Developing Innovative Shotcrete as Rock Support for Underground Mining in Canada’s North

开发创新喷射混凝土作为加拿大北部地下采矿的岩石支撑

• 批准号: RGPIN-2017-05537
• 负责人: Liu, Wei
• 金额: $ 1.46万
• 依托单位: University of Alberta
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2017
• 资助国家: 加拿大
• 起止时间: 2017-01-01 至 2018-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=636456
• 关键词: Developing; Innovative; Shotcrete; Rock; Support

Shotcrete refers to a cement-based mixture projected pneumatically at high velocity towards the target substrate. Shotcrete has been widely used in underground mines as rock support; however, permafrost poses significant challenges to the design and use of shotcrete to support freshly excavated frozen rock/permafrost because the slow hydration of shotcrete mixture on frozen substrates leads to insufficient hardening and malfunctioning of the rock support system. This is unsafe as insufficient hardening may result in rockfalls and subsequent injuries or even fatalities of mine workers. For northern applications, the hydration of shotcrete must be accelerated to ensure adequate strength for rock support; however, excessive heat produced by shotcrete hydration and warm ventilation air within the mine causes thawing of the surrounding permafrost. Thawing is a serious problem because it triggers greenhouse gas emissions (i.e., methane) threatening global climate and it destabilizes the ground making underground operations unsafe.

喷射混凝土是指一种水泥基混合物，以气动方式高速投射到目标基材上。喷射混凝土在地下矿山中被广泛用作岩石支撑；然而，多年冻土对设计和使用喷射混凝土来支撑新开挖的冻岩/多年冻土构成了巨大的挑战，因为在冻结的基质上喷射混凝土混合物水化缓慢，导致岩石支撑系统不够硬化和失灵。这是不安全的，因为不充分的硬化可能会导致落石和随后的矿工受伤甚至死亡。对于北方应用，必须加快喷射混凝土的水化，以确保岩石支撑的足够强度；然而，喷射混凝土水化产生的过高热量和矿井内的温暖通风空气会导致周围的永久冻土融化。融化是一个严重的问题，因为它会触发温室气体排放(即甲烷)，威胁全球气候，并破坏地面的稳定，使地下作业不安全。