Inclinometer Casing

Inclinometer casing is a special purpose, grooved pipe used in inclinometer installations. It is typically installed in boreholes, but can also be embedded in fills, cast into concrete, or attached to structures. Inclinometer casing provides access for the inclinometer probe, allowing it to obtain subsurface measurements. Grooves inside the casing control the orientation of the probe and provide a surface from which repeatable tilt measurements can be obtained.

Choosing Inclinometer Casing

Although Slope Indicator casing competitively priced, price should never be the deciding factor in choosing inclinometer casing. The cost of casing is quite small relative cost of mobilizing a drill rig,and very small relative to the cost of a failed installation.

Casing Diameter

Casing is designed to deform with movement of the adjacent ground or structure. The useful life of the casing ends when continued movement of the ground pinches or shears the casing,preventing passage of the inclinometer probe. Larger diameter casing generally provides longer life.

Large Diameter Casing

(85 mm, 3.34 inch) is suitable

for landslides and long term

monitoring. It is also appropriate

for monitoring multiple shear

zones or very narrow shear

zones, and it is required for

the horizontal Digitilt inclinometer

probe.

Medium Diameter Casing

(70 mm, 2.75 inch) is suitable

for construction projects. It can

also be used for slope stability

monitoring when only a moderate

degree of deformation is anticipated.

Small Diameter Casing

(48 mm, 1.9") is suitable for applications where small deformations are distributed over broad zones. It is generally not installed in soils.

Casing Grooves

Measurement accuracy is directly

influenced by the quality of casing

grooves. For this reason, Slope

Indicator cuts grooves by machine

broaching. This process allows the

width and chamfer of the grooves to

be optimized for the wheels of the

Digitilt inclinometer probe. It also

minimizes spiralling of the grooves.

Casing Strength

In borehole installations, the annular space around the casing is usually backfilled with grout. The grouting process can generate pressure high enough to cause the casing to collapse. In very deep installations, the pressure of grout must be controlled by stage grouting, but in most other cases, the casing must be made strong enough to withstand the normal pressure of grouting. Slope Indicator makes casing strong by using thick-walled pipe and carefully controlling the depth of the grooves during broaching to prevent the walls of the casing from being weakened.

Sealable Couplings

Grout can force its way into the casing if casing joints are not adequately sealed. Then, after the grout hardens, it prevents the probe from reaching its intended depth. In some cases, the installation becomes useless. Slope Indicator offers several types of couplings and casings, all of which can be sealed easily and consistently. Our newest designs feature O-ring seals, and our older designs feature tight-fitting surfaces that are fused together with solvent cement.

Assembly

Inclinometer casing should be easy to assemble, even with an untrained crew. Slope Indicator's QC casing, which snaps together, is the current leader in quick and easy assembly. Other types of casing are assembled with shear wires or with solvent cement.

Casing Materials

Slope Indicator uses only ABS plastic for its casing for several reasons. ABS plastic retains its shape and flexibility over a wider range of temperatures than PVC plastic. ABS plastic is much easier to handle and seal than fiberglass casing. Finally, ABS plastic is suitable for long term contact with all types of soils, grouts, and ground water, unlike aluminum casing, which is no longer recommended for any application.

Installation Information

Visit the technical support section at www.slopeindicator.com to find recommended grout mixes, ways to counter casing buoyancy, and notes on other installation issues.

Shear Wire Casing, Large Diameter

Outside Diameter: 85 mm, 3.34 inches.

Inside Diameter: 73 mm, 2.87 inches.

Collapse Rating: 12.4 bar, 180 psi.

Load Rating: 225 kg, 500 lb.

Temp rating: -29 to 88 ºC, -20 to 190 ºF.

Spiral: ≤ 0.33º per 3m or 10' section.

Shear Wire Casing, Medium Diameter

Outside Diameter: 70 mm, 2.75 inches.

Inside Diameter: 59 mm, 2.32 inches.

Collapse Rating: 16.5 bar, 240 psi.

Load Rating: 225 kg, 500 lb.

Temp rating: -29 to 88 ºC, -20 to 190 ºF.

Spiral: ≤ 0.33º per 3m or 10' section.

STANDARD CASING

Slope Indicator's traditional inclinometer casing

features high-strength, flush joints and is

available in three diameters.

Grooves: Grooves are machine broached for

excellent control of width, chamfer, depth,

straightness, and spiral.

Sealing: Solvent cement and tape.

Coupling: Precision molded couplings have

interference fit for high-strength bonding. Small

diameter version has integral couplings.

Assembly: Casing and couplings are glued

together with ABS solvent cement, riveted, and

wrapped with tape.

Best for: General use. The extra-strong joints

are helpful in very deep boreholes and oversize

boreholes in which casing is not well supported.

Standard Casing, Large Diameter

Coupling OD: 89 mm, 3.51 inches.

Outside Diameter: 85 mm, 3.34 inches.

Inside Diameter: 73 mm, 2.87 inches.

Collapse Rating: 10.6 bar, 155 psi.

Load Rating: 320 kg, 700 lb.

Temp rating: -29 to 88 ºC, -20 to 190 ºF.

Spiral: ≤ 0.33º per 3m or 10' section.

Standard Casing, Medium Diameter

Coupling OD: 70 mm, 2.75 inches.

Outside Diameter: 70 mm, 2.75 inches.

Inside Diameter: 59 mm, 2.32 inches.

Collapse Rating: 15 bar, 220 psi.

Load Rating: 320 kg, 700 lb.

Temp rating: -29 to 88 ºC, -20 to 190 ºF.

Spiral: ≤ 0.33º per 3 m or 10' section.

Standard Casing, Small Diameter

Outside Diameter: 48 mm, 1.9 inches.

Inside Diameter: 38 mm, 1.5 inches.

