Users’ Manual
EDS-71V/P Single point borehole extensometer
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7
On the near end of assembled connecting rods a standard 14 cm spacer with male thread on one side and
female on the other side is always provided. The reference button (15) is threaded into the female end of
this spacer. The male thread of connecting rod most distant from the mouth of the borehole fits into the
anchor (1).
PVC tubing 14 mm od x 10 mm id in 3 m length is provided for enclosing connecting rods at time of
assembly. One end of these tubes is swaged to form a male extender such that male and female ends of
successive PVC tubes can be conveniently assembled to each other using any PVC jointing compound in-
between. After jointing, the joint should always be checked by pulling and then wrapped with PVC tape to
make it leak proof. The outer PVC tubing allows free movement to connecting rods and reference button
even after borehole is grouted.
The furthest PVC tubing is firmly sealed to the anchor to prevent any leakage of grout into the PVC tube..
This 3 m long PVC tubing is cut by 50 mm from the plain end to make it convenient for successive
connecting rods and PVC tubings to be connected together.
The near end of the PVC tubing is firmly sealed in flanged housing (5) with help of rubber bush (10), washer
(11) and hollow bolt (12). The PVC tube should be cut such that when sealed in flanged housing, its face
extends around 20 mm beyond rubber bush (10). Proper sealing in reference head assembly is especially
necessary for upwards to horizontally slanting holes for preventing any grout for leaking into reference
head assembly during grouting.
2.1.4
Anchor
2.1.4.1 Following type of anchors are available from Encardio-rite:
Encardio-rite groutable anchors
φ
20 mm x 500 mm long usually used for hard rocks. These are
lowered down or pushed in borehole along with connecting rod of appropriate length and fixed in
position by cement grout. The connecting rod is protected from cement grout by enclosing in plastic
tubing, thus allowing for its free movement. Groutable anchors may also be installed in vertical
boreholes or holes inclined upwards. Installation of groutable anchors in holes inclined upwards needs
special precautions to retain grout and prevent it from flowing out of borehole.
Encardio-rite packer anchors usually used for soft rocks and soil. These are lowered down or pushed
in borehole along with connecting rod of appropriate length and fixed in position by pumping cement
grout into the packer for taking a firm grip with the surroundings. Refer to consultant for use with
fibreglass connecting rods.
NOTE:
Encardio-rite uses convention that depth of anchor is calculated as distance from mouth of
hole to near end of anchor.
2.1.4.2 Groutable anchor for fibreglass option
2.1.4.3 Groutable anchor for AISI 410 rod option (swaged end of PVC tube slides over it)
Figure 2.4
Figure 2.5
PVC pipe (od-14x2 thk., 30 long)
Pin
Anchor
