PREDICTION OF UNCONFINED COMPRESSIVE STRENGTH OF ROCKS: A REVIEW PAPER

2015 ◽  
Vol 77 (11) ◽  
Author(s):  
Ehsan Momeni ◽  
Ramli Nazir ◽  
Danial Jahed Armaghani ◽  
Mohd For Mohd Amin ◽  
Edy Tonnizam Mohamad

Unconfined compressive strength (UCS) of rocks is a crucial parameter in designing geotechnical structures. Owing to difficulties in obtaining proper samples for UCS test as well as the point that conducting UCS is relatively expensive, the use of indirect methods for UCS estimation has drawn considerable attentions. This review paper is aimed to briefly highlight different proposed predictive models of UCS. In this regard, nearly 85 predictive models of UCS are listed in the paper which provides a good reference and database for geotechnical readers. The highlighted models are divided into two main sections. In the first section, UCS correlations with Brazilian tensile strength test, point load index test (Is(50)), Schmidt hammer and ultrasonic velocity tests are highlighted. In the second section, recently proposed artificial intelligence-based predictive models of UCS are underlined. Apart from that, using available data (106 rock specimens), which were previously published by authors, a new correlation between UCS and Is(50) is developed which can be useful for assessing the UCS of tropical rocks. Overall, although the paper suggests conducting direct UCS test for important projects, based on the region and type of rocks, employing the highlighted predictive models for assessing the UCS of rock can be advantageous

Author(s):  
Aun Zahoor ◽  
Muhammad Usman Azhar ◽  
Saif Ur Rehman ◽  
Farrukh Rahim Shehzad

In a bid to find some possible relation of Unconfined Compressive Strength (UCS) with relatively simplelaboratory tests like Point Load Test (PLT) and Schmidt Rebound Hammer Test (SRHT), some 50 core samples ofMiddle Eocene Nammal formation from Central Salt Range in Pakistan were collected and subjected to these testmethods as per respective test standards of International Society of Rock Mechanics (ISRM). The values of SRHT andPLT were separately compared to the respective values of UCS so as to find the linear relations. On the basis of the R2value of Regression Analysis, it has been found that a strong correlation with a high degree of accuracy exists betweenPLT and UCS while the degree of accuracy between SRHT and UCS was found to be low.


2019 ◽  
Vol 10 (2) ◽  
pp. 139-144
Author(s):  
Aun Zahoor ◽  
Muhammad Usman Azhar ◽  
Saif Ur Rehman ◽  
Farrukh Rahim Shehzad

In a bid to find some possible relation of Unconfined Compressive Strength (UCS) with relatively simplelaboratory tests like Point Load Test (PLT) and Schmidt Rebound Hammer Test (SRHT), some 50 core samples ofMiddle Eocene Nammal formation from Central Salt Range in Pakistan were collected and subjected to these testmethods as per respective test standards of International Society of Rock Mechanics (ISRM). The values of SRHT andPLT were separately compared to the respective values of UCS so as to find the linear relations. On the basis of the R2value of Regression Analysis, it has been found that a strong correlation with a high degree of accuracy exists betweenPLT and UCS while the degree of accuracy between SRHT and UCS was found to be low.


Materials ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3177
Author(s):  
Evelio Teijón-López-Zuazo ◽  
Jorge López-Rebollo ◽  
Luis Javier Sánchez-Aparicio ◽  
Roberto Garcia-Martín ◽  
Diego Gonzalez-Aguilera

This work aims to investigate different predictive models for estimating the unconfined compressive strength and the maximum peak strain of non-structural recycled concretes made up by ceramic and concrete wastes. The extensive experimental campaign carried out during this research includes granulometric analysis, physical and chemical analysis, and compression tests along with the use of the 3D digital image correlation as a method to estimate the maximum peak strain. The results obtained show that it is possible to accurately estimate the unconfined compressive strength for both types of concretes, as well as the maximum peak strain of concretes made up by ceramic waste. The peak strain for mixtures with concrete waste shows lower correlation values.


