ARC322 Homework 16 SOLUTION 2008

ARC322 Homework 16 SOLUTION 2008 - 2 (includes joist DL)...

Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
ARC322 Homework 16 12 Points SOLUTION 1. A building measures 40 ft by 100 ft. It carries a DL = 35 lb/ft 2 (w/o joist DL) Tributary 35 lb/ft 2 x 5 ft = 175 lb/ft It carries a LL = 20 lb/ft 2 Tributary 20 lb/ft 2 x 5 ft = 100 lb/ft The joists are spaced at 5 ft OC Select the most economical open web joist Drawing 2 Points Uniform Load each joist = 55 lb/ft 2 x 5 ft = 275 lb/ft 24K9 will carry 304 LB/FT – 12 LB/FT = 292 LB/FT > 275 LB/FT … OK 2 Points Deflection Calculation 24K9 175 lb/ft – 12 lb/ft = 163 lb/ft > 100 lb/ft . .. OK 2 points NOTE … If they selected a 24K4 or a 24K6 … they just barely makes it … so, they are OK by code … but a better selection is the 24K9 which will reduce “bounce”. 2. A building measures 36 ft x 300 ft It carries a DL = 45 lb/ft
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Background image of page 2
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: 2 (includes joist DL) Tributary 292.5 lb/ft It carries a LL = 15 lb/ft 2 Tributary 97.5 lb/ft Joists are spaced at 6.5 ft OC Select the most economical open web joist NOTE: We do not need to reduce the joist load since the problem statement tells us that the Roof DL includes the weight of the joist. Drawing 2 points Uniform Load each joist = 60 lb/ft 2 x 6.5 ft = 390 lb/ft 26K9 will carry 409 LB/FT = 409 LB/FT > 390 LB/FT OK 2 points Deflection This is the minimum drawing allowed. If they did better drawings, such as showing the tributary loads, give 1 point EC on each one problem. 26K9 will carry 284 lb/ft > 97.5 lb/ft OK 2 Points NOTE If they selected a 30K7 I only weighs 0.1 lb/ft more so OK...
View Full Document

This note was uploaded on 03/30/2008 for the course ARC 322 taught by Professor Mcgavin during the Winter '08 term at Cal Poly Pomona.

Page1 / 2

ARC322 Homework 16 SOLUTION 2008 - 2 (includes joist DL)...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online