Page - 1303 - in Book of Full Papers - Symposium Hydro Engineering

2. DAM INSTRUMENTATION & MONITORING SYSTEM It is necessary to have a combination of instruments across different sensing technologies to give complete information about potential deformations in a dam. Ease and practicality of installation/replacement of the old instruments for the and communication setup are equally important, apart from proven sensor types and core-technologies to achieve an effective and long-term dam monitoring system. Various building blocks of the system are described in the following paragraphs: 2.1 FIELD INSTRUMENTS Some surface and subsurface sensors that may be used are mentioned below. Subsurface monitoring gives important information on ground/soil movement which may affect the stability of the structure.  Tiltmeter and plumb lines to monitor dam tilt/inclination  Crack meter and joint meter to monitor cracks/joint openings in blocks  Borehole extensometers to monitor subsurface settlement and deformation  In-place inclinometers to monitor lateral movement  Water level & barometric pressure sensors to monitor reservoir level  Piezometer/uplift pressure sensors to monitor pore and uplift pressure variations  Seepage/flow meter  Temperature meter  Weather station for rainfall, wind velocity, air temperature, humidity and solar radiation 2.2 AUTOMATIC 3-D DEFORMATION MONITORING SYSTEM (ATDMS) The ATDMS measures movements of targets fixed at critical locations on the dam’s structure in three dimensions (x, y & z). It comprises of the following major components:  3D prism targets  Automatic total stations (ATS)  Control box 1303