To eliminate the problems like brittle material characteristics, low crack resistivity, low tensile strength values, late curing time and rebound problems of shotcrete liners, high density polyurethane rigid foams (PRF) were investigated as an alternative liner support material in this experimental and numerical study. Its rapid polymerization makes the PRF liners be able to supply support pressure in very early times in comparison with the shotcrete liners. Some fundamental tests were carried out to determine some support performance properties of a high-density PRF product with the foam density of 180 kg/m³. Additionally, a pilot PRF liner spraying application was practiced in an underground mine to investigate whether its application is advantageous in terms of eliminating the problems of shotcrete applications. In the field study, PRF liners were comparatively investigated with the shotcrete liner sprayed in the mine. Within the numerical part of this study, a series of finite element analyses were performed to investigate support performances of the PRF liners. According to the results of both experimental and numerical analyses, high density PRF liners were found to have proper load bearing capacities as a new liner support material, and the PRF liners were assessed to be a strong candidate to be popular in rock engineering. The findings from this study are promotive for new investigations to better understand support properties of the PRF liners for improving effectiveness of their systematic use.

中文翻译：

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高密度聚氨酯硬质泡沫可用作岩石工程中的衬里支撑材料

为了消除脆性材料特性，低抗裂性，低拉伸强度值，后期固化时间和喷射混凝土衬砌的回弹问题等问题，在本实验和数值研究中，对高密度聚氨酯硬质泡沫塑料（PRF）作为替代衬砌支撑材料进行了研究。 。与喷浆衬砌相比，它的快速聚合作用使得PRF衬砌能够在很短的时间内提供支撑压力。进行了一些基本测试，以确定泡沫密度为180 kg / m ³的高密度PRF产品的某些支撑性能。。另外，在地下矿井中进行了PRF衬里喷涂试验，以研究其应用在消除喷射混凝土应用方面是否有利。在现场研究中，对PRF衬里与喷在矿井中的喷射混凝土衬里进行了比较研究。在这项研究的数值部分内，进行了一系列有限元分析，以研究PRF衬管的支撑性能。根据实验和数值分析的结果，发现高密度PRF衬砌作为新型衬砌支撑材料具有适当的承载能力，并且PRF衬砌被评估为在岩石工程中流行的强大候选材料。