Introduction Many existing bridges structure has been designed without seismic provisions are vulnerable which has demonstrated by recent earthquake. The consequent of the extensive damage to bridge structure include potential loss of life and property, and interruption of transportation system that can contribute to major economic and impact to the society. Concern about the vulnerability of bridges being damage, there are significant need to perform adequate seismic retrofit technique prior to future seismic event. Furthermore, for ensuring the existing bridge meet current safety seismic design requirement consist of detailing schemes that can offer flexural ductility, high-energy dissipation and preventing shear failure. Thus, this paper only focuses on retrofitting of bridge column/pier. Therefore, it is very important to identify potential deficiencies and examine the strategies for retrofit these bridge pier in the rehabilitation of existing bridge pier, which can upgrade the performance and extension of its service life. Common deficiencies for reinforced concrete column and piers as shown in Figure 1. Research Significance Research that had been investigated the seismic performance in area of innovative materials have been significantly shown potential and promise better in civil engineering application and solution in future. Thus, the objective this paper provides relevant an innovative seismic retrofit technique for bridges pier using innovative material include shape memory alloy (SMA) and fiber reinforced polymer (FRP) and has develop as alternative improvement to the existing bridge pier. For emphasizing each method of retrofit, comparative drawbacks and advantages on seismic performance are include in the scope of... ... middle of paper ... ...pirals.” Doctor of Philosophy in Civil Engineering, University of Illinois Yu-Fei Wu, Tao Liu, and Leiming Wang (2008). “Experimental Investigation on Seismic Retrofitting of Square RC Columns by Carbon FRP Sheet Confinement Combined with Transverse Short Glass FRP Bars in Bored Holes.” J. Compos. Constr.,ASCE.12, 53-60. Liang Chang, A.M.ASCE1; Fan Peng2; Yanfeng Ouyang, A.M.ASCE3; Amr S. Elnashai, F.ASCE4; and Billie F. Spencer Jr., F.ASCE5 DOI: 10.1061/(ASCE)IS .1943-555X.0000082. © 2012 American Society of Civil Engineers. William f. Cofer, David I. McLean and Yi Zhang, “Analytical Evaluation on Retrofit Strategies for Multi-Column Bridges”, Technical Report for research project T9902-11 Riyad Aboutaha, Fares Jnaid, Sara Sotoud, and Mucip Tapan “Seismic Evaluation and Retrofit of Deteriorated Concrete Bridge Components” Technical Report 49111-23-22 june 2013
Following the collapse of the I-35 Bridge, other bridges in the country, with similar construction designs, were scrutinized. According to federal statistics, more than 70,000 of the 607,363 or roughly 12 percent of the bridges in the United States are classified as “structurally deficient.”
According to Suspension bridges: Concepts and various innovative techniques of structural evaluation, “During the past 200 years, suspension bridges have been at the forefront in all aspects of structural engineering” (“Suspension”). This statement shows that suspension bridges have been used for over 200 years, and that people are still using them today because they are structurally better bridges. This paper shows four arguments on the advantages of suspension bridges, and why you should use one when building a bridge. When deciding on building a suspension bridge, it has many advantages such as; its lightness, ability to span over a long distance, easy construction, cost effective, easy to maintain, less risk
Compare with other types of bridges, suspension bridge can span the longest distance without using lots of material. However, if the issue of stiffness was not fully cosidered, vibration would be occurred on the bridge deck under high wind. A few week after the Tacoma Narrow Bridge was operated, the bridge start oscillation and its oscillation kept increasing day by day. Therefore engineers tried to build more cable between the bridge, but it is still unsuccessful. After four months the Tacoma Narrows Bridge was build, the bridgre which normally vibrated in a vertiacal motion, began to oscillate with the opposite side out of phase (torsional model), under the wind of 68 km/h. Due to the extremely violent oscillation, the failure bagan at the mid-...
Ali, Mir M. Moon, Kyung Sun. “Structural Developments in Tall Buildings: Current Trends and Prospects” Architectural Science Review, Volume 50, Issue 3, 2007. Web. 27 Sept. 2017.
The Tacoma Narrows Bridge is perhaps the most notorious failure in the world of engineering. It collapsed on November 7, 1940 just months after its opening on July 1, 1940. It was designed by Leon Moisseiff and at its time it was the third largest suspension bridge in the world with a center span of over half a mile long. The bridge was very narrow and sleek giving it a look of grace, but this design made it very flexible in the wind. Nicknamed the "Galloping Gertie," because of its undulating behavior, the Tacoma Narrows Bridge drew the attention of motorists seeking a cheap thrill. Drivers felt that they were driving on a roller coaster, as they would disappear from sight in the trough of the wave. On the last day of the bridge's existence it gave fair warning that its destruction was eminent. Not only did it oscillate up and down, but twisted side to side in a cork screw motion. After hours of this violent motion with wind speeds reaching forty and fifty miles per hour, the bridge collapsed. With such a catastrophic failure, many people ask why such an apparently well thought out plan could have failed so badly?(This rhetorical question clearly sets up a position of inquiry-which iniates all research.) The reason for the collapse of the Tacoma Narrows Bridge is still controversial, but three theories reveal the basis of an engineering explanation. (Jason then directly asserts what he found to be a possible answer to his question.)
