Geometry Control of The Steel Box Girder of Jiashao Bridge at The Fabrication Stage

2014 ◽  
Vol 501-504 ◽  
pp. 1255-1259
Author(s):  
Shao Min Jia ◽  
Lei Zhao ◽  
Xiang Gu
Keyword(s):  
Control Method ◽  
Measured Data ◽  
Research Subject ◽  
Box Girder ◽  
Precise Control ◽  
Control Practice ◽  
Steel Box Girder ◽  
Bridge Girder ◽  
And Control ◽  
Main Girder

The fabrication precision of steel box girder segments is critical to ensure the erection of girder segments is smooth. Taken Jiashao bridge as the research subject, based on geometry control theory, control elements of a steel box girder and control method were introduced, and measured data in the fabrication control of Jiashao bridge girder was given. Control practice shows the erection of the girder is smooth due to the precise control of steel box girder segments at the fabrication stage, and the profile of main girder at completion stage can achieve smoothly the design profile.

Steel Box Girder - Steel Tube Arch Bridge Fall-Girder System Conversion Technology Construction Control Research

2014 ◽  
Vol 501-504 ◽  
pp. 1390-1397
Author(s):  
Kai Zhong Xie ◽  
Feng Fan ◽  
Xian Zhi Huang
Keyword(s):  
Optimal Control ◽  
Control Method ◽  
Steel Tube ◽  
System Transformation ◽  
Bridge Construction ◽  
Monitoring Method ◽  
Box Girder ◽  
Arch Bridge ◽  
Steel Box Girder ◽  
And Control

In order to make steel box girder - steel tube arch bridge into the bridge state more reasonable, this paper studies the construction monitoring method regarding the fall girder method adopted to conduct system transformation. Using optimal control theory to determine the fall girder method girder jack-up height, control the line shape and stress of arch and girder and derrick force, and control the Vietnam Da Nang Dragon Bridge construction process. Studies have shown that fall girder method to conduct the system conversion can meet the design requirements, and optimal control method in fall girder method system conversion can obtain good effects. Fall girder method and optimization control method is worth extending to the similar bridge construction and control.

Design of floating bridge girders against accidental ship collision loads

2016 ◽  
Author(s):  
Yanyan Sha ◽  
Jørgen Amdahl
Keyword(s):  
Finite Element Models ◽  
Cruise Ship ◽  
Box Girder ◽  
Global Response ◽  
Ship Structure ◽  
Steel Box Girder ◽  
Floating Bridge ◽  
Bridge Girder ◽  
Ship Collision ◽  
The Impact

The Norwegian Public Roads Administration is running a project “Ferry free coastal route E39” which includes replacing ferry crossings by bridges or tunnels across fjords in Western Norway. A floating bridge concept was proposed in the fjord-crossing project for Bjørnefjorden. As there are regular cruise routes passing by the bridge, it raises the concern for the consequences of accidental ship collision with the bridge girder. During the collision, the interactions between the bridge girder and the ship structure can be significant. Thus, in the design of the proposed bridge it is vital to evaluate the safety of the ship and the bridge. In this paper, detailed finite element models of a cruise ship and a steel box girder are developed. The impact scenarios and structural damages are studied. The results show that the proposed bridge girder design is generally safe to resist normal accidental ship collision loads. Numerical model of the whole bridge is also developed for further study of bridge global response subjected to ship collision load.

scholarly journals Mechanical Performance Analysis and Parametric Study of a Self-Anchored Suspension Bridge with Ultra-Wide Double-Sided Steel Box Girder

2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Fangwen Wu ◽  
Wenlong Tang ◽  
Shuo Liu ◽  
Yanpeng Feng ◽  
Guangqian Wang ◽  
...  
Keyword(s):  
Mechanical Performance ◽  
Suspension Bridge ◽  
Design Parameters ◽  
Shear Lag ◽  
Shear Lag Effect ◽  
Box Girder ◽  
Vehicle Load ◽  
Steel Box Girder ◽  
Lag Effect ◽  
Main Girder

A sufficient understanding of mechanical performance of self-anchored suspension bridge with double-sided steel box girder is essential for design and normal use as such bridges are widely built in urban bridge. Using the Yunlongwan Bridge which is a suspension bridge with ultra-wide double-sided steel box girder as an example, this paper investigates its deformation and mechanical performance under vehicle load. Firstly, based on the field test results, the deformation performance of the bridge and the stress distribution of the main girder are analysed, with emphasis on the shear lag effect of double-sided steel box girder. Then, a multiscale model of the bridge was built, and the accuracy of the model was verified by comparison with the test data. Finally, the influence of design parameters on the mechanical behaviour of double-sided steel box girder is studied by numerical simulation. The results show that the deformation of the bridge has good symmetry, there is obvious shear lag effect on the main girder, and the U-rib thickness, diaphragm spacing, and vehicle load could significantly affect the stress of the main girder top plate. The obtained analytical results lead to a better understanding of the mechanical performance and provide reference for the design of self-anchored suspension bridge with double-sided steel box girder.

