bluuebunny/crossref_metadata_2025 huggingface dataset:
Fatigue of Threaded Rods in Cable Anchorages due to Vortex Shedding
Authors: Snijder Bert , Maljaars Johan
Published: November 2013

The ‘Hovenring’ is a bicycle roundabout flyover built as a signature bridge with a central steel pylon carrying a circular bridge deck suspended through stay-cables. Shortly after installation of the bridge, the stay-cables turned out to vibrate in the wind due to vortex shedding. These vibrations have possibly caused fatigue damage in the threaded rods of the cable anchorages. Therefore, fatigue assessments were made using both traditional S-N-curves (Wöhler curves) in combination with the Palmgren-Miner damage accumulation rule as well as fracture mechanics analyses using crack growth data. The design fatigue life of the threaded rods appeared to be extremely short and therefore it was decided to replace them. This paper shows that it is a dangerous design procedure to deliberately not consider vortex shedding and possible fatigue damage in the design stage and to take measures against vortex shedding only after completion of a bridge structure.
Equilibrium Equation for Spatial Frame Structure Constructed in Stages and Its Applications
Authors: Qin Shunquan
Published: November 2013

For a spatial frame structure constructed in stages, the unstressed state of an element is defined as its initial geometric shape with zero internal stress. Using energy method, a new equilibrium equation for spatial frame structure constructed in stages is established. In this paper, a simple spatial truss is used as an example to illustrate the application of this new equilibrium equation.

Calculation demonstrates that the final member forces and structural displacements can be uniquely determined for a structure constructed in stages with any given structure type, loading and boundary conditions and without knowing the actual construction processes and methods, as long as the unstressed state of all structure modules or components remain unchanged. And the final internal forces and structural displacements are irrelevant to construction processes.
Reliability-based design of long-span bridges – Wind load combination
Authors: Yoo Chul-Hwan , Kim Ho-Kyung
Published: November 2013

This research introduces the process of determining the reliability-based wind load factor. Limit state is focused on strength limit of pylon along with in-plane moment. Reliability analysis is performed based on the probability model of wind load which is composed of analysis factor, pressure coefficient, exposure coefficient, gust factor and wind speed and the probability model of moment resistance of pylon. Target reliability indices are determined based on the moment resistance of real bridges and the minimum required resistance obtained from design code. The wind load factor satisfying the limit state is proposed.
Quantification of the Effects of Turbulence in Wind on the Vortex-induced Vibrations
Authors: Abbas Tajammal , Morgenthal Guido
Published: November 2013

Vortex-induced Vibrations (VIV) of structures may be influenced by the turbulence inherent in the wind. Generally, turbulence is believed to decrease the VIV amplitudes. For a rational design, it important to consider the influence that turbulence has on the VIV phenomenon. This study aims at developing a method for quantifying the effects of turbulence on VIV. Numerical simulations are performed and an approach to generate turbulence by placing geometrical shapes in the flow is used. This is analogous to well accepted laboratory wind tunnel approaches. The generated turbulent flow is studied and the properties of the flow are quantified. An example is presented for the case of a circular cylinder considering different flow situations. The study shows that there is a distinct difference in the resulting vortex shedding behaviour between uniform and turbulent flow. The merits and limitations of the approach are also discussed.
Minimum Wind Design Considerations for Long Span Bridges – Case Studies
Authors: Kumar K. Suresh , Stoyanoff Stoyan , Dallaire Pierre-Olivier
Published: November 2013

Bridges are susceptible to wind-induced vibrations, especially when their span is long and with bluff deck sections. Even when the earthquake loading governs the design of a particular bridge, its vulnerability to wind has to be checked for aerodynamic stability confirmation. Wind tunnel tests have been often used for the wind engineering design of bridges. For preliminary studies, computational and analytical simulations are also performed at times. Regardless of the span or complexity of the bridge under consideration, certain studies need to be performed as a minimum to evaluate the wind effects on bridges. This paper focuses on the minimum design considerations for assessing the wind effects on long-span bridges.
Construction Planning for India's first "Signature Bridge"
Authors: Jatkar Mohan V. , Navalkar Swapnil A.
Published: November 2013

“Signature Bridge”, with an unsymmetrical steel pylon 154m high, tallest so far, is one of the most elegant and state of the art bridge presently being built in capital city of New Delhi, India.

Once completed, the Signature Bridge will be the new landmark of New Delhi. It crosses the river Yamuna at Wazirabad dramatically improving signal free approach from NH-1 (Road No. 50) on western bank and Wazirabad Road (Road No. 59 Khajuri Khas intersection) on the Eastern bank for entry and exit of traffic in two directions.

