Sediment Vibracorer Sampling System
Pollutech has recently added a VC 3.5.2 Vibracorer System manufactured by PVL Technologies Inc. to our inventory of environmental sampling equipment. The acquisition of this system enhances our current sediment sampling capabilities that include a variety of sludge and sediment samplers (e.g., standard and petite Ponar dredges, Shipek grab sampler, hand and hammer core samplers, biological dredges). The Vibracorer System supplements other resources including water column sampling equipment, monitoring instrumentation, support vessels and our in-house environmental diving and marine services group.
The acquisition of the Vibracorer System also includes a self contained pontoon vessel with trailer for easy transport and rapid deployment. Our pontoon vessel is equipped with an outboard motor, lifting tripod & winch, generator and various other safety and ancillary support equipment used in the collection of the sediment cores. A short video clip of our vibracorer sediment sampling system in operation can be viewed at https://www.youtube.com/watch?v=PqRd9bl5kRw.
Our new Vibracorer System is a relatively small and light weight unit that is ideal for rapid deployment on small vessels. The system allows for sampling of a wide range of sediment lengths using a variety of different core tubes/liners (aluminum, stainless or plastic with an inside diameter ranging from 5 to 10 cm).
The VC 3.5.2 Vibracorer System uses an electric motor to drive a pair of masses producing vibrational energy that is propagated along the core tube and into the sediments. The vibration energy re-orientates the sediment particles at the lower end of the core tube, causing them to move out of the way of the advancing core tube and into a more efficient packing. Since the sediment is saturated, the pore water pressure in the region around the core tube increases. As pore pressure increases, the effective confining stress in the sediment decreases and the strength of the sediment diminishes. With the penetration resistance (shear strength) of the sediment reduced, the core tube penetrates the sediment under the static weight of the vibracoring apparatus. While some densification of the material within the tube does occur, the stratigraphy can be maintained, which is important for establishing a timeline for sedimentation purposes and/or sediment stratification. Fine grained material which has been naturally deposited through water is the ideal candidate for vibracoring, as deposition through water yields sediment of very low density so that the potential for vibrational densification, and hence penetration, using the vibracore is excellent (modified from www.pvltech.com).
The Vibracorer System can be used in both fresh and salt water applications to a depth of 100 metres. If required, a core catcher (that acts like a one way check valve) can be attached to the bottom of the core tube to increase success rate of retaining the core sample during core extraction/retrieval to the surface. The use of clear plastic tubes allows for visual inspection of cores without physical removal/disturbance of sediments.
If you have any questions or require further details regarding services provided by Pollutech, please Contact Us to discuss how Pollutech can help you with your sediment sampling and assessment requirements