Week 12 Challenge

Aim-: calculte barge force and analyse it in stadd pro

Given Data:

Bridge span =12m, bridge width =7m, Piers dia 2.5 m x 2.5m, Rise of the bridge = 5m, Deck slab thickness 500mm

cross Girders=0.75 m x 1.8 m, Hydrodynamic coefficient(CH)= 1.25, W=52500 DWT, Speed of the Barge(V) = 60Km/hr

Calculations;

Barge Collision Energy, KE=500*CH*W*V^2

where,

Hydrodynamic coefficient(CH)= 1.25, barge displacement tonnage(W)=52500 DWT, barge impact speed(V) = 60Km/hr.=16.6667m/s

KE=500*1.25*5.2500*(16.667)^2, KE=911822.95 N-M.

Barge Damage depth,aB=3100*([1+1.3*10^-7*KE]^0.5-1)=3100*([1+1.3*10^-7*911822.9531 ]^0.5-1)

Barge Damage depth,aB=178.58mm

Barge collision impact force,PB

For aB≥100mm,pB=6*10^6+1600*aB=6*10^6+1600*(178.5881741m), pB=6285741.079N=6285.74kn

Analyse it in Staddpro-:

create a node @ origin (0,0,0) and another @ x direction at 12m as span of bridge is 12m

as it is a truss membder create nodes as steps 9 at 1.2 m spacing

now select 2nd node and 10th node and by using translitional copy node @ y dir at 1m spacing

simillarly for rest node as 3m, 4m, 4.5m, 5m repectively @ y direction and add beam and top string to create structure

add 6m pier to bridge by using translitional copy node @ -6m @ y direction and add properties to related member

pier as rectangular 2.5*2.5m

cross sectional beam as 0.75*1.5m

longitudinal beam as following dimension

after adding the whole properties assign to that property to respected member

now select the whole structure and by using translitional copy the whole structe as width ofd deck slab is 7m this copy select all in which the structure copy with its whole property

now assign other member property which is created by copy the structure @ 7m

insert node to top C channel and add beam siign property to them

now create plate for deck slab and give thickness to plate as 0.5m and copy that plate to both X and Z dir by length/0.5 for no. steps

final structure in 3d

add load case as barge impact load and run the analysis after get 0 error and warnings go to post processing the loading and resuklt we get

plate stress @ mx local and displacement reports of sectional forces are as shown below