I am looking to see if anyone has experience with replacing individual steel truss members (eyebars, pins, chords) due to extensive corrosion. The two-span steel truss bridge will be closed to traffic so I am looking to find a way to relieve the load off of the member being replaced. Temporary...
Does anybody know of any studies done or publications that show the cost/benefit of Accelerated Bridge Construction? I'm looking to see the cost of the project vs. the time saved when using this method of construction. I often get questions about how much time is saved vs. how much more will...
I'm unfamiliar with "jetting". Does this disturb the stream bed?
Proposed dolphin cluster is 7 piles at 24" diameter. Existing timber are 12 - 14" diameter piles.
Does anyone have experience in replacing a deteriorated timber dolphin cluster with a concrete pipe pile cluster? Due to geometric constraints, we need to replace in the exact same location as the existing timber dolphin cluster. I'm expecting the timber piles to snap when they try to extract...
Hello, I'm designing a standard reinforced concrete slab bridge and was wondering if there's any published criteria on calculating short/long term deflections of the slab? It seems that you'd still want to incorporate some sort of camber into the slab in order to provide a net long term...
Does anyone know of any requirements or specifications in AASHTO or ACI regarding the minimum spacing between legs of double vertical stirrups in a cap or beam for shear design? I'm referring to the spacing across the width of the member, not the longitudinal spacing. For wide beams, it seems...
Looking for other interpretations of AASHTO LRFD 10.6.1.3 "Effective Footing Dimensions"...
It appears AASHTO allows a reduced footing for geotechnical purposes, but this will eliminate any uplift calculation...(since the concentrated force is now centered on the footing in the effective area)...
Hello all,
How have you all distinguished between the FR and TU force calculation for a steel Fixed or Expansion Bearing? In my experience, I have applied 10% of the DL as the Friction Force for Expansion Bearings. However, AASHTO is vague on how to calculate the Thermal Force TU for a Fixed...
Hello All,
I am designing my first cross-frame (K-type) for a straight, two-span continuous bridge under LRFD specs. I am looking at a typical intermediate cross-frame, and a pier cross-frame. I have several questions regarding each:
Intermediate: Per AASHTO LRFD, it says that wind loading...
Anyone know the equivalent grade of A-7 steel? 33 ksi steel seems to be the best guess but I can never understand why they didn't associate a grade with this steel back in the day.
Bridge was built in 1952....
The bearing stiffener on a steel plate girder has been misconstructed and is offset ~ 1 3/8" closer to the center of the span from the line of bearing. Therefore the line of bearing is not acting directly on the bearing stiffener.
What kind of check should be performed? There is now an...
My company has paid for approximately half of the degree, so I have still paid a substantial portion out of pocket. The tuition reimbursement rates standard and are are company wide.
I will be finishing my Masters in Civil Engineering degree (MEng) with structural emphasis in 6 months through an evening program for professionals. Any idea about what sort of salary increase I should ask my employer for? I currently have 6 years experience doing structural design work for a...
Thanks for your reply. Do you have the AASHTO/NSBA publication reference by any chance?
I've seen several DOT's examples of haunch calculations that are considering slab deflections only, and not superimposed dead loads once the deck is poured. It seems that these composite load deflections...
I am designing a prestressed concrete bridge, and have a question regarding the haunch thickness. The haunch should account for cross slope and vertical curve camber, but what Dead Load Deflection should be used?
It seems that non-composite and composite deflections should be accounted for to...
