Cable effective length model error-based bridge performance warning method under thermal action

2021 ◽  
pp. 136943322110480
Author(s):  
Yan Wang ◽  
Dong-Hui Yang ◽  
Yu-Zheng Zhou ◽  
Ting-Hua Yi

The cables of long-span cable-stayed bridges are subjected to substantial tension during long-term service and are more susceptible to corrosion and fatigue failure than concrete structures. Most existing structural health monitoring (SHM) systems do not have monitoring equipment to directly measure cable length, and long-term monitoring of the change in cables is less involved. The displacement response of a bridge is induced by the combination of dynamic effects (wind and highways) and quasi-static effects (temperature). In this paper, the dynamic responses were eliminated by averaging the displacement data for 10 min, and the relationship between temperature and displacement was studied. Based on the monitoring data, the distribution of the thermal field for the bridge was studied and the time variability of the tower displacement was investigated. The correlation was analyzed to study the relationship between the temperature and the tower displacements, the north tower–south tower distance and the tower–girder distances. A strong linear relationship between the temperature and quasi-static responses of the displacements was observed. The thermal expansion coefficient of the effective length of cables was proposed as a quantitative index for long-term cable monitoring. The error in the cable effective length is proposed as the warning index for performance warning research. The results show that the proposed performance warning method can monitor cables and perform warnings when the cable is damaged.

Author(s):  
A.H. Adzhiev ◽  
G.V. Kupovykh ◽  
R.A. Gyatov ◽  
Z.M. Kerefova

For study the relationship between number of days with a thunderstorm recorded by weather stations and duration of thunderstorms in hours for these days, instrumental observations of the thunder direction-finding network of High-Mountain Geophysical Institute were used. We used data on thunderstorms in the North Caucasus for a long-term observation period in 2008-2019. Based on these data, they are grouped for various territories for analysis: the number of days with thunderstorms per month, per year, and the duration of thunderstorms per month and per year. A correlation analysis was performed between the number of days with thunderstorms and the duration of thunder-storms in hours according to LS 800 data. Thus, the dependence of the number of days with thunderstorms on the duration of thunderstorms is clearly traced - with an increase in the number of days with thunderstorms per year, the observation point increases in direct proportion to the duration of thunderstorms per year. With an increase in the number of days with thunderstorms on a given territory by one day, for the month in question, the duration of thunderstorms increases by 3.89 hours.


Author(s):  
A. J. Southward

The inshore fishery for the pilchard in Cornish waters has existed for several hundred years, and such records as are available concerning fluctuation in catches and market conditions have been reviewed by Couch (1865), Cushing (1957) and Culley (1971). Although pilchard have been landed from Lyme Bay, from the eastern half of the Channel, and from the southern North Sea (Couch, 1865; Furnestin, 1945; Cushing, 1957; personal communications G. T. Boalch) the catches have usually been incidental to other fisheries and more sporadic than in Cornish waters. Traditionally there are three areas fished for the Cornish pilchard: on the north-west coast around St Ives; in Mounts Bay and towards the Scillies; and between the Lizard Pt and Bolt Tail in Devon (Couch, 1865; Culley, 1971). The latter region, constituting the inshore waters of south-east Cornwall and south Devon, effectively forms the eastern limits of the regular occurrence of commercial shoals. Knowledge of the breeding and life-history of the fish in this region has always been scarce and subject to much hearsay evidence (reviewed in Southward, 1963). Up to quite recently it was thought that the main spawning area lay well to the west of the entrance to the Channel, and it was not until the investigations reported by Corbin (1947,195°) a nd Cushing (1957)tnat it was conclusively shown that extensive spawning can occur within the English Channel from May to October. The relationship of the spawning in the western Channel to the other areas of spawning off the entrance to the Channel and in the northern Bay of Biscay is illustrated in a recent series of reports (Arbault & Boutin, 1968; Arbault & Lacroix-Boutin, 1969; Arbault & Lacroix, 1971; Wallace, P. D. & Pleasants, C. A., duplicated ICES meeting paper CM 1972/J: 8), and is further demonstrated by Demir & Southward (1974) in discussing the results of a study of small scale seasonal changes in spawning intensity in inshore waters.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Chuang Zhang ◽  
Wenxu Dong ◽  
Kiril Manevski ◽  
Wenpei Hu ◽  
Arbindra Timilsina ◽  
...  

