Proceedings - 13th International Workshop on Micropiles - 2017, Vancouver, BC, Canada, (ISM, DFI, ADSC)
Deep Resonant Micro Piling for Netherlands Grade Separation
Mathew Janes, M.E.Sc., P.Eng.
The Resonator RD 260 Resonant Pile Driver delivers ground disturbance free, high production micro pile installation. The Resonator was recently used at the site of a major grade separation south of Amsterdam, at Den Haag, to install 34 m long micro piles. The micro piles are used as both compression and tension elements for the support of the structure walls and roof and to hold down the roadway base due to hydraulic uplift forces. A test program involving several installation methods proved the Resonant driver would install the 168 mm dia 34 m length test pile to full depth in just 11 to 15 minutes. The Resonator was crane mounted and drove a single length 34 m tube through mixed sands and silts with CPT Qc of over 300 Bar. The single pass pipe was installed with a loss bit and no flushing. Thus, the micro pile was installed with zero ground vibration, no spoil and no flushing fluids to contend with. Competing methods included sonic drilling (which could only penetrate to 19 m depth) and conventional water flush drilling which took over 90 minutes to reach a depth of 28 m. The micro piles were pressure grouted during casing re val at intervals of 3 m and at grout pressures of 20 Bar. Load testing confirmed the cro pile capacity to be 1125 kN to 2160 kN, depending upon the grouting procedures.
|article #2640; publication #1033 (ISM- 2017)|