introduction to structural engineering 12-100 introduction to civil and environmental engineering...
TRANSCRIPT
![Page 1: Introduction to Structural Engineering 12-100 Introduction to Civil and Environmental Engineering Fall 1997 Lecture 3](https://reader036.vdocuments.site/reader036/viewer/2022081507/551b2ba3550346dd1a8b4b43/html5/thumbnails/1.jpg)
Introduction to Structural Engineering
12-100 Introduction to Civil and Environmental Engineering
Fall 1997
Lecture 3
![Page 2: Introduction to Structural Engineering 12-100 Introduction to Civil and Environmental Engineering Fall 1997 Lecture 3](https://reader036.vdocuments.site/reader036/viewer/2022081507/551b2ba3550346dd1a8b4b43/html5/thumbnails/2.jpg)
Outline
• Objective of Structural Engineering
• Structural Engineering Process
• Types of loads
• Types of structures
• Load paths in structures
• Summary
![Page 3: Introduction to Structural Engineering 12-100 Introduction to Civil and Environmental Engineering Fall 1997 Lecture 3](https://reader036.vdocuments.site/reader036/viewer/2022081507/551b2ba3550346dd1a8b4b43/html5/thumbnails/3.jpg)
Civil Engineering Subdisciplines
• structural
• geotechnical
• environmental
• transportation
• construction
![Page 4: Introduction to Structural Engineering 12-100 Introduction to Civil and Environmental Engineering Fall 1997 Lecture 3](https://reader036.vdocuments.site/reader036/viewer/2022081507/551b2ba3550346dd1a8b4b43/html5/thumbnails/4.jpg)
Objectives of Structural Engineering
Structural engineering is the science and art of designing and making, with economy and elegance, buildings, bridges, frameworks, and other structures so that they can safely resist the forces to which they may be subjected.
The Structural Engineer,
Official Journal of the British Institute of Structural Engineers
![Page 5: Introduction to Structural Engineering 12-100 Introduction to Civil and Environmental Engineering Fall 1997 Lecture 3](https://reader036.vdocuments.site/reader036/viewer/2022081507/551b2ba3550346dd1a8b4b43/html5/thumbnails/5.jpg)
Structural Engineering Process
• Determine types magnitudes of loads
• Determine structural context • geometric and geological information• cost / schedule / height/ etc. limitations
• Generate alternative structural systems
• Analyze one or more alternatives
• Select and perform detailed design
• Implement (usually done by contractor)
![Page 6: Introduction to Structural Engineering 12-100 Introduction to Civil and Environmental Engineering Fall 1997 Lecture 3](https://reader036.vdocuments.site/reader036/viewer/2022081507/551b2ba3550346dd1a8b4b43/html5/thumbnails/6.jpg)
Types of loads
• Dead loads
• Live loads
• Dynamic loads (e.g., trains, equipment)
• Wind loads
• Earthquake loads
• Thermal loads
• Settlement loads
![Page 7: Introduction to Structural Engineering 12-100 Introduction to Civil and Environmental Engineering Fall 1997 Lecture 3](https://reader036.vdocuments.site/reader036/viewer/2022081507/551b2ba3550346dd1a8b4b43/html5/thumbnails/7.jpg)
Dead Loads
• weight of the structure itself• floors, beams, roofs, decks, beams/stringers,
superstructure
• loads that are “always there”
![Page 8: Introduction to Structural Engineering 12-100 Introduction to Civil and Environmental Engineering Fall 1997 Lecture 3](https://reader036.vdocuments.site/reader036/viewer/2022081507/551b2ba3550346dd1a8b4b43/html5/thumbnails/8.jpg)
Live Loads
• People, furniture, equipment
• Loads that may move or change mass or weight
• Minimum design loadings are usually specified in the building code
![Page 9: Introduction to Structural Engineering 12-100 Introduction to Civil and Environmental Engineering Fall 1997 Lecture 3](https://reader036.vdocuments.site/reader036/viewer/2022081507/551b2ba3550346dd1a8b4b43/html5/thumbnails/9.jpg)
