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Why the Water Bridge does not collapse  [PDF]
Artem Anatolievich Aerov
Physics , 2010, DOI: 10.1103/PhysRevE.84.036314
Abstract: In 2007 an interesting phenomenon was discovered: a thread of water, the so-called water bridge (WB), can hang between two glass beakers filled with deionized water if voltage is applied to them. We analyze the available explanations of the WB stability and propose a completely different one: the force that supports the WB is the surface tension of water and the role of electric field is not to allow the WB to reduce its surface energy by means of breaking into separate drops.
Multi-temporal SAR interferometry reveals acceleration of bridge sinking before collapse  [PDF]
J. J. Sousa,L. Bastos
Natural Hazards and Earth System Sciences (NHESS) & Discussions (NHESSD) , 2013, DOI: 10.5194/nhess-13-659-2013
Abstract: On the night of 4 March 2001, at Entre-os-Rios (Northern Portugal), the Hintze Ribeiro centennial bridge collapsed killing 59 people traveling in a bus and three cars that were crossing the Douro River. According to the national authorities, the collapse was due to two decades of uncontrolled sand extraction which compromised the stability of the bridge's pillars, together with underestimating the warnings from divers and technicians. In this work we do not intend to corroborate or contradict the official version of the accident's causes, but only demonstrate the potential of Multi-Temporal Interferometric techniques for detection and monitoring of deformations in structures such as bridges, and consequently the usefulness of the derived information in some type of early warning system to help prevent new catastrophic events. Based on the analysis of 52 ERS-1/2 covering the period from May 1995 to the fatal occurrence, we were able to detect significant movements, reaching rates of 20 mm yr 1, in the section of the bridge that fell into the Douro River, which are obvious signs of the bridge's instability. These promising results demonstrate that with the new high-resolution synthetic aperture radar satellite scenes it is possible to develop interferometric based methodologies for structural health monitoring.
Tackling Causes of Frequent Building Collapse in Nigeria  [cached]
S.A. Oloyede,C.B. Omoogun,O.A. Akinjare
Journal of Sustainable Development , 2010, DOI: 10.5539/jsd.v3n3p127
Abstract: A building, once properly constructed is expected to be in use for a very long time. Although every society has its own problems and Nigeria is not an exception yet the very recent challenges of buildings collapsing in various locations have been giving the various arms of government and the people of Nigeria sleepless nights in view of the enormous loss of huge investments in housing, properties and human life. The major challenge on the issue of building collapse is that individuals differ radically from one another on the professional to blame as the major cause of the collapse of a building. This study reviews current challenges in the building industry in relation to collapse of buildings, loss of lives and properties. Data for the study were obtained through structured questionnaires administered to landlords and professionals in the construction industry in addition to academia in the built environment. Historical data of past collapsed buildings in Nigeria were also discussed. Findings from the three prominent groups were varied. First, building experts blamed building collapses on the use of low quality building materials coupled with employment of incompetent artisans and weak supervision of workmen on site. Second, public opinion revealed that the blames of building collapse were due to non-compliance with specifications/standards, use of substandard building materials and equipments and the employment of incompetent contractors. Third, opinion of the academia on remote causes of building collapse showed that the route causes are mainly the non-enforcement of existing laws and endemic poor work ethics of Nigerians at large. The study recommends that the press should lay more emphasis on educating the public at large on the dangers of the collapse of a building and less on public emotions. In addition, government should, on one hand, embark on proactive steps by mustering enough political will to allow the Town Planning Authorities to perform their functions unfettered and on the other hand, provide the legal framework that can improve and ensure smoother, less time-consuming and less burdensome ways to conduct business in the functioning of law courts.
