溪洛渡水电站出线竖井爆破振动效应研究  

Study of blasting seismic effects of cable shaft in Xiluodu hydropower station

作　　者：李新平[1,2] 孟建[1,2] 徐鹏程[2,3] 

机构地区：[1]武汉理工大学道路桥梁与结构工程湖北省重点实验室,武汉430070 [2]武汉理工大学土木工程与建筑学院,武汉430070 [3]中国水利水电第八工程局有限公司,长沙410007

出　　处：《岩土力学》2011年第2期474-480,共7页Rock and Soil Mechanics

基　　金：国家自然科学基金资助项目(No.50974100)

摘　　要：对溪洛渡水电站左岸出线竖井开挖爆破的振动速度进行了现场测试。运用萨道夫斯基公式对测试数据进行回归分析,得到了竖井爆破掘进中地震波传播衰减公式。利用该式预测距离井底高程差为18.2～24.5m处范围内测点的振动速度,并与实测数据进行对比。结果显示,竖井爆破振动的传播存在高程放大效应,水平振速放大系数约为1.49～2.24,垂直振速放大系数约为1.78～2.73;通过考虑高程效应对萨道夫斯基公式进行了修正,得到考虑高程因子的衰减公式,线性关系显著,对存在高程放大效应的爆破振动预测具有借鉴意义。运用动力有限元分析方法对竖井结构在爆炸冲击波荷载作用下的结构响应进行数值模拟,数值模拟结果与现场测试结果的对比表明,当相对高差不大时,两者整体趋势比较吻合,距离井底0～15m,振动速度快速衰减,振动速度峰值衰减幅度超过总体幅度的60%;距离井底超过30m,衰减不超过总幅度的10%。采用岩石-混凝土强度破坏准则对竖井构筑物在爆炸冲击荷载作用下的稳定性进行了强度校核,为竖井后续施工安全提供了参考。Field test of vibration velocity was carried out during the excavation of cable shaft in Xiluodu Hydropower Station.The attenuation formulas of seismic wave propagation were obtained through regression analysis of the test data with Sadaovsky empirical formula.Vibration velocity of measuring points in range of 18.2-24.5 meters away from the bottom of shaft in height were predicted with the attenuation formula.Comparison between the data of in-situ test and prediction showed an elevation amplification effect in the propagation of seismic wave and the magnification coefficient of horizontal velocity was about 1.49-2.24 while the vertical was about 1.78-2.73.Sadaovsky empirical formulas were corrected by taking the amplification effect into account and corresponding attenuation formulas were obtained.The corrected formulas presented significant linear relationship and to be references to similar projects.Dynamic finite element method was used to simulate the responses of the shaft under the load of blasting.It is indicated that the trend of the numerical simulation results is fit with that of the field testing data when the height from the bottom of the shaft to the measuring points were not so large.The vibration velocity attenuated rapidly when the distance from the measuring points to the bottom of the shaft were within 0-15 meters and more than 60% of overall vibration velocity attenuated in this range.Less than 10% of the overall vibration velocity attenuated when the distance was over 30 meters.Strength failure criterion of rock-concrete was adopted to check the stability of the shaft under blasting load and references for the safety of the following construction were provided.

关 键 词：出线竖井 爆破振动 回归分析 高程放大效应 数值模拟 

分 类 号：TV72[水利工程—水利水电工程]