A finger-up overflow measuring instrument that can be used to measure the subsidence of the roof of underground caverns

Abstract

The invention relates to a measuring head upward-pointing type overflow measuring instrument capable of measuring subsidence of a roof of an underground cavern, which comprises a measuring tube, an overflow tube, a modified dial indicator, an upright rod and a communicating tube connected with the measuring tube and the overflow tube. The sinking surface of the roof can be measured via the following steps of: assembling and connecting the measuring tube and the overflow tube, and fixing the measuring tube on the bottom plate of the cavern; supporting the overflow tube in a handholding way or with a temporary support rod until a round bubble on a water collecting plate is centered and a ball-shaped measuring head on the upper part of the upright rod abuts against one measuring point on the roof to be tested; slowly filling water into the measuring tube, ensuring no air bubbles in the measuring tube, and making water flow into the overflow tube through the communicating tube until water flows out through a triangular overflow port of the overflow tube; and measuring the vertical distance between the water level in the measuring tube and the upper surface of a top cover with the modified dial indicator, and taking the measured vertical distance as a measured value of the measuring point; and repeating the above steps and marking the sinking surface of the roof according to the measured values. The measuring head upward-pointing type overflow measuring instrument has the advantages of high accuracy of measurement, convenience in operation, low cost of measurement, no damage to the roof of the tested cavern and the like.

Description

technical field [0001] The invention relates to an overflow connector for measuring the sinking of the roof of an underground cavern, in particular to a finger-up overflow measuring instrument with a measuring head. Background technique [0002] For a cavern (including ancient caverns), after excavation, it will produce displacement caused by excavation, including the vertical displacement of the roof, that is, subsidence. Theoretically, the aforementioned displacements will change over time. Theoretically, there will be a sinking surface of the roof at every moment, or each sinking surface of the roof is a fragment (or one of the processes) in the vertical deformation process of the roof, even within a certain period of time The top plate is no longer deformed, and what is seen is also a fragment or process of its deformation process during that time period. The main purpose of measuring and studying the sinking surface of the ancient cave roof is: first, under certain co...

AI Technical Summary

Problems solved by technology

It is expected to achieve good measurement results when used for the above-mentioned purpose two, but there is still a problem of excessive error when used for the above-mentioned inversion purpose (that is, purpose one), and its measurement error may be greater than 2mm

When processing data, sometimes there are some human errors due to the determination of the datum

In addition, because this kind of instrument is very expensive, its measurement cost is also high

Occasionally, such instruments are not yet available for field measurements

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