土岩复合地层条件下爆破振速衰减模型优选

随着城市化进程的加快,地下工程建设日益增多,爆破施工是较常见的一种施工工法,对周围建筑物和已有线路的影响较大.爆破药量、爆心距和高程差等因素的不同都会使爆破振速产生较大的差异,造成不可挽回的影响.为了优选更合理的爆破振速衰减模型对预测爆破振动效应,以青岛地铁某线施工为背景,采用多段爆破的爆破方式,设置多个监测点记录爆破振速,对比分析不同爆破振速预测模型效果和适用性,并在此基础上进行模型优化.结果表明:爆破振动在地面传播过程中空洞效应的影响较大;爆破振动效应是多种因素综合作用的结果,模型涉及因素越多,则爆破振速预测模型的结果与实测值越接近;根据空洞效应建立的分段预测模型能有效地预测爆破振动在地面的衰减规律,可被类似工程借鉴.面对复杂的爆破施工场地,应根据条件进行爆破振速衰减模型的选择.

Optimization of blasting vibration velocity attenuation model under the Condition of Soil-rock strata

In recent years, with the advancement of urbanization, underground construction is increasing. Blasting construction is a common construction method, which has randomness, harmfulness and complexity, and has a great influence on surrounding buildings and existing lines. Therefore, it is indispensable to study the effects of blasting vibration effects. In China, the blasting vibration velocity is the basis of blasting vibration intensity. The factors such as blasting charge, blasting distance and elevation difference will cause large differences in blasting vibration velocity, resulting in irreversible effects. In order to optimize the blasting vibration velocity attenuation model to predict the blasting vibration effect, this paper combined multiple blasting and one blasting multiple monitoring points to compare and analyze the effects and applicability of different blasting vibration velocity prediction models, based on the engineering background of a station in Qingdao Metro. The results show that blasting vibration has a great influence on the cavity effect during the propagation of the ground. And blasting vibration effect is the result of the comprehensive action of many factors. The more factors involved in the model, the closer the result of the blasting vibration velocity prediction model is to the measured value. The piecewise prediction model based on the cavity effect can effectively predict the attenuation law of blasting vibration on the ground, which is a reference for similar engineering. It is concluded that in the face of complex blasting construction site, the selection of blasting vibration velocity attenuation model should be carried out according to the conditions.