Selecting Equivalent Strength for Intact Rocks in Heterogeneous Rock Masses
METADATA ONLY
Loading...
Author / Producer
Date
2018-08
Publication Type
Journal Article
ETH Bibliography
no
Citations
Altmetric
METADATA ONLY
Data
Rights / License
Abstract
Many surface and underground structures are constructed in heterogeneous rock formations. These formations have a combination of weak and strong rock layers. Due to the alternation of the weak and strong layers, selecting the equivalent and appropriate geomechanical parameters for these formations is challenging. One of these problems is choosing the equivalent strength (i.e., uniaxial compressive strength) of intact rock for a group of rocks. Based on the volume of weak and strong parts and their strength, the equivalent strength of heterogeneous rocks changes. Marinos and Hoek (Bull Eng Geol Environ 60(2):85–92, 2001) presented the “weighted average method” for defining the uniaxial compressive strength (UCS) of heterogeneous rock masses based on the volume of weak and strong parts. Laubscher (1977) used the volume ratio of the strength of a weak part to a strong part (UCS weak/UCS strong) to determine the equivalent strength. In this study, the two methods are compared and their validity is evaluated by experimental data and numerical analyses. The geomechanical parameters of two heterogeneous formations (Aghajari and Lahbari) in the west of Iran were estimated using these methods. The results of the present study obtained through numerical analyses using particle flow code are compared with those of previous studies and discussed. Laboratory and numerical results show UCS decrease and approach to weak strength with an increasing in volume of weak part. When strength ratio of strong to weak rock increase, equivalent strength decrease more severely. The findings show that Laubscher’s method gives more appropriate results than the weighted average method.
Permanent link
Publication status
published
External links
Editor
Book title
Journal / series
Volume
26 (4)
Pages / Article No.
1975 - 1989
Publisher
Springer
Event
Edition / version
Methods
Software
Geographic location
Date collected
Date created
Subject
Heterogeneous rocks; Uniaxial compressive strength; Weighted average method; GSI; Geomechanical parameters; numerical analysis; PFC
Organisational unit
03465 - Löw, Simon (emeritus) / Löw, Simon (emeritus)