Japan is a mountainous country comprising several islands,in which mountains occupy 70%of the entire land.Therefore,numerous transmission line towers have been constructed in the shallow space of steep mountainous are...Japan is a mountainous country comprising several islands,in which mountains occupy 70%of the entire land.Therefore,numerous transmission line towers have been constructed in the shallow space of steep mountainous areas.In such construction,monorails and/or cableways are generally used to transport materials and equipment to the construction site instead of using a construction road,as the former method is more economically viable.However,with this method,drill rigs or vertical shaft sinking machines cannot be transported to the site.Four small-diameter vertical shafts of 2.5 or 3.0 m as the foundation for high-voltage transmission line towers in mountainous areas are traditionally constructed manually in Japan.Over the past two decades,however,dangerous and poor environmental conditions for workers regarding the manual construction of these small-diameter vertical shafts have become a major problem.Meanwhile,owing to the poor environmental conditions of small-diameter vertical shafts to be constructed in the shallow space of steep mountainous areas,a decrease has occurred in the number of young workers entering these projects.Namely,the construction of transmission line towers with using the manually traditional small-diameter vertical shafts is becoming difficult in Japan from abovementioned problems.Hence development of a new technology to solve the problems is necessary for Japan’s economic growth.With this knowledge,the authors have developed a new small-diameter vertical shaft construction system,in which workers do not have to enter the vertical shaft during construction,as machines are used instead.The applicability of the proposed system was confirmed by means of the construction of three actual vertical shafts at two construction sites,as well as in factory and field tests.The applicability and details of the final proposed system are summarized in this paper.展开更多
The damage of the overburden is a complex nonliear mechanical problem. To immediately master the stress state of the vertical shaft in process of the damage of overburden, and protect the shaft, in this paper, a serie...The damage of the overburden is a complex nonliear mechanical problem. To immediately master the stress state of the vertical shaft in process of the damage of overburden, and protect the shaft, in this paper, a series of new type of rock mass stress and strain compatible sensors are used. The vertical shaft wall mechanical parameter and surrounding mechanical parameter are calculated by the result of the measurement. A set of the calculation method of the vertical shaft and surrounding rock parameter are defined.展开更多
Vertical shaft is main form of drivage in deep mineral depoist. They also serve as the entrance into and the exit from the underground mine. The main problems in shaft and tunnel engineering is to solve the contradict...Vertical shaft is main form of drivage in deep mineral depoist. They also serve as the entrance into and the exit from the underground mine. The main problems in shaft and tunnel engineering is to solve the contradiction between drivage and lining. The measurement of blasting vibration affecting concrete lining strength of vertical shaft is carried out in experiment and theory in this paper.展开更多
The creep fracture damage model of jointed rock mass is proposed, the basic methods and properties of engineering structure forecast analysis in split surrounding rock mass is discussed, numericalized way is analyzed,...The creep fracture damage model of jointed rock mass is proposed, the basic methods and properties of engineering structure forecast analysis in split surrounding rock mass is discussed, numericalized way is analyzed, and the computing program of RCFD rock mechanics problems known is modified.Moreover, this program is used to make practical forecast analysis for the stability of surrounding rock mass of one large section (vertical)shaft which is buried in the earth 300 m deep.展开更多
文摘Japan is a mountainous country comprising several islands,in which mountains occupy 70%of the entire land.Therefore,numerous transmission line towers have been constructed in the shallow space of steep mountainous areas.In such construction,monorails and/or cableways are generally used to transport materials and equipment to the construction site instead of using a construction road,as the former method is more economically viable.However,with this method,drill rigs or vertical shaft sinking machines cannot be transported to the site.Four small-diameter vertical shafts of 2.5 or 3.0 m as the foundation for high-voltage transmission line towers in mountainous areas are traditionally constructed manually in Japan.Over the past two decades,however,dangerous and poor environmental conditions for workers regarding the manual construction of these small-diameter vertical shafts have become a major problem.Meanwhile,owing to the poor environmental conditions of small-diameter vertical shafts to be constructed in the shallow space of steep mountainous areas,a decrease has occurred in the number of young workers entering these projects.Namely,the construction of transmission line towers with using the manually traditional small-diameter vertical shafts is becoming difficult in Japan from abovementioned problems.Hence development of a new technology to solve the problems is necessary for Japan’s economic growth.With this knowledge,the authors have developed a new small-diameter vertical shaft construction system,in which workers do not have to enter the vertical shaft during construction,as machines are used instead.The applicability of the proposed system was confirmed by means of the construction of three actual vertical shafts at two construction sites,as well as in factory and field tests.The applicability and details of the final proposed system are summarized in this paper.
文摘The damage of the overburden is a complex nonliear mechanical problem. To immediately master the stress state of the vertical shaft in process of the damage of overburden, and protect the shaft, in this paper, a series of new type of rock mass stress and strain compatible sensors are used. The vertical shaft wall mechanical parameter and surrounding mechanical parameter are calculated by the result of the measurement. A set of the calculation method of the vertical shaft and surrounding rock parameter are defined.
文摘Vertical shaft is main form of drivage in deep mineral depoist. They also serve as the entrance into and the exit from the underground mine. The main problems in shaft and tunnel engineering is to solve the contradiction between drivage and lining. The measurement of blasting vibration affecting concrete lining strength of vertical shaft is carried out in experiment and theory in this paper.
文摘The creep fracture damage model of jointed rock mass is proposed, the basic methods and properties of engineering structure forecast analysis in split surrounding rock mass is discussed, numericalized way is analyzed, and the computing program of RCFD rock mechanics problems known is modified.Moreover, this program is used to make practical forecast analysis for the stability of surrounding rock mass of one large section (vertical)shaft which is buried in the earth 300 m deep.