This paper focuses on challenges faced during construction planning and logistics It describes the development of the construction procedures and methodologies, through various engineering solutions evolved through elaborate planning.
Sustainability Through Innovation in Design and Construction – Second Penang Bridge, Malaysia
Authors: Mohamed Taib Ismail bin , Nandy Sajal
Published: November 2013

Jambatan Kedua Pvt. Ltd. (JKSB), a wholly-owned company of the Malaysia Ministry of Finance, Incorporated (MoF Inc.) is the concessionaire for the Second Penang Bridge Project (PB2X). The bridge with estimated cost of RM4,5 billion is set to be the longest in South-East Asia with a total length of 16,9 km over water. The construction of the Second Penang Bridge commenced in November, 2008 and currently is at 91,4% progress (as on February 2013) and to be completed by September 2013. It has faced various challenges in applying sustainability to both design and construction. The Second Penang Bridge is pioneering in Malaysia to be fully designed for seismic load for a 475 year return period earthquake and a 2500 year return period earthquake with ‘no collapse’ criteria. This paper will further discuss on the project management, the fast-track concept and innovation in the implementation of a sustainable bridge design and construction.
Role of Wind Tunnels in Assessing Wind Effects on Long Span Roofs
Authors: Kumar K. Suresh , Kumar B. Venu , Cini C.
Published: November 2013

Similar to bridges, long span roofs of stadium/airports/arena are susceptible to wind-induced vibrations. Though expected mean wind speed at such low heights is not significant, associated turbulence fluctuations will be higher at low heights. Further, any complex roof geometry can alter the wind effects considerably and the prediction of such effects may require a model scale study in the wind tunnel. The role of wind tunnels in assessing the wind effects on long span roofs is described in this paper with the help of few case studies.
Powerful plastic materials allow new structural glass roofs
Authors: Weller Bernhard , Ebert Jan , Reich Stefan
Published: November 2013

The Technische Universität Dresden, Germany was decisively involved in the development of a glazed roof structure. Especially the activation of the in-plane load transfer – a structurally membrane behaviour – of the all-glass roof was main objective of the research. After the realisation of a few prototypes and a finished project within the last years, the research focus changed to the load application of in-plane forces into the glass edge. A powerful material for the load application into the glass edge is the necessary condition for the construction of membrane glass roofs. This contribution comprehensively describes relevant contact materials for glass constructions. The broad range of plastics is investigated on their ability to transfer large compressive stresses into the glass edge. The visco-elastic material behaviour under compressive stress is described by testing data and spring-damper-elements. Long term testing of the plastics under compression deliver relevant information about the material behaviour in glass roofs over the structural lifetime. Cyclic testing allows determining the percentage of elastic, the visco-elastic and the viscous strain. By means of appropriate solid plastics the construction of an absolutely new glass roof with membrane structural behaviour was realised and demonstrates the practical relevance of the presented research.
Design Features of Roof of Weightlifting Stadium
Authors: Ray Soumya , Basu Arindam , Roy B. C.
Published: November 2013

The XIX Commonwealth Games initiated construction of several new stadiums. The basic feature of these stadiums was to provide large column free spaces, typically with long span steel roof. The paper describes the Weightlifting stadium in the Jawaharlal Nehru Stadium Complex. Weightlifting stadium, which for legacy use was planned as an auditorium, that too needed a column free space accommodating 2,500 people. The paper deals with the salient aspects of design of long span steel structures for the facility.
Great roof marquee in the new railway station for high speed trains of Málaga
Authors: Jurado Carlos
Published: November 2013

The commercial centre VIALIA and the new railway station of the AVE (high speed Spanish trains) in Malaga were inaugurated in November 2006, just on the place of the former railway station. The new railway station with an investment of 134.7 million Euros occupies a surface of 51,377 m2, five times the surface of the former station. The enclosure is the biggest intermodal and commercial centre of Spain which comprises a parking of 21,000 m2 for 1,300 parking places, one commercial area and a hotel with seven floors, with a total constructed extension of approximately 100,000 m2. The spaces of leisure contain cinemas, shops, restaurants, bowling, gymnasium, swimming pool and zones of passenger’s traffic.
New Phra Nang Klao Bridge
Authors: Imsom-Somboon Sayan , Chanintonleela Monkiat , Vanachayangkul Panit , Yindeesuk Sukit
Published: November 2013

New Phra Nang Klao Bridge is located in Nonthaburi province of Thailand and was constructed adjacent to the existing bridge. The bridge, carrying six traffic lanes crossing the Chao Phraya River, is recognized as the prestressed concrete box girder bridge with the longest main span in Thailand. The main span of 229 meters is constructed by balanced cantilever method. Due to the geometric constraint, the alignment needs to be horizontally curved toward the upstream of the existing bridge. Thus, this introduces high torsion in the box girder superstructure and transverse bending in the piers. If a symmetrical pile arrangement is adopted, the downstream piles will sustain considerably larger axial compression forces than the upstream piles. To overcome this issue, an analysis by finite element method (FEM) was performed and showed that the unsymmetrical pile arrangement, which corresponds to the torsion direction in the box girder, will result in a rather uniform axial load distribution on piles both during the construction and after the bridge was completely constructed. The unsymmetrical pile arrangement was proved to be effective and can reduce the size of foundation and the number of piles. The analysis also indicated using double-wall piers instead of single stocky column can decrease the magnitude of axial loads in the piles due to its lower flexural stiffness.
Integral Construction for Elevated Road over Barapullah Nalla from Sarai Kale Khan to Jawahar Lal Nehru Stadium
Authors: Tandon Mahesh , Srivastava Sarvagya , Srivastava Ashish
Published: November 2013

