Construction+Features+of+Bridges

Construction Features of Bridges Truss bridges: Truss- A truss is the oldest and most often used method of making more efficient bridges. A truss is a structure made from straight links connected at joints. The joints are always at the ends of the links, never in the middle. The links are called members. When a load is applied to any joint, the members will share the load, although not equally.

There are many different types of truss bridges. Some of the types of truss bridge designs prove advantageous if wood is used in the construction; this is especially useful to protect the components or truss members that face compression. Lamination: Lamination- A layered structure. They laminate wood together to make the bridge stronger. After they laminate the timber they can bend the timber and attach it to the bridge to increase its strength. They stack the pieces of wood on top of each other to increase its strength. When the timber is stacked together the grains on the wood are facing opposite directions. Corrugation: Corrugation- The curved corrugated webs produce a tremendous increase in the shear buckling strength and considerable weight saving in regard to the corresponding trapezoidal corrugated webs. The corrugation angle has a considerable effect on the behavior of curved corrugated webs, where higher corrugation angles produce a tremendous increase in the shear buckling strength of curved corrugated webs. It was found that the proposed approach provides a good prediction for the shear buckling strength of curved corrugated steel webs of bridges.

High performance steels, which are becoming increasingly available,are well suited for highway bridge applications due to their high strength, excellent toughness, as well as good weldability and corrosion resistance. These steels have the potential to produce considerable weight __savings__, although impediments to their effective use in conventional stiffened flat web plate girders include the potential for web instability, excessive deflections,and fatigue failure _Sause 1996_. To overcome these limitations, innovative designs have been proposed, including the use of corrugated webs to provide enhanced shear stability and eliminate. the need for transverse stiffeners.

Column Column- As the axial load on a perfectly straight slender column with elastic material properties is increased in magnitude, this ideal column passes through three states: stable equilibrium, neutral equilibrium, and instability. The straight column under load is in stable equilibrium if a lateral force, applied between the two ends of the column, produces a small lateral deflection which disappears and the column returns to its straight form when the lateral force is removed.

If the column load is gradually increased, a condition is reached in which the straight form of equilibrium becomes so-called neutral equilibrium, and a small lateral force will produce a deflection that does not disappear and the column remains in this slightly bent form when the lateral force is removed. The load at which neutral equilibrium of a column is reached is called the critical or buckling load.