Bustamante (SPT, Pressuremeter PMT)
The analysis of the bearing capacity of the micropile root section is based on the results of standard penetration tests (SPT) or pressuremeter tests (PMT).
The magnitude of skin friction of the micropile root qs [MPa] is available from the graphs according to Bustamante, which depends on the type of soil and the injection technology.
Shaft resistance of the micropile root Rs follows from:
where: | dr | - | diameter of the micropile root |
lr | - | length of the micropile root | |
qs | - | skin friction of the micropile root (value determined from the graph) |
Base resistance of the micropile root Rb may not be considered in the analysis or is taken as:
where: | Rs | - | Shaft resistance of the micropile root |
Base resistance of the micropile root Rb is assumed in the program in the form:
where: | Ap | - | cross-section area of the base of the micropile root |
kp | - | soil factor in the vicinity of the base of the micropile root | |
pLM | - | limit pressure according to Menard |