Mar 2, 2005 · The subgrade modulus is frequently specified in terms of pounds per cubic inch or kips per cubic inch. For a footing on the ground (say on sand) we frequently quote an allowable bearing pressure as pounds per square foot for one inch of settlement. This is essentially a subgrade modulus that considers the size and shape of the footing.

Apr 9, 2015 · The modulus of subgrade reaction is a basis for structural engineers to evaluate deformation from point loads that may or may not be applied to the slab. Say, you know a racking system will be installed in the completed building. The rack load may be applied anywhere in the building, so the structural engineer needs to account for these point ...

Aug 10, 2009 · After computing the stimated elastic settlements (using sigma - W) (project is located on a weathered limestone), I computed the subgrade modulus. Subgrade modulus K = applied load / elastic settlement underneath that footing or mat. In summary, the mass presents few porous to very porous strata (SPT-N 1 - 10). The lowest K value I got was 1.5 ...

Jun 15, 2010 · O.K. I'll jump in. . . I have a basic problem "compacting" a natural soil subgrade. In the absence of geotechnical data, you may find that the natural soil is pretty strong (i.e., suited for subgrade support), but the natural moisture content is over "optimum."

Aug 22, 2007 · Oddly, the subgrade modulus for structural considerations is considerably different than the subgrade modulus for pavement purposes. Given the same materials, the subgrade modulus for pavement purposes will be 2 to 2-1/2 times the structural value.

Jun 14, 2001 · Nowadays, more cases that the field technician is hired by contractor. When the subgrade soils cracked, heave, probed for 24 inches deep, but tested as 90-95%, the owner's soil engineer will need to ready himself/herself to answer questions from the owner, contractor, and field technician (and his/her engineer).

May 10, 2008 · I am designing a 30-foot deep by 8 foot diameter reinforced concrete caisson. The value that I need is the horizontal subgrade modulus for the rock in order to determine what deflection the foundation will see when bearing against the rock. Bowles has some empirical formulas for estimating Ks from the Es.

May 16, 2001 · A subgrade modulus for rock is not of much use. The modulus is defined as pressure/measured deflection. Rock, unlike soil, does not compress when pressure is applied (i.e. it will crack before its compressibility can be mearured). Thus, the rock will experience a brittle fracture failure instead of a slow compression as can be seen in most soils.

Apr 26, 2011 · If we have soft to firm clay, the 100 pci value is a default. However, if we start getting into very stiff clays it is near 150 pci and in granular soils, the range of vertical subgrade modulus would be in the 250 to 350+ pci range. Look up at Bowles Foundation Analysis and Design book for a range of values.

Feb 4, 2012 · I am designing a raft/slab foundation on grade for a G+1 light gauge steel hospital building in SAFE software. The soil bearing capacity is 50 KN/m2 and soil is soft clay soil but to analyze this foundation in SAFE I need to know the subgrade modulus “K” value so …