# Cee311(11)

1 May 2015
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### Cee311(11)

• 1. CEE-311 Structural Analysis-I (3.0 credit) Lecture:11 Bijit Kumar Banik Assistant Professor, CEE, SUST Room No.: 115 (“C” building) bijit_sustbd@yahoo.com Department of Civil and Environmental Engineering
• 2. Reactions due to moving concentrated loads (S&V; pp-112) Condition-1: (No wheels comes on the span during movement) 1 1. P L dP R −=∆ ∑ Where, R = change of reactions due to moving from one load over the reaction to the next P1 = the wheel which was over the reaction & is moved off the span d1 = the distance between P1 and the following wheel ∑P = the summation of all loads which are on the span & stay during movement
• 3. Reactions due to moving concentrated loads (S&V; pp-112) Condition-2: (Wheels comes on the span during movement) Where, Pʹ = load which comes on during movement e = distance which Pʹ moves on the span 1 1 .. P L eP L dP R − ′ +=∆ ∑ If ∆R, Positive → continue movement Negative → stop movement
• 4. Reactions due to moving concentrated loads (S&V; pp-112) Find maximum reaction at ‘A’ when wheels move right to left. RA 1 A B 60ʹ 1 2 3 4 5 6 7 8 9 10 11 12 13 14 5ʹ 8ʹ 6ʹ 6ʹ 6ʹ 8ʹ 4ʹ 9ʹ 4ʹ 4ʹ 12ʹ 4ʹ 4ʹ 10k 10k 36k 36k 36k 36k 10k 10k 20k 20k 20k 20k 20k 20k
• 5. Reactions due to moving concentrated loads (S&V; pp-112) A B 60ʹ Position-1: wheel 1 at ‘A’ 1 2 3 4 5 6 7 8 9 10 11 12 13 14 5ʹ 8ʹ 6ʹ 6ʹ 6ʹ 8ʹ 4ʹ 9ʹ 4ʹ 4ʹ 12ʹ 4ʹ 4ʹ 10k 10k 36k 36k 36k 36k 10k 10k 20k 20k 20k 20k 20k 20k
• 6. Reactions due to moving concentrated loads (S&V; pp-112) A B 60ʹ Position-2: wheel 2 at ‘A’ 5ʹ 1 2 3 4 5 6 7 8 9 10 11 12 13 14 5ʹ 8ʹ 6ʹ 6ʹ 6ʹ 8ʹ 4ʹ 9ʹ 4ʹ 4ʹ 12ʹ 4ʹ 4ʹ 10k 10k 36k 36k 36k 36k 10k 10k 20k 20k 20k 20k 20k 20k P = 234 k [No.2 to no.11] kR 5.910 60 5*234 +=−=∆ continue Condition-1
• 7. Reactions due to moving concentrated loads (S&V; pp-112) A B 60ʹ 1 2 3 4 5 6 7 8 9 10 11 12 13 14 5ʹ 8ʹ 6ʹ 6ʹ 6ʹ 8ʹ 4ʹ 9ʹ 4ʹ 4ʹ 12ʹ 4ʹ 4ʹ 10k 10k 36k 36k 36k 36k 10k 10k 20k 20k 20k 20k 20k 20k Position-3: wheel 3 at ‘A’ 1ʹ P = 224 k [No.3 to no.11] continue Condition-2 kR 2.2010 60 1*20 60 8*224 +=−+=∆
• 8. Reactions due to moving concentrated loads (S&V; pp-112) A B 60ʹ 1 2 3 4 5 6 7 8 9 10 11 12 13 14 5ʹ 8ʹ 6ʹ 6ʹ 6ʹ 8ʹ 4ʹ 9ʹ 4ʹ 4ʹ 12ʹ 4ʹ 4ʹ 10k 10k 36k 36k 36k 36k 10k 10k 20k 20k 20k 20k 20k 20k Position-4: wheel 4 at ‘A’ 3ʹ P = 208 k [No.4 to no.12] Stop Condition-2 kR 2.1436 60 3*20 60 6*208 −=−+=∆
• 9. Reactions due to moving concentrated loads (S&V; pp-112) So, wheel 3 at A will produce maximum reaction RA 1 A B 60ʹ 1 2 3 4 5 6 7 8 9 10 11 12 13 14 5ʹ 8ʹ 6ʹ 6ʹ 6ʹ 8ʹ 4ʹ 9ʹ 4ʹ 4ʹ 12ʹ 4ʹ 4ʹ 10k 10k 36k 36k 36k 36k 10k 10k 20k 20k 20k 20k 20k 20k ( ) 60 1 *20 60 13 *20 60 17 *20 60 21 *20 60 30 *10 60 34 *10 60 42 *36 60 48 *36 60 54 *361*36max +++++++++=AR = 150.4 k