For Commonwealth Games-2010 held in Delhi, Barapulla Elevated road was conceived as an arterial route to provide seamless connectivity from games village to Venue. This project was completed within very tight time constraint. The construction involved integral structures at entry to the entry road as well as major road/railway crossings. Present paper details the various aspects of the project including the design innovations which resulted in construction to be completed within time.
Study of the Strengthened Hybrid Structure Renovated from Railway Steel Bridge
Authors: Taniguchi Nozomu , Hansaka Masanori , Ohkubo Fujikazu , Satake Shinya , Sugino Yusuke
Published: November 2013

This research offers a new composite revamping method for railway bridges by assuming composite remodelling process of existing steel bridges having no specific fissure damages or serious corrosions and effectively making use of relatively new materials to it. Effects of noise reduction and improved stiffness were further confirmed through hammer impact tests (vibration measurement tests) and loading tests in order to prove the efficacy of the composite remodelling.
Time-domain Aero elastic Analysis of Bridge using a Truncated Fourier Series of the Aerodynamic Transfer Function
Authors: Park Jinwook , Jung Kilje , Kim Ho-Kyung , Lee Hae Sung
Published: November 2013

A truncated Fourier series approximation method for the time-domain aero elastic analysis of bridge is presented. The aerodynamic transfer functions are modified by approximating those using a truncated Fourier series to strongly enforce the causality condition in the impulse response function. The coefficients of truncated Fourier series are determined by minimizing the error between measured and modified transfer function. The impulse response functions corresponding to the modified transfer functions become a series of Dirac delta functions with the same number of the terms used in the Fourier series, which considerably reduces computational effort.
Equivalent Wind Loading of Long-span Arch Bridges
Authors: Yang Yongxin , Ge Yaojun
Published: November 2013

With the consideration of usually bluff cross sections of arch ribs and ever-growing span length, it is necessary to carry out careful investigation on wind loading of long-span arch bridges in order to ensure aerodynamic safety of arch ribs and the whole bridge. However, compared with the main girder, even the static wind load of an arch rib is more complicated for the commonly change of elevation, cross section shape and inclination angle along the axis, while different types of possible wind-induced vibrations make the dynamic wind loading more complicated. Based on engineering practices on long-span arch bridges in China, the analysis of different combinations of equivalent wind loading for different construction stages of arch bridges, including the determination of static wind load for some complicated arch rib structures were investigated and discussed.
Indian railway bridges – adoption of new bearing technology to support the progression towards long span bridges
Authors: Majumdar Santanu , Ghosh Chinmoy , Moor Gianni
Published: November 2013

The Indian railway network has a proud history of rapid expansion to meet the needs of an enormous population across an extensive territory – an expansion which has relied on developing bridge construction technology in traversing ever greater obstacles such as rivers and valleys. An important aspect of modern bridge technology is the bearing which forms the vital link between a bridge’s deck and its supports, facilitating movements and rotations, and resisting loads, as required by the structure’s design. As bridge spans increase, the demands on bearings also increase, requiring constantly improving design and manufacturing capabilities. Fortunately, state-of-the-art bearings of the highest quality are now being manufactured in India, ensuring that the needs of even the most ambitious bridge designs can be met in supporting future network expansion and improvement.
Modal Parameters Identification of Bridge Structure Based on Time-Frequency Domain
Authors: Shan Deshan , Li Qiao , Wu Zhaoxu , Huang Zhen
Published: November 2013

One innovational Hilbert-Huang Transform (HHT) is adopted to identify the modal parameters of one certain model combined cable-stayed suspension bridge. The band pass filtering method and extended random decrement technique are engaged to improve the HHT for identifying modal parameters more accurately, and a software package for the innovational algorithm is compiled on the MATLAB platform to identify the bridge structural modal parameters. The modal parameters of this model bridge are identified from the measured under ambient testing conditions, and the identified modal parameters are compared with the theoretical result of ABAQUS. The validity, practicability and superiority of the proposal method are verified. The results show that the proposed modal parameter identification algorithm can be used in the real bridge engineering to identify the modal parameters.
Experimental Study on PBL Shear Connector Composite Structures
Authors: Li Qiao , Xia Song , Zhao Canhui , Zhang Yuzhi
Published: November 2013

