Analysis profile of the fully grouted rock bolt in jointed rock using analytical and numerical methods

The purpose of this study was to investigate the effect of bolt profile on load transfer mechanism of fully grouted bolts in jointed rocks using analytical and numerical methods. Based on the analytical method with development of methods, a new model is presented. To validate the analytical model, five different profiles modeled by ANSYS software. The profile of rock bolts T3 and T4with load transfer capacity,respectively 180 and 195 kN in the jointed rocks was selected as the optimum profiles. Finally, the selected profiles were examined in Tabas Coal Mine. FLAC analysis indicates that patterns 6+7 with2 NO flexi bolt 4 m better than other patterns within the faulted zone.

Amperometric Nitrous Oxide Gas Sensor： Preparation ol Cu/PANI/Cu Electrodes and Sensing Behavior

The authors studied the changes in the electrical properties of PANI （polyaniline） when exposed to the presence of N20 （nitrous oxide）. The techniques used to determine the adsorption of gas in the polymer were the electrochemical impedance, steps voltammetry and transmission electron microscopy. The objective of this work was to determine the ability of adsorption and desorption of PANI to be used as sensor in an open environment. Measurements were performed in a controlled atmosphere, temperature and flux. The gas was passed through a glass capsule in which an electrochemical cell was designed with copper electrodes and PANI as electrolyte. The change in electrical properties of the material is analyzed using a potentiostat/galvanostat in situ. Subsequently, the material was analyzed by TEM （Transmission Electron Microscopy） elemental analysis. The measurements were performed with difl^rent concentrations of N20 with a purity of 99%. As a result of measurements, it was found that the change in electrical resistance of PANI is caused by the physical interaction that occurs when in contact with NzO and even a change in the morphology of polymer, however, the binding is weak and sufficient to increase the temperature at which 25% PANI film regains its original properties.

Optimization of the fully grouted rock bolts for load transfer enhancement

The purpose of this study is to investigate the role of bolt profile configuration in load transfer capacity between the bolt and grout.Therefore,five types of rock bolts are used with different profiles.The rock bolts are modeled by ANSYS software.Models show that profile rock bolt T_3 and T_ with load capacity 180 and 195 kN in the jointed rocks,are the optimum profiles.Finally,the performances of the selected profiles are examined in Tabas Coal Mine by FLAC software.There is good subscription between the results of numerical modeling and instrumentation reading such as tells tale,sonic extensometer and strain gauge rock bolt.According to the finding of this study,the proposed pattern of rock bolts,on 7 + 6 patterns per meter with 2 flexi bolt(4 m) for support gate road.

The generation kinetics of natural gases in the Kela-2 gas field from the Kuqa Depression, Tarim Basin, northwestern China

The Kela-2 gas field, found in the Kuqa Depression of the Tarim Basin, northwestern China, is a large-sized dry gas field (C1 /C1-5 =0.992 0.999) and characterized by ultra-high pressure (pressure factor up to 2.0 2.2). The pyrolysis experiment was carried out under isothermal gold-tube closed system, with samples collected from the Jurassic coal, Jurassic mudstone and Triassic mudstone in the Kuqa Depression. The result of gas yield showed that the Middle and Lower Jurassic source rocks have higher gas generation potential than the Triassic source rocks. The kinetic modeling of gas generation and methane carbon isotope fractionation suggested that the Kela-2 gases belong to the products of high-over mature stages and were mainly derived from the Middle and Lower Jurassic coal-bearing strata. The Triassic source rocks made a minor contribution to the Kela-2 gases. The Kela-2 gases chiefly generated from coal-bearing source rocks with R o values from 1.3% to 2.5%, and thus primarily accumulated after 5 Ma.