AbstractThe enzymatic activities and ratios are critical indicators for organic matter decomposition and provide potentially positive feedback to carbon (C) loss under global warming. For agricultural soils under climate change, the effect of long-term warming on the activities of oxidases and hydrolases targeting C, nitrogen (N) and phosphorus (P) and their ratios is unclear, as well as whether and to what extend the response is modulated by long-term fertilization. A 9-year field experiment in the North China Plain, including an untreated control, warming, N fertilization, and combined (WN) treatment plots, compared the factorial effect of warming and fertilization. Long-term warming interacted with fertilization to stimulate the highest activities of C, N, and P hydrolases. Activities of C and P hydrolase increased from 8 to 69% by N fertilization, 9 to 53% by warming, and 28 to 130% by WN treatment compared to control, whereas the activities of oxidase increased from 4 to 16% in the WN soils. Both the warming and the WN treatments significantly increased the enzymatic C:N ratio from 0.06 to 0.16 and the vector length from 0.04 to 0.12 compared to the control soil, indicating higher energy and resource limitation for the soil microorganisms. Compared to WN, the warming induced similar ratio of oxidase to C hydrolase, showing a comparable ability of different microbial communities to utilize lignin substrates. The relationship analyses showed mineralization of organic N to mediate the decomposition of lignin and enzyme ratio in the long-term warming soil, while N and P hydrolases cooperatively benefited to induce more oxidase productions in the soil subject to both warming and N fertilization. We conclude that coupled resource limitations induced microbial acclimation to long-term warming in the agricultural soils experiencing high N fertilizer inputs.


2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Yong-Hua Li ◽  
Yang Cao ◽  
Yong-Xin Wu ◽  
Xiao-Ning Bai ◽  
Jia-Wei Mao

PurposeThis paper aims to establish the relationship between crosswind speed and pantograph-catenary lateral deviation, as well as quantify the influence of crosswind speed and rod size uncertainty on pantograph-catenary contact reliability.Design/methodology/approachThe closed vector method is used to establish the pantograph-catenary kinematics formula. A new prediction model is proposed by using the bird swarm algorithm to optimize the grey model. The lateral deviation of the pantograph and catenary is predicted via the new model. Then the relationship between the effective length of the rod and operating mileage is inferred by combining the effective length theory with the Gamma process, as well as the pantograph-catenary contact reliability model is established according to reliability theory.FindingsThe results obtained show the impacts of uncertainty design parameters of pantograph rods on pantograph-catenary contact reliability index, and the results at crosswind speed of 0 ms−1 and 5 ms−1 are 5.0630 and 4.1442, respectively. The reliability decreases with the increasing crosswind speed, and can be greater than the reliability calculated for rod size degradation due to long-term use.Originality/valueMost preceding works on pantograph-catenary contact reliability were based on principles of dynamics, without considering the pantograph-catenary relative motion. This research reveals the law of pantograph-catenary relative motion for uncertainty design parameters and crosswind, and quantifies the reliability from the angle of kinematics.


2004 ◽  
Vol 11 (3) ◽  
pp. 295-301 ◽  
Author(s):  
V. N. Khokhlov ◽  
A. V. Glushkov ◽  
I. A. Tsenenko

Abstract. In this paper, we employ a non-decimated wavelet decomposition to analyse long-term variations of the teleconnection pattern monthly indices (the North Atlantic Oscillation and the Southern Oscillation) and the relationship of these variations with eddy kinetic energy contents (KE) in the atmosphere of mid-latitudes and tropics. Major advantage of using this tool is to isolate short- and long-term components of fluctuations. Such analysis allows revealing basic periodic behaviours for the North Atlantic Oscillations (NAO) indices such as the 4-8-year and the natural change of dominant phase. The main results can be posed as follows. First, if the phases of North Atlantic and Southern Oscillations vary synchronously with the 4-8-year period then the relationship between the variations of the NAO indices and the KE contents is the most appreciable. Second, if the NAO phase tends to abrupt changes then the impact of these variations on the eddy kinetic energy contents in both mid-latitudes and tropics is more significant than for the durational dominance of certain phase.


2013 ◽  
Vol 17 (2) ◽  
pp. 665-678 ◽  
Author(s):  
N. Cortesi ◽  
R. M. Trigo ◽  
J. C. Gonzalez-Hidalgo ◽  
A. M. Ramos

Abstract. Precipitation over the Iberian Peninsula (IP) is highly variable and shows large spatial contrasts between wet mountainous regions to the north, and dry regions in the inland plains and southern areas. In this work, we modelled the relationship between atmospheric circulation weather types (WTs) and monthly precipitation for the wet half of the year (October to May) using a 10 km grid derived from a high-density dataset for the IP (3030 precipitation series, overall mean density one station each 200 km2). We detected two spatial gradients in the relationship between WTs and precipitation. The percentage of monthly precipitation explained by WTs varies from northwest (higher variance explained) to southeast (lower variance explained). Additionally, in the IP the number of WTs that contribute significantly to monthly precipitation increase systematically from east to west. Generally speaking, the model performance is better to the west than to the east where the WTs approach produce the less accurate results. We applied the WTs modelling approach to reconstruct the long-term precipitation time series for three major stations of Iberia (Lisbon, Madrid, Valencia).


