Anchorage behavior of mechanically under-reamed anchors in silty sand

作者：Hsu Shih Tsung; Tang Yu Geng^*

来源：Disaster Advances, 2013, 6(10): 31-44.

• Silty sand
• under-reamed anchors
• ultimate loads
• failure modes
• numerical analysis
• field test

An under-reamed anchor can meet the requirements of having a short length and high anchorage capacity in a limited space or a restricted thickness of an anchored stratum. Furthermore, the anchor can provide more ductility to resist seismic force. To investigate the anchorage mechanisms of this anchor, a numerical program was adopted to perform the numerical analyses. The results from field anchor tests were compared with those calculated by numerical analyses to enhance the applicability of the numerical program.
Three failure modes on end bearing were identified according to the embedded depth of the under-reamed anchor. These included general shear failure for a shallow anchor, local shear failure for a transited anchor and punching shear failure for a deep anchor. No progressive yield occurred along the interface between the fixed length and soil for the anchors with length/diameter ratios (L/D) of less than 25. Therefore, the anchorage capacity increased at an increasing rate with the fixed length.

• 出版日期2013-10