Test and Analysis of Velocity Law of Flowing Water in Stratum of Bottom Contact Passages in Shield River-Crossing Section

The method of combined hole arrangement on both banks and in the middle of the river was proposed for the test and analysis of the flowing water velocity in contact passages at the bottom of the Wulong River in order to address the insufficient reliability of the existing testing method for the flowing water velocity in the bottom stratum and its failure to truly reflect the data and law of the velocity in the stratum of bottom contact passages in the shield section. Meanwhile, the measurement time of each measuring hole has experienced the fluctuation cycle of the water level, enabling the parameters and law of the flowing water velocity obtained from the test to cover the complete spatial and temporal distribution range. Compared with the existing research, the method has a greatly improved data reliability, guiding the freezing reinforcement construction of bottom contact passages successfully. At the same time, the flow distribution law, velocity range and the law of influence of water fluctuation on the flow velocity revealed in this test can provide reference for related engineering projects in the region.