Véas Theory
This solution takes into account the effect of geostatic stress at the micropile root and course of grouting.
Bearing capacity of the micropile root is provided by:
where: | Rbk | - | bearing capacity of the micropile root |
Rsk | - | skin bearing capacity of the micropile root |
Micropile skin bearing capacity:
where: | n | - | number of layers passed by the micropile root |
Asi | - | area of the wall of the micropile base in the ith layer | |
qsi | - | skin friction in the ith layer |
Bearing capacity of the micropile root is provided by:
Skin friction qs at a depth of z below the terrain surface:
where: | z | - | depth z below the terrain surface, where the magnitude of skin friction is determined |
c | - | effective cohesion of soil at a depth of z | |
δ | - | friction angle along the interface of the micropile root and the soil at a depth of z: | |
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φ' | - | effective angle of internal friction of soil at a depth of z | |
σh(z) | - | horizontal component of geostatic stress at a depth of z: | |
- | for grouting course of type IR and IRS (with monitoring of grouting pressure) and depth z ≥ 5 m: | ||
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- | other cases: | ||
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Ko | - | coefficient of earth pressure at rest | |
- | for normally consolidated soils: | ||
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- | for overconsolidated soils: | ||
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σv(z) | - | vertical component of geostatic stress at a depth of z | |
pi | - | grouting pressure for grouting course of type IR and IRS and depth z ≥ 5 m, in other cases pi = 0 | |
Fc, Fφ | - |
Literature:
Véas, Souche : Étude du flambement de pieux partiellement immergés dans un milieu offrant latéralement une réaction élastique pure, Annales de l’ITBTP, No. 423, Sene Soils et Foundations, 187, mars - avril 1984, p. 38 - 60 (French).