Piles are not deep grain storage but rather shallow... so janssen's does not apply.. the semi fluid nature of grain is tricky and designs have to work with a huge number of variables.... difficult to design safely and conservatively..... Seriously, look at shallow design theory for grain...
horizontal member 5' long x .33' wide,,,,,, for design 52 PCD x 10' =520 psf... on the 5' long 4" member....... in the grain,,,,, so wind design easy.... grain loads not so easy,,, design load is the working load......... we work on repairs designs regularly where designers under predict what...
The design load on the tower's diagonals and horizontals is basically 50 or 52 PCF times the grain's depth at any given location. Remember the design load will be the working load and that settlement and consolidation of grain over time will significantly increase the loads on the diagonals and...
PS... this post should probably be in the Agricultural section of the forums to reach more people with experience with grain storage structures.. I just happened to see the post..
Rod
We (agricultural engineers in our firm) have long term and considerable experience with grain storage piles and with towers, columns and structures in the grain pile.
You are correct that wind loading is pretty straight forward.
What you will find is that grain settlement/drag down loads are...
We are working with more large and small diameter grain bins and silos that are being filled and emptied at the same time at high rates. One current project will be filled at 20,000 BPH continuously and emptied, starting and stopping at 40,000 BPH....
What do other designers use of over...
Take a look at ASABE publications for information regarding grain properties, bulk densities.
Be careful with Janssen's formula as it is for estimating "deep" storage bin loading vs "shallow" bin loading.... Often when bins are bin diameter with relation to height, the governing soil loading is...
We tend to use overpressure factors from ACI 313 as they are more conservative than ASABE yearbook standards values. We like mass flow bin design for tall small cross section bins, so hopper inclines are steep, etc.
Soybean meal is one of the most difficult materials to for design...
Under the new 318-08 is the old alternate design method using working stress design permitted, For simple quick design and checks, we would like to still utilize work stress design..
slip
Our website is nohrengineering.com
It's been difficult to recruit engineers to come to smaller cities like some in Dakota we find.. It's a 3 hour drive to a decent airport and pay scales are low for wives with professions.
r
Thanks for the comments on "selling" an engineering business. As much as we would like lots of $ for the business. we figure that probably won't practically be in the cards.
Continuity with clients and with employees could be more important to us combined with the opportunity for me to...
We have a successful 25 year old consulting engineering business providing engineering services for bulk materials handling, storage and processing structures, equipment and systems. Projects involve bins, silos, towers, conveyors, process equipment, etc. Since we are located in a small north...
Does anyone have suggestions for references and standards regarding temporary bracing of corrugated steel grain bins during assembly, jacking and erection work.
r
Before starting any design or constructon, get a soils test done. Generally, overexcavate per the soils test recommendations and backfill and compact per recommendations.. Work with the soil test engineer and consider drain tile at the bottom of the backfill.... pay alot of attention to...
for silo fires suppression:
grain or silage??
Look to publications by MWPS, Harvestore, etc.
We have a heck of a good reference library in our offices.
We also use Nitrogen gas to suppress fires.
CO2 is cheap and available, but does have CO in it also.... so monoxide poisoning is a problem...
Part of the problem seems to be that many grain bin/tank owners, contractors and jobs can tend to be pretty farmie and everything has to be cheap.... piling, helicals, large over excavations and backfilling makes the clients and contractors really "pucker"... cheap, has to be cheap... but when...
