Reliability of measuring systems – Confidence building
The reliability of data measured from ground vibrations and air blasts plays a significant role in risk mitigation. It is essential to understand that there are two parties involved in this process. Project Management being the first, responsible for generating ground vibrations and air blasts, and the neighborhood (people living in the proximity) being the latter.
While the Project Management Team is responsible for recording data and taking measurements, the residents of the neighborhood are at the receiving end of these ground vibrations and air blasts. A dispute always seems to exist between the Generator (Project Management Team) and the Receiver (neighborhood).
On one hand, the Project Team claims to be carrying out the blasting under strict regulatory conditions and efficient control, while on the other, the neighbors tend to feel that their structures are being affected as a result of these ground vibrations, often citing out damages. Regulatory authorities like the local administration & DGMS go with the neighbors in the absence of reliable and accurate data. Even in the presence of recorded, reliable data, the Receiver has disbelief in the measured readings.
A number of parameters play a significant role here. Like the measuring device, weather, periodicity of measurement, actual time of the blast, actual time of recorded data , calibration of the instrument, methodology of instrument setting, etc. On several occasions there are errors, incorrect methods or fudging found in the data measurements. In most cases, the measurement systems are Discrete and not Continuous.
To minimize the disputes and the differences between Generators and Receivers , the Project Team needs to be build the confidence and instill trust in the minds of the Receivers by adopting transparent measuring systems and data documentation. Continuous monitoring of ground vibrations may also help in gaining their confidence and prevent small conflicts from blowing out of proportions.