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  1. BridgeSmith

    Small Pedestrian Bridge Concept Design

    With a timber deck, pretty much the entire superstructure is likely to eventually become a leaky joint, so I can't imagine painting a few feet at the ends making much difference. Doesn't sound like the owner would be amenable to painting any part of the girders, anyway. In any case, with...
  2. BridgeSmith

    Steel Pile Capacity for Lateral Loads & boundary conditions

    HTURKAK, the diagrams you posted match the ones from AASHTO for the depth to calculate L - 2nd time moment goes to zero for free head and the 3rd crossing point for a fixed head. The potential discrepancy is that the text of the AASHTO spec indicates that is the effective length (K*L), rather...
  3. BridgeSmith

    Steel Pile Capacity for Lateral Loads & boundary conditions

    From the AASHTO bridge design spec 9th Ed.: 10.7.3.13.4—Buckling and Lateral Stability In evaluating stability, the effective length of the pile shall be equal to the laterally unsupported length, plus an embedded depth to fixity.
  4. BridgeSmith

    Small Pedestrian Bridge Concept Design

    If vertical curvature (camber) is required/desirable, welded plate girders can accommodate pretty much any vertical profile that is desired. They're typically not significantly more expensive than rolled beams, and not a significant driver of the overall cost of the bridge.
  5. BridgeSmith

    Small Pedestrian Bridge Concept Design

    Using fully integral abutments typically alleviates both of those concerns, but is typically only feasible on a deep foundation on steel H-piles. If a shallow foundation is required, a semi-integral abutment type can be used, which would still alleviate the concern with leaky joints, but...
  6. BridgeSmith

    Foundation Requirement for 40m High & 2.5m diameter stack

    I assumed a 1.8-2.0m drilled shaft/caisson would be anchored into a larger cap and then the stack anchored to that. Shafts with a diameter of 3m are also feasible, but may not be economical in your area.
  7. BridgeSmith

    Foundation Requirement for 40m High & 2.5m diameter stack

    You'll have a difficult time getting enough uplift resistance from H-piles, or even caissons with the dimensions of the pile cap you've proposed. If you do drill caissons that close together, you'll have reductions for interaction of the shafts, and you'll almost certainly have to drill and...
  8. BridgeSmith

    Spalled Concrete

    It appears the first statement was in reference to shoring. The second was about lifting the beam, etc. to relieve the existing stress on it. Blocking up a beam to keep it in place, is fairly simple by comparison to actually lifting the beam, the additional analysis to determine how much it...
  9. BridgeSmith

    Small Pedestrian Bridge Concept Design

    Yep. W shapes meeting ASTM A709 (bridge steel) are readily available in Grade 50W, AKA weathering steel, as are plates, tubes, HS bolts, and other structural shapes. The only thing we've had trouble sourcing in weathering steel are high strength anchor bolts.
  10. BridgeSmith

    Small Pedestrian Bridge Concept Design

    Then rolled steel beams (WF shapes) are a viable option. If you have the clearance available for a W24 section, that would be a fairly economical option. If a concrete precaster who does prestressed bridge girders is nearby, and you're not particular about the exact initial or long-term...
  11. BridgeSmith

    Weld Group With Different Sized Welds

    Seems you may need an additional plate on the inside of the flange.
  12. BridgeSmith

    Small Pedestrian Bridge Concept Design

    What is the vertical profile of the bridge? Truss superstructures are popular for pedestrian bridges, because the truss doubles as safety fence.
  13. BridgeSmith

    Site Measuring Joists - Web Thickness

    Oh, you're right. I missed that. Sorry DanKile; didn't mean to try to steal your thunder.
  14. BridgeSmith

    Site Measuring Joists - Web Thickness

    Since it's round, you could drill a small hole, insert a straight wire to the opposite side and subtract from the OD.
  15. BridgeSmith

    Guardrail vs vehicle barrier for semi truck concrete ramp

    Btw, even on public streets, roadways with a design speed up to 30 mph and 2' shoulder only require a curb separating vehicle traffic from pedestrians on the sidewalk. It would seem a ramp where the trucks will be travelling < 5 mph would not need more than a curb, if it even needs that. I've...
  16. BridgeSmith

    Guardrail vs vehicle barrier for semi truck concrete ramp

    OSHA probably requires a handrail for pedestrian traffic, but unless your ramp is somehow considered to be a public roadway, the owner of the private property determines what, if any, barriers are needed.
  17. BridgeSmith

    Load Rating of steel bridge with straight and curved girders

    If the curvature effects can be approximated using the V-load method, you can model the bridge with straight girders and manually add the V-loads to the curved spans. Alternately, you could enter it with all spans curved, and if the controlling ratings are in one the curved spans, you'd report...
  18. BridgeSmith

    3 pile, pile cap

    Ah, now I get what the OP was talking about. I suppose the reinforcement going directly between the piles would be more efficient in material, but as Lomarandil noted, material cost is only a part of the cost, and in many markets, a small part of the total cost. That balance varies by location...
  19. BridgeSmith

    3 pile, pile cap

    Please post an example detail. I have no idea what the configuration is that you're questioning.
  20. BridgeSmith

    2 span continuous - Always a 25% increase under UDL?

    Well, at least Celt83 confirmed that my assumption regarding the deflection for equal reactions being 47% (technically 46.6667%) was correct (7/1152 / 5/384 = .46667).

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