Numerical Modeling for Engineering Analysis and Designing of Optimum Support Systems for Headrace Tunnel

Hussain, Sajjad; Rehman, Zahid Ur; Mohammad, Noor; Tahir, Muhammad Usman; Shahzada, Khan; Khan, Sajjad Wali; Khan, Mujahid; Gul, Akhtar

doi:10.1155/2018/7159873

Cited by 17 publications

(12 citation statements)

References 19 publications

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“…Pakistan has approximately 292.2 billion tonnes indicated marble reserves among these 99% exist in Khyber Pakhtunkhwa (KP). The province of Khyber Pakhtunkhwa annually produces about 87% Marble, 1% Granite and 12% slate (Khan, 2017;Rehman et al 2018). Dimension stone reserves of Pakistan are available in a wide range of colors, shades, and patterns.…”

Section: Mitigation Plan For Identified Problems Faced By the Marble mentioning

confidence: 99%

Mitigation Plan for Identified Problems Faced by the Marble Industry in Khyber Pakhtunkhwa

Raza¹,

Jadoon²,

Hussain³

et al. 2020

JEAS

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T he dimension stone industry of Pakistan has potential to impart in uplifting the national Gross Domestic Product (GDP) and produce new opportunities. Due to their attractive appearance and durability, trend in the use of dimension stones is increasing rapidly. The annual increase in use of dimension stone in Pakistan was 6.45% in 1997 which is estimated to grow up to 7.73% in 2025 with an average annual increase of 6.86% (GDM Stone Industries Handbook, 2000). According to an estimate, the world's annual stone production was over 60 million tones with an increase of 5% per year (Rathore et al., 2003) whereas the granite and marble stone production was increased by 12% in 2014 than its production in 2013. The top five producing countries of dimension stone are China, India, Turkey, Iran, and Italy and contributed about 74% of the world's production (U.S. Geological Survey, 2018). Since 1998 till now, China is leading the dimension stone world by sharing 17.87% of the world's production. Italy's share is 10.63%, Germany 7.55% and India 5.75% (Figure 1). Pakistan shares less than 0.50% in the world marble production with an average of 497,317 metric tons per year (Ashmole and Motloung, 2008; GSP Report, 2004), which is not significant and needs to be improved.

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Section: Mitigation Plan For Identified Problems Faced By the Marble mentioning

confidence: 99%

Mitigation Plan for Identified Problems Faced by the Marble Industry in Khyber Pakhtunkhwa

Raza¹,

Jadoon²,

Hussain³

et al. 2020

JEAS

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“…The total length of the 3.7-m wide single headrace tunnel for this project is 3.8 km. The maximum longitudinal section of the headrace tunnel passes through granite rock (2.8 m), followed by quartz mica schist, marble, and calcareous quartzite [36].…”

Section: Projectmentioning

confidence: 99%

An Empirical Approach for Tunnel Support Design through Q and RMi Systems in Fractured Rock Mass

et al. 2018

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Empirical systems for the classification of rock mass are used primarily for preliminary support design in tunneling. When applying the existing acceptable international systems for tunnel preliminary supports in high-stress environments, the tunneling quality index (Q) and the rock mass index (RMi) systems that are preferred over geomechanical classification due to the stress characterization parameters that are incorporated into the two systems. However, these two systems are not appropriate when applied in a location where the rock is jointed and experiencing high stresses. This paper empirically extends the application of the two systems to tunnel support design in excavations in such locations. Here, the rock mass characterizations and installed support data of six tunnel projects are used. The back-calculation approach is used to determine the Q value using the Q-system support chart, and these values are then used to develop the equations and charts to characterize the stress reduction factor (SRF), which is also numerically evaluated. These equations and charts reveal that the SRF is a function of relative block size, strength–stress ratio, and intact rock compressive strength. Furthermore, the RMi-suggested supports were heavier than the actual installed ones. If the approximate inverse relation between stress level (SL) and SRF is used, the difference between the actual and the recommended supports increases when using the RMi-recommended rock support chart for blocky ground. An alternate system is made for support recommendation using a Q-system support chart. In this system, the ground condition factor is modified from the available parameters, and a correlation is developed with a modified Q system.

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“…Unlike single tunnels with a circular or straight wall arch cross section which have been profoundly investigated [2][3][4][5][6][7][8][9], due to its special geometry, the distribution of internal forces of double-arched tunnels has not yet been well understood. Yan et al set up a comprehensive monitoring program at critical sections of a double-arched tunnel to measure the internal forces in both steel arches and secondary linings [10].…”

Section: Introductionmentioning

confidence: 99%

Analytical Solutions for the Mechanical Responses of Shallow Double-Arched Tunnel Subjected to Symmetric Loads

Yang

Dai²,

Ai³

et al. 2021

Advances in Civil Engineering

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Double-arched tunnel is a special kind of tunnel structure which is widely adopted for shallow rock tunnels. The internal forces within a double-arched tunnel are difficult to be determined due to its special geometry and complex interactions with surrounding rock masses. This paper presents a set of analytical solutions for determining the internal forces within the lining structure of shallow double-arched tunnel subjected to symmetric external loads. The double-arched tunnel is decomposed into three main parts, i.e., the arch rings, the side walls, and the middle wall. The force method and the elastic foundation beam model are employed for the arch rings and the side walls, respectively, while the middle wall is treated as a cantilever beam fixed at the bottom. Analytical solutions for the internal forces of the three parts are derived separately, which are continuous at the conjunctions of different parts. The derived analytical solutions are verified by comparing with the FEM simulation results. Finally, parametric studies are performed to investigate the influences of burial depth, elastic resistance coefficient, opening angle, and tunnel span on the internal forces based on which some recommendations are provided for the construction and design of the double-arched tunnels. The derived analytical solutions provide fast estimations for the internal forces and deformation of the double-arched lining structures, which will be a useful tool for design optimization.

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Numerical Modeling for Engineering Analysis and Designing of Optimum Support Systems for Headrace Tunnel

Cited by 17 publications

References 19 publications

Mitigation Plan for Identified Problems Faced by the Marble Industry in Khyber Pakhtunkhwa

Mitigation Plan for Identified Problems Faced by the Marble Industry in Khyber Pakhtunkhwa

An Empirical Approach for Tunnel Support Design through Q and RMi Systems in Fractured Rock Mass

Analytical Solutions for the Mechanical Responses of Shallow Double-Arched Tunnel Subjected to Symmetric Loads

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