scholarly journals Elaboration and industrial implementation of lean alloy steel rolled stock production for structures of road bridges

2020 ◽  
Vol 76 (3) ◽  
pp. 228-233
Author(s):  
A. A. Pridein ◽  
L. V. Prokopenko ◽  
O. V. Samokhina ◽  
S. P. Zubov ◽  
D. A. Shablya ◽  
...  
Keyword(s):  
Alloy Steel ◽  
Minimum Temperature ◽  
Steel Production ◽  
Steel Structures ◽  
Weather Conditions ◽  
Rolled Stock ◽  
Steel Bridge ◽  
Welding Technology ◽  
Trial Batch ◽  
Technical Specifications

Within the national project “Safe and quality automobile roads” realization a big number of bridge passages will be constructed, including steel road bridges with small (14–42 m) spans instead of reinforced concrete bridges. Application of metal rolled products of 10ХСНД, 15ХСНД, 10ХСНДА, 15ХСНДА steels in the steel structures of bridges with small spans results in unreasonable increase the costs of the bridges structures. This circumstance stipulates necessity to elaboration and implementation of cheap lean alloy steel for manufacturing standard short-spanned bridges. The steel production should involve minimal and lean alloying method and ensure complex of operation properties in normalized state. At JSC “Ural Steel” an experiment work was accomplished for elaboration lean alloy steel 12Г2СБД due to STO 13657842-1 having standard yield strength 345 MPa. In cooperation with NIZ “Mosty”, OJSC “CNIIS” and CNIIchermet after I.P. Bardin technical specifications of plates for short-spanned bridges were elaborated and approved. Comprehensive technology of 12Г2СБД steel plate production was elaborated. A trial batch of 12Г2СБД steel plates was produced and shipped to ZAO “Kurganstalmost”. Study of welding and technological characteristics of the trial batch plates was carried out. The study showed, that the plates of 12Г2СБД steel have low sensitiveness against heat action of a welding thermal cycle and can be used in welding structures of steel bridge spans providing keeping the plant and assembling welding technology by standard regimes (due to welding technology of steel 10–15ХСНД). Application of the plant and assembling technology at welding by standard regimes makes it possible to use the plates of the elaborated steel for manufacturing metal structures of short-spanned metal bridges for various weather conditions. The plated can be used for both a regular performance (the calculated minimum temperature is down to –40 °С inclusive) and a northern performance Zone A (the calculated minimum temperature is down to –50 °С inclusive).

Seismic Ratchetting of Single-Degree-of-Freedom Steel Bridge Columns

2018 ◽  
Vol 763 ◽  
pp. 295-300 ◽  
Author(s):  
Khaled Saif ◽  
Chin Long Lee ◽  
Trevor Yeow ◽  
Gregory A. MacRae
Keyword(s):  
Time History ◽  
Steel Structures ◽  
Bridge Columns ◽  
Steel Bridge ◽  
Axial Loads ◽  
Maximum Displacement ◽  
Residual Displacements ◽  
Average Maximum ◽  
Force Reduction ◽  
Nonlinear Time History

Nonlinear time history analyses of SDOF bridge columns with elasto-plastic flexural behaviour which are subject to eccentric gravity loading are conducted to quantify the effect of ratchetting. Peak and residual displacements were used as indicators of the degree of ratchetting. The effects of member axial loads and design force reduction factors were also investigated. It was shown that displacement demands increased with increasing eccentric moment. For eccentric moment of 30% of the yield moment, the average maximum and residual displacements increase by 4.2 and 3.8 times the maximum displacement, respectively, which the engineers calculate using static methods without considering ratchetting effect. Design curves for estimating the displacement demands for different eccentric moments are also developed. The current NZ1170.5 (2016) provisions were found to be inadequate in estimating the maximum displacement for steel structures, and hence, new provisions for steel structures should be presented.

