Shallow large overcoring

The Surface Overcoring tests are used to measure the plane stress state existing on the surface of rock excavations and concrete structures.

Typical areas of application are:

• underground excavations, niches, tunnel walls, tunnels, chamber-pillar mining crops
• concrete lining of the tunnels
• beams, pillars, concrete slabs
• body of concrete dams both from the internal tunnels and from the faces

The know-how, the equipment and the experimental / interpretative procedures used by us cover a wide range of applications:

• perforations in any direction
• core drilling diameter 150-240 mm
• measurements performed using a removable 200 mm mechanical strain gauge on 4 measuring bases positioned at 45 ° from each other
• measurements performed outside the over-cored surface (for small diameter perforations) or inside it (for large diameter perforations)
• drilling depth: up to the exhaustion of the deformations

The drilling with a special electric core drill is at our expense: the drilling is an integral part of the test we provide.

The determination of the elastic modulus of the material is included; it is performed on a cylindrical specimen taken from the center of the overcored sample.