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A preliminary support design is the basic output of an empirical rock mass classification system. Tunneling quality index (Q) and rock mass rating (RMR) systems are used specifically for tunnel support in moderately jointed and massive rocks; however, they do not provide any information/guidance for jointed rock masses in a highly stressed environment. Hence, this study focuses on the already supported drill and blast tunnel sections mapping data of four tunneling projects in Pakistan. The study extends the application of these systems to the tunnel support design for highly stressed jointed rock mass through an empirical approach. In each empirical approach, the parameters for the stress condition are suggested. Rock mass quality (Q or Qc) is determined from back calculations using an installed support and tunnel span. Empirical equations and charts are proposed for the stress reduction factor (SRF) characterization. In the proposed equations and charts, the SRF is a function of intact rock strength, relative block size, and strength–stress ratio. In the case of the RMR system, approximately 90% of the sections show that the actual supports are heavier than the suggested supports by RMR89. The RMR was determined from the installed support for each tunnel section through the back calculations. To select the adjustment rating factor for stress, three hypotheses are considered based on the intact rock strength to the major principal stress ratio. The RMR14 suggested support revealed that all sections are heavily supported. A strong correlation exists between RMR89 and RMR14. Three hypotheses are considered for the stress adjustment factor rating selection for RMR14 based on the correlation equation between RMR89 and RMR14. For the evaluation, the application of modified Q and RMR systems are used in the tunnel support in a case study. The exploration reports show that the tunnel will pass through a jointed rock mass under high in-situ stress environments. The comparison shows that heavy support is recommended from the modified systems for tunnel stability.

The utility tunnels used for electricity transmission are in high demand these days. The literature presents many limitations in the currently used cutterhead drive design procedure while using a shield tunnel boring machine (TBM) for the excavation of these relatively small diameter tunnels. In order to develop an appropriate design method specially for cutterhead drive, experimental data obtained through the operation of a 3560 mm diameter shield TBM were used in this research work. For experimental purpose, an earth pressure balance (EPB) shield TBM was manufactured and a facility was established for performing the full-scale tunneling tests. Numerous tests were performed through the variation of TBM operational parameters such as thrust force and the rotational speed of the cutterhead at four UCS (Uniaxial compressive strength) levels of artificial rock mass. The relationships between thrust force and torque were mainly established and the effects of UCS and rotational speed of cutterhead on these relationships are analyzed through a representative case of 100 MPa UCS. A novel torque estimation method is also presented in this study which can be conveniently used in the cutterhead drive design while using small diameter shield TBMs.

Objective. Attempts to understand the emotion have evolved from the perspective of an independent cognitive system of the mind to that of an interactive response involving the body. This study aimed to quantify and visualize relationships between different emotions and bodily organ systems from the perspective of East Asian medicine. Methods. Term frequency-inverse document frequency (tf-idf) method was used to quantify the significance of Five Viscera and the gallbladder relative to seven different emotions through the classical medical text of DongUiBoGam. Bodily organs that corresponded to different emotions were visualized using a body template. Results. The emotions had superior tf-idf values with the following bodily organs: anger with the liver, happiness with the heart, thoughtfulness with the heart and spleen, sadness with the heart and lungs, fear with the kidneys and the heart, surprise with the heart and the gallbladder, and anxiety with the heart and the lungs. Specific patterns between the emotions and corresponding bodily organ systems were identified. Conclusion. The present findings will further the current understanding of the relationship between the mind and body from the perspective of East Asian medicine. Western medicine characterizes emotional disorders using “neural” language while East Asian medicine uses “somatic” language.

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&ndash, 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.

The non-open-cut method is used for constructing tunnels under existing roads without blocking traffic. Various non-open-cut methods use pipe roofs made of medium- and large-diameter steel pipe piles. However, the risk of ground settlement or heave is involved during the application of such piles. Therefore, research is conducted through model tests and numerical analysis on the non-open-cut method to investigate these problems using small-diameter piles. The progress of tunnel construction is divided into two repetitive steps. The first step (Stage 1) involves pulling back the pressure panel, and the second step involves propelling the precast structure (Stage 2). The behaviors of the pipe piles and ground displacement are analyzed according to the cover depth, tunnel size, existence and nonexistence of the shoe structure, and progress of tunnel construction. Small-diameter piles reduce the displacement during both stages. With a decrease in cover depth, the stress acting on the pile decreases during Stage 1 and increases during Stage 2. The presence of the shoe structure reduces the stress on the pile during both stages. The ground behavior based on the construction progress indicates that the ground settlement increases during Stage 1, however, no correlation is observed during Stage 2 at low depth.