In the composite structures used in steel-concrete connection, the steel structures are embedded in concrete. The behavior of the shear connectors in such structures is different from that in a composite beam. 38 perfobond leisten (PBL) shear connector specimens and 2 anchorage specimens containing PBL shear connector array are designed in 3 successive experimental tests in the laboratory. The test results manifest that PBL shear connectors show a characteristics of concrete when the slip is relatively small whereas, however, seem to be fairly ductile as the bearing capacity is nearly approached. The diameter of inner bar has a greater effect on the bearing capacity of PBL shear connectors than the outer diameter of embraced concrete column does. The first three ranks in a PBL shear connector array can take about 60% of the external load. The shear connectors closer to the loading point will take greater portion of external loads.
Traffic Actions for the Design of Roadway Bridges: A Comparison of International Codes
Authors: Matar Hany B. , Bakhoum Mourad M. , Ishac Ishac I.
Published: November 2013

Highway Bridge Design Codes and Loads from AASHTO LRFD, EUROCODE and Egyptian Codes are considered. Comparisons of action effects due to Traffic Actions (Live Loads) only, and Traffic actions combined with Permanent actions ( Dead Loads) are carried out. Load combinations at ULS & SLS are considered. It is noted that comparing Traffic actions alone, a large difference is observed between codes (about 40%). When combined with Permanent actions (assuming concrete bridges), this difference reduces considerably to about 13%. Comparison of Live Load models in the Codes is not sufficient to give a full comparison of Code requirements. Hence, a brief comparison of resistance of

R.C. sections in flexure and axial forces at ULS is also presented.
Scheme Comparison of Super-Large Span Bridge under the Condition of Limited Building Height
Authors: Gao Yanmei , Zhou Zhixiang
Published: November 2013

Rongjiang super-large bridge is a part of the highway from Chaozhou to Huizhou in Guangdong province which is near to Chaoshan civil airport crossing Rongjiang River. In order to ensure the normal navigation under the bridge and meet the requirements of Airfield Height Control, both the span and the height of the bridge are limited, thus the main span should not be less than 380m while the bridge heights of the pier on the Chaozhou and the other side should respectively not be more than 96.65m and 109m .Due to the double restrictions of span and bridge height, three schemes are considered which include the scheme of steel-concrete composite box girder low-pylon

cable-stayed bridge , self-anchored suspension bridge and prestressed steel truss-concrete composite through continuous rigid frame bridge which is proposed in this paper. Aiming at the prestressed steel truss-concrete composite through continuous rigid frame bridge, the design ideas are described, the general layout and the detailed construction are discussed and the mechanics property analysis

in period of construction and service are also made to demonstrate the feasibility and reasonability of this scheme under given conditions .
Izmit Bay Suspension Bridge
Authors: Christensen Søren Christen
Published: November 2013

This paper describes advantages of incorporating local analysis models in a Global Analysis Model (GAM) as compared to a more traditional design approach. Time History Analyses introduce a problem for detailed local analyses of special structural elements as the influence from the super structure is dynamic time dependent and thus more traditional verification approaches are not feasible.

Incorporating local models in the GAM requires special software capable of handling the complexity of exchanging integral parts of the combined model. The detailed design of the Izmit Bay Suspension Bridge is used as an example, and descriptions are given of the local models prepared during design as well as the used analysis software.
Izmit Bay Suspension Bridge – Overview of the Project
Authors: Kawakami Takeshi , Yanagihara Masahiro , Yamasaki Yasutsugu , Shaura Junichi , Kasuga Tomoo , Cetinkaya Tunc
Published: November 2013

The scale of the bridge and the tight schedule in the EPC contract requires the state of the art and robust design and well proven but challenging construction method leading to the technical and financial success of the project. The papers deals with the project overview and the design development from the tender stage to the detailed design stage for the substructure and the superstructure.
Individual Differences in Reading Development
Authors: Pfost Maximilian , Hattie John , Dörfler Tobias , Artelt Cordula
Published: November 2013

The idea of Matthew effects in reading—the widening achievement gap between good and poor readers—has attracted considerable attention in education research in the past 25 years. Despite the popularity of the topic, however, empirical studies that have analyzed the core assumption of Matthew effects in reading have produced inconsistent results. This review summarizes the empirical findings on the development of early interindividual differences in reading. We did not find strong support for the general validity of a pattern of widening achievement differences or for a pattern of decreasing achievement differences in reading. The inclusion of moderating variables, however, allowed a clearer picture to be painted. Matthew effects were more likely to occur for measures of decoding efficiency, vocabulary, and composite reading scores when the achievement tests were not affected by deficits in measurement precision. Furthermore, moderators such as the applied analytic method or the orthographic consistency of the language were of less importance for the emergence of Matthew effects in reading. An additional meta-analysis of studies reporting correlations between a baseline level and a growth parameter yielded a small, negative mean correlation (r = −.214), which again was moderated by properties of the measures. Possible explanations for the reported findings are discussed.
Statin-Induced Rhabdomyolysis: A Comprehensive Review of Case Reports
Authors: Mendes Polyana , Robles Priscila Games , Mathur Sunita
Published: November 2013

