Hello bridge guys,
I'm going to assess a 20 years old post tensioned bridge of which the concrete deck was cast in-situ with travelling gantry attached to cantilever ends.
My question is, after 20 years have gone, is the creep induced by the weight of the gantry still "significant"? I mean is...
In designing transverse prestress in top slab of a box girder, do I have to consider the bending stiffness of the webs which !0 stops the tob slab from "free elastic shortening" and 2) picks up "some prestress load effect" reducing prestressing force in the slab betweem the webs?
uxbridge,
i was busy with something else last week and didn't look at my problem further...But I will pick it up next week.
I start to agree to what you think: the plan bracings are very effective to stabilize the steel troughs against global torsional buckling. I remember I read a book a few...
Thanks for your reply.
I knew local buckling has not to be considered and it worries me. It is because I am not able to check whether the steel trough would fail in overall buckling until I got the first global buckling mode and its load factor…
Funny thing about it is that if I assign the...
Hello,
I am doing the design check of a multi-span steel composite box girder viaduct but struggle to get elastic buckling analysis done.
To check the stability of the bare steel section under self weight of fresh concrete (i.e a steel trough supporting wet conrete), I set up a 3D model formed...
I am going to do a quick analysis for a steel box girder of 20 ft wide top flange, 14-2/3ft bottom flange and 8 ft deep.
The bridge is of 11 spans (each span approx. 165 ft long) and several spans are curved in plan on a radius of 1000 ft. Over each pier, the box is strengthened with a plate...
When I did my FE course at university, I was taught how to do FE formulation (e.g. transforming a PDE into a weak form, defining primary/secondary variables) but not how to apply the results to real engineering problems.
For instance, I know how to solve FE equations to find out say shear...
The slope is at about 40 degrees to horiz line.
The central walls are designed to support a bridge deck. After the bridge deck or the wall has been in place, a section of the embankment is removed and a new road will be contructed
Is it possoble to do secant bored piled walls on the side slopes of embankment AND a diaphragm wall in the centre of the embankment??
The embankment is 10m wide and 6m high??
I am going to do the preliminary design of a RC arch bridge (pinned at both ends) and would like to know the vert and horiz reactions and bending moment at the apex (Is it equal to zero??) if the arch is subject to a vertical UDL. I don't need an exact value but want to know the "order of...
Three weeks ago, I read a trade newspaper which reported a foundation contractor put some kind of steel sleeve over the top, say 6m, of the bore piles so that the pile would not impose any stress on the top layer of soil. Unfortunately, I can’t remember what it is now.....
Dose anybody know...
I found from some bridge design codes assume the effective length of a column to be 0.85 (say) x physical length if the bottom end is fixed against horiz movement and rotation and the top is restrained from any horiz movement but not the rotation (i.e. a pinned joint). However, I don’t...
When I learnt prestressed beam design at college, the section properties (e.g. I value) of the girder don’t change with time or construction stage on which equations or inequalities for the estimations of prestress force and I value are formed.
However, the current problem is a beam and slab...
The problem I have is pile foundations for a bridge. The bridge has to span over a 12m wide moat and the slopes/banks on both sides are 8m height at 35 degrees. In addition, the site constraint includes that the construction of piles must not stabilize or loosen the soil slope.
Could any...
