/m)* Wind load on Live load:Transverse loading= 100 lb/ft (1.46 kN/m)Longitudinal loading= 40 lb/ft (0.58 kN/m)The transverse and longitudinal loads are to be placed simultaneously for both thestructure and love load. Another loading consideration is the effect of overturning. Toaccount for this, AASHTO specifies a 20 lb/ft overturning force to be applied at quarterpoints on the windward chord. Channel forces are those loads imposed on a structure due to water course-relatedfeatures. These forces include, but are not limited to, stream flow, floating ice, andbuoyancy. Channel forces, similar to seismic forces, primarily affect substructureelements. When a bridge is subject to loads, its constituent elements develop internal forceswhich resist those loads. In general, the resisting of loads of* Bending force* Shear force* Torsional force* Axial forceWhen a load is placed on a structural member, the member will respond bybending. This bending is resisted by an internal rotational force or moment. Theserotational forces are equal and opposite couples which act in a common plane. From basicstatics, it is known that a moment can be quantified as a force times a distance. Since theloads on bridges are relatively large, U.S. values are typically given as ft-kips where a kipis a 1000-pound force. The SI equivalent unit is kN-m. Stresses in a member that resultfrom bending forces are referred to as bending stresses or sometimes as flexural stresses.In bridges design, primary members are the elements that are most affected bybending forces. As the load acts downward the effects of which are compression at thetop most part of the beam and tension at the bottom. It is at the top and bottom of thegirder where stresses are the greatest. Stresses decrease to zero approaching the neutralsurface of the girder.A shear force will cause an internal force in a member which acts in the plane ofthe section. The shear stress will be referen...
