Study On The Acoustic Characteristics Of Sediment And Root Stone In The Xiaolangdi Reservoir Area And Inversion Of Physical Parameters

The sedimentation problem in the Xiaolangdi reservoir area seriously affects the reservoir operation efficiency and water environment,and even directly affects the life and property safety of the people in the reservoir and downstream areas,which brings difficulties to the treatment of Yellow River.The analysis of the sludge monitoring and detection data can accurately grasp the water and sediment movement,the change of sediment in and out of the reservoir and the change law of reservoir erosion and siltation,and then scientific and feasible methods can be used to effectively control the siltation of the reservoir area;the root stone is the protective layer of the Yellow River dam and the bank,which is an important factor affecting the safety of the dike,to ensure the safety of the Yellow River flood control project,it is necessary to detect the river bottom stone and obtain the distribution range and depth of the root stone.At present,the sediment observation methods in deep water reservoir mainly include acoustic detection and sampling analysis.Sound wave detection can be used to quickly obtain the structural surface information of sediment deposition,and sampling technology can be used to more accurately obtain the physical property information of sediment points.The combination of acoustic detection and sampling analysis provides technical support for sediment analysis and root stone detection in the Xiaolangdi reservoir area.This paper introduces the physical properties(particle size,porosity,permeability,etc.)of sediment in the Xiaolangdi reservoir area and the concept,measurement method and calculation formula of geoacoustic properties(wave velocity).Based on the reading of reflection wave signal and FFT transform,the characteristics of reflection signal of sediment and sediment layer in Xiaolangdi reservoir area of the Yellow River were extracted through laboratory test and field detection.Based on Biot theory,the relationship between the physical parameters of sediment and the acoustic parameters is established,that is,the relationship between reflection coefficient and porosity,and the relationship between attenuation coefficient and permeability.Based on the theory of pore media,the inversion method of sediment parameters is proposed and verified in Xiaolangdi reservoir area,and good results are obtained.