Construction Elements’ Research of Steel Box Girder Based on the 6 σ Quality Control Method

2010 ◽  
Vol 163-167 ◽  
pp. 858-861
Author(s):  
Yi Sha Zhang ◽  
Yun Shi Yao ◽  
Zhen Zhao ◽  
Nan Yao
Keyword(s):  
Quality Control ◽  
Control Method ◽  
Good Stability ◽  
Light Weight ◽  
Box Girder ◽  
Quality Requirements ◽  
Steel Box Girder ◽  
Quality Control Method ◽  
Arterial Road ◽  
Critical Process

The steel box girder is widely used benefited from the high torsional and bending rgigidity, good entirety, light weight, better appearance and good stability. Using 6 quality control method, the problem diagnosis and quality control are made to the steel box girder’s making critical process such as assembly and jointing in the New Hi-Tech Zone of Xi'an’ s Arterial road 4# bridge , so as to meet the quality requirements.

Construction Technology of Jiu-Jiang Yangtze River Highway Bridge

2014 ◽  
Vol 501-504 ◽  
pp. 1274-1278 ◽  
Author(s):  
Yong Tao Zhang ◽  
Xin Li ◽  
Xin Peng You
Keyword(s):  
Yangtze River ◽  
Control Measures ◽  
Highway Bridge ◽  
Construction Technology ◽  
Box Girder ◽  
Cable Stayed Bridge ◽  
Long Span ◽  
North Side ◽  
Steel Box Girder ◽  
Main Girder

Jiu-Jiang Yangtze River Highway Bridge, with a main span of 818m, is another long span hybrid girder cable-stayed bridge which connects Jiang Xi province and Hu Bei province in China. Steel box girder is adopted in main span and north side span, and main girder of south side span and south tower nearby is designed of concrete box girder. The pylon is concrete structure, with the height of 242.3m and H-shape. There are 216 cables used in this bridge, of which are assembled by parallel strands. Jiu-Jiang Yangtze River Highway Bridge began to construct in 2009, and was closed in December, 2012. The bridge opened to traffic officially in the next year. Design concept, construction method and vibration control measures about Jiu-Jiang Yangtze River Highway Bridge are introduced in this article.

Perencanaan Pengendalian Kualitas Produk Pakaian Bayi dengan Metode Six Sigma Pada CV. AGP

JEMAP ◽  
2020 ◽  
Vol 3 (1) ◽  
Author(s):  
Albertus Reynaldo Kurniawan ◽  
Bayu Prestianto
Keyword(s):  
Quality Control ◽  
Continuous Improvement ◽  
Six Sigma ◽  
Screen Printing ◽  
Control Method ◽  
Operational Performance ◽  
Machine Maintenance ◽  
Quality Product ◽  
Break Time ◽  
And Control

Quality control becomes an important key for companies in suppressing the number of defective produced products. Six Sigma is a quality control method that aims to minimize defective products to the lowest point or achieve operational performance with a sigma value of 6 with only yielding 3.4 defective products of 1 million product. Stages of Six Sigma method starts from the DMAIC (Define, Measure, Analyze, Improve and Control) stages that help the company in improving quality and continuous improvement. Based on the results of research on baby clothes products, data in March 2018 the percentage of defective products produced reached 1.4% exceeding 1% tolerance limit, with a Sigma value of 4.14 meaning a possible defect product of 4033.39 opportunities per million products. In the pareto diagram there were 5 types of CTQ (Critical to Quality) such as oblique obras, blobor screen printing, there is a fabric / head cloth code on the final product, hollow fabric / thin fabric fiber, and dirty cloth. The factors caused quality problems such as Manpower, Materials, Environtment, and Machine. Suggestion for consideration of company improvement was continuous improvement on every existing quality problem like in Manpower factor namely improving comprehension, awareness of employees in producing quality product and improve employee's accuracy, Strength Quality Control and give break time. Materials by making the method of cutting the fabric head, the Machine by scheduling machine maintenance and the provision of needle containers at each employees desk sewing and better environtment by installing exhaust fan and renovating the production room.

