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Papers by MOHD MUSTAQIM MOHD NORDIN

Journal of Physics: Conference Series, 2019

Shear strength parameter is a crucial in designing the rock mass structures such slope and tunnel... more Shear strength parameter is a crucial in designing the rock mass structures such slope and tunnel. Stability of rock mass structure is affected by apparent joint sets and discontinuities present in the rock mass especially when the joint interfaces degraded and physically altered due to weathering effect. The weathered condition imposed on joint surface importantly play the role to control the shear strength characteristic and sliding behaviour. A comprehensive study and focussing on effect of weathering grade to the rock joint surface particularly for granite type of rock was introduced. A set of granite samples were collected from a quarry then been classified into respective grade of weathering based on surface hardness by using Schmidt rebound hammer and rock material density by using PUNDIT test. The standard laboratory testing of direct shear test that accordance to ISRM suggested method were carried out on jointed block samples with different grades of weathering. Detail asse...

AIP Conference Proceedings, 2018

A review of methods, techniques and approaches on investigation of rock anisotropy

AIP Conference Proceedings, 2017

Slope failures always occur in Malaysia especially during the rainy seasons. They cause damage to... more Slope failures always occur in Malaysia especially during the rainy seasons. They cause damage to properties and fatalities. In this study, a total of 24 one dimensional consolidation tests were carried out on soil samples taken from 16 slope failures in Penang Island and in Baling, Kedah. The slope failures in Penang Island are within the granitic residual soil while in Baling, Kedah they are situated within the sedimentary residual soil. Most of the disturbed soil samples were taken at 100mm depth from the existing soil surface while some soil samples were also taken at 400, 700 and 1000mm depths from the existing soil surface. They were immediately placed in 2 layers of plastic bag to prevent moisture loss. Field bulk density tests were also carried out at all the locations where soil samples were taken. The field bulk density results were later used to re-compact the soil samples for the consolidation tests. The objective of the research is to determine the slow shearing rate to be used in consolidated drained shear box for residual soils taken from slope failures so that the effective shear strength parameters can be determined. One dimensional consolidation tests were used to determine the slow shearing rate. The slow shearing rate found in this study to be used in the consolidated drained shear box tests especially for Northern Malaysian residual soils was 0.286mm/minute.

Rock Mechanics and Rock Engineering, 2015

Your article is protected by copyright and all rights are held exclusively by Springer-Verlag Wie... more Your article is protected by copyright and all rights are held exclusively by Springer-Verlag Wien. This e-offprint is for personal use only and shall not be self-archived in electronic repositories. If you wish to self-archive your article, please use the accepted manuscript version for posting on your own website. You may further deposit the accepted manuscript version in any repository, provided it is only made publicly available 12 months after official publication or later and provided acknowledgement is given to the original source of publication and a link is inserted to the published article on Springer's website. The link must be accompanied by the following text: "The final publication is available at link.springer.com".

Rock Mechanics and Rock Engineering, 2013

ABSTRACT Geophysical site investigation techniques based on elastic waves have been widely used t... more ABSTRACT Geophysical site investigation techniques based on elastic waves have been widely used to characterize rock masses. However, characterizing jointed rock masses by using such techniques remains challenging because of a lack of knowledge about elastic wave propagation in multi-jointed rock masses. In this paper, the roughness of naturally fractured rock joint surfaces is estimated by using a three-dimensional (3D) image-processing technique. The classification of the joint roughness coefficient (JRC) is enhanced by introducing the scan line technique. The peak-to-valley height is selected as a key indicator for JRC classification. Long-wavelength P-wave and torsional S-wave propagation across rock masses containing naturally fractured joints are simulated through the quasi-static resonant column (QSRC) test. In general, as the JRC increases, the S-wave velocity increases within the range of stress levels considered in this paper, whereas the P-wave velocity and the damping ratio of the shear wave decrease. In particular, the two-dimensional joint specimen underestimates the S-wave velocity while overestimating the P-wave velocity. This suggests that 3D joint surfaces should be implicated to obtain the reliable elastic wave velocity in jointed rock masses. The contact characteristic and degree of roughness and waviness of the joint surface are identified as a factor influencing P-wave and S-wave propagation in multi-jointed rock masses. The results indicate a need for a better understanding of the sensitivity of contact area alterations to the elastic wave velocity induced by changes in normal stress. This paper’s framework can be a reference for future research on elastic wave propagation in naturally multi-jointed rock masses.

InCIEC 2013, 2014

ABSTRACT Tropical rock weathering caused decomposition and disintegration of granite rock mineral... more ABSTRACT Tropical rock weathering caused decomposition and disintegration of granite rock minerals thus reduces it physical and mechanical properties. The conventional method of characterization and classification of weathered granite becomes a discouraging task due to low sample recovery. A shift to non-destructive technique for characterization of weathered granite by using elastic wave velocity was studied. The deterioration of the quality of weathered granite was defined in term of density as tangible variable. An experimental testing to determine the elastic wave velocity by Free–Free Resonant Column (FFRC) test was introduced and carried out on weathered granite of Grade II, Grade III and Grade IV. The results were compared to the common PUNDIT technique for reliability test. The degree of accuracy of elastic wave velocity by the two test methods showed a good consistency. From the experimental study, an empirical correlation between elastic wave velocity to the density of tropically weathered granite is proposed.

Geotechnical and Geological Engineering, 2022

Characterizing the elastic response from body waves propagating through an interbedded shale-sand... more Characterizing the elastic response from body waves propagating through an interbedded shale-sandstone geological formation with multi-orientation joints and various interlayer ratios is extremely challenging. A laboratory composite model of three layers, i.e., sandstone-shale-sandstone, with multi-angled joint orientations, i.e., 30°, 45°, 60°, and 90°, provides an expressive approach to evaluate the anisotropic behavior of body wave velocities. In this study, body wave velocities were obtained from tests using the Portable Ultrasonic Non-Destructive Indicating Tester and the Free-Free Resonant Column. The anisotropic dynamic responses of the composite model are characterized in comparison to the intact shale and the intact sandstone. Empirically, as the joint orientation approached a perpendicular angle, both velocities of the P-wave (VP) and the S-wave significantly decreased. In comparison, the wave velocity values were reduced by 35% and 66% for VP and VS, respectively, as were the increment angles of joint orientation from 30° to 90°. The anisotropic behavior of wave velocity for the composite model appears to be influenced by the joint orientation rather than the bedded shale interlayer. The increase in elastic modulus and shear modulus values with respect to the increase in interbedded angles indicates that interbedded orientation has a significant influence on the stiffness behavior of the composite model. This result was supported by the decrement of Poisson’s ratio, measured as the increment of the interbedded angle of orientation. The experimental data is then utilized to develop a semi-empirical model to predict the wave velocity at any angle of joint orientation and at any interlayer ratio.