Low-strain dynamic monitoring device for underwater pile foundation

Abstract

The invention discloses a low-strain dynamic monitoring device for an underwater pile foundation. A driving hammer and a stress wave receiving probe are arranged in a stress wave generating and receiving device together, the driving hammer can be released and retracted automatically, the stress wave generating and receiving device is fixed to the top of the pile foundation through the combination of a balance weight and a fixing device, an attaching colloidal matter layer is arranged at the lower end of the stress wave receiving probe, an openable water resistant door is arranged on the lower portion of a left cavity, rubber is arranged on the lower surface of the water resistant door, and when a pile is pressed by the stress wave generating and receiving device, a frame block presses the pile to achieve sealing together with a pile cap and then the water resistant door is opened. In this way, the left cavity contains no water all the time, and knocking effect can not be affected by friction between the driving hammer and water when the driving hammer falls down. A length adjuster is arranged to adjust the stretching length of the fixing device so that the low-strain dynamic monitoring device can be adapted to underwater pile foundations with different pile diameters.

Description

technical field [0001] The invention relates to the technical field of pile foundation detection, in particular to a pile foundation detection device in a high water pressure environment, specifically, an underwater pile foundation low-strain dynamic detector. Background technique [0002] Large-diameter cast-in-situ piles are widely used because of their high bearing capacity and low construction noise. They are usually excavated manually or drilled into holes and poured into piles underground or underwater. The quality is affected by the construction process, especially the concrete pouring. It is difficult to control due to the influence of various factors such as working procedures, so the quality problems of pile foundations generally exist, such as too thick sediment, uneven pile body (local mud, segregation, honeycomb, etc.). Therefore, before proceeding to the next process, the quality and integrity of the concrete body of the pile must be inspected and evaluated, es...

AI Technical Summary

Problems solved by technology

However, the existing low-strain dynamic measuring instrument is not suitable for use in deep water. On the one hand, when using the dynamic measuring instrument for detection, two people are generally required to cooperate. One person presses the probe on the pile head, and the other hand The hand hammer or power hammer hits the top of the pile to generate a stress wave, and another person initially judges whether the curve is qualified through the display of the pile detector connected to the probe, and records the corresponding pile number, and then uses special software to further analyze the data; On the other hand, in the deep water high pressure environment, the use of artificial diving for low-strain operations is not only high in labor costs, complicated and difficult to operate, but also the probe of the dynamic tester will seep into the water under the high pressure of deep water, resulting in a decrease in the sensitivity of the probe, and the low-strain curve knocked out Distorted messy, poor results

Expensive labor costs, high difficulty of detection and poor detection effect severely limit the application of low-strain dynamic detectors in marine and river-sea pile foundation detection

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