Evaluation of the environmental effect of blastings carried out in city foundation excavations

Environmental problems such as vibration, rock flying and air shock are frequently encountered in mining, tunnels, highways and urban building foundation excavations where blasting is inevitable. Vibrations caused by blasting may cause structural damage (cracks, etc.) in nearby residential areas. Taking vibration measurements near residential areas and scientifically evaluating the results contribute to carrying out blasting in an environmentally safer manner. In this thesis study, 36 blasting excavations carried out in urban building foundation excavations were accompanied by vibration and air shock measurements. These measurements were taken on the outer foundation ground of the settlement closest to the blasts and on the last floor foundation slab of the building. Vibration measurement results were evaluated according to the Environmental Noise Control Regulation. It was observed that the highest particle velocity values were recorded 7 pulses (pulses numbered 5, 9, 14, 15, 17, 19 and 22) measured at the building foundation exceeded the limit value allowed in the regulation, whereas all the values measured simultaneously at the top floor of the building remained within the limit. All vibration frequencies measured at the building foundation were above 40 Hz. If the PPV values measured at the building foundation are linearly compared to those at the top floor slab, they are on average 8 times higher. As a result of the statistical analysis, the equation PPV = 5712.8 x SD-1.587 was obtained with a stability coefficient (R2) of 0.7981 for the prediction of the highest particle velocity (PPV) resulting from the explosion. It was determined that in order not to exceed the maximum PPV allowed at the building foundation, shots should be made at a distance of more than 40 m from the buildings and using a maximum of 0.48 kg of explosive per delay. Since the measured air shock values (119.9-123.2 dBL) are lower than 140 dBL, there is no damage or discomfort to buildings or people.