quot;Top quot; or quot;Bottom quot; of Footing? 5 - Eng-Tips I agree that "bottom of footing" is the standard in regards to frost depth A note on JAE's comment-I don't agree the 42" footing depth versus an "average" frost depth of 26" is the correct picture of the safety factor The frost depth value to consider is the design depth of frost, which is typically the 30-year maximum value
Is Frost Depth Always Required? 1 - Eng-Tips No, frost depth is not always required if what you are supporting can withstand the movement However, for most pipe racks we have designed we have gone to frost depth There have been a few short runs where the client did not want to go that deep We informed the client of the potential heave and the possible issues (similar to you describing)
Exterior Large Equipment Pad with deep frost depths 7 - Eng-Tips So, the frost depth say 6 ft specified at local code may occur at outside of insulated SOG, but the frost depth below SOG will be around just one ft I want to add that, if the soil is collapsible ( silty clay with some organics) the ground may settle every year at the end of frost season My suggestion to BSPE90 will be;
Frost box? - Foundation engineering | Eng-Tips the depth of frost penetration depends on a lot of things One factor is the presence of water in the soil As that material is at 32 degrees, it gives off heat of fusion That heat release slows down the migration of that freezing front As an extreme of this, take the depth of frost at a lake as compared to soil on land
Crushed stone size limitation for non-expansive frostfree fill If you are referring to non-frost susceptible (NFS) material, the definition is a soil that contains no more than 3% by weight finer than 0 02 mm A #200 sieve is generally used (0 074 mm), for which the requirement is no more than 5% passing Whether crushed or not isn't a factor
Frost line depth - Foundation engineering | Eng-Tips These typically show maximum frost depth in the ground and are not associated with buildings and building foundations The presence of a building affects the frost depth as there is some level of insulating heating that occurs at the footing All that to say - do what birneys suggests Check out Eng-Tips Forum's Policies here: faq731-376
Frost Heave Calculation - Foundation engineering | Eng-Tips I view frost as an "infinite" force If conditions are right for it to form, it can lift just about anything I don't know of any calculation that will give frost pressure I've seen published values of 10 tsf, but I believe they are based on back-calculating the pressure required to lift a building where frost heave was observed
Frost protection of fill - Earthwork grading engineering - Eng-Tips For example snow covered ground will have musch less frost penetration than an area kept clear of snow The depth the frost will penetrate below the insulating layer depends on insulating value (thermal conductivity and thickness), initial ground temperature, and of course the air temperature over the freezing period
Frost depth consideration in existing rock layer 1 - Eng-Tips Leonards gives presumptive bearing capacities for quot;Soft Rock, Sedimentary Layered rock (hard shale, Sandstone and Siltstone)20,000-30,000 psf That being said, the soft rocks described are subject to frost heave if located above the frost line I had experience some time ago with layered limestone frost heaving
Frost Protection for Slab 1 - Eng-Tips It takes three things to create a frost heave: extend periods of temperatures below freezing, a frost susceptible soil and a source of moisture (infiltration, capillary rise, etc ) If you have all three and frost penetrates deeper than 12” annually, this slab will heave