19 – Geotechnical Instrumentation

Publisher Summary This chapter explains two geotechnical instruments namely inclinometer and tiltmeter. A slight movement of soil has been observed prior to most landslides, earthquakes, and slope failures. An inclinometer is designed to measure slight ground movements that occur prior to a slope failure. It is lowered into the well. The wheels are fixed at the side to guide through the well casing. The pendulum has an electrical potential. The operation of the tiltmeter is similar to a level. In a regular level, an air bubble is used to identify the tilt. If the air bubble is at the center, then the tilt is zero. Tiltmeters are filled with an electrically sensitive liquid instead of water. When the tiltmeter tilts, the bubble moves. The electrical signal coming from the tiltmeter is dependent upon the location of the bubble. Tiltmeters are used to measure the tilt in buildings, bridges, and tunnels.