2. 1.STRUCTURE : A structure is an assemblage of components which are connected in such a way that the structure can withstand the action of loads that are applied to it. These loads may be due to gravity, wind, ground shaking, impact, temperature, or other environmental sources. Examples of structures employed in civil infrastructure are buildings, bridges, dams, tunnels, storage tanks, and transmission line towers.

3. السدود نفق

4. transmission line towers أبراج خط نقل storage tanks صهاريج التخزين

5. The components are the basic building blocks of a structure. We refer to them as structural elements. Elements are classified into two categories according to their geometry: 1. Line Elements: Examples are cables, beams, columns, and arches. Another term for a line element is member. 2. Surface Elements: The elements are plate-like. Examples are flat plates, curved plates, and shells such as spherical, cylindrical, and hyperbolic paraboloids. Structural Components

6. Beams: straight horizontal members are used generally to carry vertical loads. Beams may be designed from several of element and materials – concrete, metal etc. Columns : members are generally vertical and resist axial compressive loads

7. Type of Beams : BEAM

8. Column s

10. Truss Truss is a structure composed of slender members joined together at their end points.

11. Cables and Arches

13. Frames Frames members are subjected to axial, shear and moment

14. 2.Loads: Structural loads or actions are forces, deformations, or accelerations applied to a structure or its components. Loads cause stresses, deformations, and displacements in structures.

15. Types Of Loads  Concentrated Force: single load at one point  Distributed Force: loading spread over a distance or area

16. E xternal forces are forces applied to the structure from the outside of the structure. Examples of external forces include dead loads, such as the weight of the structure itself and the non-structural materials it supports, and live loads, which include moving loads, such as occupants, goods, and furniture, as well as wind loads, seismic loads, and impact loads, among others. Despite the lack of connection between two or more objects, forces such as gravitational and electromagnetic forces can also be classified as external forces. External Forces (Surface/Body)

17. Live loads are the weights of people, furniture, supplies, machines, stores. Live loads are distinguished from dead loads which are the weights of the building itself, the secondary members and the finishing materials. Live loads are movable and variable during the use and occupancy of the building, and sometimes cause dynamic effects.

18. There are many types of supports in engineering mechanics. The types are: 1.Fixed support 2.Pin-Joint support 3.Roller support 4.Simple support Civil structures are connected to the ground at certain points called supports. When the external loading is applied to the structure, the supports develop forces which oppose the tendency of the structure to move. These forces are called REACTION FORCES. 3.Supports: