Thanks for the replies. I increased the rod diameter and it still was not working. I am going to use ptfe bearing pads/#8 mirror finish stainless steel.
I am designing falsework to support a RR bridge span. Deadload only. the span is 121' and I want to allow for thermal expansion with using 3/8" steel rods under one girder end. This is temporary, about 2 months. grease wont work, the coef. of friction (observed from previous work) is about...
Yes they are designed to take tension loads. (I am actually using KeySafe BY G20 clamps which are basically the same as Lindapter) Keysafe engr dept has told me these clamps have been used by several DOT's to hang monorails under bridges. They say to use the interaction equation for tension...
I have had to go with 2 bogeys on each end truck (4 axles=8 wheels) to keep the local stresses down, my wheels only have a contact patch of 1/2" so the maximum "a" dimen would be 1/4" but i am using i/8" for clearances. the clamps actually bear on the edge of the flange the bearing strip is...
Yes, ToadJones that is correct. The loads on the top flange are not point loads, since the clamps are 2.1875" wide. however the loads are similar in that both inside surfaces of the flanges are loaded in transverse tensile whereas the outside surfaces are loaded in transverse compression. i...
Hello, I am designing an underhung crane that we will use on a bridge project. the runway beams will be attached to the floorbeams that run transverse to the roadway with Lindaptor Clamps. I am using CMAA 74, AISC dg 7, AISE rpt 13, and a few others along with osha. my question is combining...
Thanks guys for your help. A friend of mine had a copy of the MBE. Using that I determined that the steel used in that time frame is 33ksi steel. I still don't know what AS and WS stand for, but I have used the 33ksi for my design.
I was wondering the same thing. I recall a type of steel called A7, but A.S. and W.S. has me stumped. I have a book about old sections and steel grades but the "youngest" steel mentioned is 1953. Thanks for your input though.
hello all,
I am designing a jacking system to exchange out bridge bearings for an IDOT (Illinois DOT) bridge built in 1961. While looking at the drawings of the existing structure, the steel called out for is:
A.S. steel and W.S. steel.
Does anyone know what the yield and ultimate...
i am taking a preliminary look at a stanchion and horizontal lifeline system for fall protection on a project our company has. looking through the osha regs there is mentioned in 2 different test weights, 220lbs and 300lbs. i am wondering which weight applies to what circumstance.
thanks...
ishvaaag, thanks for your response. i will look further into this. the code is "Design of Below-the-Hook Lifting Devices" ASME BTH-1-2005 if anybody is wondering
bump?
i hope i have not enclosed too much information, what i am looking for is the correct interpretation of the formula:
fcr = (fx^2 -fxfy + fy^2 + 3fv^2)^.5 is less than Fcr= Fy/Nd (3-37) from BTH-1-2005
this is the interaction formula for normal and shear stresses.
thanks
i am designing a drill casing pulling lug. the lug will never see the loads it is designed for but i want to have a complete design i can stamp and file away.
Question: how do you determine the shear stress that is used in the formula (3-37) that determines fcr? the most conservative way...
Hi Guys, i am cleaning up some old files and am checking on the capacity of metal mesh used as a walk surface on our (old) work platforms. the spans are 4'x8' with the mesh welded every third intersection to the perimiter (lap weld) the capacity i am looking for is around 22psf x 4F.S. =88psf...
i am designing a scaffold that is suspended by cables. we are planning on using specific lgt cable chokers with thimbles as required per osha but i am wondering if the "fist grip" clamps can be used instead, to make enable the height adjustment to be easier. at first i was thinking they were...
thanks for your reply, Richard. i agree that i will use the FS=6.0 for the steel chokers. but the lugs that the chokers are suspended from, are designed already with a FS=2. so i am wondering if the intent of the OSHA spec is 6.0 from failure or 6.0 from the asme bth spec which has a 2.0...
i am designing the cable support system for a work platform that we fabricated years ago. we have updated the platform to the DL + 4LL as required by OSHA. during my review of OSHA subpart L - scaffolds, under General Requirements (a) (3) it states " Each suspension rope, including...
i have design bridge jacking and supporting falsework and concrete forming for the company i work for and i have a project where we have to jack and replace some bridge bearings. i will definetly need bearing stiffeners over the rams. according to aisc 9th if you provide stiffeners halfway up...
