| Abstrakt: |
During installation, the helical pile should penetrate into the ground at a rate equal to one helix pitch per rotation to prevent additional soil disturbance, as usually recommended in installation guides; however, in the field this is frequently difficult to achieve. To have a better understanding of the effects of the advancement rate (AR) on the installation torque and helix bearing capacity, six calibration chamber tests were performed on an instrumented single-helix pile installed in very dense sand using three different AR values (0.8, 1 and 1.2). For the range tested, the results indicated that AR affects the uplift and compressive capacity of the pile helix. A reduction in compressive capacity of 24% on average was observed for AR of 0.8, compared to the recommended pitch matched installation (AR = 1), while for AR of 1.2, the compressive capacity increased 12% on average. In uplift, the capacity variation was about − 26% and + 6%, respectively, for AR of 0.8 and 1.2 compared to the pitch matched installation case. The effect of AR was also observed for the capacity-to-torque factor related to the helix portion of a deep helical pile and suggests the necessity for monitoring AR to ensure the applicability of the torque factor for pile capacity control. [ABSTRACT FROM AUTHOR] |
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