◽  
Author(s):  
Eva O.L. Lantsoght ◽  
Yuguang Yang ◽  
Ane de Boer
Keyword(s):  
Laboratory Testing ◽  
Laboratory Tests ◽  
Structural Response ◽  
Bending Moment ◽  
Field Testing ◽  
Load Test ◽  
Load Testing ◽  
Load Tests ◽  
Small Change ◽  
Plain Bars

As the existing bridge stock is aging, improved assessment methods such as proof load testing become increasingly important. Proof load testing involves large loads, and as such the risk for the structure and personnel can be significant. To capture the structural response, extensive measurements are applied to proof load tests. Stop criteria, based on the measured quantities, are used to identify when further loading in a proof load test is not permitted. For proof load testing of buildings, stop criteria are available in existing codes. For bridges, recently stop criteria based on laboratory tests on beams reinforced with plain bars have been proposed. Subsequently, improved stop criteria were developed based on theoretical considerations for bending moment and shear. The stop criteria from the codes and the proposed stop criteria are compared to the results from field testing to collapse on the Ruytenschildt Bridge, and to the results from laboratory tests on beams sawn from the Ruytenschildt Bridge. This comparison shows that only a small change to the stop criteria derived from laboratory testing is necessary. The experimental evidence strengthens the recommendation for using the proposed stop criteria in proof load tests on bridges for bending moment, whereas further testing to confirm the stop criteria for shear is necessary.

A New Riser Fatigue Monitoring Methodology Based on Measured Accelerations

2014 ◽  
Author(s):  
Michael Long Ge ◽  
Jomon Kannala ◽  
Songcheng Li ◽  
Himanshu Maheshwari ◽  
Mike Campbell
Keyword(s):  
Fatigue Damage ◽  
Structural Integrity ◽  
Structural Response ◽  
Wave Loading ◽  
Offshore Drilling ◽  
Element Analysis ◽  
Direct Wave ◽  
Acceleration Data ◽  
Fatigue Monitoring

In support of its commitment to safe and reliable operations, BP has been continuously developing a program to assess and maintain structural integrity for offshore drilling risers and conductors. This paper presents recent efforts by BP, in conjunction with 2H Offshore, to develop a new fatigue monitoring methodology for drilling riser systems due to both wave and vortex-induced-vibration (VIV) damage. BP has been monitoring structural response, including the fatigue damage, of riser systems in the Gulf of Mexico over the past ten years. To date, the focus has predominantly been on determining the fatigue damage due to VIV, since VIV and its effects on structural response are considered a not well-understood phenomenon. In addition to VIV fatigue, direct wave loading and vessel motions also contribute to the total fatigue damage, and sometimes wave fatigue may have a larger contribution than VIV fatigue damage. Therefore, it is necessary to determine fatigue due to both wave and VIV effects to confirm the long-term fatigue integrity of the drilling risers. To take full advantage of the accumulated monitoring data, a new fatigue monitoring methodology was developed using an analytical solution to account for the damage due to both wave and VIV effects. With this method, the measured acceleration data are converted into curvature, and then fatigue damage along the length of riser and conductor are calculated. This new methodology has been validated with both finite element analysis (FEA) and field data, and sensitivities to various parameters have been considered.

Behavioral load testing of the Disraeli facility

1987 ◽  
Vol 14 (1) ◽  
pp. 103-110
Author(s):  
W. J. McCulloch ◽  
C. Militano ◽  
S. Rizkalla
Keyword(s):  
Structural Response ◽  
Load Test ◽  
Red River ◽  
Load Testing ◽  
Testing Procedures ◽  
Gross Vehicle Weight ◽  
Bridge Crossing ◽  
Predicted Values ◽  
Girder Bridge ◽  
Plate Girder

The Disraeli facility, which was completed in 1960, consists of several overpasses utilizing rolled steel beam construction and a riveted steel plate girder bridge crossing the Red River in Winnipeg, Manitoba. The total length of the facility is approximately 707 m (2320 ft). In 1984, the City of Winnipeg commissioned Reid Crowther and Partners Limited to perform a load test on the facility to ascertain the possibility of increasing the maximum gross vehicle weight limit. The tests were performed on three consecutive Sundays, from September 23 to October 7, 1984.Three spans were tested. One normal and one skewed span were selected for the overpasses to study possible differences in their behavior along the exterior span of a three-span continuous riveted plate girder bridge over the Red River. The test was designed to determine the structural response of the bridges at different load levels, to determine the load distribution characteristics, and to investigate dynamic impact values for the test vehicles.This paper describes the instrumentation layout, data acquisition system, test vehicles, and testing procedures. Test results and comparisons with the predicted values utilizing conventional analysis are included.

