Ground Vibration is a technical term used to describe most of the man-made vibrations on the ground, in contrast to the Earth's natural vibrations studied by seismology. For example, vibrations caused by explosions, construction works, trains and road transport, etc. - everything including the vibration of the ground.
Video Ground vibrations
General information
As in seismology, earth vibrations are associated with various types of elastic waves that spread through the soil. These are surface waves, mostly Rayleigh waves, and massive longitudinal waves and transverse waves (or shear waves) spread to the depth of the ground. The typical frequency range for ground environment vibration is 1 - 200 Hz. Low-frequency waves (below 1 Hz) are usually called microseisms, and they are usually associated with natural phenomena, such as water waves in the oceans. The vibration of the environment land generated by rail and road traffic can cause disruption to nearby residents of buildings either directly or through the noise of the building's interior. Very strong earth vibrations, e.g. produced by heavy lorries on a stumbling road, can even cause structural damage to buildings that are very close. The magnitude of the ground vibration is usually explained in terms of the particle vibration velocity (in mm/s or m/s). Sometimes they are also described in decibels (relative to the reference particle velocity of 10 -9 m/s). Typical values ​​of the particle vibration velocity associated with a vehicle passing over the traffic that calms the road bump are in the range of 0.1 - 2 mm/s. The magnitude of the soil vibration is considered to cause structural damage to buildings above 10-20 mm/s.
Maps Ground vibrations
Land vibration from the railroad
The main source of ground vibration generated by the railway is the dynamic force transmitted from the track to the ground. These forces are associated with a complex interaction process of rail-based train carriages supported by elastic soil. The magnitude of this power generally increases with the increase of train speed. Therefore, the resulting ground vibration rate may be large in the case of high-speed trains. If the speed of the train becomes greater than the speed of Rayleigh waves on the ground, an enormous additional increase in the resulting ground vibration occurs. This phenomenon is called the ground vibration boom, and it is similar to the sonic boom produced by supersonic aircraft.
Land tremors from road traffic
The main mechanism responsible for generating ground vibration by moving cars and lorries is the dynamic power associated with vehicle travel over road irregularity, such as mounds, peat, etc. This strength, and hence generated ground vibration, can be reduced by keeping the road surface in good condition.
Vibration of the ground under construction
The main sources of ground vibration in construction are pile steering, dynamic compaction, blasting, and heavy construction equipment operation. This vibration can affect the surrounding buildings, and their effects range from residual disturbances to visible structural damage.
See also
- The wave of love
- Shear wave
References
- Skipp, B.O. (ed), Soil Dynamics and Man-Made Process , Civil Engineers Institute, London, 1998.
- Krylov, V.V. (ed), Noise and Vibration from High Speed ​​Trains, Thomas Telford Publishing, London, 2001.
- Santos, J.A. (ed), Application of Stress Wave Theory to Piles: Science, Technology and Practice , IOS Press BV, Amsterdam, 2008.
- Bull, J.W. (ed), Linear and Nonlinear Numerical Analysis of Foundations , Taylor & amp; Francis, New York, Abingdon, 2009.
External links
- Land vibration in construction
- Earth vibrations caused by blasting
Source of the article : Wikipedia
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