Determination and applications of rock quality designation (RQD)

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• 作者：Lianyang Zhang ; ^{lyzhang@email.arizona.edu" class="auth_mail" title="E-mail the corresponding author}Author Vitae
• 关键词：Rock quality designation (RQD) ; Rock mass classification ; Deformation modulus ; Unconfined compressive strength ; Empirical methods
• 刊名：Journal of Rock Mechanics and Geotechnical Engineering
• 出版年：2016
• 出版时间：June 2016
• 年：2016
• 卷：8
• 期：3
• 页码：389-397
• 全文大小：1814 K

文摘

Characterization of rock masses and evaluation of their mechanical properties are important and challenging tasks in rock mechanics and rock engineering. Since in many cases rock quality designation (RQD) is the only rock mass classification index available, this paper outlines the key aspects on determination of RQD and evaluates the empirical methods based on RQD for determining the deformation modulus and unconfined compressive strength of rock masses. First, various methods for determining RQD are presented and the effects of different factors on determination of RQD are highlighted. Then, the empirical methods based on RQD for determining the deformation modulus and unconfined compressive strength of rock masses are briefly reviewed. Finally, the empirical methods based on RQD are used to determine the deformation modulus and unconfined compressive strength of rock masses at five different sites including 13 cases, and the results are compared with those obtained by other empirical methods based on rock mass classification indices such as rock mass rating (RMR), Q-system (Q) and geological strength index (GSI). It is shown that the empirical methods based on RQD tend to give deformation modulus values close to the lower bound (conservative) and unconfined compressive strength values in the middle of the corresponding values from different empirical methods based on RMR, Q and GSI. The empirical methods based on RQD provide a convenient way for estimating the mechanical properties of rock masses but, whenever possible, they should be used together with other empirical methods based on RMR, Q and GSI.