Fetr6 is an underground mine using the stope-and-pillar mining method. As there was some evidence regarding pillar failure in this mine, improving works such as roof support and replacing existing pillars with concret...Fetr6 is an underground mine using the stope-and-pillar mining method. As there was some evidence regarding pillar failure in this mine, improving works such as roof support and replacing existing pillars with concrete pillars (CP) were carried out. During the construction of the second CP, in the space between the remaining pillars, one of the pillars failed leading to the progressive failure of other pillars until 4 000 m 2 of mine had collapsed within a few minutes. In this work, this phenomenon is described by applying both numerical and empirical methods and the respective results are compared. The results of numerical modelling are found to be closer to the actual condition than those of the empirical method. Also, a width-to-height (W/H) ratio less than 1, an inadequate support system and the absence of a detailed program for pillar recovery are shown to be the most important causes of the Domino failure in this mine.展开更多
The paper aims at proffering a solution for college English who experience a dilemma that they cannot tap their potential fully to improve the effectiveness and efficiency of writing in English. The author recommends ...The paper aims at proffering a solution for college English who experience a dilemma that they cannot tap their potential fully to improve the effectiveness and efficiency of writing in English. The author recommends model thinking which entails habitual application of models and thus formulating a kind of efficient thinking in composing and arranging the existent linguistic and disciplinary resources established in the students' mind as an approach for those students to further their English writing skills.展开更多
文摘Fetr6 is an underground mine using the stope-and-pillar mining method. As there was some evidence regarding pillar failure in this mine, improving works such as roof support and replacing existing pillars with concrete pillars (CP) were carried out. During the construction of the second CP, in the space between the remaining pillars, one of the pillars failed leading to the progressive failure of other pillars until 4 000 m 2 of mine had collapsed within a few minutes. In this work, this phenomenon is described by applying both numerical and empirical methods and the respective results are compared. The results of numerical modelling are found to be closer to the actual condition than those of the empirical method. Also, a width-to-height (W/H) ratio less than 1, an inadequate support system and the absence of a detailed program for pillar recovery are shown to be the most important causes of the Domino failure in this mine.
文摘The paper aims at proffering a solution for college English who experience a dilemma that they cannot tap their potential fully to improve the effectiveness and efficiency of writing in English. The author recommends model thinking which entails habitual application of models and thus formulating a kind of efficient thinking in composing and arranging the existent linguistic and disciplinary resources established in the students' mind as an approach for those students to further their English writing skills.
