Timely Constructed and Enhanced Lining for Managing Extensive Deformations of Tunnel in Coal Stratum: A Case Study
Yiming Wang1, 2, *, Hazrina Mansor1, Thevaneyan Krishta David1
Identifiers and Pagination:Year: 2024
E-location ID: e18741495284171
Publisher ID: e18741495284171
Article History:Received Date: 24/10/2023
Revision Received Date: 06/12/2023
Acceptance Date: 13/12/2023
Electronic publication date: 11/01/2024
Collection year: 2024
open-access license: This is an open access article distributed under the terms of the Creative Commons Attribution 4.0 International Public License (CC-BY 4.0), a copy of which is available at: https://creativecommons.org/licenses/by/4.0/legalcode. This license permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
The Sanlian Tunnel case study exemplifies that even after implementing the initial support within the coal stratum, the surrounding rocks exhibited ongoing deformation devoid of stabilization indications. Addressing this issue calls for innovative control technologies that mitigate extensive deformations and redefine safe and sustainable coal stratum tunnel construction.
The field experiment was adopted to select the appropriate technical measures to control extensive deformations. Three experiment schemes were developed and applied to the construction. Scheme One was the enhanced initial support structure, and Scheme Two was the combined use of enhanced initial support structure, lengthened sidewall anchor rods and added steel pipe piles. Scheme Three was the “timely constructed and enhanced lining structure” proposed on the basis of Scheme Two, and the secondary lining was applied if the horizontal displacement exceeded 450mm. Then, field observations of displacements and stresses were implemented to evaluate the effectiveness of different experimental schemes in controlling extensive deformations.
Scheme One and Two cannot control extensive deformations effectively, as the displacement of the initial support continued to increase with no sign of stabilization. Regarding Scheme Three, structural deformation progressively attained a state of stability around 80 days subsequent to the secondary lining construction. Additionally, the stress within the support structure remains stable below the permissible threshold, affirming the secure condition.
Emanating from the field monitoring results, it is evident that the suggested “timely constructed and enhanced lining structure” scheme control technology holds substantial promise for practical implementation in engineering scenarios.