Research on dynamic characteristics of cutter breaking frozen soil and optimal drum rotation speed of the new shaft tunneling machine

Abstract

Abstract To improve the efficiency of frozen soil excavation, the new shaft tunneling machine was developed. The new shaft tunneling machine exerts pressure on the frozen soil through the cutter under the joint action of its own gravity, the drum rotational force and the inertia force, and the frozen soil is damaged. By unique way of breaking frozen soil to improve the efficiency of frozen soil excavation, the drum rotation speed is one of the factors affecting the performance of frozen soil excavation. This article applies SolidWorks software to establish the model of cutter breaking frozen soil, takes advantage of Hyper Mesh finite element software coupled with LS-DYNA solver to acquire the regular pattern of change in the force change, frozen soil stress–strain and specific energy of cutter crushing frozen soil, etc., which analyzes the destruction of frozen soil when the drum of the new shaft tunneling machine is rotating at the speed of 25–40 rpm. Combine with field test to investigate the mechanism of cutter breaking frozen soil under the optimal drum rotation speed. The investigation results demonstrate that: when frozen soil's self-bearing capacity is lower than the force of cutter, it breaks up and detaches from the soil body, and frozen soil undergoes tensile, compressive and shear damages. For this research, it is instructive for practical engineering.

Keywords

• The new shaft tunneling machine
• Rolling cutter
• Dynamic damage mechanism
• Finite element
• Specific energy