Purpose: To identify case reports of statin-induced rhabdomyolysis and summarize common predisposing factors, symptoms, diagnostic findings, functional outcomes, characteristics, treatment, and rehabilitation. Method: MEDLINE, CINAHL, SCOPUS, and PEDro databases were searched (1990–2013) for relevant case reports using the search terms “Statins,” “Rhabdomyolysis,” “Myalgia,” “Muscle damage,” “Muscle injury,” and “Myopathy.” Relevance (based on title and abstract) was assessed by one investigator; two investigators independently reviewed the relevant articles to determine inclusion in the review. Results: A total of 112 cases met the inclusion criteria. The majority were in men (70%) and people over 45 years of age (mean 64 [SD 14] years). Simvastatin was the most commonly reported statin (n=55); the majority of cases reported the use of concomitant medications such as fibrates (n=25). Weakness (n=65) and muscle pain (n=64) were the most common symptoms. In 19 cases, the patient was referred to rehabilitation, but the case reports do not include descriptions of the treatment. Conclusion: Statin-induced rhabdomyolysis was more commonly reported when statins were used in conjunction with other drugs, which potentiated its effect. Research is needed to identify the role of exercise and rehabilitation following statin-induced rhabdomyoloysis since muscle damage may be severe and may have long-term effects on muscle function.
The Quality of Reports of Randomized Controlled Trials Varies between Subdisciplines of Physiotherapy
Authors: Moseley Anne M. , Elkins Mark R. , Janer-Duncan Lee , Hush Julia M.
Published: November 2013

Purpose: The quality of reports of randomized trials of physiotherapy interventions varies by year of publication, language of publication and whether the intervention being assessed is a type of electrotherapy. Whether it also varies by subdiscipline of physiotherapy has not yet been systematically investigated. The purpose of this study was to determine whether the quality of trial reports varies according to the subdiscipline of physiotherapy being evaluated. Methods: Reports of physiotherapy trials were identified using the Physiotherapy Evidence Database (PEDro). Quality of the trial report was evaluated using the PEDro scale (total PEDro score and 11 individual PEDro scale items). Multiple linear and logistic regressions were used to predict the quality of trial reports, with subdisciplines, time since publication, language of publication, and evaluation of electrotherapy as independent variables in the model. Results: Total PEDro scores are higher when trial reports are more recent; are published in English; investigate electrotherapy; and are in the subdisciplines of musculoskeletal, neurology, cardiopulmonary, gerontology, continence and women's health, orthopaedics, or paediatrics. Trials in the subdisciplines of ergonomics and occupational health, oncology, and sports are associated with lower total PEDro scores. The musculoskeletal subdiscipline had a positive association with six of the PEDro scale items, more than any other subdiscipline. Conclusions: There is scope to improve the quality of the conduct and reporting of randomized trials across all the physiotherapy subdisciplines. This study provides specific information about how each physiotherapy subdiscipline can improve trial quality.
Stroke-Related Knowledge, Beliefs, and Behaviours of Chinese and European Canadians: Implications for Physical Therapists
Authors: Li Zhenyi , Jongbloed Lyn , Dean Elizabeth
Published: November 2013

Purpose: To improve cross-cultural health education on risk-reducing behaviour change by examining the stroke-related knowledge, beliefs, and behaviours of Chinese Canadians (CCs). Methods: Participants (103 first-generation CCs and 101 European Canadians [ECs] representing the dominant cultural group in Canada) completed a cross-sectional questionnaire about knowledge, health behaviours, and beliefs related to stroke. Results: Compared with ECs, CCs were less aware of risk factors, warning signs, and appropriate responses to stroke in others. Information sources about stroke included mass media, family, and friends. CCs were less likely to smoke and drink alcohol but were also less likely to be physically active or to participate in structured exercise, less likely to have a healthy diet, and more likely to report stress. Conclusions: Theoretical dimensions of culture may explain variations in stroke-related knowledge, behaviours, and beliefs between CCs and ECs. Awareness of cultural differences can help physical therapists evaluate clients and appropriately tailor lifestyle-related health education.
The Use of a Trained Dog as a Gait Aid for Clients with Ataxia: A Case Report
Authors: Abbud Gabriela , Janelle Caroline , Vocos Maria
Published: November 2013

Purpose: To illustrate the use of a trained dog as a therapeutic tool to optimize physical and psychosocial adaptation of clients with ataxia. Method: The gait pattern and gait speed of two people with cerebellar ataxia using different gait aids, including a trained intervention dog and an assistance dog, were compared. Participants' experience of working with the dogs was documented via semi-structured interviews. Results: The use of an intervention dog as part of rehabilitation allowed clients to explore the benefits of an assistance dog and to optimize their physical functioning. The assistance dog had a less destabilizing effect than other walking aids on the clients' self-image. Conclusion: Trained dogs may represent an innovative and positive alternative for mobility for people with ataxia, improving both physical and psychosocial parameters. Assistance dogs seem to be a suitable gait aid, since they facilitate ambulation, promoting independent mobility.
Estimation of Time Rate of Settlement for Multilayered Clays Undergoing Radial Drainage
Authors: Farnsworth Clifton B. , Bartlett Steven F. , Lawton Evert C.
Published: November 2013

