Method for measuring volume of rock-fill dam test pit through handheld three-dimensional laser scanning

Abstract

The invention discloses a method for measuring a volume of a rock-fill dam test pit through handheld three-dimensional laser scanning. The method comprises the following steps: firstly, leveling a dam charge level, placing a lantern ring, and excavating the test pit; then, according to the diameter and depth of the test pit and the stacking and filling material, determining the dot spacing, the laser color and the scanning mode; using a handheld color three-dimensional scanner to extend into the test pit, scanning according to the curvature of the pit wall from small to large, processing obtained point cloud: denoising, simplifying, packaging and filling, and then selecting a circle of annular area on the top of the test pit model for optimal plane fitting; finally, taking the fitting plane as an xoy plane, and enabling the z-axis direction to face downwards; and projecting the whole test pit model to the xoy plane, enabling the projection area to be an integral interval S, calculating the volumes of the small prisms of the test pit model, and adding to obtain the volume of the whole test pit. The method is flexible and simple to operate, and can quickly scan various types of test pits, obtain high-quality point cloud data, efficiently and quickly process the data and accurately calculate the volume of the test pit.

Description

technical field [0001] The invention relates to the technical field of earth-rockfill dam construction quality inspection, in particular to a hand-held three-dimensional laser scanning method for measuring the volume of a rockfill dam test pit. Background technique [0002] The construction quality of an earth-rock dam is directly related to the safety of the dam, and effectively controlling the quality of the dam filling and rolling is the key to ensuring the safety of the dam. The filling volume of high rockfill dams is huge, and the rolling quality of the dam filling materials is very important. Appropriate intelligent and mechanized compaction detection methods should be adopted to improve the detection speed and accuracy. At present, the method of excavating pits and filling water is still a common method for testing the rolling quality of earth-rock dams, mainly following the provisions of the "Code for Construction of Rolling Earth-rock Dams" (DL / T 5129-2001). In the...

AI Technical Summary

Problems solved by technology

The irrigation method does not take into account the gaps between the plastic film, the pit wall, the dam material surface, and the collar; the water droplets that appear during the back and forth irrigation process; artificially judge whether the water surface is flush with the edge of the collar, which is highly subjective

[0006] (3) It is greatly affected by human factors

[0010] 1. When measuring the transition material and rockfill material test pit by water irrigation method, the measurement speed is slow due to the large amount of water irrigation; various human factors such as artificially reading the amount of water irrigation, recording data and calculation data lead to occasional wrong data, and the accuracy is low

[0011] 2. The fixed 3D laser scanner needs to be set up multiple times or set up multiple instruments at one time to complete the scan. After the scan is completed, data splicing is required to obtain a complete test pit model, which is time-consuming and laborious

[0012] 3. The fixed 3D laser scanner was placed outside the test pit to scan the test pit, but the test pit wall of the transitional material and the rockfill site was severely uneven, and a large number of scanning blind areas appeared when the fixed 3D laser scanner was used to scan the test pit. When processing point cloud data, a large number of holes need to be filled, resulting in a large deviation between the test pit model and the actual test pit, which seriously affects the volume accuracy

[0013] 4. The method of calculating the volume of the test pit by two scans before and after the excavation of the test pit, and then using the characteristic marks to splice the scanning results before and after excavation to calculate the volume of the test pit, theoretically increases the volume calculation accuracy, but the actual situation is that during the excavation process The damaged surface of the dam material makes splicing difficult, and at the same time increases the amount of point cloud data and point cloud data processing steps, resulting in slower subsequent data processing speed and reduced volume calculation efficiency

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