Civil engineering has historically played a fundamental role by changing ways in which people live, travel, and work. It is a broad scope of engineering field that ranges from construction and design of structures, roads and highways construction and processes of pollution control to the organization and management of our engineered and natural resources. Its wide range has lead to its division in a number of sub-disciplines, including transportation engineering, structural engineering, geotechnical engineering, construction management, environmental engineering materials and water resources engineering. Civil engineering incorporates a number of science disciplines, among which are physics, geology, chemistry, material science, microbiology statistics, mathematics and economics (Billington, 1996).
Transportation engineering is a sub-discipline of civil engineering that has the mandate to ensure good quality of our transportation system. It helps meet the ever increasing travel needs on our sea, air and land and helps move people, materials and goods efficiently and safely. Transportation engineering entails construction, designing and maintaining all kinds of transportation facilities, among which are railroads, airfields, highways and ports. It helps upgrade the transportation potential through improving control of traffic and mass transport systems and by initiating new methods of transportation.
Water is fundamental to our lives and has to be supplied to agricultural fields and for purposes of drinking. Therefore, identification of proper storage and appropriate water resources is vital. Water resources engineering entails planning, identifying and building structures designed to retain water, like dams and tanks. It involves the designing, maintenance and construction of dams, pipelines, canals, hydroelectric power facilities, locks and pumping stations, and seaport facilities.
Environmental engineering materials provide a healthy public environment through protecting our planet’s fragile resources. Vehiclar traffic increase and industrialization has lead to an increase in air pollution, which makes it obligatory to focus on protection and maintenance of our natural and environmental resources. Environmental engineering transforms the physical, biological and the chemical processes into systems. This removes water pollutants, reduces volumes of non-hazardous solid wastes, destroys toxic substances, develops groundwater supplies and helps eliminate air contamination.
Geotechnical engineering, in its turn, deals with the analysis of soil and rocks to determine the foundation’s safe bearing capacity for buildings. It incorporates the study of ground development techniques and how they affect building structures. Project developments in this field include foundations of buildings, tunnels, and offshore platforms. Geotechnical engineering evaluates the stability of fills and slopes, ground water seepage, the potential building settlements, and also earthquake effects.
Structural engineering is a very exciting field in engineering concerned with the building’s structural design and analysis; it deals with the planning and design of various structures including bridges, flyovers, towers, offshore structures as well as gas and oil fields and tunnels (David, 2003). It involves load identification upon a structure and all forces and stresses arising within structures, and then successful designing of the structure to resist and support such a loading. Loads include structure self weight, live loads, dead loads, moving load, load due to temperature variations, earthquake load etc.
Bridges are structures built to ease problems of physical obstacles and provide passage through water, roads, and valleys (Whitney, 2003). Bridge designs vary depending on the condition of terrain, bridge functions, the materials for construction and the finance available to build it. There exist many bridges types depending on the terrain’s nature and purposes of the bridge (Brown, 2005). These include cantilever bridges, which are built through extending a cantillever arm from each side. The Devil’s Slide Bridge found in California is one example of a cantilever beam whose construction techniques avoided the temporary building of its supports. Other types of bridges include suspension bridges, which employ the use of a box roadway section reinforced by cables of high tensile strength. The Akashi Kaikyo is the world’s biggest suspension bridge with a length of 1991m, while the Great Belt Bridge is the world’s second largest suspension bridge. Beam bridges represent the simplest form of bridges supported at either end by piers. The other types of bridges are the arch bridges, truss bridges and cable-stayed bridges, which have become an efficient substitute to suspension bridges, especially where the span is long. The Sutong Bridge in China is the world’s largest kind of cable stayed bridges with a span of 1088meters (3570ft).
Bridge construction is rapidly shifting with the beginning of the new millennium (Whitney, 2003). New materials and new technological techniques are up-coming, and several beautiful bridge designs have been already built using new technology. The New Francisco Bridge that connects Oakland and San Francisco built by the Chinese is an example of the application of new technology in the construction of bridges. It extends by 2050ft across the San Francisco bay.
Therefore, it is important to take into consideration the structural and economic efficiency of a certain bridge. A bridge must be designed to meet the set specifications for the safety of its users. These design specifications include stiffness, strength and stability of bridges when they are subjected to different loadings. Other important considerations are safety, cost, aesthetics, constructability and sustainability. Therefore, developing appropriate combination of construction materials is of great significance.
Finally, training and education programs in inspection of bridges, assessment, and bridge design integrating cutting edge technology supporting lifetime learning are likely to be fashioned.