Unformatted text preview: University of California, Berkeley Department of Civil and Environmental Engineering CE120 / Instructor: Marios Panagiotou / Spring 2009 04/22/09 Mid‐term Exam 2 Duration (2 hours and 15 minutes) Name: Maximum Points Score Problem 1 30 Problem 2 30 Problem 3 30 Problem 4 20 Total 110 1 Problem 1 (30 points) For the beam structure shown below: i) Compute the reactions and draw the bending moment and shear force diagrams. ii) Draw qualitatively the deflected shape. iii) Check if the beam has adequate longitudinal reinforcing steel on top. iv) Design the bottom longitudinal reinforcing steel as well as the reinforcing steel for shear. Show clear sketches of the side view and section view of your design. Notes: 1) For the design part you have to use the LRFD method. Do not consider any load factors. 2) For concrete it is given fc’=4 ksi and for steel fy=60 ksi. 12" 50kips
10' 50kips
10' 3' 2"
5 #6Bars 22" Beam Section 2 Problem 2 (30 points) For the frame structure shown below: i) Compute the reactions and draw the bending moment, shear force and axial force diagrams. ii) Find the dimension bf of the I‐section in order members BC and CD to have adequate flexural and shear strength. iii) Find the minimum section moment of inertia IAB in order member AB to have adequate strength against buckling. The critical buckling load is Pcr = π2EI / (κL)2, κ=1. Notes: 1) For the design part you have to use the LRFD method. Do not consider any load factors. 2) Find only one bf which is adequate for bending and shear for both members BC and CD. 3) Consider A36 steel, E=29000 ksi. 100 kips 20 kips
B bf C 1"
15'
1''
A 10" 12" 1" D
Beam Section 25' 3 Problem 3 (30 points) For the structure shown below find the value of force P for which point C will touch the ground. Which face (vertical or horizontal) of the ground point C will touch? Members AB, BC have the same EI shown below. E = 29000 ksi
I = 100 in4 0.5"
C
0.5" B Vertical
ground face Horizontal
ground face P
10'
5'
A 10' 4 Problem 4 (20 points) The structure shown below is indeterminate to the first degree. It is given that the developed force in member BC is FBC = 3.83 kips and is tension. What is the section area ABC of member BC? For all members E=29000 ksi. FBC=3.83 kips (tension)
5 kips 5 kips
B 10' C
4 IAB = 100 in A ICD = 20 in4 D
10' E=29000 ksi
(all the members) 5 ...
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 Spring '09
 CHOW
 Harshad number, Hebrew numerals, ksi, LRFD method.

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