Ward, D. E., Jemal, D. A., Cokkinides, D. V., Singh, D. G., Cardinez, C., Ghafoor, A., et al. (2008, December 31). . Wiley Online Library. Retrieved April 29, 2014, from http://onlinelibrary.wiley.com/doi/10.3322/canjclin.54.2.78/full
The failure of beam-to-column connections in steel Special Moment Resisting Frames had the most to do with most of the damage in these buildings. In response to the pattern of buildings including SMRF's, there have been studies to improve the design and construction practices to allow for better and more improved buildings. The higher building codes wanted engineers to find new ways to allow homes, apartments or skyscrapers the ability to sustain a powerful earthquake. These engineers borrowed the model from New Zealand engineer Bill Robinson. His method was to use lead-rubber bearings, which minimize the vibrations caused by the earthquake, improving its performance during seismic activity. Many of the old buildings that took damage during the earthquake had to be retrofitted. This was done by either infilling the walls, adding braces, adding buttresses, adding new frames, exterior or interior, completely rebuilding or isolating the building. All of these techniques of retrofitting a building all add extra support to the remainder of the building. Most of the residential structures that took damage and were deemed uninhabitable were the apartments or condominiums that were made of light, wood frames. Also, many houses made using stucco took extensive damages. This was due to the fact that the stucco was not properly installed in the first place,
The 1.78 mile western span of the bridge between San Francisco and Yerba Buena Island presented the first obstacle. The bay was up to 100 feet deep in some places and required a new foundation-laying technique. Engineers developed a type of foundation called a pneumatic caisson to support the western section. A series of concrete cylinders were grouped together and then capped-off, having the air pressure of each cylinder identical to balance the beginning of the structure. From there, the workers added sets of new cylinders until the caisson reached the bottom of the bay. Then, in order to reach the bedrock, they inserted long drills down the cylinders, digging until they reached bedrock. After the caisson was balanced at the bottom of the bay, workers filled it with 1 million cubic yards of concrete, more concrete than was used for the construction of the Empire State Building! This caisson connected the two suspension bridges that make up the western part of the bridge.
Fiberglass reinforced concrete (GFRC) is most suitable for construction because it is a great material for restoration of old buildings and also used for the exterior of the buildings. It is also widely used for walls and ceilings. GFRC allows almost perfect replication of building terra-cotta and ornaments. It’s very low shrinkage allows molds to be made from existing structural ornamentation, then cast in GFRC to replicate the original designs. GFRC is lightweight compared to other traditional concrete, which is very important for construction.
Furthermore, FRP materials do not exhibit yielding; rather, they are elastic failure. So efforts are being made to establish recommendations for design with FRP reinforcement.
Reinforced concrete is stronger than basic concrete. Steel reinforcing bars known as rebar is incorporated in the concrete structure to act together in resisting the force. The steel reinforcing bars absorbs tensile and compression because plain conc...
(Engg, 2013), investigated the structural properties of foamed concrete with and without pulverized bone. The tensile strength was evaluated by subjecting 150 x 150 x 750 mm unreinforced foamed concrete beams to flexural test and 150 x 300 mm cylinder specimens were subjected to splitting test. At the designed density of 1600 kg/m3, the modulus of rupture and splitting tensile strength were 2.53 and 1.63 MPa respectively with ratio of 0.64.
Offshore engineering is a new and rapidly developing field. Even though the main interest is still oil production related, offshore structures are also widely used for energy production from ocean waves, mining, port structure and other similar fields. By definition an offshore structure can be defined as the structure or a facility which is being installed in marine environment, mainly in the sea in order to produce and transmit electricity, gas, oil and also other resources. Offshore structure can be classified into two major group; floating and fixed structures. As for the fixed structures, it can be further divided into steel jackets tower, compliant towers, concrete gravity based structure, jack-ups structure and also the tension leg structure (TLP).
Sustainable concrete materials and sustainable steel reinforcement have been introduced to civil engineers to get closer to the sustainable development. Sustainable buildings constructed with use of these materials have shown an increased service life and the final cost has been reduced due to them.
Civil Engineering is evolving and its evolution needs to increase. This report endeavours to place the progression of technology and the addition of engineering into its archival background. With the increasing problems that tackle the world of civil Engineering and Structural designs, solutions need to be yielded to protect and maintain structural forms not just in our present age but in the future to come. The major setback is that our present approach to advancement is unsustainable. We are severely abusing resources, generating pollution and making species extinct. One cannot stress enough the need for development at a sustainable level. I also intend to explain the physical and material properties of steel, the process of its production and how sustainable it is in construction of structures.