Research Article
A Method for Detecting the Spacing of Steel Arch Frames in Construction Tunnels Based on Three-Dimensional Laser Technology
Chuanyi Ma,
Hongzheng Luo,
Chuan Wang,
Gaohang Lv*
Issue:
Volume 11, Issue 4, July 2023
Pages:
40-43
Received:
15 October 2023
Accepted:
7 November 2023
Published:
13 November 2023
Abstract: The present invention provides a point cloud spacing extraction algorithm for tunnel steel arch frames. This method first calculates the angle between the point cloud of the tunnel steel arch construction section and the adjacent coordinate axis and rotates it so that its axial direction is parallel to the adjacent coordinate axis. Then, the point cloud axial normal vector is calculated, and a threshold is set based on the calculated normal vector to extract the steel arch point cloud. Then, a clustering algorithm is used to extract the single steel arch point cloud, Use the C2C-Distance method based on the kd tree to calculate the closest distance from each point in a single steel arch point cloud to another single steel arch. Take the average value to obtain the distance between the tunnel steel arches, fit the single arch point cloud, fit a spatial circular point cloud, calculate the difference between the single point cloud and the spatial circular point cloud, and extract the excessively distorted part in the single point cloud. This method has good robustness and is suitable for various working conditions of tunnels. It can effectively extract point clouds of steel arch frames and obtain point cloud spacing with millimeter level errors, making it suitable for monitoring tunnel construction quality.
Abstract: The present invention provides a point cloud spacing extraction algorithm for tunnel steel arch frames. This method first calculates the angle between the point cloud of the tunnel steel arch construction section and the adjacent coordinate axis and rotates it so that its axial direction is parallel to the adjacent coordinate axis. Then, the point ...
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Research Article
An Experimental Investigation on the Causes of Flexible Pavement Failures: A Case Study on Tarcha - Yalo Road Section
Hailemichael Debalke Damota*,
Abel Tesfaye,
Anteneh Geremew
Issue:
Volume 11, Issue 4, July 2023
Pages:
44-53
Received:
2 June 2023
Accepted:
31 October 2023
Published:
24 November 2023
Abstract: This study has been conducted on Tarcha-Yalo Road segment. The objective of this study is to investigate the causes and remedial measures for asphalt pavement distresses. To meet the objective a systematic methodology is used to investigate field survey and laboratory tests were carried out. Soil samples were collected using purposive techniques of sampling from severely damaged and non-damaged sections. Severely damaged section distresses were corrugation, block cracking, ravelling and stripping. Based on selection, the representative samples of soil was collected for the three failed and two non-failed section from the study area. The condition survey has been conducted for the evaluation of pavement condition and the average PCI of the study area fall in the average PCI value indicates the pavement performance condition of the total road length (47.4 km) is under category of good (60%) and very good (40%) condition of pavement condition rating. Average thicknesses of each layer of failed sections were measured and Asphalt 2.13cm, base course 10.5cm, and sub-base 11.67cm. And the average thicknesses of non-failed sections were 3.35cm for asphalt, 9cm for base course and 12.5 cm for sub base. According to AASHTO and Unified Soil Classification of soil Subgrade was A-7 and SC, sub base A-2-4 and GP and base course A-1-a and GW respectively. An average LL, PL and PI of failed sections of base course (5%, 0%, 5%), sub-base (33.33%, 25%, 8.33%) and subgrade (52.5%, 31.33%, 21.33%) whereas an average LL, PL and PI of the non-failed sections were (4.5%, 0%, 4.5%), (35.5%, 25.5%, 10%) and (46.5%, 33%, 13.5%) for base course, sub base and sub grade materials respectively. Compaction (MDD (g/cc), OMC (%)) of failed section of base course (1.73, 10.92), sub base (1.67, 12.23) and sub-grade (1.58g/cc, 20.33% whereas the non-failed sections were (1.76, 9.95), (1.74, 11.1), (1.65, 14.4) for base course, sub base and sub grade respectively. The CBR% of base course 80%, sub-base 60% and sub-grade 9% obtained. The Los Angeles Abrasion test values of sub base and base course were sampled with two trials of tests for each. Based on the laboratory test result and condition survey the pavement failure is due to insufficient thickness design, improper compaction, heavy traffic load, and poor drainage, absence of shoulder and poor-quality of construction materials. Finally it is recommended that the periodic maintenance such as fog seal, slurry seal and crack sealing for failed section in Tarcha-Yalo road section.
Abstract: This study has been conducted on Tarcha-Yalo Road segment. The objective of this study is to investigate the causes and remedial measures for asphalt pavement distresses. To meet the objective a systematic methodology is used to investigate field survey and laboratory tests were carried out. Soil samples were collected using purposive techniques of...
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