We have entered the bridge into STAAD 2004, and it does appear that the torsion is a result of the curvature, even though we do have the ends braced against bending. I am unfamiliar with Roark. What does he have in regards to shear stress in poen sections?
Thanks for the input.
Thanks rb1957. These equations do work for our live load analysis where the concrete deck is assumed to be rigid and can distribute the live loads. However, in determining the dead load stresses, the deck is considered as wet concrete, only applying load to the open steel section. The section...
I am analyzing a curved open box girder that is subjected to torsional effects. The section is composite with the concrete deck, so I am assuming it is a closed section under live load stresses. To determine the dead load stresses, I need to assume that the deck does not have any stiffness...
I am performing a load rating of a steel multi-girder bridge with a concrete deck - a fairly routine analysis. We have five girders, and the curb-curb width is 14 feet. To determine the LL distribution for the interior girders, we used Table 3. 23.1 which gave us S/7 for a single lane. For...
Thanks for the responses.
The girder does bear on the bottom flange, but it doesn't at the very end due to the hole. I agree with your method for moment capacity, but what about shear?
We are performing the load rating of a bridge that exhibits significant corrosion of the steel webs near the abutments. The webs have holes near the bottom flanges, the largest of which is 2" high, 16" long. I am having trouble calculating the shear capacity. I am uncomfortable using the...
We are performing a load rating on a bridge that exhibits significant corrosion of the steel webs near the abutments. There are several holes in the webs near the bottom flanges, the largest of which is 2" high, 16" long. I am having trouble calculating the shear capacity. I am uncomfortable...
Thank you J1D for your response. If there are studies out there on this matter that you know about, that would be great. Unfortunately, our load rating does change significantly when we add rigidity to the connection. Our STAAD model gives us moments in the members. Even though the moments...
We are currently load rating a truss where the connections are welded using gusset plates. When we input the truss into STAAD we assumed fully fixed connections at the ends. The resultant moments in the members were relatively small, but since the members bend in the weak axis, the load rating...
We are currently load rating a truss where the connections are welded with gusset plates. When we input the truss into STAAD we assumed fully fixed connections at the ends. The resultant moments in the members were relatively small, but since the members bend in the weak axis, the load rating...
We are currently load rating a truss where the connections are welded with gusset plates. When we input the truss into STAAD we assumed fully fixed connections at the ends. The resultant moments in the members were small, but since the members bend in the weak axis, the load rating is very low...
We are currently load rating a truss where the connections are welded using gusset plates. When we input the truss into STAAD we assumed fully fixed connections at the ends. The resultant moments in the members were relatively small, but since the members bend in the weak axis, the load rating...
We are working on a steel girder where we want to cut a void in the web, and replace the portion with a new plate. The hole is next to the bearing stiffener. When running the model in STAAD, we get a high buckling stress concentration, right at the top corner of the void. Effectively, in two...
We are working on a steel girder where we want to cut a void in the web, and replace the portion with a new plate. The hole is next to the bearing stiffener. When running the model in STAAD, we get a high buckling stress concentration, right at the top corner of the void. Effectively, in two...
We are working on a steel girder where we want to cut a void in the web, and replace the portion with a new plate. The hole is next to the bearing stiffener. When running the model in STAAD, we get a high buckling stress concentration, right at the top corner of the void. Effectively, in two...
You are correct, the impact was from a vehicle. Each of the four verticals is bent, but all connections are still intact. The extent of leaning is not major, and at first glance you may not even see it. Is heat straightening an expensive option? If it is heat straightened, will it stay...
Our firm has been asked to solve a problem with a pony truss. It appears that one of the trusses has been impacted. The vertical members are bent in the direction of traffic, but the truss itself is leaning out from the bridge. Since it is a pony truss, the addition of ties at the top of the...
Thanks for all the replies. This culvert is slated for major reconstruction or replacement under a capital project. The project is fairly major, so it will not be complete for several years. This would be something to hold it over. The signs of distress are some vertical cracks near the base...
Thank you very much for your reply. I have heard a little about the use of tape extensometers before, and was thinking this may be a solution to our problem. Our main goal is to obtain long term static results to serve as a warning of any imminent failure. We are concerned over the signs of...