土石体边坡失稳模拟与阵列挡板阻滑效果研究

在抽蓄电站建设过程中形成了众多大型土石体边坡,其稳定性严重影响着工程的可靠运行。为准确反映土石料特性、边坡失稳的大变形特性及挡板阻滑效果,采用三维离散元仿真方法,研究其失稳过程与影响范围。依据滑移体的堆积形态及速度变化规律,将土石体边坡的失稳过程分为快速滑移、二次滑移、平稳滑移和蠕动滑移4个阶段。通过监测不同位置颗粒的运动速度、能量演化规律,分析了无防护措施下边坡失稳对下游河道、建筑物的影响。通过制定矩形、圆形和三角形截面挡板的离散元模拟方案,构建了包含冲击力、堆积体速度、堆积体位移、挡板截留能力等多个评价指标的阵列挡板阻滑效果评价体系。经综合分析,建议镇安抽蓄电站土石体边坡工程采用三角形截面阵列挡板。本文也可为类似边坡工程的失稳模拟和防护设计提供参考。

Direction-of-arrival estimation for a uniform circular acoustic vector-sensor array mounted around a cylindrical baffle

This work investigates the direction-of-arrival(DOA) estimation for a uniform circular acoustic Vector-Sensor Array(UCAVSA) mounted around a cylindrical baffle.The total pressure field and the total particle velocity field near the surface of the cylindrical baffle are analyzed theoretically by applying the method of spatial Fourier transform.Then the so-called modal vector-sensor array signal processing algorithm,which is based on the decomposed wavefield representations,for the UCAVSA mounted around the cylindrical baffle is proposed.Simulation and experimental results show that the UCAVSA mounted around the cylindrical baffle has distinct advantages over the same manifold of traditional uniform circular pressure-sensor array(UCPSA).It is pointed out that the acoustic Vector-Sensor(AVS) could be used under the condition of the cylindrical baffle and that the UCAVSA mounted around the cylindrical baffle could also combine the anti-noise performance of the AVS with spatial resolution performance of array system by means of modal vector-sensor array signal processing algorithms.