lecture18 - Lecture 18 Design Lecture 18 Design July 18,...

Info iconThis preview shows pages 1–14. Sign up to view the full content.

View Full Document Right Arrow Icon

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

View Full DocumentRight Arrow Icon

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

View Full DocumentRight Arrow Icon

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

View Full DocumentRight Arrow Icon

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

View Full DocumentRight Arrow Icon

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

View Full DocumentRight Arrow Icon

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

View Full DocumentRight Arrow Icon

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

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

Unformatted text preview: Lecture 18 Design Lecture 18 Design July 18, 2003 CVEN 444 Lecture Goals Lecture Goals Slab design example Total beam design One-Way Slab Example One-Way Slab Example The cross section of a continuous one-way solid slab in a building is shown. The slabs are supported by beams that span 24 ft. Between simple supports. The dead load on the slabs is that due to self-weight plus 60 psf; The live load is 120 psf. Design the continuous slab and draw a detailed section. Given: f c = 3 ksi, f y = 40 ksi. One-Way Slab Example One-Way Slab Example Determine the thickness of the slab. 12 ft. Minimum thickness of interior bay: 12 in. 12 ft 1 ft. 5.14 in. 28 28 L h = = = One-Way Slab Example One-Way Slab Example Use h= 6 in. Dead weight b coverage 2 0.5 in. 6 in. 0.75 in. 5.0 in. 2 d d h =-- =-- = ( 29 sl 3 2 2 1 ft 6 in. 150 lb/ft 60 lb/ft 12 in. 135 lb/ft DL h DL = + = + = One-Way Slab Example One-Way Slab Example Determine the load on the floor For slab design is seldom > 0.01. Use c/d = 0.2 ( 29 ( 29 2 2 2 2 1.2 1.6 1.2 135 lb/ft 1.6 120 lb/ft 354 lb/ft 0.354 k/ft U DL LL = + = + = ( 29 ( 29 ( 29 ( 29 ( 29 1 u c 1 0.85 1 2 0.85 0.2 0.85 3 ksi 0.85 0.2 1 0.397 ksi 2 k R f k =- =- = One-Way Slab Example One-Way Slab Example Find the coefficient of the moment diagram The maximum moment is ( 29 2 2 2 u n u 0.354 k/ft 11 ft. 10 10 4.28 k-ft/ft w l M = = = One-Way Slab Example One-Way Slab Example Find the design d for a one-foot strip If b =12-in. then d = 3.46-in., which for c/d = 0.2, so d = 5-in., the slab is OK. u 2 u 3 12 in. 4.28 k-ft/ft ft 0.9 R 0.397 ksi 143.9 in /ft M bd = = = One-Way Slab Example One-Way Slab Example Find the coefficient of the shear The maximum shear is ( 29 2 u u v 0.354 k/ft 11 ft. 1.15 2 2 2.24 k/ft w l V C = = = One-Way Slab Example One-Way Slab Example Check the shear capacity of the slab ( 29 ( 29 ( 29 ( 29 u c w 0.75 2 0.75 2 3000 12 in. 5 in. 4930 lb. 4.93 k > 2.24 k V f b d = = = = Use h = 6-in., d = 5-in. and w u = 0.354 k/ft One-Way Slab Example One-Way Slab Example Minimum about of steel is (use ACI 7.12 ) ( 29 ( 29 ( 29 s min 2 0.0020 0.002 12 in. 6 in. 0.144 in A bh = = = Moment capacity of the slab (12-in. beam) u s y 2 a M A f d =- ( 29 0.925 0.925 5 in. 4.625 in. 2 a d d- 2245 = = Assume One-Way Slab Example One-Way Slab Example Compute the moments Moment capacity of the beam A B C D E l n 11 ft. 11 ft. 11 ft. 11 ft. 11 ft. M coef 1/24 1/14 1/10 1/11 1/16 M u 1.78 k-ft 3.06 k-ft 4.28 k-ft 3.89 k-ft 2.68 k-ft A min 0.144 in 2 0.144 in 2 0.144 in 2 0.144 in 2 0.144 in 2 A s 0.128 in 2 0.221 in 2 0.309 in 2 0.280 in 2 0.193 in 2 One-Way Slab Example One-Way Slab Example Compute the moments ( 29 ( 29 ( 29 ( 29 2 u u u s y y 2 0.354 k/ft 11 ft 1.78 k-ft 24 0.925 2 12 in....
View Full Document

This note was uploaded on 10/03/2011 for the course CVEN 444 taught by Professor Staff during the Summer '08 term at Texas A&M.

Page1 / 61

lecture18 - Lecture 18 Design Lecture 18 Design July 18,...

This preview shows document pages 1 - 14. Sign up to view the full document.

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