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 and updated for this purpose. In this study, these internationally accepted design tools are evaluated to improve results for tunnel support design. The rating system is simplified and improved for some parameters through the use of equations to replace the discrete/lump characterization with a continuous rating. Recent developments in characterization and support are used in proposing the back analysis approach of rock mass quality calculation from tunnel span and installed support. This approach is used for two tunnel projects which experience high stresses. Approximately 90% of the tunnel sections show that actual supports have rock bolt spacing and shotcrete thickness which are heavier than those indicated by RMR89, indicating a system limitation. Another assessment using RMR14 indicates that its rating is higher than that of RMR89. A strong correlation exists between them, as supported by the literature and data from analyses of 462 tunnel sections. Despite its new version, RMR89 still preserves its importance. Evaluating the different correlations between RMR and Q through published data indicates that the rock mass fabric index gives comparatively better results.

The purpose of this study is to analyze the structural performance of the lining according to the magnitude as well as shape of rock load. Four cases of rock load shape were applied on the final lining (concrete lining) to perform structural analysis using beam spring model. This study includes two contents; firstly, the stability of the lining was analyzed using capacity diagrams. Secondly, the serviceability of the lining was analyzed using the cracked hinge model. While assessing the stability of the lining, FS = 2.45 was used according to LRFD specifications. The stress-crack opening relationship, represented by g(w) function, was used to assess the serviceability of the lining. The critical parameters used in this study are the K0 condition, load direction and application of the wedge load. Based on the results obtained after analysis, it was concluded that the K0 condition could change the thrust force-bending moment relationship which affects the stability and serviceability of the lining. Rock load in vertical direction affected the lining more than that in horizontal direction. Lastly, the development of wedge load proved to be more adverse than the application of larger uniform rock load on the lining.

A ground load prediction method is suggested herein based on the deterioration of the primary support during its durable life. This study includes two contents; firstly, the real behavior of primary support was evaluated and secondly, it was used to propose back analysis procedure based on measurement data. To predict the ground load acting on the primary support, it is important to estimate the real behavior of shotcrete and steel sets by performing experiments. Thus, large-scale experiments were performed on archshaped specimens, combining the application of axial forces and bending moments. The results show that shotcrete can resist only axial forces but steel sets can withstand both axial and flexural loads. Based on these results, back analysis was performed to predict ground load, using the measurement data from a domestic construction site. Compared to other widely used methods, the proposed method predicts 21% to 51% smaller ground load values in different zones. Because the proposed method predicted different ground loads in the same ground conditions, it was deduced that these ground load values were more realistic than the previously predicted results.

The present study concerns the leaching of alkali ions in terms of leaching capacity and leaching rate. Tests were performed in two conditions: air-tight and aerated. As a result, it was found that the leaching capacity was strongly dependent on binder type rather than the W/C. 30% PFA and 60% GGBS had lower leaching capacity, compared to OPC. The pH of media was crucial to leaching rate. At 11.4 and 12.4 in the pH, alkali metallic and hydroxyl ions are mainly extracted from the specimen respectively. The alkali leaching converted the pH profile in the cement matrix. After the alkali leaching, the pH in the vicinity of the surface was even lower than in the inner matrix, where no influence of leaching reached. In an aerated condition, the pH of media was increased initially within several hours, but decreased to 8.31–9.08, presumably due to a precipitation of leached ions.

The present study concerns the immobilisation of hexavalent chromium (Cr (VI)) ions in the cement matrix. Both the water-soluble and acid-soluble Cr (VI) ions in cement were measured using the spectrophotometer. As a result, the concentration of water-soluble Cr (VI) in cement ranged from 12.3 to 19.0 mg/kg-cem, and the dissolution of acid soluble Cr (VI) was strongly dependent on the pH of solvent, ranging from 172.4 to 318.2 mg/kg-cem. Simultaneously, the influence of cement hydration on the Cr (VI) solubility was investigated. After a cement hydration for 28 days, the water-soluble Cr (VI) was sharply decreased to about 2.0 mg/kg-cem, whilst no particular change in the acid-soluble Cr (VI) was observed. The reduction of water-soluble Cr (VI) may be attributed to a physical adorption of Cr (VI) ions in the cement matrix then to immobilise them, rather than chemical reaction with C3A or ettringite, being postulated in previous studies.

