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3. Calculation of Ultimate Bearing Capacity
Calculation of ultimate
bearing capacity
Method of structural calculation that checks the required performance for each item.
→ Either allowable unit stress or ultimate bearing capacity should be chosen.
→ This rule does not need to apply to the majority of specification
regulations excluding those that cannot be checked by structural
calculations, such as durability or constructibility. Its application is,
however, necessary for specification regulations in calculation of allowable unit stress.
Structural calculation should be made to check the following performance:
The building should not suffer deformation or vibration that prevents intended
use of the building by its own dead weight or applied loads .
The building should not suffer collapse or destruction in the event of large-scale snowfall, storm or earthquake that very rarely happens.
The building should not suffer damage in the event of medium scale snowfall,
storm or earthquake that can happen once or more in the service life of the building.
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{ For instance, safety of a building against a major earthquake is
checked by the following structural calculations:
In
calculating the ultimate lateral strength,
it is assumed that the building complies with certain specification standards.
A relatively simple method is used to evaluate tenacity or shape characteristics of each floor,
and an equation to calculate ultimate lateral strength
is specified as the standard method of calculation.
For
calculation of ultimate bearing capacity,
it is not based on the assumption of the deformation that occurs to the building by the seismic force and the seismic force that acts on
the building when such deformation is caused, but a highly versatile calculation method to
ensure detailed verification is used.
1
Maximum deformation safety
limit displacement occurring to each
floor
when the floor resists lateral force
equal to its ultimate lateral strength is
calculated. 2
Seismic force acting on each floor
during a major earthquake is calculated,
while considering vibration characteristics
of the building under displacement equal to
the
safety limit displacement
.
3
The seismic force in 2 should be smaller
than the ultimate lateral strength.
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4. Advanced Structural Calculations
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