Application
  Single- or multirod extensometer (Rockmeter) to measure displacements and deformations in dams, foundations, embankments, slopes, tunnels, bridges a.s.o.
   
Description
  Displacements along a borehole axis can be determined with the rockmeter. Rigs consisting of several single rods are protected and sheated in plastic tubes. The pointed ends are anchored on several levels in boreholes.

The slim rockmeter head is grouted in the borehole. The anchors at one end of the rods and the head of the rockmeter are the fixpoints between the sections. The relative movement between the fixpoints are measured.

The borehole has to be 1 m longer than the longest rod. Towards the end, closed to the borehole opening, the 0.5 m must be enlarged of approx. 120 mm.

The rockmeter is not depending on position. It can be installed at any inclination. The rod lengths of the rockmeters can be more than 80 m.

All instrument parts are made of stainless steel. The instrument is very solid and made for short- as well as for longterm applications even under rough environmental conditions. The measuring head is not sensible to any water entries. After complete installation, the space between the protective tube and the borehole wall is filled by grout. Herewith a perfect anchorage of the rods is achieved. This is a basic requirement for a precise and secure measuring of the displacement. Displacements are measured either with Setdeflectometers (manually) or by using the fix mounted electrical transducers (automatically).

Rockmeters can be equipped with 1 to 6 rods in the same borehole (more than 6 rods on request). The rods can have different lengths, depending on the conditions. With the multirod rockmeter it can be located in which depth there are displacements. This is important for instance when determining the installation depth of prestressed anchors.

If major changes in temperature are to be expected in the surroundings of the rockmeter rig, thermometers can be installed in the borehole (e.g. HUGGENBERGER Telethermeters). By them the temperature influenced changing in lengths can be corrected accordingly.

   
 

Rockmeter RME3

Rockmeter TRME4
   
Technical data
 
Type
RME
TRME
Installation
not depending on position, can be installed in any inclination
Diameter of measuring head
(T)RME1 Ø30mm
(T)RME2/3/4 Ø60mm
(T)RME5/6 Ø80mm
Measuring points
1-6 anchors per borehole
Length of rods
more than 80m if required
Measuring range
±25mm, adjustable ±25mm
Reading
Setdeflectometer (E)RDM
RDT
Indipoc µP20, Tensologger TL
Resolution
0.01mm
0.05mm
0.01mm
Electrical transducer
-
Linear potentiometric transducers TE1
Borehole diameter
(T)RME1/2 Ø56mm
(T)RME3/4 Ø66mm
(T)RME5/6 Ø76mm
Important notice:
1. The borehole should be 1 m longer than the longest rod.
2. Towards the end, closed to the borehole opening, the 0.5 m must be enlarged of approx. 120 mm.
   
Downloads
 
Adobe Acrobat document(*.pdf)