Rockburst Hazard Control Using the Excavation Compensation Method (ECM): A Case Study in the Qinling Water Conveyance Tunnel

Abstract

Rockburst disasters occur frequently during deep underground excavation, yet traditional concepts and methods can hardly meet the requirements for support under high geo-stress conditions. Consequently, rockburst control remains challenging in the engineering field. In this study, the mechanism of excavation-induced rockburst was briefly described, and it was proposed to apply the excavation compensation method (ECM) to rockburst control. Moreover, a field test was carried out on the Qinling Water Conveyance Tunnel. The following beneficial findings were obtained: Excavation leads to changes in the engineering stress state of surrounding rock and results in the generation of excess energy ΔE, which is the fundamental cause of rockburst. The ECM, which aims to offset the deep excavation effect and lower the risk of rockburst, is an active support strategy based on high pre-stress compensation. The new negative Poisson’s ratio (NPR) bolt developed has the mechanical characteristics of high strength, high toughness, and impact resistance, serving as the material basis for the ECM. The field test results reveal that the ECM and the NPR bolt succeed in controlling rockburst disasters effectively. The research results are expected to provide guidance for rockburst support in deep underground projects such as Sichuan–Xizang Railway.

Keywords

• Rockburst
• Excavation compensation method
• Pre-stressed support
• Negative Poisson’s ratio bolt
• Tunnel boring machine