This paper demonstrates how the finite difference technique can be used to estimate the time rate of settlement for soft, compressible clayey soils treated with prefabricated vertical drains at sites where primary consolidation settlement is occurring in a multilayered system at varying rates. Semiempirical methods based on surface settlement monitoring have typically been used to estimate the progression of primary consolidation settlement. However, interpretation of such methods can be problematic for multilayered soil profiles. For such sites, it is crucial to obtain a reasonable characterization of the foundation soils’ horizontal drainage properties and include these estimates in the time rate of settlement projections. Field monitoring of subsurface instrumentation is extremely valuable in providing additional information about the consolidation behavior of different layers. When subsurface field measurements are coupled with the proposed numerical method, far more reliable projections are obtained. This paper focuses on how to integrate field and laboratory data with projections of time rate of settlement obtained from semiempirical and finite difference methods to predict more accurately the time rate of consolidation behavior of multilayered foundation soils.
Passive Force–Deflection Behavior for 0° and 30° Skewed Abutments
Authors: Marsh Aaron K. , Rollins Kyle M. , Franke Bryan , Smith Jaycee , Palmer Katie
Published: November 2013

Accounting for seismic forces and thermal expansion in bridge design requires an accurate passive force–deflection relationship for the abutment wall. Current design codes make no allowance for skew effects on passive force; however, small-scale experimental results indicate a significant reduction in peak passive force as skew angle increases for plane-strain cases. To explore this issue further, large-scale field tests were conducted at skew angles of 0° and 30° with unconfined backfill geometry. The abutment back wall was 11 ft (3.35 m) wide by 5.5 ft (1.68 m) high, and backfill material consisted of dense, compacted sand. The peak passive force for the 30° skew was found to be 58% of the peak passive force for the 0° skew case, which was in good agreement with the available laboratory and numerical results; however, the small difference between field and available laboratory results suggests that backfill geometry may have some effect on the reduction in peak passive force with respect to skew angle. Longitudinal displacement of the back wall at the peak passive force was found to be between 3% and 5% of the back wall height for field tests of both the 0° and 30° skew, which was consistent with previously reported values for large-scale passive force–deflection tests. For both tests, the failure geometry extended approximately 4 to 5 ft (1.22 to 1.52 m) beyond the edge of the pile cap and 16 to 18 ft (4.88 to 5.49 m) from the face of the cap when measured perpendicular to the back wall.
Pullout Resistance Factors for Inextensible Mechanically Stabilized Earth Reinforcements in Sandy Backfill
Authors: Lawson William D. , Jayawickrama Priyantha W. , Wood Timothy A. , Surles James G.
Published: November 2013

This paper presents results from a laboratory program of 402 pullout tests of inextensible reinforcements used for walls of mechanically stabilized earth (MSE). Results focus on the evaluation of pullout resistance factors for ribbed-steel strip and welded-steel grid reinforcements embedded in sandy backfill that marginally met AASHTO requirements for select granular fill. This project used Texas Tech University's large-scale MSE test box with dimensions of 12 3 12 3 4 ft and an applied overburden capacity of 40 ft of backfill. This test box facilitated pullout testing at a scale not unlike typical field construction. The research design evaluated pullout resistance factors for both ribbed-strip and welded-grid reinforcements for a variety of independent variables, including overburden pressure, reinforcement length, level of compaction, grid wire size, and grid geometry, such as transverse and longitudinal wire spacing. Appropriate statistical analyses were used to interpret the data within the context of published AASHTO design guidance for inextensible MSE reinforcements. The results show that pullout behaviors of both ribbed strips and welded grids in properly compacted sandy backfill are conservative compared with the default pullout resistance factors provided by AASHTO. The data also suggest that the current AASHTO equations for pullout resistance factors for grid reinforcement do not accurately capture the influence of transverse and longitudinal bar spacings.
Probabilistic Framework for Strength Limit and Service Limit Checks of Drilled Shafts considering Soil Spatial Variability
Authors: Fan Haijian , Liang Robert
Published: November 2013