Collapse Rating: 24 bar, 350 psi.

Load Rating: 320 kg, 700 lb.

Temp rating: -29 to 88 ºC, -20 to 190 ºF.

Spiral: ≤ 0.33º per 3 m or 10' section.

QC CASING

QC (Quick Connect) casing features snap together

convenience and strong, flush joints.

Grooves: Grooves are machine broached for

excellent control of width, chamfer, depth,

straightness, and spiral.

Sealing: O-ring seals prevent entry of grout.

Coupling: Built-in couplings snap together to

make a flush joint. Unique locking mechanism

engages full inner circumference of casing, providing

much stronger joints than other snap-type

casings.

Assembly: Press casing sections together until

joint snaps closed. The resulting joint is strong,

flush, and grout-proof. Solvent cement, rivets, or

tape are not required. O-ring lubricant is applied

at factory. Extra O-rings and lubricant are supplied

with each box of casing.

Best for: General use.

QC Casing, Large Diameter

Outside Diameter: 85 mm, 3.34 inches.

Inside Diameter: 73 mm, 2.87 inches.

Collapse Rating: 12.4 bar, 180 psi.

Load Rating: 635 kg, 1400 lb.

Temp rating: -29 to 88 ºC, -20 to 190 ºF.

Spiral: ≤ 0.33º per 3m or 10' section.

QC Casing, Medium Diameter

Outside Diameter: 70 mm, 2.75 inches.

Inside Diameter: 59 mm, 2.32 inches.

Collapse Rating: 16.5 bar, 240 psi.

Load Rating: 635 kg, 1400 lb.

Temp rating: -29 to 88 ºC, -20 to 190 ºF.

Spiral: ≤ 0.33º per 3m or 10' section.

SHEAR-WIRE CASING

Shear-Wire casing features flush joints that can

be assembled easily in cold weather.

Grooves: Grooves are machine broached for

excellent control of width, chamfer, depth,

straightness, and spiral.

Sealing: O-ring seals prevent entry of grout.

Coupling: Built-in couplings lock together with

removable nylon shear wire to make flush joint.

Assembly: Press casing sections together, then

insert shear wire. The result is a flush, groutproof

joint. Solvent cement, rivets, and tape are

not required. O-ring lubricant is applied at the

factory. Extra O-rings, lubricant, and shear wires

are supplied with each box of casing.

Best for: Easy assembly in weather that is too

cold for solvent cement or snap-together joints.

Generally used in water-filled boreholes.

EPIC CASING

EPIC casing is an economical casing that can be cut and coupled at any point along its length.

Grooves: Grooves are formed during extrusion and are less precise than broached grooves.

Sealing: Solvent cement, mastic, and tape.

Coupling: Oversize couplings make very strong joints.

Assembly: Casing and couplings are glued together with ABS solvent cement. The joint must then be sealed with mastic and tape.

Best for: General use. Some care must be taken to seal the coupling.

EPIC Casing, Medium Diameter

Coupling OD: 78 mm, 3.07 inches.

Outside Diameter: 70 mm, 2.75 inches.

Inside Diameter: 59 mm, 2.32 inches.

Collapse Rating: 15 bar, 220 psi.

Load Rating: 320 kg, 700 lb.

Temp rating: -29 to 88 ºC, -20 to 190 ºF.

Spiral: ≤ 0.5º per 3 m or 10' section.

CPI CASING

CPI casing features quick assembly and disassembly and is available in 3 diameters.

Grooves: Grooves are machine broached for

excellent control of width, chamfer, depth,

straightness, and spiral.

Sealing: O-ring seals prevent entry of grout.

Coupling: Oversize couplings and shear wires make high strength joint.

Assembly: Apply grease to O-rings, press coupling onto casing, and insert shear wire.

Best for: Cold weather assembly or temporary

installations that involve repeated disassembly.

CPI Casing, Large Diameter

Coupling OD: 94 mm, 3.7 inches.

Outside Diameter: 85 mm, 3.34 inches.

Inside Diameter: 73 mm, 2.87 inches.

Collapse Rating: 11 bar, 155 psi.

Load Rating: 635 kg, 1400 lb.

Temp rating: -29 to 88 ºC, -20 to 190 ºF.

Spiral: ≤ 0.33º per 3m or 10' section.

CPI Casing, Medium Diameter

Coupling OD: 76 mm, 3 inches.

Outside Diameter: 70 mm, 2.75 inches.

Inside Diameter: 59 mm, 2.32 inches.

Collapse Rating: 15 bar, 220 psi.

Load Rating: 400 kg, 900 lb.

Temp rating: -29 to 88 ºC, -20 to 190 ºF.

Spiral: ≤ 0.33º per 3m or 10' section.

CPI Casing, Small Diameter

Coupling OD: 54 mm, 2.12 inches.

Outside Diameter: 48 mm, 1.9 inches.

Inside Diameter: 38 mm, 1.5 inches.

Collapse Rating: 24 bar, 350 psi.

Load Rating: 320 kg, 900 lb.

Temp rating: -29 to 88 ºC, -20 to 190 ºF.

Spiral: ≤ 0.33º per 3 m or 10' section.

GROUT VALVES

Grout valves allow placement of grout

backfill in boreholes that cannot accommodate

an external grout pipe. The one-way valve is

installed in the bottom section of casing. A

grout pipe is lowered through the casing to

mate with the grout valve and deliver the grout.

TELESCOPING SECTIONS

Optional telescoping sections accommodate

150 mm (6 inches) of compression or

extension. Fully extended, each telescoping

section adds 0.76 m (2.5 feet) of length to the

casing.

Slope Indicator Head Office 12123 Harbour

Reach Drive, Mukilteo, WA, 98275 USA

Email: solutions@slope.com

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