After trying to replicate the problem, I have found out that the huge differences in moments originate from the curve. I made 3 similar models with different offsets from the longitudinal axis.
With regards to straight model, the difference between column moments are not too high, especially...
The image above (Piers P142, P143, P144, P145 respectively) shows the deflection for transverse earthquake.
Longitudinal direction is along the bridge while transverse direction is perpendicular to that direction. Both are on the horizontal plane.
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Good Day!
I am designing a 13-span curved bridge for railway, part of which is shown in the image uploaded. The members between piers in the image are the girders. Piers P142 and before support a pocket track which is why there are 3 girders. P143 onwards only support 2 girders. These are...
DLBridge:
Thanks for pointing to the commentary!
SlideRuleEra:
It's hard to find code for light rail transits so we used AREMA and AASHTO LRFD for the designs.
Anyways,
The height of the collision load is 1.2m high, I might increase the height of the barrier to 1.6m. For the thickness, at...
SlideRuleEra:
the barriers are used to prevent trains going to the highway on either side of the track.
dhengr:
My first question was about the thickness to consider when designing a single slope barrier? Is the average thickness ok?
With regards to the load, I will just request information...
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In our railway project, there are concrete barriers at both guide-way edges.
The formula I used is the one on AASHTO LRFD 2012 Page 13-19
If the barrier is sloping (150mm at top, 200mm at bottom, 1200mm in height), what is the thickness that should be considered when calculating for...
Thank you for all the answers!
Realignment is good considering maintenance issues but can be costly since right of way extension might be needed.
I would consider lightweight fill if it can resist collision and seismic forces.
For the meantime, is there a good reference or sample...
The pipe runs along/parallel to the embankment. The embankment height increases from 3.5m to 8.0m at a distance of around 190m. The pipe curves at some point so it doesn't run along all 190m, but still a significant distance. I would consult with client and the local government if the pipe could...
It is a railway with MSE walls on both sides of the alignment. As of now, the top of the pipe is 1.2m below the NGL. An 8m high fill with 9m width for a span of 40m would be added on top of the NGL. The fill would be supported by MSE walls.
In short, there's already 1.2m soil on top of the...
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I am designing 8m high MSE Wall. There is a 0.6m diameter high pressure water supply pipe 1.2m below NGL, along the wall alignment. What could be done to prevent any settlement from the MSE Wall?
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I am designing an mse wall abutment (stub abutment supported by deep foundation). I have already designed MSE walls before the bridge abutment (along/parallel to traffic). In my understanding, if the conditions for back-to-back MSE walls in the NHI code are satisfied (length of...
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We tried to replace some of the fine aggregates with different materials. In my understanding, the equipment we have can test concrete cylinders or cubes for compressive strength. The samples would be unreinforced. But for checking of flexure using centre load test, should we add...
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For bridges, should the mass of pile or other foundations below ground surface be considered for response spectra or seismic analysis? Why or why not?
Thanks!
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I was assigned to determine the bearing capacity for a group of drilled shaft/bored piles. I used AASHTO LRFD 2012 as basis for my design. The cap would be 5m x 5m with 4 to 5 piles of 1m diameter. The cap thickness would be 1m to 2m.
Is it correct that I based my reduction factor...
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I have been assigned to design barrier for a railway. Here is the definition from our design criteria:
"For Piers and other guideway support element situated in less than 3m from the edge of adjacent highway shall be designed for horizontal static force of 1000kN, unless protected by...
Thanks! I have adjusted the base wind pressures from the wind table. But adjusting the base wind velocity also adjusted the formula for the design pressures. The design pressures I was able to get were still the same.
Good day everyone!
I have to apply wind load on the bridge I'm designing using AASHTO LRFD 2012.
The problem is that the base wind pressures on the code are based on a 100mph wind velocity (160kph).
The area I'm designing it for has 200kph wind velocity, so the table would be inaccurate to...
