9 Civil Engineering Objectives Define civil engineering Describe
9 Civil Engineering
Objectives • • • Define civil engineering. Describe structural forces, loads, and components. Identify different types of bridges. Understand the structure of a skyscraper. Describe the purpose of land surveying. © Goodheart-Willcox Co. , Inc. Permission granted to reproduce for educational use only.
About Civil Engineering • Considered to be oldest field in engineering • Mission is to build safe facilities that meet needs of society • Public works projects – Roads – Bridges – Dams – Municipal water systems • Broad field that includes many subfields © Goodheart-Willcox Co. , Inc. Permission granted to reproduce for educational use only.
Subfields of Civil Engineering • • • Structural engineering Water resources engineering Transportation engineering Environmental engineering Construction engineering Geomatics engineering © Goodheart-Willcox Co. , Inc. Permission granted to reproduce for educational use only.
Education Typically Required • High school courses – Physics and other high-level science courses – Calculus and other high-level math courses • College courses – Fundamentals of engineering – Statics – Dynamics – Materials – Engineering design © Goodheart-Willcox Co. , Inc. Permission granted to reproduce for educational use only.
Professional Societies • American Society of Civil Engineers (ASCE) – Oldest and largest civil engineering society – Founded in 1852 – Currently has over 144, 000 members • International Association for Bridge and Structural Engineers (IABSE) • Institute of Transportation Engineers (ITE) • American Planning Association (APA) © Goodheart-Willcox Co. , Inc. Permission granted to reproduce for educational use only.
Civil Engineering Principles • Must understand large knowledge base • Specialization areas requires more specialized knowledge • All areas of civil engineering must have a good understanding of structures © Goodheart-Willcox Co. , Inc. Permission granted to reproduce for educational use only.
Structures • • • Built to support specific load for practical purpose Structural loads Structural forces Structural components Structural materials Structural analysis © Goodheart-Willcox Co. , Inc. Permission granted to reproduce for educational use only.
Structural Loads • Structures designed to transmit loads from structure into ground • Two main types of loads – Static loads – Dynamic loads • Structures in state of equilibrium – Can oppose external forces – Can transfer load throughout structure © Goodheart-Willcox Co. , Inc. Permission granted to reproduce for educational use only.
Structural Forces • • • Compression – crushing force Tension – pulling force Shear force – forces acting in opposite directions Torsion – turning force Bending force – force causing sagging © Goodheart-Willcox Co. , Inc. Permission granted to reproduce for educational use only.
Types of Forces Goodheart-Willcox Publisher © Goodheart-Willcox Co. , Inc. Permission granted to reproduce for educational use only.
Structural Components • Beams – transmit loads to columns – Floor joists – I-beams • Columns – transmit load from above • Braces – provide resistance from forces – Struts – Ties • Joints – connect structural members together © Goodheart-Willcox Co. , Inc. Permission granted to reproduce for educational use only.
Types of Braces Goodheart-Willcox Publisher © Goodheart-Willcox Co. , Inc. Permission granted to reproduce for educational use only.
Structural Materials • • Stone Bricks Wood Concrete Steel Reinforced concrete Carbon fiber © Goodheart-Willcox Co. , Inc. Permission granted to reproduce for educational use only.
Structural Analysis • • • Responsibility of structural engineer Ensures structure has sufficient strength Ensures structure is as efficient as possible Makes best use of materials Incorporates physics, especially mechanics – Statics – Dynamics © Goodheart-Willcox Co. , Inc. Permission granted to reproduce for educational use only.
Truss Structural Analysis • Trusses are usually triangular in shape • Made of structural members pinned together at joints • Analysis begins with a free body diagram • Determine structural stability of truss • Calculate reactions and internal forces • Often done by computer software © Goodheart-Willcox Co. , Inc. Permission granted to reproduce for educational use only.
A Free Body Diagram of a Truss • The structural members and joints • The supports • The loads or forces applied Goodheart-Willcox Publisher © Goodheart-Willcox Co. , Inc. Permission granted to reproduce for educational use only.
Stability Formula Example Goodheart-Willcox Publisher © Goodheart-Willcox Co. , Inc. Permission granted to reproduce for educational use only.
Design Civil Engineering Software • Helps engineers create and communicate designs – Planning – Drawing – Organization – Simulation • Many programs specific to types of civil engineering • Typically includes symbols © Goodheart-Willcox Co. , Inc. Permission granted to reproduce for educational use only.
