The Efficiency of Direct Push
2 min read
Direct push machines perform rapid percussive blows unto a drill string to advance or push various soil sampling tooling through a range of subsurface lithology. Unlike traditional drill rigs, direct push rigs do not rely on rotary drilling to collect sample. This eliminates the clean-up cost of auger cuttings and the risk associated with rotating augers. Direct push rigs are highly effective at sampling through sand, soft clay, tight silt, swelling clay, heaving sand, and gravel thanks to their dual tube sampling system.
Dual tube sampling is the collection of continuous soil samples through a cased hole. This is achieved by driving two sets of rods into the ground simultaneously, one providing an outercasing while the inner set holds a sample liner. Once the liner is full the inner rods are pulled out to retrieve the sample with the outer rods remaining in place to case the hole. A newliner is then attached to be advanced further.
All Profile Drilling Inc. liners are made outof PVC which eliminates any cross-contamination potential.
Direct push drills like our Powerprobe 9700 VTR Pro sample at double the rate that traditional drill rigs do and are more cost effective. Dual tube sampling is true continuous sampling since outer casings sit in the earth oncesampling is complete and eliminate chances of cave-ins. Along with direct push, our Powerprobe 9700s are also capable of advancing 4.25” ID hollow stem augers necessary for the proper installation of 2”monitors.
Drive inner and outer rods into the ground simultaneously. Ensuring it reaches a depth to fill the liner without it bursting - about four feet.
Once the liner is full drill cap and rod collar are removed. Begin retrieving sample by removing inner rods until sample liner is retrieved and replaced with a new liner.
A new rod pair is then properly assembled upon the existing casing to be advanced further. The retrieved sample rests inside pvc liner and transported to an on-site technician for examination.
The outer casing is not removed at any time in the drilling process unless to mobilize to a different location or finish sampling. This is because the outer casing keeps the hole from collapsing inside itself. Ensuring the samples retrieved are accurate depth.
Benefits:
Safe - Direct push does not involve auger rotation making it one of the most risk averse options in the industry.
Efficient - The dual tube sampling system is fast and effective at retrieving soil sample. Sampling can be done at twice the speed allowing for rapid BH completion.
Clean - Direct push technology eliminates auger cuttings altogether at the sampling stage, reducing overhead costs associated with the collection and disposal of excavated material.
Compact - With a low mast, the Powerprobe is an ideal rig for low headroom conditions inside buildings or garages.
Lightweight - Much faster than traditional rigs, the Powerprobe is ideal for projects where an abundance of overburden must be sampled over a widespread area.
Accurate - Samples gathered through direct push drilling are collected inside pvc liners, eliminating the chances of cross contamination at the extraction stage.
Here are a list of services our Direct push rigs have to offer:
Geotechnical
Environmental
Monitoring well installation.
Vapor sampling
Well Decommissioning.
