The Blasting Vibration Effect On The Surrounding Buildings Structure Analysis

With the continuous development of the national economy, the blasting technique is widely applied to the buildings demolition and the traffic engineering. Although it brings great benefits on the construction by the use of the blasting technique, the damaging effects it produces is what we need to focus on. The blasting vibration damage with the characteristics such as randomness, fuzziness, indefinite as well as the complicated failure mechanism and criterion research is one of the serious effects. Though a lot of effort of the reference standard of the blasting vibration damage effects has been done by many experts at home and abroad, and as a result some corresponding reference standard is made. However there are great differences among each point, so many aspects deserve to be studied. Under the premise of relevant literature and combining with a long-term engineering field monitoring, This paper, the main research results obtained after some related research are as follows:1. The destruction mechanism of the the blasting vibration is analyzed at home and abroad and the destruction standard of different countries is compared, and then it can be obtained that the maximum energy input method is the best way to study the buildings damage under the influence of blasting vibration.2.The damage threshold of the different age shotcrete layer under blasting vibration could use the crack velocity of shotcrete layer to be criteria, the age is1day,3days,7days,14days,28days, and the crack velocity is0.93cm/s,1.18cm/s,1.38cm/s,1.56cm/s,2.52cm/s.3. By the use of the damage factor and combined with some relative hypothesis the simple formula which is used to calculate blasting vibration cumulative damage is obtained after the N blast working.4. Taking the SaDaoFu empirical formula as the standard, large amounts of monitoring data is compared, and the situation that only safe charge and safe distance are considered does not meet the blasting situation. The scale distance should more appropriate and conform to the actual situation for the analysis of blasting vibration damage criterion, and on this basis the change relation of peak velocity and scale distance is got according to the nonlinear fitting about the monitoring data.5.By using the large amount of monitoring data of He Jia Chong tunnel, calculating every blasting cumulative damage by that formula and drawing by ORIGIN, the safety of shotcrete layer from low to high is top step, middle step, down step is got through the analysis.6.Combining the actual situation of He Jia Chong tunnel, some reasonable and effective vibration control measures is taken, the average vibration reduction rate as33.4%is calculated.7. When the tall buildings is blasted, the effect of the blast vibration is less than touchdown vibration. The dominant frequency of touchdown vibration is the same as buildings between10Hz and20Hz, which can bring in the around constructs damage. It lasts longer and the horizontal damage is primary, so the air break phenomenon must be paid attention to when the building is very high.