Search published articles


Showing 3 results for Point Load

Dr Ali M. Rajabi, Alireza Hossini, Alireza Heidari,
Volume 11, Issue 3 (1-2018)
Abstract

In many rock engineering projects, accurate identification of rock strength properties is very important. Uniaxial compressive strength is one of the most important features to describe the resistive behavior of rocks which is used as an important parameter in the design of structures especially underground openings. Determination of this parameter using direct methods, including uniaxial compressive strength tests is costly and time-consuming, and also sometimes preparation of standard samples in many rocks is difficult. In such cases, the implementation of some simple and non-destructive tests and using empirical relations can increase the evaluation speed and reduce costs. These relations even regional or local (For example within a geological formation or a single lithology) can help in the estimation of these parameters in order to be used in geotechnical projects. In this study, samples of existing limestones in south west of Tehran (Capital of Iran) were prepared and uniaxial compressive strength, point load, Schmidt hammer and Shear wave velocity tests on which have been performed. Then by the statistical evaluations of the results, the empirical relations between uniaxial compressive strength and the results of other tests are obtained. The comparison between the predicted and observed values of uniaxial compressive strength represents the validity of obtained empirical relations. The application of the proposed relations for limestones in the study area and those with similar geological conditions will provide acceptable results.
Mojtaba Rahimi Shahid, Gholam Reza Lashkaripour, Naser Hafezi Moghaddas,
Volume 19, Issue 6 (12-2025)
Abstract

The Sanandaj–Sirjan Structural-Sedimentary Zone is one of the most important geological regions in Iran, where the limestone formations play a key role in civil engineering and mining projects. Precise knowledge of the mechanical properties of these rocks, especially the Uniaxial Compressive Strength (UCS Dry) and the Dry Point Load Index (Is ₅₀-Dry), is essential for the safe and economical design of structures. Due to the high cost and time-consuming nature of direct testing methods, this study employs indirect modeling techniques, including regression and neural networks, to predict these properties.Initially, a comprehensive database was compiled by collecting physical, mechanical, dynamic, and chemical data of limestone samples from the region. Then, univariate, bivariate, and multivariate regression analyses were conducted to extract statistical relationships among the variables. Subsequently, multilayer perceptron neural network models with various architectures based on the Levenberg–Marquardt learning algorithm were developed. The comparison results of model performance indicated that neural networks, due to their ability to identify complex and nonlinear relationships between parameters, provide more accurate predictions of the limestone mechanical properties compared to statistical models. A comparison of the correlation coefficients of multivariate regression equations and neural network models showed that, overall, using neural network models improves the accuracy of UCS Dry predictions by 14.89% and the Is ₅₀-Dry predictions by 4.70%. The application of these models can contribute to cost reduction, increased speed of rock engineering studies, and improved safety in civil projects.
 


Page 1 from 1     

© 2025 CC BY-NC 4.0 | Journal of Engineering Geology

Designed & Developed by : Yektaweb