scholarly journals 3D PRINTING OF FOAMED CONCRETE

2020 ◽  
pp. 7-8
Author(s):  
RABAB ALLOUZI ◽  
AMER ALKLOUB
Keyword(s):  
3D Printing ◽  
Structural Integrity ◽  
Structural Response ◽  
Housing Crisis ◽  
Short Term ◽  
Acoustic Characteristics ◽  
Concrete Material ◽  
Foamed Concrete ◽  
Sufficient Strength

This paper discusses the needs for 3D printing in comparison to conventional construction and proposes foamed concrete material for printing. Example of 3D printing projects under study to overcome housing crisis are presented. Stability and sufficient strength and structural integrity are the main parameters to look for when looking of printable material. The details of these parameters are explained in this paper. Foamed concrete exhibits enhanced mechanical, thermal and acoustic characteristics. Such properties seem to be a suitable alternate choice to fit evolving properties required in the housing industry. Structural response of foamed concrete is still new including mechanical properties, flexural strength, shear strength, short-term and long-term deflections and are still under study by authors.

REHABILITATION AND LOAD TESTING OF A BRIDGE

2016 ◽  
Vol 3 (1) ◽  
Author(s):  
Kawan G. Alani ◽  
Abdullah S. Ahmed
Keyword(s):  
Crude Oil ◽  
Structural Integrity ◽  
Load Test ◽  
Oil Fields ◽  
Load Testing ◽  
Test Results ◽  
Repair Work ◽  
Tigris River ◽  
The Impact ◽  
Good Agreement

Al-Fatha Bridge is constructed on Tigris River at Baiji town, about 220 km north of Baghdad. Beside its main purpose of connecting the main highway west of Tigris River with the Kirkuk city, its deck structure is purposely designed to carry pipes conveying crude oil from Kirkuk oil fields to Baiji refinery and to the oil exporting network of the country. During the war on Iraq in spring 2003, the bridge was subjected to an air strike. In addition to the damages caused by the impact and explosion of the munitions, the great fire of the crude oil erupted and lasted several days caused much heavier damages in different parts of the structure. The parts of the bridge damaged beyond repair, were replaced, while the parts which were found to have sufficient structural integrity were repaired. This paper addresses the repair and testing of the most affected span exposed to fire. The efficiency of the repair work had been evaluated by carrying out a load test on the above mentioned span. The deflection at different stages of loading were recorded at specified points and compared with theoretical results. Good agreement was obtained between the theoretical and measured deflections, which prove the adequacy of the repair work. This paper introduces briefly an assessment of damages of the bridge, the rehabilitation work, analysis and load test results.

Maximizing Outcomes in Group Treatment of Aphasia: Lessons Learned From a Community-Based Center

2014 ◽  
Vol 24 (3) ◽  
pp. 100-105 ◽  
Author(s):  
Darlene Williamson
Keyword(s):  
Group Treatment ◽  
Treatment Protocol ◽  
Lessons Learned ◽  
Group Program ◽  
Community Based ◽  
Multiple Treatment ◽  
Use Of Technology ◽  
Communication Impairments ◽  
Treatment Settings

Given the potential of long term intervention to positively influence speech/language and psychosocial domains, a treatment protocol was developed at the Stroke Comeback Center which addresses communication impairments arising from chronic aphasia. This article presents the details of this program including the group purposes and principles, the use of technology in groups, and the applicability of a group program across multiple treatment settings.

Periodic monitoring of vampire bats and rabies: a new framework for animal restoration projects in the Neotropics

2020 ◽  
Author(s):  
Fernando Gonçalves ◽  
Daniel G. Streicker ◽  
Mauro Galetti
Keyword(s):  
Disease Transmission ◽  
Lessons Learned ◽  
Multidisciplinary Teams ◽  
Risk Area ◽  
Food Web Structure ◽  
Land Bridge ◽  
High Risk Area ◽  
Restoration Project ◽  
Vampire Bats

