Bearing Capacity of Cross Section Loaded by Normal Force
Tension normal force
In case of tension force, the stress in steel part of cross section is calculated using the following formula:
where: | σs | - | stress in steel |
N | - | normal force acting in section | |
As | - | area of the steel part of the micropile cross section |
Compressive normal force
Bearing capacity of the cross section in compression, reduced by buckling coefficient, is determined as:
where: | χ | - | |
As | - | area of the steel part of the micropile cross section | |
Ac | - | area of the cement mixture part of the micropile cross section | |
Rsd | - | design strength of steel | |
Rcd | - | design strength of cement mixture in compression |
Design strengths are equal to standard values in the verification based on the factor of safety.
Design strengths of steel and cement mixture are calculated in the verification based on the theory of limit states as follows:
where: | Rs | - | standard strength of steel, entered in the "Material" frame |
γss | - | reduction coefficient of steel strength, entered in the "Micropiles" tab | |
Rc | - | standard strength of cement mixture in compression, entered in the "Material" frame | |
γsc | - | reduction coefficient for cement mixture, entered in the "Micropiles" tab |
The stress in the steel part of the cross section is determined as:
where: | N | - | normal force acting in section |
Nc,u | - | bearing capacity of the cross section in compression, reduced by influence of buckling | |
Rsd | - | design strength of steel |