As an aid to the architect in coordinating beam and

  • No School
  • AA 1
  • 374

This preview shows page 28 - 30 out of 374 pages.

amount of reinforcing required. As an aid to the architect in coordinating beam and girder web penetrations with the building ductwork and pip- ing services, the following guidelines are suggested: ! Penetrations through members that have a depth-to-web thickness, d/t w > 75 should be avoided. Domestically available rolled shapes generally fall outside this criterion. ! The ratio of hole length to depth should be lim- ited to 2.5. ! The hole depth must be limited to a maximum of 70 percent of the member depth. ! A minimum 15 percent of the member depth must remain from the edge of the hole to the outside face of the flange. ! Corners of penetrations must be made with a radius of approximately one inch. This must be considered in determining the size of penetra- tion to accommodate ductwork and piping serv- ices. ! Concentrated loads from beams and column transfers must not be made within the length of the hole. ! Multiple holes should have a minimum two times the hole length between hole edges. ! Beams are to be laterally supported by the floor/roof construction. ! Penetrations in members that are at or near deflection limits or that have sensitive vibrations should be avoided. ! All penetrations must be investigated by a qualified structural engineer to insure the structural integrity of the member. SYSTEMS PAGE 16 Figure 14. Concentric and eccentric web penetrations CONCENTRIC WEB PENETRATION ECCENTRIC WEB PENETRATION A Hole Width A Hole Width 0.15 d (min.) Hole Depth Member Depth B 0.15 d (min.) Hole Depth Eccentricity ( e ) B d Member Depth d
Image of page 28
PAGE 17 SYSTEMS THERMAL MOVEMENT OF STRUCTURAL STEEL One of the most difficult things to evaluate throughout the life of a building, and particularly during the con- struction period, is the amount of horizontal movement, expansion and contraction. It is difficult to design for movement since the designer cannot control some of the parameters. Expansion or contraction requirements for a structure under construction will be determined by the greatest change in temperature that the structure is exposed to prior to being enclosed and conditioned. Thermal movement is a concept that is not unique to exposed structural steel. In fact, it is not unique to steel as a building material. Movement applies to all building materials and must be accounted for in all types of construction. However, for these purposes discussion will be limited to movement of structural steel resulting from changes in temperature. For example, it is reasonable for a steel building that is under construction in the Midwest to be erected in sum- mer where the temperature of the steel exposed to the sun can exceed 100° Fahrenheit. The same building may not be enclosed by January, when the night temperatures can dip well below zero. The building would see a tem- perature change of more than 100° Fahrenheit from summer to winter. The type of temperature differential might not appear to be significant. The integrity of the steel structure would not be affected by the thermal changes. However, the movement and stresses in the steel structure associated with a 100 ° change in temperature could be substantial.
Image of page 29
Image of page 30

You've reached the end of your free preview.

Want to read all 374 pages?

  • Fall '19
  • Structural steel

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern

Stuck? We have tutors online 24/7 who can help you get unstuck.
A+ icon
Ask Expert Tutors You can ask You can ask You can ask (will expire )
Answers in as fast as 15 minutes
A+ icon
Ask Expert Tutors