Encardio-rite Mechanical Borehole Extensometer Model EDS 63U/D is befitted for upward, downward, or inclined boreholes. It is specifically designed to assist civil engineers and geologists with the measurement of deformation of rock mass and adjacent or surrounding soul. It essentially consists of one or more anchors and a reference plate.
Let’s look at the Mechanical Borehole extensometer installation procedure.
Borehole extensometer installation procedure- Tools & accessories required
You will require the listed tools and accessories to successfully install a multi-position borehole extensometer:
Loctite 290 and Loctite 415 or equivalent
Acetone (commercial)
Spanner size 22 Screwdriver
Allen key
Hacksaw with 150 mm blade
Pliers 160 mm 150 mm flat file
Tube cutter M6 threading tap with handle
M6 threading die with handle
Wire brush
Cloth for cleaning (lintless)
Insulation tape
Micrometre depth gage 100 mm rang
Borehole Extensometer Installation Procedure with Fibreglass rod assembly NOTE: Please keep in mind that the procedure described below is used to install Encardio-rite borehole extensometer up to 6 points in a downward sloping hole with the help of groutable anchors. If you’re looking to install in an upward to the horizontally sloping borehole, using packer anchors, alter the procedure as required.
Site preparation before the borehole extensometer installation procedure:
Using the drilling machine, make a hole of 102mm diameter with a depth of 0.5 m – 1 m more than the length of the deepest anchor. NOTE: In case you’re looking to mount the Mechanical borehole extensometer horizontally, it is advised to provide, if design allows, a downward slope of 5 degrees or more to the borehole. Doing so will promote grouting of the anchor, allowing the grout to readily flow in.
Where the hole commences, stretch the diameter of the hole to 125 mm up to a depth of 225 mm. This is done to make way for the wrapping outside of housing with rags or jute cloth strips covered in cement.
Take the reference head assembly and insert it in the centre of the 125 mm borehole. Taking holes on the flange as a reference, drill four holes 18 mm diameter x 150 mm deep for fastening flange to the borehole. Once done, remove the reference head assembly from the borehole.
Clean the hole up to the bottom by pumping in freshwater.
Borehole Extensometer Installation Procedure (Fibreglass rod assembly):
In case the installation requires less than six points, use a standard rubber plug, steel washer, and hollow hex bolts to plug other points on reference head assembly.
Identify the machined portion of groutable anchor and apply Loctite 415 or equivalent on it. Utilising Loctite 290 as thread sealant, screw male end connector of longest fibreglass rod assembly to groutable anchor. Doing so will also allow the nylon tubing to strongly grip the groutable anchor.
Referring to the image above, separate the cover (6.13) from the flanged housing (6.1), and place the latter on the ground. Once done, loosen all hollow bolts (6.6) minutely.
Implant the groutable anchor in the borehole until the fibreglass rod can be seen 1 m – 1.5 m outside the borehole. To bare the female connector, trim the nylon sleeve by around ...[Continue Reading]
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