FBG-based full-sea-depth self-adaptive high-precision full-flow penetration spherical probe

Abstract

The invention relates to an FBG-based full-sea-depth self-adaptive high-precision full-flow penetration spherical probe, which comprises a probe rod and a spherical CPT probe, the probe rod and the spherical CPT probe are connected through a probe rod connector, the spherical CPT probe is provided with a pore pressure measuring hole and a permeable stone, and the pore pressure measuring hole is communicated with a lower cavity pore pressure passage of an excess pore pressure sensor; n differential pressure sensors (n is greater than or equal to 2) of which the ranges are gradually increased are sequentially arranged in the probe rod connector from bottom to top, the adjacent differential pressure sensors are connected through an interlocking device to form a multi-stage sensor nested structure, and when the full range of the low-stage sensor is reached, the low-stage sensor is locked through the interlocking device. Measurement is carried out through a next-stage higher-order differential pressure sensor, the measuring range of the sensor can be protected, the optimal precision can be obtained under the condition of effective measurement, self-adjustment of the measuring range andthe precision is achieved, and the mechanical property of the full-sea-depth seabed sediment can be accurately obtained. The FBG-based full-sea-depth self-adaptive high-precision full-flow penetrationspherical probe is of great significance to deep sea scientific research, resource and energy development engineering activities and marine safety national defense engineering.

Description

technical field [0001] The invention relates to the field of testing the mechanical properties of seabed sediments, in particular to an FBG-based full-depth self-adaptive high-precision full-flow penetration spherical probe. Background technique [0002] Focusing on the research on in-situ measurement devices for the mechanical properties of seabed sediments, for the sea area shallower than 4000m, there are commercial products for measuring the mechanical properties of sediments below the seabed surface 1-2m. The static penetration equipment has successfully served a number of marine projects at home and abroad. At present, the CPT with the largest working water depth is GOST developed by MARUM in 2010. The maximum working water depth is 4000m. [0003] As an emerging sensing technology, optical fiber sensors have unique advantages in the measurement of mechanical properties of seabed sediments. The working principle of fiber Bragg Grating (FBG) sensors is to measure the T...

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Problems solved by technology

[0005] If you follow the traditional method of selecting a sensor with a suitable range, it is difficult to decide what kind of sensor to choose for detection. Some people propose to choose according to the range of tens of Kp. However, the current investigation and research on the deep sea environment are very lacking. There is not enough understanding of the distribution and variation of the strength of seabed sediments. Considering that if there are rocks on the seabed, the sensor may be scrapped directly. On the other hand, when the probe penetrates into the water, an overload pressure will be generated, and the overload pressure will also be It may lead to the explosion of the sensor range. At present, there is no device in the world that can realize the mechanical properties of deep seabed sediments in the whole sea.

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