Transition Wave in the Collapse of the San Saba Bridge  [PDF]
Michele Brun,Alexander B. Movchan
Frontiers in Materials , 2014, DOI: 10.3389/fmats.2014.00012
Abstract: A domino wave is a well-known illustration of a transition wave, which appears to reach a stable regime of propagation. Nature also provides spectacular cases of gravity-driven transition waves at large scale observed in snow avalanches and landslides. On a different scale, the micro-structure level interaction between different constituents of the macro-system may influence critical regimes leading to instabilities in avalanche-like flow systems. Most transition waves observed in systems, such as bulletproof vests, racing helmets under impact, shock-wave-driven fracture in solids, are transient. For some structured waveguides, a transition wave may stabilize to achieve a steady regime. Here, we show that the failure of a long bridge is also driven by a transition wave that may allow for steady-state regimes. The recent observation of a failure of the San Saba Bridge in Texas provides experimental evidence supporting an elegant theory based on the notion of transition failure wave. No one would think of an analogy between a snow avalanche and a collapsing bridge. Despite an apparent controversy of such a comparison, both these phenomena can be described in the framework of a model of the dynamic gravity driven transition fault.
The bridge: suggestions about the meaning of a pictorial motif  [PDF]
Omar Calabrese
Journal of Art Historiography , 2011,
Abstract: Developing research begun at the Warburg Institute in 1983, this paper reflects on the construction of meaning in a work of art, through the analysis of the bridge’s function in painting. It tries to reply to some objections the author received there from Gombrich, about the chance of finding a stable content in the configuration of the bridge. Hence, the study reconsiders the concept of ‘motif’ applied to this structure. In a semiotic perspective a motif is partially independent as regards to a single textual organization, because it has a mobile and migrant feature. However, it is also partially flexible as it depends upon the same organization. The inquiry shows that bridge’s internal structure corresponds to the category of a ‘junction’, with two opposite items, ‘conjunction’ and ‘disjunction’. The development of this theoretical object can be carried out also by figures that are not ‘bridges’, in the natural sense of the word. Furthermore, its meaning does not depend upon the number of examples we can find but only upon their relevance for constructing a ‘grammar of cases’. Differently from the traditional iconographical approach, but also from panofskian iconology, the analysis moves not only towards the simple or complex content of a figure but also towards its description.
Analysis of the Cause for the Collapse of a Temporary Bridge Using Numerical Simulation  [PDF]
Changsung Kim, Jongtae Kim, Joongu Kang
Engineering (ENG) , 2013, DOI: 10.4236/eng.2013.512121
Abstract:

The purpose of this study was to suggest the measures and methods for securing the stability of temporary bridges by analyzing the cause for the collapse of the temporary bridge built for the construction of the GunNam flood control reservoir located at the main channel of the Im-Jin River. Numerical simulations (one-, two-, and three-dimensional) were performed by collecting field data, and the results showed that the collapse occurred because the height of the temporary bridge was lower than the water level at the time of the collapse. Also, the drag force calculation showed that when the guardrail installed on the upper deck structure was not considered, there was no problem as the calculated values were lower than the design load, whereas when the guardrail was considered, the stability was not secured as the calculated values were higher than the design load, 37.73 kN/m. It is thought that the actual force of the water flow applied on the bridge increased due to the accumulation of debris on the guardrail as well as the upper deck.

The Review about Continuous Rigid Frame Bridge in Guizhou Mountain Area
Xing Zhang, Bin Du, Tao Wang
Open Access Library Journal (OALib Journal) , 2016, DOI: 10.4236/oalib.1103244
Abstract:
Based on Guizhou mountain area, the characteristic of Guizhou mountain area and the characteristic of continuous rigid frame bridge were thought. An analysis about the advantage of this bridge type and the reason why this bridge type had energetic development in Guizhou mountain area was made. According to the collected literature and design information, the development status, including construction features, building materials, design theory and method, the key technique of construction and development prospect were revealed. Firstly, a review about the achievement of this bridge type in Guizhou mountain area was made. Then an induction and conclusion were given. In construction features, the parameter of bridge span and section was mainly introduced and a conclusion for the choice of this parameter was given. In materials, the characteristic and problem of present materials were analyzed, and then an outlook and advice for new materials, including lightweight and ultra high strength concrete and fiber reinforced composites, were given. In design, the method and key point in continuous rigid frame bridge design were reviewed; then mainly focusing on the durableness design, the limitation of the old bridge design specifications was concluded, and some ideas and an outlook were put forward for the new bridge design specifications. In construction, the construction method, the key step in construction, the common problems and solution were focused on. And the method, the affect and value of construction control in continuous rigid frame bridge were then simply introduced. In the end, the development of continuous rigid frame bridge is looking forward the future. This paper is expecting making some contribution for bridge construction in Guizhou mountain area and offering some basic information for beginners in bridge engineering.
