9 Civil Engineering

Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. 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.

Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. 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

Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. Subfields of Civil Engineering Structural engineering Water resources engineering Transportation engineering Environmental engineering Construction engineering Geomatics engineering

Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. 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

Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. 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)

Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. 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

Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. Structures Built to support specific load for practical purpose Structural loads Structural forces Structural components Structural materials Structural analysis

Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. 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

Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. Structural Forces Compression – crushing force Tension – pulling force Shear force – forces acting in opposite directions Torsion – turning force Bending force – force causing sagging

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Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. 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

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Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. Structural Materials Stone Bricks Wood Concrete Steel Reinforced concrete Carbon fiber

Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. 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

Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. 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

Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. A Free Body Diagram of a Truss The structural members and joints The supports The loads or forces applied Goodheart-Willcox Publisher

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Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. Civil Engineering Software Helps engineers create and communicate designs –Planning –Drawing –Organization –Simulation Many programs specific to types of civil engineering Typically includes symbols Design

Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. Civil Engineering Applications Bridges –Beam bridges –Arch bridges –Suspension bridges –Specialty bridges Skyscrapers Geomatics engineering

Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. Bridges Each structure must meet specific constraints –Length of span –Type of foundation –Environment –Available materials Basic components –Piers –Abutments –Roadway

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Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. 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

Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. 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

Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. Suspension Bridges Longest type of bridge Main section is similar to upside-down arch bridge Utilize tension forces Main components –Towers –Main cables –Anchorages

Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. 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

Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. 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

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Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. Other Structural Civil Engineering Applications Dams Tunnels Sports stadiums with removable roofs

Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. Geomatics Engineering Determines locations of objects on earth –Land masses –Rivers –Oceans –Human-built structures Engineers create land and resource maps Conduct boundary and other land surveys Design and utilize GIS

Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. 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

Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. Creating Subdivision Plans Robert Adrian Hillman/Shutterstock.com

Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. 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 Tools

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Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. 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