Effect on buckling behavior and seismic performance of steel piers corrosion-damaged near ground

2021 ◽  
Author(s):  
Takuma Rokutani ◽  
Kazutoshi Nagata ◽  
Takeshi Kitahara
Keyword(s):  
Seismic Performance ◽  
Rectangular Cross Section ◽  
Steel Structures ◽  
Corrosion Damage ◽  
Bridge Piers ◽  
Response Analysis ◽  
Steel Bridge ◽  
Seismic Response Analysis ◽  
Economic Miracle ◽  
Buckling Behavior

<p>In Japan, many steel structures were constructed during the period of the high economic miracle, and they are now more than 50 years old and are aging. Corrosion has been confirmed at corners and the boundary of concrete-wrapped concrete in steel piers. It was found that corrosion damage at the corner of steel piers causes a decrease of seismic performance in our previous investigations that carried out seismic response analysis. Subsequently, in this study, the effect of corrosion damage at the near ground edge of steel bridge piers with a rectangular cross-section was investigated in detail on the buckling behaviour and seismic performance of structures. As a result, it is found that the buckling at the base causes a decrease in load bearing performance compared to the buckling in the entire panel. It is necessary to properly maintain to prevent buckling at the base caused by corrosion.</p>

Genetic Algorithm-Based Searching Method for Piping Path Routing in Coal-Fired Boiler Buildings

2011 ◽  
Author(s):  
Naohiro Kusumi ◽  
David E. Goldberg ◽  
Noriyuki Ichinose
Keyword(s):  
Genetic Algorithm ◽  
Computer Aided Design ◽  
Steel Structures ◽  
Search Space ◽  
Design System ◽  
Dynamic Programming Method ◽  
Plant Design ◽  
Technical Specifications ◽  
The Many ◽  
Searching Method

Power plant design using digital engineering based on 3-D computer-aided design has become a mainstream technology because of possessing higher speed and improvement in design accuracy. To take a coal-fired boiler building as an example, it has many complex structures with several million parts including the boiler itself, large fans, steel structures, and piping in varying sizes. Therefore, it is not easy to maintain integrity of the whole design throughout all the many engineering processes. We have developed a smart design system for coal-fired boiler buildings to solve the integrity problem. This system is capable of creating and allocating 3-D models automatically in accordance with various technical specifications and engineering rules. Lately, however, there has been a growing demand for more effectiveness of the developed system. We have begun to look into the feasibility of further improvements of the system function. The first point to note, when considering effectiveness, is the piping path routing process in the coal-fired boiler building. The quantity of piping is large, and it has a considerable impact on performance of the whole plant because hot steam is fed into the steam turbine and cold steam is taken from it through the piping. A considerable number of studies have been made on automatic searching methods of piping path routing. Although, the decision of piping path routing by using the Dynamic Programming method is most commonly, a previously decided routing becomes an interference object because of the single searching method. Therefore, basically, the later the order of the routing becomes, the longer the length of the routing becomes. To overcome this problem, in this paper we have proposed a new searching method based on the Genetic Algorithm (GA). The GA is a multipoint searching algorithm based on the mechanics of natural selection and natural genetics. Virtual prohibited cells are introduced into the proposed search method as a new idea. The virtual prohibited cells are located in a search space. The different paths are generated by avoiding the virtual prohibited cells while searching for the piping path routing. The optimum locations of the prohibited cells which are expressed in a genotype are obtained by using the GA in order to get a lot of paths independent of the order of the routing. The proposed method was evaluated using a simple searching problem. The results showed that many effective paths are generated by making the virtual prohibited cells.

scholarly journals Effects of Surrounding Earth on Shell During the Construction of Flexible Bridge Structures

2019 ◽  
Vol 41 (2) ◽  
pp. 67-73
Author(s):  
Czesław Machelski
Keyword(s):  
Steel Structure ◽  
Steel Structures ◽  
Static Condition ◽  
Steel Bridge ◽  
Interfacial Interactions ◽  
Soil Medium ◽  
Bridge Structures ◽  
Internal Forces ◽  
Bearing Loads ◽  
Corrugated Plates

AbstractA characteristic feature of soil-steel structures is that, unlike in typical bridges, the backfill and the carriageway pavement with its foundation play a major role in bearing loads. In the soil-steel structure model, one can distinguish two structural subsystems: the shell made of corrugated plates and the backfill with the pavement layers. The interactions between the subsystems are modelled as interfacial interactions, that is, forces normal and tangent to the surface of the shell. This is a static condition of the consistency of mutual interactions between the surrounding earth and the shell, considering that slip can arise at the interface between the subsystems. This paper presents an algorithm for determining the internal forces in the shell on the basis of the unit strains in the corrugated plates, and subsequently, the interfacial interactions. The effects of loads arising during the construction of a soil-steel bridge when, for example, construction machines drive over the structure, are taken into account in the analysis of the internal forces in the shell and in the surrounding earth. During construction, the forces in the shell are usually many times greater than the ones generated by service loads. Thus, the analytical results presented in this paper provide the basis for predicting the behaviour of the soil medium under operational loads.

