Optimizing rig utilization creates business advantages, especially as you look to enter or expand your place in the CPT market. Conducting Cone Penetration Testing for soil strength analysis with a combination machine provides you and your customers maximum flexibility when assigning machines to jobs. Geoprobe® has engineered a variety of these combination machines to easily and effectively complete CPT as well as other direct push, rotary and geotechnical applications.
The Geoprobe® 7822DT is the industry-benchmark combination rig, saving you time and money accomplishing the work historically completed by deploying multiple limited function drill rigs. Its small site footprint and stable track base make it much easier to mobilize to off-road work sites than conventional rigs.
When running CPT, up to 15 tons of push is typical for the 7822DT. Earth anchors are used to provide reaction force to offset the pushing capacity of the rig as the cone is advanced through static push rather than by hammer percussion. Switching between drilling tasks and pushing CPT is quick on the 7822DT and only takes a few additional components.
Depending on site lithology, a one or two anchor setup can be used. When installing two anchors, the wide range of drill mast movement makes setup efficient and places the drill mast in position to install the first anchor with the rotary head. Using the extend and swing functions, the mast is moved into location opposite of the first anchor. The second anchor is then installed with the rotary head. The drill mast foot is then positioned between the anchors.
Next, an anchor bridge beam is placed over the anchors and onto the drill mast foot. Two anchor pinning brackets are connected to the anchors to secure the drill mast for pushing.
Once anchoring is complete, the CPT logging equipment can now be setup. A stringpot tracks vertical movement of the head to record logging depth and CPT software will log the data from the cone.
The rig is now ready to begin pushing the CPT cone. Using an optional head feed control kit, automatic rate control provides cone advancement at the standard 2 cm per second rate specified by ASTM Standard D5778.
Rods are added to the tool string and advanced until the desired logging depth is reached. The 7822DT typically has 15 tons of push and 24 tons of pull. All this power is safely and efficiently managed through the precise controls at the driller’s fingertips.
Upon completion of the CPT log, the tool string is retrieved using the Geoprobe® designed rod grip puller.
Designed to easily switch between multiple sampling and logging methods - including pushing CPT tooling - the Geoprobe® 7822DT expands your application offerings and your customer base.
For more information on the 7822DT, visit our website at geoprobe.com/7822dt or call us at 785-825-1842.