Basic Understanding of Earth Tunneling by Melting. Volume II. Earth Structure and Design Solutions.

摘要

A novel technique,which employs the melting of rocks and soils as a means of excavating or tunneling while simultaneous generating a glass tunnel lining and/or primary support,was studied. The object of the study was to produce a good basic understanding of the fundamental process,its limits and capabilities,as applied to large scale (approximately 10 m diameter) transportation tunnels. Basic physical principles are used to derive functional equations governing the primary process variables in five separate areas:thermal power and penetrator temperature (end of Volume I),thrusting force,earth structural,glass liner structural,and melt cooldown. These were related to independent variables of penetration velocity and tunnel geometry and to the geologic model properties. Some potential design solutions are proposed to obviate some problems and limitations. A comparison with small scale test data indicates that the process is predictable but that thermal stress cracking of the glass liner would minimize its consideration for the primary tunnel support. (Modified author abstract)