Jet Grouting, Soil Mixing, Micropiles, Siesmic Anchors, Shotcrete Shoring, Permeation Grouting, Compaction Grouting, etc.

Drilled Micropiles, Anchors and Grouting

  • Grouting - Applications include Jet Grouting, Soil mixing, Permeation Grouting, Compaction Grouting and other specialty applications.
  • Micropiles - Small diameter, drilled replacement pile for compression or tension.
  • Anchors - Structural element used in seismic applications to resist uplift loading.

Challenging projects require special solutions. Southwest has a range of equipment and experience to install any siesmic anchor, micropile, tiedown anchor, rock anchors, soil nails, pipe piles or spiles. Anchor types range from IBO's (Injection BOred) to DCP's.(Dywidag Anchors) From Jet Grout shoring to Strand Anchor installations.

Micropiles

A Micropile is a small diameter (less than 300mm) drilled pile, composed of placed or injection grouted, with some steel reinforced element to resist tension or compression loads

  • drilledMP003.jpg
    Client:
    Vanbots Construction Inc.
    Date:
    Not available
    Summary:
    These Micropiles provided foundation support for a residential apartment building placed over an existing ravine with 23 Ft of fills overlying very dense native sandstone bedrock.

Low Overhead Anchors

One of the main reasons micropiles are effective is because they can be installed with smaller equipment in areas with tight access or limited overhead clearances. Our Baretta drill rig can bore holes up to 60' deep in sand or rock, and can be driven through a standard doorway. In areas of limited overhead clearance, we can drill with 8'6" headroom.

Helichal Anchors & Piles

Helical piles or "chance" anchors are commonly used in cohesioinless ground for loads to 50 kips in compression and tension. Because the helix penetration resistance is directly related to the torque to install these anchor capacities are directly linked to the hydraulic pressure of the drill rig installing them. Therefore, the capacity can be proven immediately upon installing.

  • drillunderBridge.jpg
    Client:
    Date:
    Not available
    Summary:
    No summary available.
  • DockDrill.jpg
    Client:
    Vancouver Port Authority
    Date:
    April 2002
    Summary:
    The design of choice by the Vancouver Port Authority for anchoring marine piling to resist seismic tension forces is the drilling of centralized anchors beneath the base of the pipe pile. First Canada Place Pier Extension used 9" casing to 150' deep and one central DCP anchor.
  • MarinePile001.jpg
    Client:
    Vancouver Port Authority
    Date:
    April 2002
    Summary:
    The design of choice by the Vancouver Port Authority for anchoring marine piling to resist seismic tension forces is the drilling of centralized anchors beneath the base of the pipe pile.

Jet Grouting

More commonly used for shoring in water bearing sands to resist water penetration and caving ground but it can also be used for piling. This technique uses european technology to inject grout under high pressures (6000 psi) to create overlapping columns of weak concrete that is later excavated to create shoring or left in place to provide a cutoff wall. Column diameters and strengths are dictated by pull speed and cement content and diamaters of 3' to 5' are common.

The ancillary equipment includes grout mixing tanks, pressure pumps, and cement silos so a storage footprint of 20' x 60' is required. Experience with this high tech equipment and techniqes to generate coluumns of sufficient strength and size is critical. Our JV with Condon Johnson in the US has ensured proper training and has further exposed us to new technology from Europe through their own JV's with the french. This serves to provide the lowest possible cost to shore the most extreme ground condition.

  • jetgroutshoring001.jpg
    Client:
    Mondiale Development
    Date:
    January 2006
    Summary:
    Water bearing sands being fed from the mountains above the base of the north shore mountains were intercepted with the shoring required for the Esplanade Development "The Pier" which required jet grouting to seal the water prior to excavating.

Soil Mixing

Soil mixing is similar to jet grouting in that it forms overlapping columns in water bearing ground for use as shoring in difficult ground. The only difference is that is is commonly used in silts and clays instead of sands and relys on mechanical mixing at lower grout pressures to accurately form a panel 3' x 5' using dual paddles. This techniqe is quite fast and grout is better controlled so it is generally cheaper than jet grouting but only used in silts and clays. Beams are simply set into the wet mix.

Compaction Grouting

Compaction grouting uses a low slump sanded grout injected at high pressure from the base of a drilled pipe (usually 3" diameter) to pressure weak ground to help increase its strength. Grout pressures, mix ratios, and pull speed are critical to achieve the improvement. The drilling is performed with our jet grout rig.

  • wharf1.jpg
    Client:
    Walter Construction
    Date:
    April 1999
    Summary:
    Drill and grout seal. Drilled and installed grout valves to 80' deep in gravel, cobble deposit. After hydraulic testing, controlled pumping of 17,000 bags of grout formed an impermeable wall and tremie seal.

Horizontal Drains

Horizontal drains are usually installed to over 100' in length to drain water to help improve slope stability. Depending on the strata special bits and casing methods are required to remove the inner string and leave the drainage pipe in place. Our cubex drill rig, developed in the mining world, has a mast that can spin 180 degrees so can be layed flat to install the casing.