- 256 views
- 307 downloads
Evaluation of Backfill Solution for Micro-Trenching in Cold Regions
-
- Author / Creator
- Afonso Velasco Rios, Vinicius
-
In an era of innovative technologies and constant development, reliable and effective infrastructure is paramount. Fiber optic cable deployment, although extremely efficient, still lacks in infrastructure investment, preventing technologies like self-driving cars and G5 networks from being fully implemented. Micro-trenching is a three-step procedure that was introduced as a fast-paced and cost-effective solution to this constraint. The method consists of marking the micro-trench route; cutting and cleaning the inside of the trench; laying the cables and backfilling. Although micro-trenching has been successfully applied in many projects, there are still challenges to overcome. Backfilling materials must comply with a series of requirements, which include but are not limited to effectively bonding with the existing structure, providing structural support, and sealing the surface to water infiltration. Failing to satisfy such characteristics, can significantly reduce the service life of the technique. The small dimensions of the trench and the cold climate of Canada demand extra care, and this has been the topic of many studies since the introduction of micro-trenching in 2005.The focus of this research is to assess different materials for use as backfilling for micro-trenching applications in cold regions. Studies began with laboratory tests to compare the resistance of regular and foam grout to freezing/thawing cycles. Specimens were cured for different time frames and conditioned in multiple cycles before being tested for compressive strength according to ASTM standards. The amount of absorbed water and failure mechanisms were observed for each sample in order to better understand reasons behind differences in performances. In the end, a material cost comparison was drawn based on each individual component of the mixes to provide information on the use of novel materials for industry applications. In 2013, the University of Alberta and TELUS started a pilot study to address the short and long-term performance of micro-trenching applications. Existing trench configurations were performed by specialized companies, in addition to distinct backfilling materials and composite backfills proposed by the University after successful laboratory tests. In order to provide continuation to this study, visual observations were made to identify common pavement distresses that may have developed as a consequence of the trench installation, as well as ground penetration radar (GPR) analysis was conducted to locate and distinguish conduit movements inside the trench. Recommendations for future applications were proposed regarding issues observed during operation and novel materials introduced throughout the study.
-
- Graduation date
- Spring 2019
-
- Type of Item
- Thesis
-
- Degree
- Master of Science
-
- License
- Permission is hereby granted to the University of Alberta Libraries to reproduce single copies of this thesis and to lend or sell such copies for private, scholarly or scientific research purposes only. Where the thesis is converted to, or otherwise made available in digital form, the University of Alberta will advise potential users of the thesis of these terms. The author reserves all other publication and other rights in association with the copyright in the thesis and, except as herein before provided, neither the thesis nor any substantial portion thereof may be printed or otherwise reproduced in any material form whatsoever without the author's prior written permission.