MERIT imaging provides precise imaging for geotechnical investigation of sinkholes.

The problem with traditional geophysics in investigating sinkholes is that typical methods do not reach where sinkhole development occurs. MERIT has the ability to identify the sinkhole throat and sinkhole development in the limestone. This is key in common scenarios where cover material greater than 30 feet over the limestone. This dramatically reduces the need to investigate using exploration drilling. As shown in the video, MERIT has the ability to direct exploration drilling directly to the sinkhole location.
Sinkhole imaged in a Tampa, FL apartment complex.

MERIT can illuminate and assist with sinkhole identification and remediation through:

  • Vertical and surface mapping of water movement to identify the area of infiltration.
  • 3D Modeling using an offset method.
  • Providing a framework to correlate SPT data.
  • Images 2x deeper than surface Electrical Resistivity (ER).
  • Images more than 5x deeper than Ground Penetrating Radar.
  • Higher resolution images of the subsurface.
  • Implants can be left in place to provide monitoring of ground stabilization efforts.
  • Requires only half the distance of surface ER.
  • Direct push technology makes installation cost effective.

Case Study: Sinkholes With No Surface Expression

This MERIT image shows two sinkholes with no surface expression. The sinkhole at 18 m was confirmed by Standard Penetration Test borings BH3 and Cone Penetrometer Test CPT 16 and was considered not to be active. The sinkhole at BH4, 5, 6, 7, 8, 9 and 10 is considered to be active.
An example of the offset method of taking slices of the subsurface to create a 3D model as shown above.
MERIT implants and surface electrodes create a vertical plane. When the surface electrodes are moved to an angle the MERIT image creates a slice, much like medical CT scans do. These slices can be combined to create a 3D image.

Case Study: Lake County, FL

MERIT image taken in Lake County, Florida. The MERIT array was comprised of 28 surface electrodes and 28 implants set at 48 feet bls. The total array length was 540 feet. 26 SPT and CPT were performed at the location of the MERIT image.
This image shows the potential of MERIT system. The tomographic image seen is 170 feet deep and clearly shows the sinkhole depression infilled with sand (Upper Red), the geometry of the sinkhole, materials infilling the sinkhole (Blue) comprised of silts, clay, and organics and the location of the sinkhole throat, as well as the weathered limestone (Green) and Competent Limestone (Lower Red).
The MERIT’s patent pending technology is unique in the ability to obtain tomographic images from the surface well into the bedrock, where results of Standard Penetration Test or Cone Penetrometer Testing can easily be compared to MERIT image.