> That's the way it's not supposed to happen, but: A few years back the
> Ohio state patrol stopped a load in Central Eastern Ohio with a 200 ton
> load (not including the truck, etc.) enroute from Indiana to Some
> Eastern State (that was more than 2/3 the way across Ohio. The load was
> not permitted to move further, just happened that was next to a railroad
> track. It took the railroad some weeks to schedule a special flat car,
> and then the load proceeded. The item of interest is that a legal
> maximum load in Ohio is around 40 - 45 ton, and this was 5 times that
> had overloaded many facilities in both Indiana and Ohio. Every once in a
> while we hear of a bridge in the back roads collapsing due to overload,
> usually destroying the bridge, but no one hurt.
>
> Many years ago, I was part of a small crew inspecting railroad bridges
> at the Republic Steel Co. Youngstown steel mill. One day the bridge
> creaked more than usual as a train carrying molten steel passed overhead
> while we were underneath. The dispatcher later said he sent several
> loaded cars next to each other with the locomotive close coupled with no
> empties as standard procedures required. If those several hundred tons
> of molten steel would have ended in the river below, the explosion would
> have be huge!
>
> 85% of structural failures are due to details, and not main members like
> beams or columns. The I-35 bridge in Minn. failure was due to a gusset
> plate (small plate joins several main members). Several years ago, Ohio
> closed a large bridge on I-90 near Painesville, Oh. for a similar plate
> failing. The plate had rusted to where it actually buckled lowering one
> end of the bridge several inches, and crews were investigating the bump
> when they found the problem.
>
> Alex Harford wrote:
>
>> On Mon, Jul 14, 2008 at 2:25 PM, Carl Denk <
cdenk
KILLspamalltel.net> wrote:
>>
>>
>>> I think this thread belongs at [OT], and am duplicate posting there.
>>>
>>> The factor of safety on structures (not necessarily bridges) is commonly
>>> 1.4 on the dead load, 1.7 on the live load. These are there to account
>>> for both variability of dimensions of members, actual strength
>>> differing from the assumed design strength and variability of the
>>> loading.There may be a factor of 0.9 or 0.85 applied to allowable
>>> stresses to allow for certain types of loading.
>>>
>>>
>> So you're telling me that they don't keep driving bigger and bigger
>> trucks over it until it collapses, then build an exact replica of the
>> bridge?
>>
>> www.s-anand.net/Calvin_and_Hobbes_Dad_explains_science.html
>>
>>