Vibration Recommendations

Table 11. Summary of vibration recommendations.

Vibratory Motion	Freq. Range	Sensor Type	Motion Measured	Application
Tilt, or Rotations	0-1Hz	Tiltmeter, Inclinometer	Rotation from vertical in degrees, sometimes expressed as the sine of the angle of tilt	Monitoring slopes and landslides to detect zones of movement and establish whether movement is constant, accelerating, or responding to remedial measures. Monitoring diaphragm walls and sheet piles to check that deflections are within design limits, that struts and anchors are performing as expected, and that adjacent buildings are not affected by ground movements. Monitoring the effects of tunneling operations to ensure that adjacent structures are not damaged by ground movements. Providing settlement profiles of embankments, foundations, and other structures. Monitoring deformation of the concrete face of a retaining wall.
Settlement	0-1Hz	Settlement cells	Changes in elevation, mm or inches	Monitoring settlement or heave in embankments and embankment foundations. Monitoring subsidence due to tunneling. Monitoring consolidation under structures. Monitoring settlement due to dewatering or preloading. Monitoring settlement in marine fills.
Motion due to earthquakes	0-200Hz	Accelerographs, Structural monitoring system	Absolute acceleration, m/sec²	Monitor the performance of individual structures during earthquakes, such as piers, large retaining walls, and foundations. Monitoring the performance of large structural systems during earthquakes, such as bridges.
Motion due to blasting	1-200Hz	Blast seismograph	Particle velocity, m/sec	Monitoring ground motion during blasting.
Strains due to motions	0-100Hz	Strain gages Bonded, Weldable	Strain, mm/mm or in/in	Monitoring stresses in structural elements at critical location, both steel and concrete. Evaluate fatigue in structural elements.
Motion due to construction	1-200Hz	Construction seismograph	Particle velocity, m/sec	Monitoring ground motion during construction operations, like pile driving.
Motion due to ambient vibration, used to evaluate human perception,structural characteristics	1-100Hz	Vibration Monitoring, Human	Acceleration, m/sec² sometimes velocity, m/sec	Monitor construction vibrations to evaluate potential for damage to nearby structures. Monitor effects of roadway deterioration (such as potholes) on nearby critical processes.