Controlled urban blasting is a planned and monitored method that fragments rock safely near settlements and infrastructure by limiting vibration, noise and flyrock.
Principles of application
- Vibration control: the blast design is calculated so as not to damage surrounding structures
- Charging: the maximum charge per hole is limited
- Delay timing: controlled delays with electronic detonators reduce vibration and noise
- Flyrock precautions: holes are tightly stemmed and safety distances are observed
Criteria used
USBM RI 8507 (US Bureau of Mines) and DIN 4150-3 (German standard) are the main criteria used to assess the effect of vibration on structures. Which criterion applies depends on the project specification and local regulations.
Benefits
- Protection of surrounding structures
- Noise and vibration kept below limits
- Occupational and environmental safety
- Transparent, record-based reporting with vibration monitors throughout the project
Frequently asked questions
Is blasting in a city safe?
Planned, controlled and monitored blasting limits vibration, noise and flyrock. Safety depends on correct design, measurement and site safety measures applied together.
How is vibration monitored?
Blasting seismographs at nearby structures record vibration velocity on three axes and dominant frequency; results are compared with the chosen criterion and fed back into the design of later blasts.
Which standards are used?
USBM RI 8507 and DIN 4150-3 are the main criteria; the applicable limit is set by the project specification and local regulations.
Is a pre-blast survey necessary?
A pre-blast survey records the existing condition of structures and allows comparison if damage is claimed later. Its scope is set by the project specification.