The finite element method is used to simulate the rectification process of shield machine, to study the relationship between rectification moment and angle and to explore the influence laws of different soil parameter...The finite element method is used to simulate the rectification process of shield machine, to study the relationship between rectification moment and angle and to explore the influence laws of different soil parameters and buried depth on rectification moment. It is hoped that the reference value of rectification moment can be offered to operator, and theoretical foundation can be laid for future automatic rectification technology. The results show that the rectification moment and angle generally exhibit good linear behavior in clay layers with different soil parameters or buried depths, and then the concept of rectification coefficient, that is, the ratio of rectification angle to rectification moment, is proposed; different soil parameters and buried depths have different influences on rectification coefficient, in which elastic modulus has great influence but others have little influences; the simulations of rectification process are preformed in clay layers with different elastic modulus, and fitting results show that elastic modulus and rectification coefficient present the quadratic function relation.展开更多
Several malfunctions of the shield tunneling machine （STM） caused by structural interference have been encountered in actual tunnel excavation. This paper is focusing on providing an effective method to avoid the st...Several malfunctions of the shield tunneling machine （STM） caused by structural interference have been encountered in actual tunnel excavation. This paper is focusing on providing an effective method to avoid the structural interference based on making the reachable and the required workspaces of the thrust system match each other. The main structure of the thrust mechanism is analyzed, and coordinate systems are built up to describe the pose and workspace of the thrust mechanism. Constraint conditions are derived and the formulation of each constraint condition is carried out to facilitate the analysis of the reachable workspace of the thrust mechanism. Meanwhile, a reachable workspace determination algorithm is introduced based on interval analysis method. The mathematical model for determining the required workspace of the thrust mechanism is presented based on the analysis of the process when the STM excavates along a specific tunnel axis. Two applications are included to show how to avoid these problems by choosing reasonable parameters of the designed tunnel axis and the key structural parameters of the thrust mechanism based on workspace matching.展开更多
基金Project(2007CB714006)supported by the National Basic Research Program of China
文摘The finite element method is used to simulate the rectification process of shield machine, to study the relationship between rectification moment and angle and to explore the influence laws of different soil parameters and buried depth on rectification moment. It is hoped that the reference value of rectification moment can be offered to operator, and theoretical foundation can be laid for future automatic rectification technology. The results show that the rectification moment and angle generally exhibit good linear behavior in clay layers with different soil parameters or buried depths, and then the concept of rectification coefficient, that is, the ratio of rectification angle to rectification moment, is proposed; different soil parameters and buried depths have different influences on rectification coefficient, in which elastic modulus has great influence but others have little influences; the simulations of rectification process are preformed in clay layers with different elastic modulus, and fitting results show that elastic modulus and rectification coefficient present the quadratic function relation.
基金supported by the National Natural Science Foundation of China (Grant No. 51605071)National Basic Research Program of China (Grant No. 2013CB035400)the special grade of the China Postdoctoral Science Foundation (Grant No. 2016T90218)
文摘Several malfunctions of the shield tunneling machine （STM） caused by structural interference have been encountered in actual tunnel excavation. This paper is focusing on providing an effective method to avoid the structural interference based on making the reachable and the required workspaces of the thrust system match each other. The main structure of the thrust mechanism is analyzed, and coordinate systems are built up to describe the pose and workspace of the thrust mechanism. Constraint conditions are derived and the formulation of each constraint condition is carried out to facilitate the analysis of the reachable workspace of the thrust mechanism. Meanwhile, a reachable workspace determination algorithm is introduced based on interval analysis method. The mathematical model for determining the required workspace of the thrust mechanism is presented based on the analysis of the process when the STM excavates along a specific tunnel axis. Two applications are included to show how to avoid these problems by choosing reasonable parameters of the designed tunnel axis and the key structural parameters of the thrust mechanism based on workspace matching.
