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