In-Situ Observation System of Pore Water Pressure in Shallow Sea Based on the Principle of Vibration Liquefaction

Abstract

The invention relates to a beach shallow sea pore water pressure in situ observation system based on a vibratory liquefaction principle, comprising a liquefaction vibration device, a pore water pressure observation system, and an auxiliary ship used for laying and recycling. The liquefaction vibration device comprises a vibration casing, a piston vibration system, a pile casing, an anti-sedimentation disc and a permeable flexible material. The pore water pressure observation system comprises a pore water pressure observation detecting rod, the interior of which is provided with a pore water pressure collection cabin and a pore water pressure sensor, and the top of which is provided with a floating body and is in connection with a pore pressure laying cable. In laying, the liquefaction vibration device and the pore water pressure observation system are placed on a sea surface through the auxiliary ship, and local liquefaction occurs to a seabed soil body through the liquefaction vibration device to complete laying of the pore water pressure observation system; the vibration frequency of the liquefaction vibration device can be adjusted through the control system on the auxiliary ship so as to lay the pore water pressure observation system under different seabed conditions. The system completes laying the pore water pressure observation system based on a vibratory liquefaction principle, is simple to operate, improves work efficiency and reduces research costs.

Description

technical field [0001] The invention relates to an in-situ observation system for pore water pressure in shallow seas based on the principle of vibration liquefaction, and belongs to the technical field of marine observation and the field of marine engineering geology. Background technique [0002] Under the periodic dynamic load of waves, seabed sediments will cause continuous dynamic changes in pore water pressure, and the dynamic accumulation of pore water pressure will lead to a decrease in the effective normal stress of seabed sediments, which in turn will lead to changes in the mechanical properties of seabed sediments. Changes, which have an important impact on the stability of the seabed and offshore structures (such as breakwaters, submarine pipelines, etc.). The in-situ observation of pore water pressure can effectively reflect the dynamic geological process of the seabed, which is of great significance for the study of the dynamic response of seabed sediments unde...

AI Technical Summary

Problems solved by technology

In the actual deployment process, the drilling method requires a drilling rig to be provided during the deployment of the pore water pressure observation system, which increases the cost of pore water pressure observation. To avoid shrinkage cavity or collapse in the process of hole forming, this method is cumbersome to operate; the static pressure method often needs to provide huge back pressure, which makes the deployment operation complicated, and cannot guarantee that the probe maintains a vertical posture in the soil, and at the same time, it is accompanied by a certain security risks

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