Study on Influence Law of Blasting Vibration and Vibration Reduction Technology in Urban Tunnelling

On the basis of the Donghai tunnel in Quanzhou, the paper, starting from the structural safety of surrounding surface buildings and the psychological endurance of people to blasting, explores the influence law of construction blasting on surface buildings through numerical simulation calculation and on-site monitoring. The influence of construction blasting on the psychological tolerance of nearby people is explored by means of designing the questionnaire on the psychological tolerance of people to blasting vibration, and carrying out statistical analysis of the results of 309 questionnaires by using t-distribution curve. On the basis of the maximum blasting vibration velocity, the blasting vibration reduction control technology for different sur-rounding rocks is put forward through theoretical derivation and regression fitting. The research results show that, considering the two major influence factors, namely, the safety of surface building structure and the psychological tolerance of people to blasting, the blasting vibration velocity in urban tunnel construction should be less than 1.11 cm/s; from the point of view of people′s psychological tolerance to blasting, the minimum safety distances for blasting vibration in surrounding rocks with various grades should be 35.9 m (Grade Ⅴ), 35.1 m (Grade Ⅳ) and 45.6 m (Grade Ⅲ) respectively, when the explosive charge is in the range of 24.63~ 34.5 kg.