Showing posts with label system. Show all posts
Showing posts with label system. Show all posts

Tuesday, November 29, 2016

Foundations

Question:

For the foundations presentation, what exactly are you looking for? 
I [thought] that the geotechnical systems of the soils would play a major role in the foundations but it really doesn't so I would really like your input. 

Response:

The foundation system is a combination of the soils on which the building rests and the below-grade structure that transfers the building loads into the soils.  Typically one needs to address a number of questions, giving and labeling assumptions if necessary:
  • What is the soil profile, down to the bedrock if it's anywhere near the surface?
  • What are the bearing capacities of those soils?
  • What members of the above-grade structure carry loads into the soils?
    • Typically these are either columns or bearing walls
  • What are the magnitudes of loads being transferred through those above-grade structures?
  • What are the below-grade structures that transfer the loads to the soils?
  • What are the sizes and stresses in those below-grade structures?
  • Why was that system below-grade system chosen over other possible systems?
    • Here's a search link that illustrates many types of such below-grade foundation systems.

Monday, September 5, 2016

Building Systems – Rules of Thumb

Site

  • Site - to Consider
    • Zoning
    • Setback
    • Parking Requirements
  • Height limitations
  • Relationship to other buildings
  • Shading issues
    • More in other countries than US at the moment

Architecture

  • SF/ Person - 200-400
  • Circulation % of building 15%-50%
  • Exiting requirements
    • 2 separate exit paths (protected) with 20' of exit from room or suite
  • Floor to Floor
    • 9' in apartments/hotels
    • 12-14+ in commercial

Structure

  • Depth of Beam in 1/12 of Length
    • Ie. Depth in inches = Length in Ft
    • This is conservative - often 2/3 to 3/4 of this
    • Studio Companion is great Resource
  • Design Loads
    • Live Loads
    • Gravity
      • 40#/SF residential
      • 80-100#/SF commercial
      • 250#/SF+ for storage and other special conditions
      • Snow - up to 30#/SF
    • Dead Loads
      • Self-weight
    • Lateral Loads
      • Live
        • Wind - 90mph ~ 28#/SF
        • Seismic
        • Blast

HVAC

  • Duct velocity - 800FPM to 3,000FPM
  • Chiller Sizing - 200-400 SF/Ton
  • Ventilations - 10-40 CFM/person - depending on activity
  • Equest is great resource for first approximation
  • Design Temperatures
    • Indoor
      • 72-78 DegF depending on age, season, culture
    • Outdoor
      • 14 DegF Winter
      • 90 DegF Summer

Electrical

  • Typical feeds (in Philadelphia) 13.2KV 3-phase
  • Typical in-Bldg voltages
    • 480/277 - motors and lights
    • 208/120 - Convenience, portable appliances, some lights
  • Emergency System
    • Range from corridor lights only (2fc -> battery packs)
    • 100% backup
    • Duplicate feeds from separate substations
    • Emergency Generator
    • Depends on purpose of building, client desires
    • Increasingly will see tied to alternative energy &/or electrical storage (batteries mostly)

Other Systems – Non-Exhaustive list

  • Geotech
  • Fire Protection
  • Stormwater
  • Lighting
  • Circulation
  • Transportation
  • Plumbing
  • Security
  • Telecom


Google Docs Sheet with many of the same rules of thumb