Empirical classification systems do not provide details of the factors that affect the performance of fully grouted rock bolts, as they are based on average values. Fully grouted rock-bolt patterns during tunnel-support design are a part of the composite support, and they are functions of rock-mass quality and tunnel span. Various fully grouted rock bolts are used in situ in different environments, along with other tunnel-support materials in static and dynamic environments during tunnel construction. The rock-bolt performances are evaluated through pull-out tests that follow ASTM standards. Several field pull-out tests were conducted on cement and resin grouted rock bolts. Under groundwater flow conditions, inflated steel tube rock bolts were tested and the results were compared with fully grouted rock bolts. Based on field experiments and previous studies, the factors that affect rock bolt performances are divided into five groups with respective sub-factors. Natural parameters cannot be controlled to ensure safety, economy, and stability in tunnels. The controllable factors, too, can be varied only within a practical range. In conclusion, the factors investigated here should be considered with the empirical support pattern of rock-mass classification systems for safe and economical design.

Rockburst is an unstable failure of a rock mass which is influenced by many factors. During deep excavations, the presence of nearby geological structures such as minor faults, joints, and shear zones increases the likelihood of rockburst occurrence. A shear zone has been observed in the headrace tunnel in the Neelum Jhelum Hydropower Project, Pakistan, which has played an important role in major rockburst events in the project&rsquo, s history. A rockburst is a seismic event that involves the release of a great amount of energy as the dynamic wave radiated from the seismic source reaches the excavation boundary. In this paper, the FLAC 2D explicit numerical code has been used to simulate the dynamic phenomenon of rockburst near the shear zone in a headrace tunnel. The behavior of the rock mass around the tunnel has been studied under both static and dynamic loading. According to modeling results, rockburst significantly affected the upper left quadrant of the tunnel similar to the actual failure profile with a depth of approximately 5 m. The dynamic impact of rockburst has also affected the loading conditions of the support system in the adjacent tunnel. This study elucidates one of the most important rockburst controlling factors through numerical analysis and recommends yielding support measures that can withstand the dynamic impacts of rockburst in deep, hard rock tunnels.

After studying the characteristics of three different evaluation methods of rock load; namely theoretical method, empirical method and numerical method, there were too many limitations for them to be applied on tunnels. Therefore, in this research paper, the method based on numerical analysis is selected to use as this method is the most reasonable one since it considers all parameters that are necessary for rock load estimations, and it also considers the interaction between ground and tunnel support. The critical shear strain concept formulated by Sakurai (1981) was used in order to measure exact rock load values based on numerical analysis. Evaluation on a Level 1 rock load height, which is depicted by the stable region in the graph shows that rock load is not affecting between ground grade 1~3, and it was evaluated that the fourth and fifth grades show less values of rock load height which led to the conclusion of a more economical design of concrete lining.

This study attempts to examine how students participate and interact in different discussion modules organized with different group size in an online environment. It adopts a case study methodology where full semester online course with two small-group and three class-wide discussion forums was examined. The researcher counted the number of messages and hits (i.e. the number of students' clicks on other messages) and analyzed that to classify the level of interactivity of every individual message into four categories, i.e. independent, quasi-interactive, interactive (elaborative) and interactive (negotiating). It found that the class guidelines and active encouragement by the instructor had contributed to the high number of total messages and hits representing students' overall participation in all discussion forums. However, large discussion forums in the course had their limitations in promoting higher level of interactivity among the students. On the other hand, two small-group discussion forums had a higher number (by 21%) of enhanced interactivity (elaborating and negotiating mode). The study then concludes that a high quality participation in a large online class could be effected through sub-grouping. It further alludes that other practices should be taken into consideration to promote interactivity in discussion.

This study it to verify the validity of Korean version of DELES (distance education learning environment survey) and analyze its relationship with learning achievement and distance education satisfaction. The target population of this study is students of K cyber university and a total of 254 cases are used for the analysis. Exploratory and confirmatory factor analysis is applied to verify 6 factors of DELES and structural equation analysis is applied to examine the relationship between distance education learning environment and learning achievement and distance education satisfaction. The study result shows that DELES is composed of six factors such as instructor support, student interaction & collaboration, personal relevance, authentic learning, active learning and student autonomy and its model fits are appropriate. The result of structural equation analysis shows distance education learning environment significantly influences distance education satisfaction directly as well as indirectly mediated by learning achievement. Learning achievement also significantly influences distance education satisfaction. Conclusions and implications are followed.

