臺灣博碩士論文加值系統

Ground improvement by Dynamic Compaction (DC) is a commonly used method for the densification of in-situ sandy soil to a large depth. After pounding, a crater on the ground is formed, and surface heaved. To evaluate the effectiveness of pounding, the volume change of crater and ground heave before and after pounding needs to be measured. Traditionally, the volume of dynamic compaction induced crater and ground heave is measured by means of level surveying and ruler measurement. However, since ground heave around the crater and the shape of the crater itself are irregular, it is not only difficult but also time-consuming to accurately measure the volume of crater and ground heave. This study proposes a method that adopts the image processing (photogrammetry) technology to accurately measure the crater volume and the ground heave around it. A commercial software, which is initially used for the drone, is used here to generate point cloud of the crater and its surrounding area using the images captured with a video camera or smartphone. The accuracy of this method was calibrated with a known volume box in the laboratory first before it was used in a field trial test. The study will present and discuss the operation procedure and image processing of this method. The crater volume measured from the photogrammetry method is compared with that measured from the traditional measuring method. It is found that the volume of DC crater can be better approximated by cone shape crater than by truncated cone shape crater, which is commonly used in the DC industry and can seriously overestimate the actual volume of DC craters.

Ground improvement by Dynamic Compaction (DC) is a commonly used method for the densification of in-situ sandy soil to a large depth. After pounding, a crater on the ground is formed, and surface heaved. To evaluate the effectiveness of pounding, the volume change of crater and ground heave before and after pounding needs to be measured. Traditionally, the volume of dynamic compaction induced crater and ground heave is measured by means of level surveying and ruler measurement. However, since ground heave around the crater and the shape of the crater itself are irregular, it is not only difficult but also time-consuming to accurately measure the volume of crater and ground heave. This study proposes a method that adopts the image processing (photogrammetry) technology to accurately measure the crater volume and the ground heave around it. A commercial software, which is initially used for the drone, is used here to generate point cloud of the crater and its surrounding area using the images captured with a video camera or smartphone. The accuracy of this method was calibrated with a known volume box in the laboratory first before it was used in a field trial test. The study will present and discuss the operation procedure and image processing of this method. The crater volume measured from the photogrammetry method is compared with that measured from the traditional measuring method. It is found that the volume of DC crater can be better approximated by cone shape crater than by truncated cone shape crater, which is commonly used in the DC industry and can seriously overestimate the actual volume of DC craters.

Abstract
Acknowledgement
Table of Contents
List of Figures
List of Tables
List of Symbols and Abbreviations
Chapter 1 Introduction
1.1 Research Motivation
1.2 Research Objectives
1.3 Thesis Outline
Chapter 2 Literature Review
2.1 Introduction
2.2 Heavy Pounding Compaction
2.2.1 Dynamic Compaction
2.3 Photogrammetry
2.4 Digital Image Capturing
2.4.1 Image Acquisition Plan
2.4.2 Camera Setting Configuration
2.4.3 Geo-referencing and Ground Control Point (GCP)
2.5 Image Processing Software
2.5.1 Image Processing Steps
2.5.2 Volume Calculation in Photogrammetry Software
2.6 Summary
Chapter 3 Research Methodology
3.1 Introduction
3.2 Standard Operation Procedure of Photogrammetry Method
3.3 Photogrammetry Calibration
3.4 Dynamic Compaction Pilot Test
3.4.1 Traditional Measurement
3.4.2 Photogrammetry Measurement
Chapter 4 Data Analysis and Findings
4.1 DC Craters Volume Measurement
4.1.1 Traditional Measurement Results
4.1.2 Data Acquiring and Processing of Photogrammetry Measurement
4.1.3 Photogrammetry Measurement Results
4.2 Analysis of Volume Measurement
4.3 Findings
Chapter 5 Conclusions and Future Study
5.1 Conclusions
5.2 Future Study
References
Appendix

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