Nowadays, restoration project might lead to increased public engagement and enthusiasm for biodiversity and is receiving increased media attention in major newspapers, TED talks and the scientific literature. However, empirical research on restoration project is rare, fragmented, and geographically biased and long-term studies that monitor indirect and unexpected effects are needed to support future management decisions especially in the Neotropical area. Changes in animal population dynamics and community composition following species (re)introduction may have unanticipated consequences for a variety of downstream ecosystem processes, including food web structure, predator-prey systems and infectious disease transmission. Recently, an unprecedented study in Brazil showed changes in vampire bat feeding following a rewilding project and further transformed the land-bridge island into a high-risk area for rabies transmission. Due the lessons learned from ongoing project, we present a novel approach on how to anticipate, monitor, and mitigate the vampire bats and rabies in rewilding projects. We pinpoint a series of precautions and the need for long-term monitoring of vampire bats and rabies responses to rewilding projects and highlighted the importance of multidisciplinary teams of scientist and managers focusing on prevention educational program of rabies risk transmitted by bats. In addition, monitoring the relative abundance of vampire bats, considering reproductive control by sterilization and oral vaccines that autonomously transfer among bats would reduce the probability, size and duration of rabies outbreaks. The rewilding assessment framework presented here responds to calls to better integrate the science and practice of rewilding and also could be used for long-term studying of bat-transmitted pathogen in the Neotropical area as the region is considered a geographic hotspots of “missing bat zoonoses”.

Individual differences in white and grey matter structure associated with verbal habits of thought

2019 ◽  
Author(s):  
Justin C. Hayes ◽  
Katherine L Alfred ◽  
Rachel Pizzie ◽  
Joshua S. Cetron ◽  
David J. M. Kraemer
Keyword(s):  
Individual Differences ◽  
White Matter ◽  
Cognitive Processing ◽  
Grey Matter ◽  
Structural Changes ◽  
Structural Integrity ◽  
Diffusion Tensor ◽  
Self Report ◽  
White Matter Tracts

Modality specific encoding habits account for a significant portion of individual differences reflected in functional activation during cognitive processing. Yet, little is known about how these habits of thought influence long-term structural changes in the brain. Traditionally, habits of thought have been assessed using self-report questionnaires such as the visualizer-verbalizer questionnaire. Here, rather than relying on subjective reports, we measured habits of thought using a novel behavioral task assessing attentional biases toward picture and word stimuli. Hypothesizing that verbal habits of thought are reflected in the structural integrity of white matter tracts and cortical regions of interest, we used diffusion tensor imaging and volumetric analyses to assess this prediction. Using a whole-brain approach, we show that word bias is associated with increased volume in several bilateral language regions, in both white and grey matter parcels. Additionally, connectivity within white matter tracts within an a priori speech production network increased as a function of word bias. These results demonstrate long-term structural and morphological differences associated with verbal habits of thought.

Long-term Piloting Of Osmotic MBR For Potable Reuse: Performance, Life-Cycle Assessment, and Lessons Learned

2016 ◽  
Vol 2016 (14) ◽  
pp. 830-854
Author(s):  
Tzahi Y Cath ◽  
Ryan W Holloway ◽  
Leslie Miller-Robbie ◽  
Mehul Patel ◽  
Jennifer R Stokes ◽  
...  
Keyword(s):  
Life Cycle Assessment ◽  
Life Cycle ◽  
Lessons Learned ◽  
Potable Reuse

Comparison of the Bidirectional Load Test with the Top-Down Load Test

2005 ◽  
Vol 1936 (1) ◽  
pp. 108-116 ◽  
Author(s):  
Oh Sung Kwon ◽  
Yongkyu Choi ◽  
Ohkyun Kwon ◽  
Myoung Mo Kim
Keyword(s):  
Load Transfer ◽  
Measurement Data ◽  
Load Test ◽  
Load Testing ◽  
Pile Head ◽  
Top Down ◽  
Simple Method ◽  
Testing Method ◽  
Settlement Behavior ◽  
Cell Test

For the past decade, the Osterberg testing method (O-cell test) has been proved advantageous over the conventional pile load testing method in many aspects. However, because the O-cell test uses a loading mechanism entirely different from that of the conventional pile loading testing method, many investigators and practicing engineers have been concerned that the O-cell test would give inaccurate results, especially about the pile head settlement behavior. Therefore, a bidirectional load test using the Osterberg method and the conventional top-down load test were executed on 1.5-m diameter cast-in-place concrete piles at the same time and site. Strain gauges were placed on the piles. The two tests gave similar load transfer curves at various depth of piles. However, the top-down equivalent curve constructed from the bidirectional load test results predicted the pile head settlement under the pile design load to be approximately one half of that predicted by the conventional top-down load test. To improve the prediction accuracy of the top-down equivalent curve, a simple method that accounts for the pile compression was proposed. It was also shown that the strain gauge measurement data from the bidirectional load test could reproduce almost the same top-down curve.

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