Although rock-mass rating (RMR) and tunneling quality index (Q) systems are used in different rock engineering projects as empirical design tools, their application tunnel is widely accepted these were developed updated for this purpose specifically. This paper reviews the work conducted by various researchers since development of two with respect to only. Compared other classification systems, received international acceptance still tools due continuous updates form characterization...

The main aspects that require attention in tunnel design terms of safety and economy are the precise estimation probable ground conditions behavior during construction. variation rock mass due to excavation sequence plays an important role construction stage. purpose this research is numerically evaluate effect on for Lowari project, Pakistan. For stability, observed actual partial face compared with top heading bench sequence. purpose, intact parameters used along characterization joints...

Rockburst is a hazardous phenomenon in deep tunnels influenced by geological structural planes like faults, joints, and shear planes. Small-scale shear-plane-like structures have damaging impact on the boundaries of tunnel, which act as barrier accumulate high stresses. A plane combined with stress conditions very dangerous excavations. Such exposed side wall right headrace tunnel Neelum-Jehlum Hydropower Project. This project constructed tectonically active Himalayas under conditions. The...

The primary output of the rock mass rating (RMR) and tunneling quality index (Q) system is a preliminary tunnel support design, as these methods are empirically developed updated for this purpose. In study, internationally accepted design tools evaluated to improve results design. simplified improved some parameters through use equations replace discrete/lump characterization with continuous rating. Recent developments in used proposing back analysis approach calculation from span installed...

During underground construction, the behavior of ground is influenced by characteristics rock mass with situ stresses and water, cross section excavation area, method, rate excavation. These fundamental features are considered to ensure support stability excavations achieve long-term successful operation. However, composition Himalayas hinders tunnel excavation, especially in case mechanized tunneling; this causes time cost overruns. This study has reviewed recently completed Neelum–Jhelum...

The adsorption equilibria of toluene and gasoline vapors on activated carbon were measured by a static volumetric method. equilibrium experiments conducted at (298.15, 318.15, 338.15, 358.15, 378.15) K pressures up to 3.1 kPa for 8.0 gasoline. experimental data obtained correlated the UNILAN Sips models, which are generally used microporous adsorbents such as carbon. Henry constant was calculated characterize interactions between adsorptive adsorbent.

Empirical classification systems do not provide details of the factors that affect performance fully grouted rock bolts, as they are based on average values. Fully rock-bolt patterns during tunnel-support design a part composite support, and functions rock-mass quality tunnel span. Various bolts used in situ different environments, along with other materials static dynamic environments construction. The performances evaluated through pull-out tests follow ASTM standards. Several field were...

Rockburst is an unstable failure of a rock mass which influenced by many factors. During deep excavations, the presence nearby geological structures such as minor faults, joints, and shear zones increases likelihood rockburst occurrence. A zone has been observed in headrace tunnel Neelum Jhelum Hydropower Project, Pakistan, played important role major events project’s history. seismic event that involves release great amount energy dynamic wave radiated from source reaches excavation...

Rockburst is a hazardous phenomenon in deep tunnels influenced by geological structural planes like faults, joints, and shear planes. Small-scale shear-plane-like structures have damaging impact on the boundaries of tunnel, which accumulate high stresses. Such plane was exposed side wall right headrace tunnel Neelum-Jehlum Hydropower Project. This project constructed tectonically active Himalayas with stress conditions. A combined conditions very dangerous excavations. The influence zone...

The utility tunnels used for electricity transmission are in high demand these days. literature presents many limitations the currently cutterhead drive design procedure while using a shield tunnel boring machine (TBM) excavation of relatively small diameter tunnels. In order to develop an appropriate method specially drive, experimental data obtained through operation 3560 mm TBM were this research work. For purpose, earth pressure balance (EPB) was manufactured and facility established...

In multi-arch tunnels, the increased rock load on concrete lining of main tunnel and side walls due to excavation adjacent tunnels is critical must be considered in design stage. Therefore, this study estimates a using two-dimensional numerical analysis, considering mass classifications, overburden, construction steps. The estimated two criteria: factor safety stress variable. underestimated when applied class III. However, variable method reveals reasonable as overburden increases....

The adsorption kinetics and equilibria of N2 CH4 in pelletized zeolite 4A, 5A CaX were studied theoretically experimentally at the range 273–293 K 0.0–0.8 atm. Using isothermal nonisothermal rate models, diffusion mechanism was investigated from experimental uptake curves through a gravimetric method. While rates controlled by micropore they significantly affected macropore 5A. In case CaX, controlling changed to as pressure increased. N2/4A system faster than that CH4/4A due sieving effect...

Empirical systems for the classification of rock mass are used primarily preliminary support design in tunneling. When applying existing acceptable international tunnel supports high-stress environments, tunneling quality index (Q) and (RMi) that preferred over geomechanical due to stress characterization parameters incorporated into two systems. However, these not appropriate when applied a location where is jointed experiencing high stresses. This paper empirically extends application...

This study focuses on evaluating the engineering properties of three types geogrids (warp knitted, woven, and membrane drawn geogrid). Short-term tensile geogrid showed very low elongation results compared to other types. However, estimated long-term creep deformation indicated that 30 % Tult loading level was optimum value satisfied criteria in case (60 warp knitted 65 woven The durability test had good resistance installation damage, chemical, biological ultraviolet with textile type...

Mechanical methods of tunnel excavation are widely used because their high output, and the selection appropriate technology depends on ground composition project-related features. Compared with boring machines (TBMs) roadheaders, mechanical pre-cutting in widening have proven to be reliable capacity expansion. other machines, characteristics not systematically analyzed rare use. In this study, a machine laboratory based linear cutting tests performed four rock specimens different uniaxial...

Owing to several advantages, mechanical pre-cutting techniques were first introduced in the United States and subsequently used Europe for tunneling. Pre-cutting machines perform excavation tunneling using cutting tools such as tunnel boring (TBMs) roadheaders. Linear tests are reliable widely predict performance of TBMs In this study, effect tool shape a machine was analyzed linear tests. Assuming basic tool, clearance rake angles designated variables that determine shape. The experimental...

Most of the tunnel excavation methods involve use explosion and vibration techniques that is not feasible in urban areas due to unavoidable production noise, vibration, dust. The environmental considerations tunneling projects demand which minimum dust produced. In this study, non-vibrational rock splitting method introduced involves fragmentation segments using a split-wedge system inserted into already drilled boreholes. main objective study investigation important parameters involved for...

In extensively used empirical rock-mass classification systems, the rating (RMR) and tunneling quality index (Q) system, quality, tunnel span are for selection of rock bolt length spacing shotcrete thickness. both thickness based on same principle, which is back-calculation quality. For back-calculation, there no criterion rock-bolt-spacing-based weightage along with tunnel-span-based weightage. To determine this effect during five cases selected, explained through example, applied using...

There are two primary causes of the ground movement due to tunnelling in urban areas; firstly lost and secondly groundwater depression during construction. The was usually not considered as a cause settlement previous research works. main purpose this study is analyze combined effect these phenomena on transverse trough. Centrifuge model tests numerical analysis were primarily selected methodology. characteristics trough analyzed by performing centrifuge where acceleration reached up 80g...

A smart geotextile for hydraulic end-use applications, such as filtration and drainage, has been manufactured. For biodegradable prefabricated vertical drains (PVDs) were fabricated using special conditioned filter plastic cores to improve their degradability. Aliphatic polyester-based PVDs showed higher tensile strengths than starch-based PVDs. Biodegradable lower properties normal PVDs, however, the magnitude of difference was not large. In terms chemical resistance biodegradation, better...