Process for driving and cementing in ground anchors, apparatus and anchor bars for said process
OwnerClaude C. Louisinventor
Life of this patent
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Abstract
Process using a ground anchor (1) with a longitudinal hole (7), on which is fitted an interface device (12) comprising a cylinder containing a chamber connected to the said hole (7); a grout is pumped under pressure to the tip (6) of the hole in the ground; the cylinder is struck mechanically, and transmits the mechanical shock wave to the ground anchor. The grout injected is a liquid mix (L); the grout is injected by means of a pump (21) at a pressure greater than 20 MPa; the grouting pressure is sufficient to fragment the ground by means of the injected grout, and the cylinder is struck by a percussion/vibration hammer (2) at a frequency greater than 10 Hz.
Claims14
Process for driving and cementing anchors in ground comprising the steps of:
- taking an anchor rod with a longitudinal duct open at a tip located at the remote end of the rod in the ground,
- taking an interface device connected at the other end of the rod, said interface device comprising a cylinder acting as a dolly and having a top end which forms a helmet, said cylinder containing a chamber communicating with the longitudinal duct of the rod,
- taking a grout sufficiently liquid to be pumped at high pressure, and,
- taking a high-pressure pump for puming and ejecting said liquid grout through said longitudinal duct so that the kinetic energy of the grout emerging from the duct through the tip of the rod is high enough to produce hydraulic fracturing of the ground,
- and using a percussion/vibration hammer or the like to strike the helmet of the cylinder to mechanically transmit its energy of impact to the rod and hence to the ground as a mechanical shock wave, wherein the hammer strikes at a frequency that is sufficient to prevent the ground reforming between successive impacts, which frequency is greater than 10 Hz.
Apparatus for driving and cementing anchors in the ground, comprising:
- an anchor rod with a longitudinal duct open at a tip located at the remote end of the rod in the ground,
- an interface device connected at the other end of the rod, said device comprising a cylinder acting as a dolly and having a top end which forms a helmet, said cylinder containing a chamber communicating with the longitudinal duct of the rod,
- a grout sufficiently liquid to be pumped at high pressure,
- a high-pressure pump for pumping and injecting said liquid grout through said longitudinal duct so that the kinetic energy of the grout emerging from the duct through the tip of the rod is high enough to produce hydraulic fracturing of the ground,
- and a percussion/vibration hammer to strike the helmet of the cylinder which mechanically transmits the energy of the impact to the rod, said hammer having means for striking at a frequency that is sufficient to prevent the ground reforming between successive impacts, this frequency being greater than 10 Hz.
Apparatus for driving and cementing in ground anchors using an anchor rod with a longitudinal hole open at its remote end in the ground and at the other end of which is an interface comprising a cylinder acting as a dolly and containing a chamber communicating with the longitudinal hole in the rod, said apparatus comprising pump means for pumping a liquid grout under pressure to the remote end of the rod in the ground, and hammer means for striking the cylinder to transmit mechanisally, the energy of impact to the rod, said pump means comprising means for injecting the grout at a static liquid pressure greater than 20 MPa, and said hammer means comprising means for striking the cylinder with a percussion hammer at a frequency greater than 10 Hz and sufficient to prevent the ground from reforming between successive impacts, and control means for producing short pump discharge pressure increases, and for changing the timing and frequency of the pressure increases.
Dependencies are inferred from the claim text.