scholarly journals A Comparison Between Schmidt Rebound Hammer Test and Point Load Index Test (IS50) for the Effectiveness in Estimating the Unconfined Compressive Strength of Intact Rock- A Case Study with respect to Limestone of Early Eocene Nammal Formation, Central Salt

2019 ◽  
Vol 10 (2) ◽  
pp. 139-144
Author(s):  
Aun Zahoor ◽  
Muhammad Usman Azhar ◽  
Saif Ur Rehman ◽  
Farrukh Rahim Shehzad
Keyword(s):  
Compressive Strength ◽  
Unconfined Compressive Strength ◽  
Point Load ◽  
Load Test ◽  
Index Test ◽  
Rebound Hammer ◽  
Point Load Index ◽  
Test Standards ◽  
Schmidt Rebound Hammer ◽  
High Degree

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.

scholarly journals A Comparison Between Schmidt Rebound Hammer Test and Point Load Index Test (IS50) for the Effectiveness in Estimating the Unconfined Compressive Strength of Intact Rock- A Case Study with respect to Limestone of Early Eocene Nammal Formation, Central Salt

2019 ◽  
Vol 10 (2) ◽  
pp. 139-144
Author(s):  
Aun Zahoor ◽  
Muhammad Usman Azhar ◽  
Saif Ur Rehman ◽  
Farrukh Rahim Shehzad
Keyword(s):  
Compressive Strength ◽  
Unconfined Compressive Strength ◽  
Point Load ◽  
Load Test ◽  
Index Test ◽  
Rebound Hammer ◽  
Point Load Index ◽  
Test Standards ◽  
Schmidt Rebound Hammer ◽  
High Degree

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.

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
Keyword(s):  
Compressive Strength ◽  
Predictive Models ◽  
Unconfined Compressive Strength ◽  
Review Paper ◽  
Test Point ◽  
Point Load ◽  
Index Test ◽  
Point Load Index ◽  
Geotechnical Structures ◽  
Ucs Test

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

Investigation of Point Load Index Using Novel Discrete Based Model

2016 ◽  
Vol 846 ◽  
pp. 348-353
Author(s):  
Somayeh Behraftar ◽  
Joshua Heslin ◽  
S. Galindo Torres ◽  
Alexander Scheuermann
Keyword(s):  
Compressive Strength ◽  
Material Properties ◽  
Mechanical Model ◽  
Rock Type ◽  
Correlation Factor ◽  
Point Load ◽  
Load Test ◽  
Point Load Index ◽  
Bonded Particles ◽  
The One

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.

scholarly journals Point Load Test of Half-Cylinder Core Using the Numerical Model and Laboratory Tests: Size Suggestion and Correlation with Cylinder Core

2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Fengyu Ren ◽  
Huan Liu ◽  
Rongxing He ◽  
Guanghui Li ◽  
Yang Liu
Keyword(s):  
Numerical Model ◽  
Laboratory Tests ◽  
Failure Load ◽  
Field Tests ◽  
Point Load ◽  
Diameter Ratio ◽  
Load Test ◽  
Index Test ◽  
Point Load Test ◽  
Calculation Procedures

The point load test (PLT) is intended as an index test for rock strength classification or estimations of other strength parameters because it is economical and simple to conduct in the laboratory and in field tests. In the literature, calculation procedures for cylinder cores, blocks, or irregular lumps can be found, but no study has researched such procedures for half-cylinder cores. This paper presents the numerical model and laboratory tests for half-cylinder and cylinder specimens. The results for half-cylinder and cylinder specimens are then presented, analysed, and discussed. A correlation of failure load between half-cylinder and cylinder specimens is established with a suitable size suggestion and correction factor. It is found that the failure load becomes stable when half-cylinder specimens have a length/diameter ratio higher than 0.9. In addition, the results show that the point load strength index (PLSI) of half-cylinder cores can be calculated using the calculation procedures for diametral testing on cylinder cores, and it is necessary to satisfy the conditions that the length/diameter ratio be higher than 0.9 and the failure load be multiplied by 0.8.

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