Pile-forming process dynamic testing device for underwater sand compaction pile

Abstract

The invention provides a pile-forming process dynamic testing device for an underwater sand compaction pile. The testing device is connected with a pile pipe and comprises a fiber bragg grating soil pressure sensor, multiple sets of fiber bragg grating strain meters and two sets of acceleration sensors, wherein the fiber bragg grating soil pressure sensor and the multiple sets of fiber bragg grating strain meters are connected with a dynamic fiber bragg grating demodulation instrument, the two sets of acceleration sensors are connected with a vibration and dynamic signal acquisition analyzer, cable protection structures are arranged outside the cable of the fiber bragg grating soil pressure sensor, the cables of the fiber bragg grating strain meters and the cables of the acceleration sensors, and the fiber bragg grating soil pressure sensor is fixedly arranged on an end plate of the pile pipe; the fiber bragg grating strain meters are distributed along the pile pipe from top to bottom and fixedly arranged on the outer side wall of the pile pipe; the two sets of acceleration sensors are arranged on the outer side faces, close to the pile top and the pile bottom, of the pile pipe respectively. The pile-forming process dynamic testing device for the underwater sand compaction pile is not prone to being influenced and limited by environmental conditions and structure conditions, can guarantee test precision and is more suitable for pile-forming process dynamic testing for the underwater sand compaction pile.

Description

technical field [0001] The invention relates to a measuring device, in particular to a dynamic testing device for the pile-forming process of an underwater compacted sand pile. Background technique [0002] With the rapid development of the global economy and the container transportation industry, it has become an inevitable development trend for seaports and terminals to develop into offshore, open, and deep water areas. It has become an indispensable construction technology in the construction of open sea ports. Compared with traditional foundation treatment methods, underwater compacted sand piles have unique advantages—the reinforcement effect is obvious, and the bearing capacity of the foundation can be quickly increased, so the construction process can be quickly promoted, the construction period can be shortened, and it creates a new foundation for the construction of gravity structures on weak foundations. conditions. [0003] As a new technology for foundation rei...

AI Technical Summary

Problems solved by technology

However, it is greatly affected by environmental conditions and has shortcomings such as low resolution.

The steel string sensor uses the principle that the steel string has different fixed frequencies under different tensions to achieve force measurement. The advantage is that the structure is simple and the effect is obvious. The disadvantage is that it is easily affected by the structure and the adaptive frequency band is relatively narrow.

However, the dynamic test of the pile formation process of the underwater compacted sand pile is carried out in a corrosive environment such as humidity, acid, alkali and salt. The resistance sensor and the steel string sensor have poor corrosion resistance, short life, and cannot work reliably for a long time.

The pile tube used to set the sand pile is relatively long, so the wire connected to the sensor during the test is also required to have a very long length. The wire itself has resistance, which will cause signal loss during the transmission of the test signal, thus reducing the test time. The precision of the result

In addition, since resistive and steel string sensors cannot be transmitted remotely, a certain scale of signal transmission equipment and a monitoring room are required at the test site, which increases the cost of work

The dynamic test device in the prior art has not taken into account the influence of factors such as the underwater application environment, test depth, pile pipe length, wind, wave and current, etc., so it is not suitable for the test of underwater compacted sand piles

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