Modulus of Horizontal Reaction of Subsoil
The soil surrounding the micropile can be represented using horizontal springs along micropile characterized by the Winkler constant kh. For buckling of micropile into the soil in the direction of the x axis it is possible to write:
where: | ph | - | reaction of soil caused by the displacement of micropile in direction of x axis (soil in compression) |
kh | - | stiffness of Winkler spring (modulus of subsoil reaction Ep) | |
x | - | shift of a micropile in the direction of x axis |
Providing we consider the reaction of soil to pressing of micropile per one meter run of the micropile we arrive at:
where: | Er | - | reaction of soil in the horizontal direction |
ph | - | reaction of soil caused by the shift of micropile in direction of x axis per one meter run of micropile | |
x | shift of micropile in the direction of x axis |
The above equations identify the relation between the modulus of subsoil reaction Ep [kN/m3] and the reaction of soil in the horizontal direction Er [kN/m2] (assuming constant Er in the soil):
where: | D | - | diameter of micropile |
kh | - | stiffness of Winkler spring (modulus of subsoil reaction Ep) |
The reaction of soil in the horizontal direction Er can be post calculated based on the knowledge of the pressuremeter modulus Em.