Selecting Equivalent Strength for Intact Rocks in Heterogeneous Rock Masses
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 fo...
| Main Authors: | , , |
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| Other Authors: | |
| Format: | Article |
| Language: | English |
| Published: |
Springer Science and Business Media LLC
2022
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| Online Access: | https://hdl.handle.net/1721.1/131456.2 |
| _version_ | 1811088214680666112 |
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| author | Behnia, Mahmoud Rahmani Shahraki, Ahmad Moradian, Zabihallah |
| author2 | Massachusetts Institute of Technology. Department of Civil and Environmental Engineering |
| author_facet | Massachusetts Institute of Technology. Department of Civil and Environmental Engineering Behnia, Mahmoud Rahmani Shahraki, Ahmad Moradian, Zabihallah |
| author_sort | Behnia, Mahmoud |
| collection | MIT |
| description | 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. |
| first_indexed | 2024-09-23T13:58:31Z |
| format | Article |
| id | mit-1721.1/131456.2 |
| institution | Massachusetts Institute of Technology |
| language | English |
| last_indexed | 2024-09-23T13:58:31Z |
| publishDate | 2022 |
| publisher | Springer Science and Business Media LLC |
| record_format | dspace |
| spelling | mit-1721.1/131456.22024-06-14T14:28:42Z Selecting Equivalent Strength for Intact Rocks in Heterogeneous Rock Masses Behnia, Mahmoud Rahmani Shahraki, Ahmad Moradian, Zabihallah Massachusetts Institute of Technology. Department of Civil and Environmental Engineering Massachusetts Institute of Technology. Earth Resources Laboratory 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. 2022-03-15T15:07:58Z 2021-09-20T17:17:09Z 2022-03-15T15:07:58Z 2018-01 2017-08 2020-09-24T21:14:44Z Article http://purl.org/eprint/type/JournalArticle 0960-3182 1573-1529 https://hdl.handle.net/1721.1/131456.2 en https://doi.org/10.1007/s10706-017-0440-4 Geotechnical and Geological Engineering Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use. Springer International Publishing AG, part of Springer Nature application/octet-stream Springer Science and Business Media LLC Springer International Publishing |
| spellingShingle | Behnia, Mahmoud Rahmani Shahraki, Ahmad Moradian, Zabihallah Selecting Equivalent Strength for Intact Rocks in Heterogeneous Rock Masses |
| title | Selecting Equivalent Strength for Intact Rocks in Heterogeneous Rock Masses |
| title_full | Selecting Equivalent Strength for Intact Rocks in Heterogeneous Rock Masses |
| title_fullStr | Selecting Equivalent Strength for Intact Rocks in Heterogeneous Rock Masses |
| title_full_unstemmed | Selecting Equivalent Strength for Intact Rocks in Heterogeneous Rock Masses |
| title_short | Selecting Equivalent Strength for Intact Rocks in Heterogeneous Rock Masses |
| title_sort | selecting equivalent strength for intact rocks in heterogeneous rock masses |
| url | https://hdl.handle.net/1721.1/131456.2 |
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