土压平衡盾构双螺旋输送机力学机理简析

螺旋输送机是土压平衡盾构的重要组件，对维持盾构开挖面土压平衡起着至关重要的作用。通常一台土压平衡盾构中只配备一节螺旋输送机，但近来在一些水土压力较大的地区采用土压平衡盾构时，一节螺旋输送机难以平衡地层压力，利用双节串联螺旋输送机来解决土压平衡问题。根据土压平衡原理，建立了双节串联螺旋输送机的力学模型，得出双节串联螺旋输送机底部压力在静力平衡条件下的力学表达式，并在此基础上讨论了双节串联螺旋输送机底部压力与其设备参数及渣土性质参数的相关关系，为合理设计、改造、选用和评价土压平衡盾构双节串联螺旋输送机提供了一个简便的方法。

Mechanical Analysis of Double Screw Conveyors in Earth Pressure Balance Shield Boring

Screw conveyor is an important tool of controlling earth pressure balance in EPB shield boring and plays a significant role in maintaining the earth pressure at the face of the shield. Usually EPB shield has a single screw conveyor. However, the single screw conveyor can not balance the earth pressure at the tunnel face in some high pressure areas. Therefore, EBP shield with double screw conveyors is designed to solve this problem. In the paper, mechanical model of the double screw conveyors in EPB shield is established on basis of EPB principle and mechanical formula for the pressure at the bottom of the double screw conveyors under static balance conditions is obtained, on basis of which the relationships between the pressure at the bottom of the double screw conveyors and the equipment parameters and the muck property parameters are discussed. The paper provides a simple method for the design, alteration, selection and evaluation of the double screw conveyors in EPB shield.