thread507-500937
I am running into the same query posted in the linked thread mentioned above.
Bridge Project. Application: Embed Vertical rebar for a new concrete barrier into existing concrete below. Concrete barrier can see lateral load from vehicular collision. so rebar will see shear and...
I am working on some rehabs in an existing building and trying to make sense of the Notes provided in the Structural Drawings for Live Load.
See below extracts of the Structural Drawings dated 1960. Educational Building located in Massachusetts.
Design Live Load = 100psf on beams, 150psf on...
@SWComposites: Not really easy to completely reject the product unless we can justify that there is no other option to use the product.
@JLNJ: cutting the plate short of the brick will create a 12" cantilevered plate which can lead to undesirable deflections under the load.
@WinelandV: I agree...
The plate warping has a big delta. so I was thinking of removing an entire brick course at the plate elevation and solid grout it while accommodating the warped edge to fit within the brick veneer:
Any thoughts/concerns on this approach?
Agree with SRCELL. This detail puts torsion into the perimeter W310 beam, so you need to either ensure the beam can take this torsion without excessive rotation or find a means to restrict torsion in the beam.
Looking for suggestions to figure out how to resolve a canopy support issue.
I designed a canopy support at the Overhead garage door openings at a building for the configuration proposed by the architect.
The structural framing is primarily HSS tubes supporting the canopy deck with HSS members...
Thank you all for your review and suggestions.
@BridgeSmith: yes, the state DOT is aware of the configuration and special member inspections at shorter intervals seem to be happening to monitor the deterioration of these splice plates.
@rb1957: Agree to what you are saying if we were still designing the bridge. The current scope of my work is to evaluate the condition of the existing bridge as is. We would be recommending a repair of the deteriorated components and evaluation to provide a catcher's mitt approach or other means...
@BridgeSmith:
For the worst case with plate thickness b=0.35", depth d=31"
Elastic section modulus (S=bd^2/6) = 56.0in3
Plastic section modulus (Z=bd^2/4)= 84.1in3
Net Plastic section modulus at bolt hole (Ref. AISC Eg 15-5 in snapshot below),Znet = 52.5in3
The allowable stresses for Inventory...
@BridgeSmith:
I think I am considering all the required provisions:
(1)bolt shear/bolt bearing to calculate the capacity of the bolt group
(2)Flexural yielding of the plate at the gross section (middle portion without holes)-conservatively using S or using Z Per Eq 6.12.2.2.7-1(upper limit...
@dhengr: Thank you for the caution. I understand for the deteriorated plates especially with the rough edges or 100% loss at edges can cause a failure to happen before the theoretical computed capacities.
Will review it closely once I confirm my approach and get to evaluating each plate.
@BridgeSmith:
I am referring back to AASHTO LRFD Equation 6.12.2.2.7-1 for "Rectangular Bars and Solid Rounds" and trying to understand why this section is not applicable to the web splice plate.
Per my understanding, this section is still applicable for plates, except that for the web splice...
@ProgrammingPE: Thank you for the detailed explanation of the AISC equation and the reasons for using Z vs S.
I made a mistake in my earlier calc, so the % difference is larger. Have Checked that:
Fy*S < Fu*Znet. Indicates plate will begin to yield at the gross section at the middle of the...
@BridgeSmith: I checked that for one of the splices and the Flexural rupture strength of the plate/beam web (through the bolt holes) is higher (6%) than the Flexural yield strength at gross section of the plate. This is using Elastic section modulus (S) for the evaluation of Flexural yield...
Another question I had while evaluating the Flexural strength of the web-Splice plate.
In the below extracts from AISC manual and examples, why is the Plastic section modulus (Z=bd2/4) used for evaluation. Shouldn't this be the Elastic section modulus (S=bd2/6)?
Thank you for your responses. I ran some numbers and below is my summary:
Considering Simple spans & hinge at the splice location, splice connection as a shear connection to resist shear and the resultant moment caused by eccentricity of the shear load. For the splice plate, rating...
I am involved in a discussion regarding the behavior of a Bolted Web Splice Joint and looking for some clarity to understand the true behavior of the connection.
In an existing bridge(several simple spans), one of supports appears to have been constructed incorrectly (shifted by 3ft, whereas all...