Load Example: Live Load in Ballroom
Live Load = 100 lb/ft^2Ballroom
![Page 10: Introduction to Structural Engineering 12-100 Introduction to Civil and Environmental Engineering Fall 1997 Lecture 3](https://reader036.vdocuments.site/reader036/viewer/2022081507/551b2ba3550346dd1a8b4b43/html5/thumbnails/10.jpg)
Dynamic Loads
• Moving loads (e.g. traffic)
• Impact loads
• Gusts of wind
• Loads due to cycling machinery
![Page 11: Introduction to Structural Engineering 12-100 Introduction to Civil and Environmental Engineering Fall 1997 Lecture 3](https://reader036.vdocuments.site/reader036/viewer/2022081507/551b2ba3550346dd1a8b4b43/html5/thumbnails/11.jpg)
Load Example: Dynamic Load
HVAC
F
t
![Page 12: Introduction to Structural Engineering 12-100 Introduction to Civil and Environmental Engineering Fall 1997 Lecture 3](https://reader036.vdocuments.site/reader036/viewer/2022081507/551b2ba3550346dd1a8b4b43/html5/thumbnails/12.jpg)
Load Example: Water in a dam
Water, = density
h p = gh
![Page 13: Introduction to Structural Engineering 12-100 Introduction to Civil and Environmental Engineering Fall 1997 Lecture 3](https://reader036.vdocuments.site/reader036/viewer/2022081507/551b2ba3550346dd1a8b4b43/html5/thumbnails/13.jpg)
Earthquake Loads
• Structure loaded when base is shaken
• Response of structure is dependent on the frequency of motion
• When frequencies match with natural frequency of structure - resonance
![Page 14: Introduction to Structural Engineering 12-100 Introduction to Civil and Environmental Engineering Fall 1997 Lecture 3](https://reader036.vdocuments.site/reader036/viewer/2022081507/551b2ba3550346dd1a8b4b43/html5/thumbnails/14.jpg)
Load Example: Earthquake Load
Base Motion
Earthquake Load
Earthquake Load
![Page 15: Introduction to Structural Engineering 12-100 Introduction to Civil and Environmental Engineering Fall 1997 Lecture 3](https://reader036.vdocuments.site/reader036/viewer/2022081507/551b2ba3550346dd1a8b4b43/html5/thumbnails/15.jpg)
![Page 16: Introduction to Structural Engineering 12-100 Introduction to Civil and Environmental Engineering Fall 1997 Lecture 3](https://reader036.vdocuments.site/reader036/viewer/2022081507/551b2ba3550346dd1a8b4b43/html5/thumbnails/16.jpg)
![Page 17: Introduction to Structural Engineering 12-100 Introduction to Civil and Environmental Engineering Fall 1997 Lecture 3](https://reader036.vdocuments.site/reader036/viewer/2022081507/551b2ba3550346dd1a8b4b43/html5/thumbnails/17.jpg)
Settlement
![Page 18: Introduction to Structural Engineering 12-100 Introduction to Civil and Environmental Engineering Fall 1997 Lecture 3](https://reader036.vdocuments.site/reader036/viewer/2022081507/551b2ba3550346dd1a8b4b43/html5/thumbnails/18.jpg)
Some Types of Structures
• Arch
• Planar Truss
• Beam/Girder
• Braced Frame
• Rigid Frame
• Space Truss
• Cable Suspended Structure
![Page 19: Introduction to Structural Engineering 12-100 Introduction to Civil and Environmental Engineering Fall 1997 Lecture 3](https://reader036.vdocuments.site/reader036/viewer/2022081507/551b2ba3550346dd1a8b4b43/html5/thumbnails/19.jpg)
Arch
![Page 20: Introduction to Structural Engineering 12-100 Introduction to Civil and Environmental Engineering Fall 1997 Lecture 3](https://reader036.vdocuments.site/reader036/viewer/2022081507/551b2ba3550346dd1a8b4b43/html5/thumbnails/20.jpg)
![Page 21: Introduction to Structural Engineering 12-100 Introduction to Civil and Environmental Engineering Fall 1997 Lecture 3](https://reader036.vdocuments.site/reader036/viewer/2022081507/551b2ba3550346dd1a8b4b43/html5/thumbnails/21.jpg)
Planar Truss