An Efficient Approach for Modeling and Control of a Quadrotor

2016 ◽  
Vol 4 (2) ◽  
pp. 1-16
Author(s):  
Ahmed S. Khusheef
Keyword(s):  
Pid Control ◽  
Control Method ◽  
Mechanical Design ◽  
Loop Control ◽  
Modeling And Control ◽  
Loop Control System ◽  
And Control ◽  
Close Loop Control ◽  
Close Loop Control System ◽  
Made In

 A quadrotor is a four-rotor aircraft capable of vertical take-off and landing, hovering, forward flight, and having great maneuverability. Its platform can be made in a small size make it convenient for indoor applications as well as for outdoor uses. In model there are four input forces that are essentially the thrust provided by each propeller attached to each motor with a fixed angle. The quadrotor is basically considered an unstable system because of the aerodynamic effects; consequently, a close-loop control system is required to achieve stability and autonomy. Such system must enable the quadrotor to reach the desired attitude as fast as possible without any steady state error. In this paper, an optimal controller is designed based on a Proportional Integral Derivative (PID) control method to obtain stability in flying the quadrotor. The dynamic model of this vehicle will be also explained by using Euler-Newton method. The mechanical design was performed along with the design of the controlling algorithm. Matlab Simulink was used to test and analyze the performance of the proposed control strategy. The experimental results on the quadrotor demonstrated the effectiveness of the methodology used.

Barriers to infection prevention and control practice among Amhara region teaching hospitals in Ethiopia: Qualitative study

2019 ◽  
Vol 15 (2) ◽  
Author(s):  
Walelegn Worku Yallew ◽  
Abera Kumie ◽  
Feleke Moges Yehuala
Keyword(s):  
Healthcare Worker ◽  
Prevention And Control ◽  
Healthcare Workers ◽  
Infection Prevention ◽  
Teaching Hospitals ◽  
Infection Prevention And Control ◽  
Amhara Region ◽  
Implementation Barriers ◽  
Control Practice ◽  
And Control

Healthcare workers have good perception towards infection prevention, but there has been a poor practice towards it. Therefore, the aim of this study was to explore barriers to practice of infection prevention and control practice in teaching hospitals in Amhara region. A phenomenological approach used to explore the lived experience of healthcare workers and management staffs towards infection prevention practice and control. The data was collected from ten in-depth interviews and 23 focus group discussion participants, by face to face interview using open ended interview performed in safe and quiet places. Data was managed using OpenCode software version 4.03 and contents were analyzed thematically. Totally ten different barriers were identified, such as availability of facilities, shortage of material supply, lack of maintenance of facilities and equipment, high patient flow, experience, emergency situation, healthcare worker behaviour and healthcare worker’s information about infection prevention, low awareness of patients and visitors and overflow of families and visitors to the hospital. For effective infection prevention practice implementation, barriers should be considered via identifying specific organizational, healthcare worker, patients and visitors as targets.

The Influence of Slab Concreting Sequence on a Continuous Composite Girder Bridge

2016 ◽  
Vol 691 ◽  
pp. 96-107
Author(s):  
Tomas J. Zivner ◽  
Rudolf B. Aroch ◽  
Michal M. Fabry
Keyword(s):  
Concrete Slab ◽  
Transverse Cross Section ◽  
Slab Thickness ◽  
Slab Width ◽  
Composite Girder ◽  
Steel Members ◽  
Composite Bridge ◽  
Bridge Girder ◽  
Girder Bridge ◽  
Main Girder

This paper deals with the slab concreting sequence and its influence on a composite steel and concrete continuous highway girder bridge. The bridge has a symmetrical composite two-girder structure with three spans of 60 m, 80 m, 60 m (i.e. a total length between abutments of 200.0 m). The horizontal alignment is straight. The top face of the deck is flat. The bridge is straight. The transverse cross-section of the slab is symmetrical with respect to the axis of the bridge. The total slab width is 12 m. The slab thickness varies from 0.4 m on main girders to 0.25 m at its free edges and 0.3075 m at its axis of symmetry. The center-to-center spacing between main girders is 7 m and the slab cantilever on either side is 2.5 m long. Every main girder has a constant depth of 2800 mm and the thicknesses of the upper and lower flanges are variable. The lower flange is 1200 mm wide whereas the upper flange is 1000 mm wide. The two main girders have transverse bracing at abutments and at internal supports and at regular intervals in every span. The material of concrete slab is C35/45 and of steel members S355. The on-site pouring of the concrete slab segments is performed by casting them in a selected order and is done after the launching of the steel two girder bridge. The paper presents several concreting sequences and their influence on the normal stresses and deflections of the composite bridge girder.

Sign in / Sign up

Export Citation Format

Share Document