scholarly journals Agricultural losses related to frost events: use of the 850 hPa level temperature as an explanatory variable of the damage cost

2014 ◽  
Vol 14 (9) ◽  
pp. 2375-2386 ◽  
Author(s):  
K. Papagiannaki ◽  
K. Lagouvardos ◽  
V. Kotroni ◽  
G. Papagiannakis
Keyword(s):  
Minimum Temperature ◽  
Crop Production ◽  
Methodological Approach ◽  
Weather Conditions ◽  
Lower Atmosphere ◽  
Crop Damage ◽  
Daily Minimum Temperature ◽  
Near Surface ◽  
Damage Costs ◽  
Agriculture Risk

Abstract. The objective of this study is the analysis of damaging frost events in agriculture, by examining the relationship between the daily minimum temperature in the lower atmosphere (at an isobaric level of 850 hPa) and crop production losses. Furthermore, the study suggests a methodological approach for estimating agriculture risk due to frost events, with the aim of estimating the short-term probability and magnitude of frost-related financial losses for different levels of 850 hPa temperature. Compared with near-surface temperature forecasts, temperature forecasts at the level of 850 hPa are less influenced by varying weather conditions or by local topographical features; thus, they constitute a more consistent indicator of the forthcoming weather conditions. The analysis of the daily monetary compensations for insured crop losses caused by weather events in Greece shows that, during the period 1999–2011, frost caused more damage to crop production than any other meteorological phenomenon. Two regions of different geographical latitudes are examined further, to account for the differences in the temperature ranges developed within their ecological environment. Using a series of linear and logistic regressions, we found that minimum temperature (at an 850 hPa level), grouped into three categories according to its magnitude, and seasonality, are significant variables when trying to explain crop damage costs, as well as to predict and quantify the likelihood and magnitude of damaging frost events.

Numerical Analysis of the Influence on High Humidity in a T-Joint Fillet Weld for High Strength Low Alloy Steel

2014 ◽  
Vol 651-653 ◽  
pp. 56-59
Author(s):  
Song Ping Chen ◽  
Yong Xian Li ◽  
Yan Ji Xie
Keyword(s):  
Residual Stress ◽  
Alloy Steel ◽  
Steel Structures ◽  
High Strength ◽  
Computational Procedure ◽  
Steel Plates ◽  
Transient Temperature ◽  
High Humidity ◽  
Low Alloy Steel ◽  
Port City

Welding at high humidity is frequently needed for the harbor hoisting machinery of steel structures in the coastal port city. A computational procedure is proposed for analyzing residual stress and temperature distributions induced by the T-joint welding in two types of St52-3 high strength low alloy steel plates both 6 mm in thickness. The relative humidity conditions varied from 75 to 90% at constant pressure. The finite element models are employed to evaluate the transient temperature and the residual stress during welding. According to the analysis results, the higher residual stress and the highest concentration of hydrogen are distributed in and surround the heat affected zone (HAZ), and vary with different humidity.

scholarly journals Risk-Cost Optimized Maintenance Strategy for Steel Bridge Subjected to Deterioration

2021 ◽  
Vol 14 (1) ◽  
pp. 436
Author(s):  
Le Li ◽  
Mojtaba Mahmoodian ◽  
Alireza Khaloo ◽  
Zhiyan Sun
Keyword(s):  
Failure Modes ◽  
Cost Optimization ◽  
Steel Structures ◽  
Steel Bridge ◽  
Maintenance Strategy ◽  
Total Risk ◽  
Chloride Attack ◽  
Risk Cost ◽  
Structural Engineers ◽  
Asset Managers

This paper aims to develop a deteriorated bridge maintenance strategy that ensures the safe operation of steel structures and minimizes the total risk. Five common failure modes are considered for the deteriorated bridge: flexure, shear, deflection, fatigue failure for girder, and chloride attack for the concrete deck. Time-dependent and system reliability analyses are carried out to find the probability of failure under these failure modes. Risk-cost optimization is then used to determine the maintenance strategy. This method was applied to a working example. It was found that the developed maintenance strategy can predict when, where, and what to maintain for a bridge to ensure its safe and serviceable operation during its lifespan. The proposed methodology can help structural engineers and asset managers repair and maintain bridges under deterioration.

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