Essay On Structural Components

To fix the failing infrastructure problem, one must identify why the structures, in this case bridges, are failing in the first place. Civil engineers have identified that the problem is not cause by one singular factor, but a multitude of factors including age, materials, environment, faulty design, and lack of maintenance. Environmental factors are the biggest concern engineers run into because it is

In the specimens, all showed a brittle fracture due to how the stress vs strain slope looked and where the Ultimate Tensile Strength was located. Also, how the composited specimens failed look consistent that there were any defects in the specimens. The 0°/90° carbon/epoxy specimen failed in the longitudinal direction because of how the fibers were aligned in that direction. The two ±45° glass/ epoxy specimen failed in the 45-degree direction do to how the fibers were aligned in the specimens. These failures would make sense because composites fail when fiber become unconnected so the epoxy failed first and then cause the fibers to fail next. The fibers individual are weak but when are combined and form a pattern with other fibers is how the strength

Compression is the force pressing a material and compacting it and acts on the towers of a suspension bridge, this force is created from the weight of the towers and the load on the bridge. Compression forces will also act on the surface of the bridge deck as when a load is applied it will have some flexibility and bend, it will then travel up the cables, ropes or chains to transfer the compression forces to the towers. The towers then dissipate the compression directly into the earth. (Bagga 2014).

ACI 318-63 requires that the minimum ratio of longitudinal bars shall be at least 1.0%. Also, The vertical center-to-center spacing of the lateral ties shall be one of the smallest of: (1) 16 longitudinal bar diameters to restrain longitudinal bars from buckling, (2) 48 tie diameters to ensure sufficient tie area to restrain the lateral displacement of the reinforcing bars, and (3) the least lateral dimension of the column to develop the maximum strength of the concrete core. As shown in Fig. 1, The dimensions and steel reinforcement details of the columns involved in this experimental program were particularly selected to represent relatively older columns. In this experimental program, the longitudinal reinforcement ratio, ρl, was constant

Two weeks ago, there was an incident at Truss Construction Shop. A hoist operator was placed into an induced coma due to a large part of a Truss breaking apart during a QA Truss load test. The Truss broke apart because the testing was pushed beyond the threshold. This

An example of this is shrinkage cracks. As concrete cures and hardens, it loses water and shrinks. During this shrinkage, the concrete steadily gets more rigid which in turn resists the shrinkage. At some point the concrete's rigidity resists any further shrinkage. By this time however, a great deal of built-up internal stress causes the concrete to develop small cracks. These are usually hairline or less than 1/8 inch in width and tend to wander about. Sometimes they will stop at one spot and then start up again a short distance away. They often radiate out from the corners of rectangular holes in the concrete and from embedded objects such as pipes and drains. Weathering will also cause non-structural cracks on the concrete's

Although the Tacoma Narrows Bridge is oft considered “the most spectacular failure in bridge engineering history”, it was far from being the first unsuccessful suspension bridge. There were ten prior suspension bridges that failed due to unaccounted wind/oscillating forces. However, the Tacoma Narrows Bridge collapsed 50 years after the last bridge, and it was the most expensive and longest- more than double any previous bridge- that is the reason why its failure is so significant. The remains of this bridge now serve as “one of the world’s largest manmade

Shear occurs in bridges when the weight of the bridge itself or the weight of the load on the bridge causes materials to slide by each other or shear off. An overload of weight on the bridge can cause

Under these circumstances, the center span of the bridge collapsed and fell into the Mississippi River. All four gusset plates at the U10 nodes fractured since they were inadequate in strength for the demand being exerted on to them. When these first gusset plates fractured, other gusset plates started to fracture and break too because the design of the bridge was non-load-path-redundant. In other words, if one piece, such as the U10 gusset plate, failed, then the whole bridge would fail too.

In 1989, an earthquake caused the top deck of the bridge to collapse. This has raised concern in recent years in the case of a large scale earthquake. During an inspection in September of 2009, a 1.5 inch crack was found in a structural truss called an eyebar. The system of the truss is meant to distribute report will describe the tensile load from the weight of the bridge over 4 eyebars. One of them being broken, this same load was now distributed between only 3 eyebars. Because these eyebars were not designed to carry extra load, it became crucially important to repair the eyebar as soon as possible. However, because the bridge is so old, its mechanisms were more complex than what would be designed now in the current day. The engineering company C.C. Myers was contracted to do the repair. C.C Myers decided to repair the eyebar by welding a crossbar to the saddles which had been placed on each end of the broken eyebar (Alfrey, 2010). Four tie rods were then bolted to distribute the tensile load (Reid, 2010). This repair was completed in only 70 hours (Carlsen,

When the bridge was tested, at 26 pounds of pressure, it began to buckle. The top support near the middle of the bridge on one side caved in, and as the weight increased, more of the top supports collapsed. At 47.3 pounds of pressure, the bridge snapped in half. By the end of the testing, the bridge had lost all of it’s top supports, two sections of diagonal supports on either side, and a small portion of the roadway.

Improperly designed welds on the cross bracing led to the failure of 3 of the bridge’s beams. Extremely cold weather and constant morning rush-hour traffic also added to the list of causes. This caused the bridge to buckle inwards.

•Torsion occurs when opposite ends of structure twist in opposite directions. It could also result from shearing.

If the truck weight increases beyond first cracking, flexural cracks will propagate in all directions and cause yield in steel girders, which may lead to a collapse of the bridge such as collapse of the interstate 35 bridge near Minneapolis in United States. It collapses due to overload by heavy trucks as shown figure 1.2.

(Fabian, 2010), the tensile strength of concrete is important when considering cracking. For specimens loaded under uniaxial compression, cracking parallel to the line of action of the load implies some influence of the tensile strength of the specimens units. Depending on the load impact, tensile strength can be divided into flexural tensile strength, splitting