The loads acting on shield tunneling machines are basic parameters for the equipment design as well as key control parameters throughout the entire operation of the equipment. In the study, a mechanical analysis for t...The loads acting on shield tunneling machines are basic parameters for the equipment design as well as key control parameters throughout the entire operation of the equipment. In the study, a mechanical analysis for the coupled interactive system between the cutterhead and the ground at the excavation face is conducted. The normal and tangential loads acting on the cutterhead are decoupled and solved, with consideration of the influence of three key factors on loads: geological condition, operating status and equipment structure. Then analytical expressions for the thrust and the torque acting on the equipment under uniform geological condition are established. On this basis, the impact of soil-rock interbedded ground on acting loads is further considered. A theoretical model for loads prediction of earth pressure balance (EPB) shield machines working under soil-rock interbedded ground is proposed. This model is subsequently applied to loads prediction for a shield tunneling project under soil-rock interbedded ground. The computational value of the thrust and the torque, the measured loads and the load ranges from Krause empirical formula are compared. Thus, this model for loads prediction acting on shield tunneling machines under soil-rock interbedded ground has been proved to be effective.展开更多
As the most significant performance, compliance of hydraulic system is defined as the capacity to accommodate the sudden change of the external load. Due to the different requirements of the compliant tasks, the exist...As the most significant performance, compliance of hydraulic system is defined as the capacity to accommodate the sudden change of the external load. Due to the different requirements of the compliant tasks, the existing method for mechanical systems cannot be used in the analysis and design of the hydraulic system. In this paper, the definition and expression of compliance of hydraulic system are proposed to evaluate the compliance of the hydraulic system operating under sudden change load. Because the unexpected geological conditions during excavation may exert sudden change load to the shield tunneling machine, the compliance theory has found a right application in the thrust hydraulic system. By analyzing the basic operating principle and the commonly used architectures of the thrust hydraulic system, a compliance based thrust hydraulic system design method is presented. Moreover, a tunneling case is investigated in the paper as an example to expound the validation of design procedure. In conclusion, the compliance of the hydraulic system can be served as an evaluation of the capability in conforming to the load impact, giving supports for the design of the thrust hydraulic system of shield tunneling machines.展开更多
基金supported by the National Natural Science Foundation of China (Grant No. 11127202)the National High-Tech Research & Development Program of China ("863" Program) (Grant No. 2012AA041801)
文摘The loads acting on shield tunneling machines are basic parameters for the equipment design as well as key control parameters throughout the entire operation of the equipment. In the study, a mechanical analysis for the coupled interactive system between the cutterhead and the ground at the excavation face is conducted. The normal and tangential loads acting on the cutterhead are decoupled and solved, with consideration of the influence of three key factors on loads: geological condition, operating status and equipment structure. Then analytical expressions for the thrust and the torque acting on the equipment under uniform geological condition are established. On this basis, the impact of soil-rock interbedded ground on acting loads is further considered. A theoretical model for loads prediction of earth pressure balance (EPB) shield machines working under soil-rock interbedded ground is proposed. This model is subsequently applied to loads prediction for a shield tunneling project under soil-rock interbedded ground. The computational value of the thrust and the torque, the measured loads and the load ranges from Krause empirical formula are compared. Thus, this model for loads prediction acting on shield tunneling machines under soil-rock interbedded ground has been proved to be effective.
基金supported by the National Basic Research Program of China ("973" Program) (Grant No. 2007CB714004)the Open Fund of State Key Laboratory of Fluid Power Transmission and Control of Zhejiang University (Grant No. GZKF-201210)the National High-tech R&D Program of China ("863" Program) (Grant No. 2012AA040701)
文摘As the most significant performance, compliance of hydraulic system is defined as the capacity to accommodate the sudden change of the external load. Due to the different requirements of the compliant tasks, the existing method for mechanical systems cannot be used in the analysis and design of the hydraulic system. In this paper, the definition and expression of compliance of hydraulic system are proposed to evaluate the compliance of the hydraulic system operating under sudden change load. Because the unexpected geological conditions during excavation may exert sudden change load to the shield tunneling machine, the compliance theory has found a right application in the thrust hydraulic system. By analyzing the basic operating principle and the commonly used architectures of the thrust hydraulic system, a compliance based thrust hydraulic system design method is presented. Moreover, a tunneling case is investigated in the paper as an example to expound the validation of design procedure. In conclusion, the compliance of the hydraulic system can be served as an evaluation of the capability in conforming to the load impact, giving supports for the design of the thrust hydraulic system of shield tunneling machines.