![Page 22: Introduction to Structural Engineering 12-100 Introduction to Civil and Environmental Engineering Fall 1997 Lecture 3](https://reader036.vdocuments.site/reader036/viewer/2022081507/551b2ba3550346dd1a8b4b43/html5/thumbnails/22.jpg)
![Page 23: Introduction to Structural Engineering 12-100 Introduction to Civil and Environmental Engineering Fall 1997 Lecture 3](https://reader036.vdocuments.site/reader036/viewer/2022081507/551b2ba3550346dd1a8b4b43/html5/thumbnails/23.jpg)
Beam/Girder
![Page 24: Introduction to Structural Engineering 12-100 Introduction to Civil and Environmental Engineering Fall 1997 Lecture 3](https://reader036.vdocuments.site/reader036/viewer/2022081507/551b2ba3550346dd1a8b4b43/html5/thumbnails/24.jpg)
![Page 25: Introduction to Structural Engineering 12-100 Introduction to Civil and Environmental Engineering Fall 1997 Lecture 3](https://reader036.vdocuments.site/reader036/viewer/2022081507/551b2ba3550346dd1a8b4b43/html5/thumbnails/25.jpg)
Frames
Braced Rigid
![Page 26: Introduction to Structural Engineering 12-100 Introduction to Civil and Environmental Engineering Fall 1997 Lecture 3](https://reader036.vdocuments.site/reader036/viewer/2022081507/551b2ba3550346dd1a8b4b43/html5/thumbnails/26.jpg)
![Page 27: Introduction to Structural Engineering 12-100 Introduction to Civil and Environmental Engineering Fall 1997 Lecture 3](https://reader036.vdocuments.site/reader036/viewer/2022081507/551b2ba3550346dd1a8b4b43/html5/thumbnails/27.jpg)
Cable Suspended Structure
![Page 28: Introduction to Structural Engineering 12-100 Introduction to Civil and Environmental Engineering Fall 1997 Lecture 3](https://reader036.vdocuments.site/reader036/viewer/2022081507/551b2ba3550346dd1a8b4b43/html5/thumbnails/28.jpg)
![Page 29: Introduction to Structural Engineering 12-100 Introduction to Civil and Environmental Engineering Fall 1997 Lecture 3](https://reader036.vdocuments.site/reader036/viewer/2022081507/551b2ba3550346dd1a8b4b43/html5/thumbnails/29.jpg)
Cable Stayed Bridge
![Page 30: Introduction to Structural Engineering 12-100 Introduction to Civil and Environmental Engineering Fall 1997 Lecture 3](https://reader036.vdocuments.site/reader036/viewer/2022081507/551b2ba3550346dd1a8b4b43/html5/thumbnails/30.jpg)
![Page 31: Introduction to Structural Engineering 12-100 Introduction to Civil and Environmental Engineering Fall 1997 Lecture 3](https://reader036.vdocuments.site/reader036/viewer/2022081507/551b2ba3550346dd1a8b4b43/html5/thumbnails/31.jpg)
Load Paths in Structures
• Load Path is the term used to describe the path by which loads are transmitted to the foundations
• Different structures have different load paths
• Some structures have only one path
• Some have several (redundancy good)
![Page 32: Introduction to Structural Engineering 12-100 Introduction to Civil and Environmental Engineering Fall 1997 Lecture 3](https://reader036.vdocuments.site/reader036/viewer/2022081507/551b2ba3550346dd1a8b4b43/html5/thumbnails/32.jpg)
Load Path in Framed Structure
![Page 33: Introduction to Structural Engineering 12-100 Introduction to Civil and Environmental Engineering Fall 1997 Lecture 3](https://reader036.vdocuments.site/reader036/viewer/2022081507/551b2ba3550346dd1a8b4b43/html5/thumbnails/33.jpg)
Load Path in a Tied Arch
![Page 34: Introduction to Structural Engineering 12-100 Introduction to Civil and Environmental Engineering Fall 1997 Lecture 3](https://reader036.vdocuments.site/reader036/viewer/2022081507/551b2ba3550346dd1a8b4b43/html5/thumbnails/34.jpg)
Summary
• Structural Engineering:• identifies loads to be resisted• identifies alternatives for providing load paths
(arch, truss, frame, ...)• designs structure to provide safe and economical
load paths (material, size, connections)• to be economical and safe, we must be able to
predict what forces are in structure.