2016 ◽  
Vol 2 (3) ◽  
pp. 273-292
Author(s):  
Matthew R. Sanderson

This paper empirically assesses, for the first time, the relationship between immigration and national economic development in both the global North and the global South. A series of panel models demonstrate that immigration exacerbates North-South inequalities through differential effects on average per capita incomes in the global North and global South. Immigration has positive effects on average incomes in both the North and the South, but the effect is larger in the global North. Thus the relationship between immigration and development evinces a Matthew Effect at the world level: by contributing to differential levels of economic development in the North and South, immigration widens international inequalities in the long term, resulting in the accumulation of advantage in the North. The implications of the results are discussed in the context theory and policy on the migration-development nexus.


2006 ◽  
Vol 45 (3) ◽  
pp. 411-430 ◽  
Author(s):  
Serge Collet

By setting the uniqueness of inshore coastal fishing communities in the Mediterranean as a social halieutical morphology inscribed in the very long span of time, this article underlines why, without any romanticism, these communities have to be scaled up, valorized. It demonstrates how and why some of these robust communal appropriation forms have worked with a low discount rate, which embeds wisdom of the sea, or halieusophy, based on the principle of giving for keeping. Backed by these successful experiences, the author analyses the trajectories of community re-invention, the pathways of their empowering through the setting up of a new institution, ecomuseums for the sea, as ethically based local governance institutions capable of fine-tuning and improving the relationship between humans and marine entities. In the last, thought-provoking, part, the author raises the question: why does this strategic pathway have to come back to the very essence of the scope of the valuable, i.e. women? And he answers: because women in inshore coastal fishing communities ensure, more than in other communities, the holding and ordering of the fluctuations and contingency in family life, and, at a more ontological level of reflection, they embody a disposition for a long-term time horizon and a nondestruction principle. The governance perspectives in fisheries in their global and local modalities have to be en-gendered.


2021 ◽  
Vol 15 ◽  
Author(s):  
Tatiana Teixeira Barral de Lacerda ◽  
Ana Paula Miranda Neves ◽  
Giselle Layse Andrade Buarque ◽  
Denise Cuoghi de Carvalho Veríssimo Freitas ◽  
Mariana Medeiros Mota Tessarolo ◽  
...  

OBJECTIVES: To map the number and geospatial distribution of Brazilian long-term care facilities (LTCFs) for older adults. Additionally, we sought to highlight the relationship between these findings and the number of older people in the country’s 27 Federation Units, demonstrating the growth of these facilities in the last decade. METHODS: This is a descriptive observational study, using secondary data, which was performed in 3 stages: 1) searching and consolidating national and subnational data from different sources and mapping LTCFs; 2) preparing a geospatial map using Brazilian postal codes; and 3) triangulating the number of facilities and of older people in each state and all 5 Brazilian regions. RESULTS: We found 7029 LTCFs in the country, mostly in the Southeast and South regions: São Paulo, Minas Gerais and Rio Grande do Sul had the highest numbers of facilities while states in the North region represented only 1.12% of Brazilian LTCFs. Geospatial mapping highlighted that 64% of the 5 570 Brazilian municipalities did not have any LTCFs for older adults. CONCLUSIONS: We observed a large difference between Brazilian regions regarding the provision of long-term care.


2021 ◽  
Vol 14 ◽  
pp. 194008292110232
Author(s):  
Raísa da Silva Costa Rêgo ◽  
Caio Henrique Gonçalves Cutrim ◽  
Amanda Soares Miranda ◽  
Juliana Loureiro Almeida Campos ◽  
Vinícius Albano Araújo

Natural environment has undergone rapid transformations, primarily attributed to human actions that threaten ecosystems' balance. Understanding the relationship between humans and nature is essential to generate effective strategies for sustainably using resources. In this study, we analyzed the environmental perception and knowledge about the biology of sea turtles through 120 informal interviews with visitors at beaches on the north-central coast of Rio de Janeiro state. Residents noticed garbage more often than tourists, as did women and younger individuals. The perception of initiatives necessary to increase the preservation of the beaches was higher for people with higher education. In general, there were no differences in biological knowledge about sea turtles between residents, tourists and people who work or study at the cities. The results point to the need for oceanic education strategies that can help raise environmental awareness through long-term conservation programs.


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