摘要(英) |
A
continuous strain hardening-softening and volumetric dilatancy
model named SHASOVOD, and FLAC3D software were adopted to study
the anchorage behavior of inclined-multiple-anchorage anchors in
silty sand. To enhance the applicability of numerical analyses,
the results of field tests are compared with those from
numerical analyses. After the calibration, parametric studies
were then carried out by numerical analyses.
It was found that the numerical results are in a good agreement
with those by field tests. The friction force dominates the
anchorage capacity of a shaft multiple anchorage anchor. It can
be inferred, the optimum position of the upper anchorage body is
6m form the bottom for a double-anchorage anchor. Moreover, for
a triple-anchorage anchor, a distance of 12m is the best
location for upper anchorage body from the middle one. Even
though anchorage bodies were installed in the condition of
optimum location, the anchorage capacity could not be the
summation of the ultimate load of each anchorage body, this
phenomenon is caused by carried load of each anchorage body do
not reach peak values at same anchor displacement.
Whether embedded depth, overburden depth or fixed length of an
anchor increased, the anchorage capacity of an anchor also
increased. For a multiple-anchorage anchor, increasing fixed
length should be the best choice to increase the anchorage
capacity, ultimate load per unit fixed length was around 60kN/m.
However, as the fixed length of a double-anchorage anchor is
greater than 30m, the anchorage capacity per unit fixed length
was decreased due to progressive yield of friction stress along
fixed end. Instead, a triple anchorage methodology could be
applied to conquer the progressive yield of above situation. A
tension force was generated beneath the anchorage body, Hence
the grouted body was cracked and led to an erosive steel strand.
No utilization to a multiple-anchorage anchor is really complete
without applying a double protection on fixed length. |