Assessment of Rock Mass Quality and Deformation Modulus by Empirical Methods along Kandiah River, KPK, Pakistan

Abstract

The pivotal aim of this study is to evaluate the rock mass characterization and deformation modulus. It is vital for rock mass classification to investigate important parameters of discontinuities. Therefore, Rock Mass Rating (RMR) and Tunneling quality index (Q) classification systems are applied to analyze 22 segments along proposed tunnel routes for hydropower in Kandiah valley, Khyber Pakhtunkhwa, Pakistan. RMR revealed the range of fair to good quality rocks, whereas Q yielded poor to fair quality rocks for investigated segments of the rock mass. Besides, E m values were acquired by empirical equations and computer-aided program RocLab, and both methods presented almost similar variation trend of their results. Hence, the correlations of E m with Q and RMR were carried out with higher values of the regression coefficient. This study has scientific significance to initially understand the rock mass conditions of Kandiah valley. 948Open Journal of Geology have been conducted by using RMR and Q schemes e.g. [2]-[12]. Among the rock mass parameters, deformation modulus (E m ) has very significance in rock mechanics because it provides the initial idea about mechanical behavior of rock mass before failure. In this regard, there are several direct procedures to determine the deformation modulus in the laboratory, but these methods are costly and time consuming. Therefore, empirical methods have been suggested for indirect estimation of deformation modulus [13] [14]. As a consequence, various researchers [7] [15]-[25] have been proposed different empirical relations for estimation of deformation modulus. Pakistan is facing a serious shortage of electricity, and Government is trying to develop hydropower, especially in Northern Pakistan to overcome the electricity disorder. In this regard, small hydropower is proposed along Kandiah River in Kandiah valley, KPK, Pakistan. Hence, the present study focuses on preliminary rock mass characterization with an assessment of required support and estimation of deformation modulus along proposed tunnel routes. Therefore, to achieve this goal, field observations including geological mapping, discontinuity surveys and sampling were conducted.

Reliable stability analysis of surrounding rock for super section tunnel based on digital characteristics of joint information

“…According to the corresponding relationship of rack mass level between Q and RMR method revised after 1993 as shown in Table 2 (Grimstad and Barton 1993;Cai et al 2010;Akram et al 2018), the surrounding rock is relatively good and rated as level III. However, there were several continuous weak intercalated layers and controlling wide structure planes developed in the excavation face of this tunnel section.…”