103b: Building Loads and Forces Flashcards
2 structural loads? Full stop.
1) static
2) dynamic
Why isn’t snow a dead load?
Snow comes and goes, building components are permanent
Are people in a structure ever considered dynamic loads?
No. Structures are engineered to account for the movement of people.
Is there anything in building materials or manufactured building structures such as footings that is NOT a dead load?
No. All the components of a building are a dead load.
Would you consider a Christmas tree to be a live load?
Yes. It’s moved around the house during the year, and can put pressure on different areas of a floor
If you need to build a second bed one weekend a month to house your friend. Are they and the bed live or dead loads?
Bed is live as it isn’t permanent.
Friend is live as structure is built to account for them.
Can a static load ever be dynamic?
Wind CAN be dynamic if it is sudden enough. But wind is engineered for, and is therefore static live load.
Why is a vibrating tamper in a backyard not considered a live load?
1) not putting pressure on house directly, so environmental
2) can potentially be vibrating soil that house sits on
What kind of load buckles vinyl siding?
Environmental. Heat can cause expansion/contraction
Even if my 50lb fish tank has been in my house for a year, is it still a live load if my dog knocked it over?
No. It’s dynamic because hitting the floor puts sudden pressure on the floor system.
Oliver stood on your stomach. Is his paw a concentrated or distributed load?
Concentrated
Why use teleports in a basement?
You add living space without building a supporting wall.
I want to build a deck with storage room underneath. Should I build a supporting wall around the edge or something more “focused”?
Use posts at the corners. Concentrate the weight. Leave room for storage access.
Do we ever put teleports under each joist?
No. Floor systems need loads distributed across them
Does soil have a force?
Yes. Compressing it with the house weight also causes it to “press back”. It’s part of the dead loads on a house
If I run across the house, which way does my “load” go?
Always down the structure. Floor systems move pressure to exterior walls and down to footings
What kind of FORCE occurs in the physical earth during an earthquake?
Shearing force across tectonic plates
I helped my uncle tear up his shit floor boards, and they were an inch narrower than the ones at work. Did the environment change them?
The environmental load on the old boards caused them to shrink from moisture loss over time.
Why is it important for soil to evenly carry loads over time?
All buildings settle and uneven settlement over time can cause foundation issues
Why do we pour a slab in a basement even if we never plan to use it?
It helps hold the foundation walls in place as the soil puts lateral load pressures on it
When I pulled on my rope, it got nice and tight then suddenly snapped. What did my pulling force do?
Put tension on the rope until failure
My couch cushion is half the height of when I originally bought it years ago. WhT gives?
My fat ass loaded it up over time and compressed it
I put a mark on the foundation wall at grade before we started building our high rise. Now we’re up 20 floors up and when I checked on my lunch break I couldn’t find it. How come? foundation wall, and now it has shrunk a couple inches
Each floor added more compressive force to the f
I tore a piece of paper by pulling on the bottom corners, but when it ripped at the bottom it left a bunch of wrinkles at the top. How come?
The paper had tension at the bottom, and compression at the top when the bottom corners were pulled apart.
I forgot to drill a hole to run my new Reno’s pot light. Can I remove a little ceiling drywall and drill a little hole in the bottom of the joist? Just one?
No. The bottom of the joist exhibits the most tensile force, drillling there makes it weaker and prone to breaking.
My pocket door is caught on the frame and I can only move it inches at a time….like I have to force it
Your pushing load is causing a shear force between the door and frame
My mattress is perfect! But when I sit on it the edges poke off the bed frame. Is it me?
No. The mattress exhibits horizontal shear with the frame when you put pressure in the middle.
Got down and dirty last night and my bed snapped RIGHT where the corner leg meets the frame…
Your body weight on top caused vertical shear at the frame/leg joint
What is a carpenter’s main goal regarding loads and forces?
Transfer the load/force TO THE GROUND