Causes of Early Age Cracking on Concrete Bridge Deck Expansion Joint Repair Sections  [PDF]
Jared R. Wright,Farshad Rajabipour,Jeffrey A. Laman,Aleksandra Radlińska
Advances in Civil Engineering , 2014, DOI: 10.1155/2014/103421
Abstract: Cracking of newly placed binary Portland cement-slag concrete adjacent to bridge deck expansion dam replacements has been observed on several newly rehabilitated sections of bridge decks. This paper investigates the causes of cracking by assessing the concrete mixtures specified for bridge deck rehabilitation projects, as well as reviewing the structural design of decks and the construction and curing methods implemented by the contractors. The work consists of (1) a comprehensive literature review of the causes of cracking on bridge decks, (2) a review of previous bridge deck rehabilitation projects that experienced early-age cracking along with construction observations of active deck rehabilitation projects, and (3) an experimental evaluation of the two most commonly used bridge deck concrete mixtures. Based on the literature review, the causes of concrete bridge deck cracking can be classified into three categories: concrete material properties, construction practices, and structural design factors. The most likely causes of the observed early-age cracking were found to be inadequate curing and failure to properly eliminate the risk of plastic shrinkage cracking. These results underscore the significance of proper moist curing methods for concrete bridge decks, including repair sections. This document also provides a blueprint for future researchers to investigate early-age cracking of concrete structures. 1. Introduction Longitudinal early age cracking of concrete repair sections adjacent to bridge deck expansion dam replacements (Figure 1) has been observed on several newly rehabilitated bridge decks. This research was aimed at assessing the causes of cracking in these full-depth concrete repair sections and creating a methodology to quantify these causes. Transverse early age cracking of concrete bridge decks has been a common problem reported by many state DOTs [1–11]. Although many studies have been performed since the 1980s to identify the causes and effective mitigation practices for early age cracking on concrete bridge decks, very few studies have focused on cracking in repair sections, especially next to rehabilitated deck expansion dams. The published literature addressing cracking in deck repair sections is limited [12–17] and focuses mostly on closure pour acceleration [12], complete shear failure of reinforcing steel [14], or the durability of specific repair materials such as polymer-modified cementitious concrete and epoxy-binder concretes [15–17]. This paper evaluates the causes of the observed longitudinal cracking by assessing the
About some infinite family of 2-bridge knots and -manifolds  [PDF]
Yangkok Kim
International Journal of Mathematics and Mathematical Sciences , 2000, DOI: 10.1155/s0161171200003422
Abstract: We construct an infinite family of 3-manifolds and show that these manifolds have cyclically presented fundamental groups and are cyclic branched coverings of the 3-sphere branched over the 2-bridge knots (ℓ
A Qualitative Study of Males’ Perceptions about Causes of Eating Disorder  [PDF]
Karin Wallin, Gunn Pettersen, Tabita Bj?rk, Maria R?stam
Psychology (PSYCH) , 2014, DOI: 10.4236/psych.2014.515187
Abstract: Our knowledge about males’ perceptions about causes of eating disorder is very limited, but can be useful in the treatment planning for males. The aim of this study was to describe how male former patients perceived causes of onset of their eating disorder. Fifteen males previously treated for eating disorders and now considering themselves as recovered where interviewed at ages 19 - 52. All interviews were recorded and analyzed qualitatively using a phenomenographic approach. Three categories of perceived causes of onset of eating disorders were found. The first category: self-dissatisfaction, was presented with three conceptions: “High achievements and demands”, “Body-dissatisfaction” and “Low self-esteem”. The second category: family environment, comprised the two conceptions: “Difficulty in family interaction and communication” and “Excessive expectations from family members”. The third category was stressful events outside the family, and consisted of the three conceptions: “Bullying, bad situation at school”, “Moving to new places/separation from friends” and “Societal ideals”. Males’ perceptions of causes of onset of their eating disorder were in many aspects similar to those earlier described for women. In treatment, it is important that the clinicians show a sincere interest in perceived causes, since it may facilitate a good working alliance with the patient.
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