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Installation Instructions for Snap Seal Inclinometer Casing 6.2 Installation Methods Pipe Clamp Method This method involves using pipe clamps to hold the casing at the borehole collar while you add the next section of casing. Two pipe clamps are needed. In dry boreholes or in situations where down-hole problems seem likely, rig a safety line to provide extra security and a way to retrieve the casing if necessary. 1 Install an end cap on the first section of casing (section 5.2). 2 Attach one clamp to the top of the first section of casing. Lower the casing into the borehole until the clamp rests on the borehole collar. 3 Attach a second clamp to the top of the next section of pipe. Connect the two sections according to the instructions outlined in section 5.3. Remove the first clamp and lower the section into the borehole. Repeat steps 2 and 3 until installation is complete. When to depth, verify the alignment of the grooves by running a dummy probe to the hole bottom. If the probe will not pass,jumps track, or returns in another set of grooves, pull the casing and rectify the problem. In deep boreholes, it is advantageous to use a safety line to restrain the casing during installation. This can be used in conjunction with the casing clamps to lower the casing a controlled rate. Note that using the safety line by itself may induce spiraling due to the spiral lay of the rope, and is not recommended. 6.3 Casing Buoyancy If the borehole is filled with water or mud, ballasting the casing with clean water can neutralize the casings' buoyancy. Exercise caution with this technique, as in dry boreholes, the differential pressure caused by the head of water may cause the casing to fail. Casing also becomes buoyant during the process of grouting the borehole. The two following methods can be used to prevent the casing from floating out of the borehole during grouting: 1 Drill rods may be inserted inside the casing to hold the string from the bottom. 2 The bottom of the casing may be anchored in grout, then the balance of the borehole grouted. Note Applying a down-force to the top of the casing will likely distort the casing profile. Never use the drilling rig as a reaction force, or wedge the collar of the borehole. This will cause the casing to assume a large radius bend, making readings virtually useless. In many cases, it is standard practice to attach a weight to the bottom of the casing to counteract the buoyancy effects of the casing. In situations where the casing is being inserted into a freshly grouted borehole, these buoyancy forces can be significantly large. RST cautions against using too large of a weight as it may fail the joint on the bottom cap or elsewhere in the casing. 10