The aim of this study is to evaluate the cytotoxic and antiproliferating effects of intravenous anesthetics on an mouse fibroblast in vitro cell culture system. The cells were exposed to the usual clinical plasma concentration of intravenous anesthetics, i.e., midazolam (0.15 μg/ml), propofol (2 μg/ml), remifentanil (2 μg/ml), thiopental (10 μg/ml), for 4, 8, or 24 h. Cell proliferation (n = 6 for each) under intravenous anesthetics was analyzed using the MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay. Cytotoxicity (n = 6 for each) of intravenous anesthetics was investigated using a LIVE/DEAD viability assay kit. Intravenous anesthetic exposure time did not affect the proliferation rate of mouse fibroblasts. The cytotoxicity of intravenous anesthetics did not differ in accordance with exposure time. Our results showed that intravenous anesthetics may not affect mouse fibroblast proliferation and viability.

There are many factors that influence distance learning especially in higher education where collaborative and communicative discourse is necessary for pursuing knowledge. Social presence, among other factors, is an important concept to be facilitated, developed and sustained in distance higher education as it promotes and supports discourse based learning. This study examines the relationship among demographic and other variables, social presence and learning satisfaction. Results showed demographic variables, such as gender, online learning experience and work status were not significant factors in terms of influencing on either social presence or learning satisfaction. While media integration and instructor's quality teaching were significant predictors of both social presence and learning satisfaction, interactivity among participants was a predictor of social presence but not of learning satisfaction. Along with the study findings, some implications were discussed for online learning practitioners in higher education setting.

Although rock-mass rating (RMR) and tunneling quality index (Q) systems are used in different rock engineering projects as empirical design tools, their application in tunnel design is widely accepted as these systems were developed and updated for this purpose specifically. This paper reviews the work conducted by various researchers since the development of these two systems with respect to tunneling only. Compared to other empirical classification systems, these systems received international acceptance and are still used as empirical design tools in tunneling due to their continuous updates in the form of characterization and support. As the primary output of these systems is the initial support design for tunnel, however, their use in the calculation for rock-mass properties is an essential contribution of these systems in rock engineering design. Essential for the tunnel design, these rock-mass properties include the modulus of deformation, strength, Poisson’s ratio, Mohr-Coulomb parameters and Hoek-Brown constants. Other application for tunneling include the stand-up time and rock load. The uses and limitations of these systems as empirical tunnel design tools are also included in this review article for better results. Research to date indicates that if the ground behavior is also taken into account, the application of these empirical systems will be more beneficial to the preliminary design of tunnels.

The demand for a net protection system for mitigating debris flow has increased recently for which new energy absorption devices have been hereby developed. The purpose of this study is to analyze the behavior and energy absorption rate of a brake frame, to find an efficient approach for its numerical simulation, and to increase its field applicability by analyzing its effects. Three methodologies were used for this purpose. Firstly, quasi-static load tests were conducted for analyzing the behavior of the brake frame. Secondly, three-dimensional FE modeling was performed to analyze the buckling and fractural behavior of steel rings. Lastly, the effects of the brake frame were numerically analyzed based on a proposed equivalent model. The results show that the brake frame can withstand the external force by elastic/local buckling, fracture of a steel ring, and elastic/plastic behavior of wire rope, and has the energy absorption rate of 53 kJ. It is deduced that the proposed equivalent model is capable to accurately simulate the behavior of the brake frame and can replace the three-dimensional model. The tensile force reduction in the system by using brake frames was observed to be about 75%. It is concluded that the proposed equivalent model for brake frame design is practically applicable.

The physicochemical properties of the potent reversible proton pump inhibitor YJA20379-8, 3-butyryl-4-[(R)-1-methylbenzylamino]-8-ethoxy-1,7-naphthyridine, were studied. YJA20379-8 is essentially nonhygroscopic pale yellowish crystalline powder. It is practically insoluble in water, and its lipid solubility is high. The pH solubility profile exhibits an L-shaped curve, indicating YJA20379-8 is a basic substance having a soluble ionized form in acidic conditions. This is consistent with the result of an experiment to determine pKa. The solid-state stability study shows that YJA20379-8 is stable at various temperatures and humidities, but is decomposed by light.