This paper presents a performance-based, probabilistic framework for design of a drilled shaft under axial and lateral loading that can consider spatial variability of soil properties at a project site. The performance criteria of a drilled shaft are stated in relation to the limiting tolerable deformations for strength limit and service limit, respectively. The computational algorithm for calculating the deformation of a drilled shaft is based on the commonly adopted load transfer method and the p-y method. “Geotechnical failure” is defined as an event in which the specified performance criteria are not met. Three failure modes are considered: axial movement, lateral deflection, and angular distortion. The spatial variability of soil properties is considered by using random field modeling techniques in which correlation length is introduced to account for site variability in addition to mean and variance. The method of fitting a sample autocorrelation function to a prescribed correlation function by using the method of ordinary least squares is introduced for determining site-specific correlation length for soil parameters. Geostatistical principles known as kriging are employed to estimate unknown parameters at unsampled locations from neighboring sampled locations. A numerical example is given to illustrate the application of the proposed methodologies. The example demonstrates that correlation length is an important statistical descriptor for characterizing site variability. Performance-based design provides unified consideration for both strength limit and service limit. Finally, the overall probability of failure for a drilled shaft when all three failure modes are considered is greater than the failure probability for any individual failure mode.
Use of Geothermal Deep Foundations for Bridge Deicing
Authors: Xiao Suguang , Suleiman Muhannad T. , Naito Clay J. , Neti Sudhakar
Published: November 2013

Winter deicing practices reduce the longevity of bridge infrastructure and make it difficult to achieve the national goal of a bridge service life of 100 years or more, which was set by SHRP 2. The vast majority of these bridges are supported on deep foundations. The goal of this study was to evaluate the concept of employing geothermal deep foundations (energy piles) to heat the bridge slab and thereby minimize or eliminate the use of deicing salt. This concept had the advantage of using required foundation elements to function also as heat exchangers with the surrounding soil, which approximated a constant temperature below a depth of 1 to 3 m (depending on the region). This paper describes a two-dimensional (2-D) finite element model used to assess the power demands to heat a typical bridge slab. Initially, the 2-D model of a conventional bridge (not incorporating the geothermal system) was validated by using a case study for a bridge in Rhode Island for which the temperature of the bridge slab was monitored for about 1 year. Once validated, the model was extended to include the effects of geothermal deep foundations for weather conditions in Philadelphia, Pennsylvania, as an example. Analyses were conducted to simulate the performance of the geothermal system with and without preheating of the bridge slab before the snow or ice formation event.
Reinforcement Pullout Capacity in Mechanically Stabilized Earth Walls with Marginal-Quality Soils
Authors: Hatami Kianoosh , Granados Jaime E. , Esmaili Danial , Miller Gerald A.
Published: November 2013

Pullout capacity of geotextile reinforcement is an important consideration in the analysis of internal stability of reinforced soil structures, especially those constructed with marginal soils. Precipitation, ground water infiltration, and seasonal variations of water content during the construction process or service life of the structure could result in significant reductions in the matric suction and lead to a reduction in the strength of the soil–geotextile interface. Consequently, the reinforced soil structure may experience unacceptable deformations or even failure during its construction or postconstruction periods. The loss of matric suction in the soil influences both the shear strength of the soil and the soil–reinforcement interface. However, the focus of this study was merely on the latter. Nine pullout tests and 18 interface shear tests were performed to measure the pullout resistance of a reinforcement geotextile in a marginal soil that was compacted at different gravimetric water contents (GWCs). The marginal soil was selected to meet the limiting requirements of the National Concrete Masonry Association guidelines for segmental retaining walls with respect to fines content, gradation, and plasticity. The range of GWC values investigated varied from the dry to the wet side of the optimum moisture content of the soil. The matric suction in the soil was measured to evaluate its influence on the soil–reinforcement interface shear strength. A moisture reduction factor is proposed to account for the reduction in the soil–geotextile interface strength as a result of the loss in matric suction.
Modeling in Situ Performance of Cement-Stabilized Granular Base Layers of Urban Roads
Authors: Soares Roberto , Haichert Rielle , Podborochynski Diana , Berthelot Curtis
Published: November 2013

This study used a three-dimensional nonlinear orthotropic computational road model to measure the performance of reclaimed and recycled portland cement concrete (PCC) aggregates and reclaimed asphalt pavement (RAP) aggregates stabilized with cement as a base layer in a typical local road structure in the city of Saskatoon, Saskatchewan, Canada. The pavement structure was composed of 45-mm hot-mix asphalt concrete on a 225-mm granular base built directly over an in situ subgrade. The cross section was analyzed with a conventional granular base layer as a baseline and PCC and RAP base layers with 2% cement stabilization. The cement-stabilized PCC and RAP base layers showed improved shear strain and horizontal strain behavior when compared with the conventional granular base layer (which was not cement stabilized). This improvement con-firmed that cement stabilization of reclaimed PCC and RAP materials provided an enhanced primary response. This study demonstrated that typical thin Saskatoon pavement structures were highly dependent on the constitutive properties of base layer material. Stabilizing the PCC and RAP base layers with 2% cement reduced the maximum shear strains at the edge of the pavement structure by 12% and 25%, respectively, compared with the unstabilized conventional granular base layer. It was believed that the increased fracture and cohesion of the residual cementitious materials inherent to recycled granular base, as well as the cementitious binder added, improved structural performance.
Food and Eating Environments: In Canadian Schools
Authors: Browning H. Frances , Laxer Rachel E. , Janssen Ian
Published: November 2013

Purpose: This national study was conducted to examine healthy eating programs, healthy eating education, and the food retail environments of schools.

