Base Anchorage
An anchorage of wall footing can be specified in the "Cantilever Wall" program. It is necessary to specify an anchor location, dimensions of a drill hole, and spacing of anchors.
Two limit states of bearing capacity are defined for an anchor:
- bearing capacity against pulling-out Re [kN/m]
- strength of anchor Rt [kN]
Base anchorage
Bearing capacities can be either input or computed from the input values using the following expressions:
where: | Tp | - | pull-out resistance |
d | - | drill hole diameter | |
a | - | ultimate bond | |
SFe | - | safety factor against pulling-out |
where: | Rt | - | strength of anchor |
ds | - | anchor diameter | |
fy | - | yield strength of the anchor | |
SFt | - | safety factor against pulling-apart |
Approximate values of bearing capacity against pulling-out
Material | Ultimate bond [N/mm2] | Ultimate strength for specified hole diameter [kN/m] | ||||
65 mm | 75 mm | 90 mm | 100 mm | 150 mm | ||
Soft shale | 0.21 - 0,83 | 42 - 169 | 49 - 195 | 59 - 234 | 65 - 260 | 98 - 391 |
Sandstone | 0.83 - 1,73 | 169 - 350 | 195 - 407 | 234 - 486 | 260 - 543 | 391 - 562 |
Slate, Hard Shale | 0.86 - 1,38 | 175 - 281 | 202 - 325 | 243 - 390 | 270 - 433 | 405 - 562 |
Soft Limestone | 1.00 - 1.52 | 204 - 310 | 235 - 358 | 282 - 429 | 314 - 477 | 471 - 562 |
Granite, Basalt | 1.72 - 3.10 | 351 - 562 | 405 - 562 | 486 - 562 | 540 - 562 | 562 - 562 |
Concrete | 1.38 - 2.76 | 281 - 562 | 325 - 562 | 390 - 562 | 433 - 562 | 562 - 562 |