In-situ test device and monitoring method for critical starting shear stress of tidal flat sediment

Abstract

The invention provides an in-situ test device for tidal bay sediment critical starting shear stress. The device comprises a sleeving mandrel, a Plexiglass materialn inner cylinder, a Plexiglass material outer cylinder, a Plexiglass material shear ring, an OBS turbidity sensor, an upper structure composed by an OBS wireless data transmitting apparatus and a receiving apparatus, a lower structure composed by an inner round plate at the bottom of the Plexiglass material, an outer round plate at the bottom of the Plexiglass material, an aluminum alloy outer sleeve and an aluminum alloy inner sleeve as well as a fixing support. With the method, it is possible to realize an in-situ test to the tidal bay sediment critical starting shear stress with reduced sand disturbance.

Description

technical field [0001] The invention relates to the technical field of water and sand observation, in particular to an in-situ testing device and monitoring method for critical starting shear stress of tidal flat sediment. Background technique [0002] Sediment initiation is one of the most basic issues in the study of sediment transport, river course evolution, coastal landform changes, and water-sediment response relationships. The critical shear stress of sediment is the critical value for judging whether sediment can initiate. The traditional method of obtaining the critical starting shear stress of sediment is to collect sand samples from the field, bring them back to the laboratory, and measure the critical starting stress of the sediment with an indoor annular tank test device. During the process of collecting sand samples from the field and bringing them back to the laboratory, many Large disturbances will change the consolidation strength of the sand sample in situ ...

AI Technical Summary

Problems solved by technology

The traditional method of obtaining the critical starting shear stress of sediment is to collect sand samples from the field, bring them back to the laboratory, and measure the critical starting stress of the sediment with an indoor annular tank test device. During the process of collecting sand samples from the field and bringing them back to the laboratory, many Large disturbances will change the consolidation strength of the sand sample in situ and the distribution of sediment particles with different particle sizes. The starting shear stress value measured in the laboratory is quite different from the starting shear stress value before the sand is disturbed on site. ; In order to reduce the disturbance to the on-site sediment, a bottomless cylinder combined with a propeller to stir the water flow was used in situ to measure, but the spiral water flow structure produced by this device is significantly different from the open channel water flow, and its rationality needs to be further verified

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