2016 ◽  
Vol 846 ◽  
pp. 348-353
Author(s):  
Somayeh Behraftar ◽  
Joshua Heslin ◽  
S. Galindo Torres ◽  
Alexander Scheuermann

In this study, a micro-mechanical model is developed to study the correlation of the point load index in rocks with uniaxial compressive strength (UCS) tests. The model is represented by an array of bonded particles simulated by a novel discrete based model, which was introduced by the authors previously. The point load test (PLT) is performed in the field on rock samples to classify and estimate the UCS of a rock type via the index-to-strength correlation factor k. Numerical analyses, such as the one presented in this work, will serve to close the knowledge gap concerning the correlation between k, UCS and other material properties of rocks.


2014 ◽  
Vol 14 (01) ◽  
pp. 1550006 ◽  
Author(s):  
M. S. Delibalta ◽  
S. Kahraman ◽  
R. Comakli

Because the indirect tests are easier and cheaper than the direct tests, the prediction of rock properties from the indirect testing methods is important especially for the preliminary investigations. In this study, the predictability of the physico-mechanical rock properties from the noise level measured during cutting rock with diamond saw was investigated. Noise measurement test, uniaxial compressive strength (UCS) test, Brazilian tensile strength (BTS) test, point load strength (Is) test, density test, and porosity test were carried out on 54 different rock types in the laboratory. The results were statistically analyzed to derive estimation equations. Strong correlations between the noise level and the mechanical rock properties were found. The relations follow power functions. Increasing rock strength increases the noise level. Density and porosity also correlated strongly with the noise level. The relations follow linear functions. Increasing density increases the noise level while increasing porosity decreases the noise level. The developed equations are valid for the rocks with a compressive strength below 150 MPa. Concluding remark is that the physico-mechanical rock properties can reliably be estimated from the noise level measured during cutting the rock with diamond saw.


2021 ◽  
Vol 5 (3) ◽  
pp. 89
Author(s):  
Dini Ayu Hanifah ◽  
Eko Santoso ◽  
Kartini Kartini

Penentuan tingkat pelapukan yang dilakukan pada penelitian ini menggunakan metode yang lebih sederhana dan sering digunakan serta dengan biaya yang terjangkau yaitu dengan pengamatan lapangan secara visual deskriptif dan pengujian di laboratorium berdasarkan uji UCS (Uniaxial Compressive Strength), Schmidt Hammer, dan PLI (Point Load Index). Metodologi yang dilakukan dan digunakan pada penelitian ini meliputi, data tingkat pelapukan berdasarkan pengamatan secara deskripsi visual yang mengacu pada penelitian terdahulu, data uji sifat fisik batulempung, dimensi batulempung, nilai rebound dari alat schmidt hammer, dan nilai kuat tekan batulempung menggunakan alat UCS (uniaxial compressive strength) dari 10 sampel batulempung, serta nilai PLI. Berdasarkan pengamatan lapangan secara visual deskriptif adapun tingkat pelapukan batulempung dalam penelitian ini termasuk ke dalam tingkat pelapukan III (lapuk sedang), IV (lapuk kuat), dan V (lapuk sempurna) yang mewakili 10 sampel ( mengacu pada penelitian Sadisun dkk, 1998 ). Sedangkan berdasarkan nilai UCS yang didapatkan dari nilai kuat tekan tertinggi sampai terendah dari 10 sampel yaitu sebesar 3,39 MPa masuk ke dalam tingkat pelapukan III (lapuk sedang), 1,98 MPa masuk ke dalam tingkat pelapukan IV (lapuk kuat), serta 0,63 MPa masuk ke dalam tingkat pelapukan V (lapuk sempurna). Berdasarkan hasil dari nilai rebound yang didukung dengan penelitian menurut ahli Hencer dan Martin (1982), tingkat pelapukan batulempung dalam penelitian ini masuk ke dalam highly weathered (lapuk kuat) dengan nilai rebound rata-rata sebesar N<25. Dan berdasarkan dari nilai PLI tingkat pelapukan pada penelitian ini masuk ke dalam tingkat pelapukan III dan IV. Kata-kata kunci: tingkat pelapukan, uniaxial compressive strength, schmidt hammer, point load index


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