Methods: A total of 436 Canadian schools were studied. Administrators completed a questionnaire designed to assess school healthy eating programs, healthy eating education, and food retail environment. The number of chain fast food restaurants, chain cafés/coffee shops, and convenience stores within 1 km of schools was measured using geographic information systems food retailer measures from DMTI Spatial Inc. and the Yellow Pages.

Results: During the preceding year, 67% of schools had initiated healthy eating lunch programs while 18% had junk food-free days. The majority of schools offered cooking classes (59%) and healthy eating media literacy education (67%), while a minority offered gardening activities (15%) and field trips to farmers’ markets (27%) and grocery stores (36%). Fifty-three percent had a school cafeteria, and most had a school tuck shop (75%) and pop/juice vending machines (76%). Fifty percent had a chain fast food restaurant, 33% had a chain café/coffee shop, and 41% had a convenience store within 1 km.

Conclusions: An important aspect of addressing childhood obesity will be improving the food environments of schools and their surrounding neighbourhoods, and providing healthy eating education for all students.
Evaluating a Fruit and Vegetable Program: In Eastern Ontario Schools
Authors: Adamo Kristi B. , Goldfield Gary S. , Colapinto Cynthia K. , Grattan Kimberly P. , Harvey Alysha , Barrowman Nick
Published: November 2013

Purpose: Effectiveness was evaluated for a fruit and vegetable program developed to encourage Canadian elementary school children to eat the recommended number of daily servings. Also examined was whether the program modified children’s personal factors, perceived social environment, and perceived physical environment.

Methods: A prospective, quasi-experimental trial was conducted to compare the eight schools receiving the intervention curriculum (Freggie Friday schools [FFS]) with six control schools (CS). A food frequency questionnaire was used to measure differences in fruit and vegetable consumption. Personal factors, perceived social environment, and perceived physical environment supporting fruit and vegetable consumption were assessed with an adapted version of the validated Pro Children study questionnaire.

Results: Of the 942 children who completed the baseline assessment, 807 also completed the follow-up questionnaire (FFS, 450; CS, 357). A mixed-effects regression model indicated no significant intervention effects on fruit or vegetable consumption, snack food consumption, or knowledge or attitudes related to fruit and vegetable consumption.

Conclusions: The results suggest that an intervention based on a single visit from an external group, followed by teacher-led programming, may be an ineffective method of eliciting dietary behaviour change in this population. Future programs may need to implement multicomponent intervention designs.
Promoting Nutritional Well-being in Seniors: Feasibility Study of a Nutrition Information Series
Authors: Manafò Elizabeth , Jose Katrina , Silverberg Dena
Published: November 2013

Better Living Health and Community Services developed a 12-week community-based nutrition information series (NIS) for people aged 55 or older. The purpose of this feasibility study was to describe briefly the process of developing and implementing the 12-week NIS and to identify the practicality and plausibility of the program in terms of its process and content attributes, using Thorncliffe Park community as the test site. A pre- and post-test design was used to identify changes in participants’ perception of their nutritional and overall well-being. Twenty-four participants who completed at least four sessions participated in the post-evaluation follow-up. Only participants’ perception of their eating habits demonstrated a significant, positive improvement (t24=2.1, P<0.05). The results suggest that the NIS has the potential to promote the health and well-being of community-living seniors. The development and implementation of the NIS provided considerations for program practicality. However, additional work is needed to examine the plausibility of the program in meeting its stated objective to promote awareness of nutrition as an important concept for healthy aging. Community-practising dietitians are instrumental in providing credible nutrition information to facilitate healthy eating in older Canadians.
A Review of the Effects of Lunch: On Adults’ Short-term Cognitive Functioning
Authors: Müller Katrin , Libuda Lars , Terschlüsen Anna Maria , Kersting Mathilde
Published: November 2013

Because of widespread irregular lunch consumption by both children and adults, information on the effects of lunch on short-term cognitive functioning is relevant to public health. In September 2012, a MEDLINE search was conducted for studies in which the effects of lunch on cognitive performance were examined. Eleven experimental studies published from 1981 to 1996 were found and evaluated; all involved adults. In three studies, the effects of lunch and lunch skipping were compared; the remaining studies involved a determination of the effects of lunch size and lunch composition. Results of studies in which lunch was compared with no lunch indicate that lunch leads to potential impairment of some aspects of cognitive functioning in the early afternoon. Lunch size may influence cognitive functioning, with impairment more likely to occur after a large lunch than a small lunch. Furthermore, in comparison with low-fat lunches, high-fat lunches seem to result in slower but more accurate responses to some cognitive tasks. However, these suggestions must be viewed with caution, as they are based on only a few studies and are not thoroughly supported by high-quality evidence. In addition, results obtained with adults are not applicable to children. Thus, the potential effects of lunch need further examination in children and adults.