利用ADV测量细颗粒泥沙浓度的试验研究  

Experimental study on measurement of fine sediments concentration using ADV

作　　者：李文杰[1] 张帅帅[2] 杨胜发[1] 韦登厚 

机构地区：[1]重庆交通大学国家内河航道整治工程技术研究中心,重庆400074 [2]重庆交通大学省部共建水利水运工程教育部重点实验室,重庆400074 [3]重庆单轨交通工程有限责任公司,重庆400081

出　　处：《水力发电学报》2014年第4期98-104,共7页Journal of Hydroelectric Engineering

基　　金：国家科技支撑计划(2011BAB09B01);国家自然科学基金(51209241);重庆市自然科学基金(cstc2013jcyjA30003)

摘　　要：在不同频率ADV、泥沙浓度和粒径级配的情况下进行了细颗粒泥沙浓度测量试验,结果表明：ADV反向散射声波强度BSI主要受泥沙浓度的影响,并可分为增强-稳定-衰减三个阶段,其浓度分界点为2 kg/m3和5-10kg/m3左右。BSI在增强阶段与泥沙浓度呈线性关系,在稳定阶段则稳定在某一值左右,在衰减阶段急剧下降,ADV可进行增强和衰减阶段的泥沙浓度测量,稳定阶段则是测量盲区。颗粒越细,增强阶段越短,BSI相对于浓度的趋势线斜率也越小,导致低浓度时有效测量浓度范围缩小且精度变差,而第三阶段则越长,越有利于细颗粒泥沙的高浓度测量。ADV声波频率越高,其敏感粒径越小,与细颗粒泥沙粒径越接近,越有利于浓度的测量,对于细颗粒泥沙浓度的实际测量,应尽量选择声波频率较高的ADV。Concentration of fine sediments has been measured under different conditions of ADV frequency, sediment concentration, and size gradation. The results indicate that the backscatter acoustic intensity （BS1） of ADV is mainly influenced by sediment concentration and can be divided into three phases of enhancement, stabilization and attenuation with demarcation values of 2 kg/m3 and 5-10 kg/m3. BSI has a linear relationship with sediment concentration in enhancement phase, remains constant in stabilization phase, and drops sharply in attenuation phase. Sediment concentration in enhancement and attenuation phases can be measured using ADV while stabilization phase is a blind zone. Finer particle size leads to a shorter enhancement phase and a smaller slope of BSI versus concentration, which further results in a reduced range and lower accuracy of effective measurement under low concentration, while it also leads to a longer attenuation phase, which benefits the measurement under high sediment concentration. The higher the ADV sound frequency, the smaller the sensitive size or the closer to fine sediment particle size, the more helpful for concentration measurement. Therefore, ADV with higher sound frequency is recommended for measurement of fine sediment concentration.

关 键 词：河流泥沙工程学 泥沙浓度 ADV试验研究 细颗粒泥沙 

分 类 号：TV143.4[水利工程—水力学及河流动力学]