Make a detailed task list (part of your scope of work). Estimate hours for each task and apply rates. Add costs for services your firm does not provide (e.g. survey, geotech, traffic, etc.). Use 10% of construction cost, mentioned above, as a check. That said, if it's a local agency job that...
Next time require inserts cast in the box for the contractor's forming and platform needs. Grout holes after work is complete. This is standard practice for precast beam construction.
I think a conventional negative moment design over the pier under factored loads at ultimate capacity would be warranted. It sounds like you need to increase your girder section over the pier to get your design to work out.
I would use a girder-line analysis and model each beam individually in this case.
I'm not sure how you could model that bridge as two separate superstructures since the superstructure is not discontinuous at the change in skew angles.
If you have enough room to drive with the timber decking removed, you could consider driving partial depth sheets under the beams that have little or no toe and design the adjacent sheeting toe and section to take the addition load from the sheets that are not toed in. You may need to use some...
Do you have a current inspection report for the bridge? IS the overlay currently debonded/spalled, etc? If not, I would agree with the state to rate it with the overlay included in the capacity. When/if it debonds the rating would be updated at that point. Just have your assumptions stated...
Mike - with direct fixation of the rails on the bridge steel, and even with a ballasted bridge deck, the RR's typically require a tight tie spacing with extra long ties near the bridge to help reduce differential deflection of the rails (or the bump if you will) at the bridge approach. Track...
1. This problem is very common in Michigan where I work. Most of the older prestressed bridges are all simply supported with expansion joints above all the substructure units making the problem even worse.
2. Michigan Tech has done a recent study for Michigan DOT on the problem. See link...
If the two truss chords are braced together, wouldn’t one chord what to stretch and the opposite chord what to compress under lateral loading?? Similar to beam bending. Seems like the displacement of the two truss chords would cause the longitudinal reactions you are questioning at the fixed...
Intersting...I can tell you the contractor's proposed solution to beam straightening: hook a dozer to each end and pull!
In addition to dealing with the beams, I suspect they will have to cut anchor rods, or other conntections between the beams and substructure, and then reset and reattach the...
Never seen or heard of anything like this. Wonder if the abutments are too stiff and not allowing thermal movements, causing internal compressive forces in the superstructure. Then once the deck was removed and not there to share some of the compressive loading, the girder turned into spaghetti.
I agree with eliminating the deck joints due to future maintenance issues. That's pretty much standard practice now where practable, as mentioned above.
If you're concerned with movement issues between your beam types, why not make all the spans prestressed??? What's the point of mixing your...
Unlike steel girders, the camber of prestressed concrete girders is not designed based on the roadway profile and anticipated deflections. The difference between the camber in the concrete girder and roadway profile is made up by haunching the deck at the beams, which can result in some large...
This comment is off topic to the OP's question and the discussion above. But, the curve shown in the attached plan view seems so slight, why would you not just design the bridge using straight girders and varying width deck overhangs?? I'm sure this was addressed in the structure study, but it...
I will typically use Table 2.5.2.6.3-1 in the AASHTO LRFD code for getting a ball park min structure depth. The table has values for girder only or girder and composite slab.
If you have a layout in mind, why can't you just do a quick run in your steel deign software to get a prelim girder...
The essence of each term is covered well by everyone here. However, as others have said, different terms are used by different agencies, and are usually connected to a very specific set of requirements for design. For example, in Michigan the DOT uses “rehabilitation”, “reconstruction”, and...