Civil Engineering Applications • Bridges – Beam bridges – Arch bridges – Suspension bridges – Specialty bridges • Skyscrapers • Geomatics engineering © Goodheart-Willcox Co. , Inc. Permission granted to reproduce for educational use only.
Bridges • Each structure must meet specific constraints – Length of span – Type of foundation – Environment – Available materials • Basic components – Piers – Abutments – Roadway © Goodheart-Willcox Co. , Inc. Permission granted to reproduce for educational use only.
Common Types of Bridges Goodheart-Willcox Publisher © Goodheart-Willcox Co. , Inc. Permission granted to reproduce for educational use only.
Bridge Components Goodheart-Willcox Publisher © Goodheart-Willcox Co. , Inc. Permission granted to reproduce for educational use only.
Beam Bridges • Bridges seen most often • Highway overpasses • Truss bridges – Load spread out through all structural members – Each structural member in compression or tension • Cantilever bridges – Two cantilevers and one suspended span – Truss framework often used on side of bridge © Goodheart-Willcox Co. , Inc. Permission granted to reproduce for educational use only.
Arch Bridges • Used for movement of vehicles and water • Rely on strength and rigidity of arch – Structural members always in compression – Can distribute load to abutments • Often have to be massive to withstand force • Impractical in areas with loose soil or little rock • Arch can support deck from above or below © Goodheart-Willcox Co. , Inc. Permission granted to reproduce for educational use only.
Suspension Bridges • • Longest type of bridge Main section is similar to upside-down arch bridge Utilize tension forces Main components – Towers – Main cables – Anchorages © Goodheart-Willcox Co. , Inc. Permission granted to reproduce for educational use only.
Specialty Bridges • Combination bridges – Sometimes a single type does not meet needs – Combination of two or more types might be best solution • Movable bridges – Drawbridges – Bridges that swing on pivot point – Bridges with sections that can be raised © Goodheart-Willcox Co. , Inc. Permission granted to reproduce for educational use only.
Skyscrapers • Structural frame, or skeleton – Can withstand dead load of building – Attached to footings and piers that extend deep into earth • Outer surface does not carry weight • Central core – Helps resist wind – More resistant to earthquakes – Contains elevator shafts and mechanical systems © Goodheart-Willcox Co. , Inc. Permission granted to reproduce for educational use only.
Main Components of a Skyscraper Goodheart-Willcox Publisher © Goodheart-Willcox Co. , Inc. Permission granted to reproduce for educational use only.
Other Structural Civil Engineering Applications • Dams • Tunnels • Sports stadiums with removable roofs © Goodheart-Willcox Co. , Inc. Permission granted to reproduce for educational use only.
Geomatics Engineering • Determines locations of objects on earth – Land masses – Rivers – Oceans – Human-built structures • Engineers create land resource maps • Conduct boundary and other land surveys • Design and utilize GIS © Goodheart-Willcox Co. , Inc. Permission granted to reproduce for educational use only.
Land Surveying • Main branch of geomatics engineering • Work has foundations in geometry and trigonometry • Relies on being able to measure distance and angles – Done with total station instrument – Total station includes electronic distance meter (EDM) – More recently, total robotic station can be used © Goodheart-Willcox Co. , Inc. Permission granted to reproduce for educational use only.
Creating Subdivision Plans Robert Adrian Hillman/Shutterstock. com © Goodheart-Willcox Co. , Inc. Permission granted to reproduce for educational use only.
Tools Surveying Bearings • Express directions of lines • Use quadrant system based on north, south, east, and west • Angles are found, measured from north-south axis • Allow surveyors to be exact in describing boundaries © Goodheart-Willcox Co. , Inc. Permission granted to reproduce for educational use only.
Four Quadrants Goodheart-Willcox Publisher © Goodheart-Willcox Co. , Inc. Permission granted to reproduce for educational use only.
Measuring Angles Goodheart-Willcox Publisher © Goodheart-Willcox Co. , Inc. Permission granted to reproduce for educational use only.
Survey Drawing Example Goodheart-Willcox Publisher © Goodheart-Willcox Co. , Inc. Permission granted to reproduce for educational use only.
Civil Engineering in Action • Civil engineers work in teams – Structural engineers – Architectural engineers – Land surveyors • US Army Corps of Engineers is largest employer – Builds military works and government projects – Is used in combat – Greatest impact is civil works projects © Goodheart-Willcox Co. , Inc. Permission granted to reproduce for educational use only.
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