The eLearning Center for Gatlin Education Services

Overview

This course will review the design process required for residential buildings (one to three-story) to withstand hurricanes and other severe natural hazard events.

The required calculations for all of the site specific design loads (forces) which will be applied to the structure is not within the scope of this course, however these site specific forces, which have been previously calculated in a case study, will be used in this course to design a structure that can withstand these forces.

To determine these site-specific design loads it is suggested that the design professional should refer to pertinent sections of the IRC 2000, in addition to those sections of the IBC 2000 which may be cited within this course.

Additional reference sources should also include one or more of the following sources in high wind zones:

  · Minimum Design Loads for Buildings and other structures (ASCE 7-98)
  · American Forest and Paper Association (AF&PA) Wood Frame Construction Manual for One and Two- Family Dwellings (WFCM)
  · Southern Building Code Congress International Standard for Hurricane Resistant Residential Construction (SSTD 10)

In this course the design method is Allowable Stress Design (ASD), so there are factors of safety (FS) built into the development of the material stresses and the forces at the connections. This design method has been chosen because (ASD) continues to be the predominant design method in light-frame, residential, wood construction.

The design process involves the following steps after determining all of the site-specific design loads (forces):

  · Determining the building's foundation, structural frame, and envelope
  · Determining the connections between individual elements
  · Determining the elevation, placement, and support for utilities
  · Selecting the appropriate materials

The course concentrates on determining the actual forces at connections and stresses on specific components, which are applied through vertical and horizontal load paths. The entire design process is based on the fundamental premise that anticipated service and natural hazard loads can and must be transferred through the building in a continuous path to the supporting soils.

Any weakness in that continuous path is a potential point of failure of the building, and any failure creates the possibility for large property losses and the potential for loss of life.

The student must take a multiple-choice quiz consisting of sixty (60) questions at the end of this course to earn PDH credits.

Specific Knowledge or Skill Attained

This course teaches the following specific knowledge and skills:

Design of structures which are capable to withstand the forces from various types of loadings which could be subjected to a one- to three-story residential buildings during hurricanes or other severe natural hazard events.

  · Dead loads
  · Live loads
  · Flood loads
  · Wind loads
  · Earthquake (seismic)
  · Snow loads

Prevention of Primary and Secondary Failure Modes

Uplift: Vertical forces caused by wind or buoyancy exceed the weight of the structure and the strength of the soil anchorage. The building fails by being lifted off its foundation or because the foundation pulls out of the soil.

Overturning: The applied moments caused by wind, wave, earthquake, and buoyancy forces exceed the resisting moments of the building's weight and anchorage. The building fails by rotating off its foundation or because the foundation rotates out of the soil.

Sliding or Shearing: Horizontal forces exceed the friction force or strength of the foundation. The building fails by sliding off its foundation, by shear failure of components transferring loads to its foundation, or by the foundation sliding.

Collapse: Collapse is a secondary mode of failure. Structural components fail or become out of plumb or level under uplift, overturning, or sliding. The building then becomes unstable and collapses.

Buildings under extremely heavy vertical downward loads, such as snow, can also fail in bending, shear, or compression of primary structural members. For purposes of this manual, it is assumed the designer is familiar with the design concepts used to support these ordinary gravity loads.

The Building Design process will be based on the following steps:

  · Use codes, standards, experience, judgment; state givens and assumptions.
  · Apply loads to building starting at the top; assume a building type, frame, and materials; assume a design approach (ASD, strength).
  · Determine forces at connections and stresses on components; apply through vertical and horizontal load paths
  · Specify connectors or connection methods to satisfy load conditions; specify materials that meet stress levels.
  · Note design assumptions on drawings; specify design details on drawings

Fact:

The National Flood Insurance Program (NFIP) regulations state that for buildings in V zones, "a registered professional engineer or architect shall develop or review the structural design, specifications and plans for the construction, and shall certify that the design and methods of construction to be used are in accordance with accepted standards of practice" for meeting the provisions of the NFIP regulations regarding buildings in V zones.

State Board Acceptance

This course can be used by professional engineers to fulfill PDH requirements mandated by state and provincial licensing boards. Decatur Professional Development is an approved provider of continuing education in all states that pre-approve course providers. In all other states that mandate continuing education for engineers, it is the individual engineer's responsibility to determine the suitability of activities for PDH credit. The state boards typically accept online* courses that cover technical, managerial** or ethical content and which are relevant to the practice of engineering. The course must have a clear purpose or objective with a content that will maintain, improve or expand the skills and knowledge of the licensee's field of practice. For questions about your mandatory PDH requirements, visit the website of your state licensing board.

*Online courses are accepted by all state licensing boards that mandate continuing education. Other than New York (which limits online courses to 18 PDH) and Iowa (which limits online courses to 6 PDH), there are no limits placed by other states on the number of hours that can be earned through online continuing education. Consult with your state licensing board if you have any questions about the acceptability of online courses.

**The New York State Board of Engineers does not accept general office management courses, but will accept project management courses that are offered by an approved provider and that are technical in nature and contribute to the engineer's professional practice.