爆破振动累积效应下边坡稳定性演化机制与定量预测模型

Evolution Mechanism and Quantitative Prediction Model of Slope Stability under Cumulative Blasting Vibration Effects

  • 摘要: 为揭示爆破振动多参数耦合对边坡动力稳定性的影响,以江西某露天矿为背景,基于课题组构建的非平稳爆破振动预测模型,通过参数敏感性分析确立了模型参数与波形特征的定量映射关系,提出基于现场实测波形的大样本参数确定方法,验证结果表明,仿真波形与实测数据在峰值振速(相对误差1.24%)和主频(相对误差0.37%)上高度吻合. 采用FLAC3D循环加载数值模拟,揭示峰值振速、主频及循环次数的耦合影响:振速7.7~12 cm/s时,边坡临界失稳循环次数加速衰减,位移与应力集中分别增加30%、35%;主频25~50 Hz时,安全系数显著降低,位移响应与应力波动幅度分别增强约40%、25%. 基于数值模拟结果采用多元非线性回归建立安全系数拟合方程,预测误差不大于6.74%,从而建立了爆破振动累积效应与边坡稳定性的定量关联模型,为边坡动力安全评估提供便捷可靠的判别方法.

     

    Abstract: To investigate the multi-parameter coupling effects of blasting vibration on slope dynamic stability, a case study of an open-pit mine in Jiangxi was conducted based on a non-stationary blasting vibration prediction model developed by the research group. Through parameter sensitivity analysis, quantitative mapping relationships between model parameters and waveform characteristics were established. A large-sample parameter determination method based on field-measured waveforms was proposed, with validation results showing high agreement between simulated and measured waveforms in terms of peak vibration velocity (relative error: 1.24%) and dominant frequency (relative error: 0.37%). FLAC3D cyclic loading simulations revealed that when vibration velocity increased from 7.7 to 12 cm/s, the critical number of cycles for slope instability decreased significantly, with displacement and stress concentration increasing by approximately 30% and 35%, respectively. When the dominant frequency rose from 25 to 50 Hz, the safety factor decreased markedly, accompanied by increases of about 40% in displacement response and 25% in stress fluctuation amplitude. Based on numerical results, a safety factor fitting equation was established using multiple nonlinear regression, achieving a prediction error of no more than 6.74%. This established a quantitative correlation model between cumulative blasting vibration effects and slope stability, providing a convenient and reliable method for dynamic slope safety assessment.

     

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