Method for wire saw excavation

Abstract

The method for wire saw excavation provides a significant savings in time, effort, and expense in the cutting of a core of material from a solid substrate such as rock or concrete. A single downhole is formed, and a robotic excavator then forms a continuous, closed loop base passage at the distal end of the downhole to define the periphery of the core to be cut. When the base passage has been completed, the robotic excavator is removed and two subsurface guide pulleys are placed in the bottom of the downhole. A wire saw is passed from a first surface pulley around the first and second subsurface pulleys and back to a second surface pulley. The surface pulleys are advanced along the predetermined periphery of the core at the same rate as the subsurface pulleys, so that the saw simultaneously cuts the periphery and the bottom of the core.

Description

CROSS REFERENCE TO RELATED PATENT APPLICATION[0001]This application is a continuation-in-part of U.S. patent application Ser. No. 14 / 104,387, filed on Dec. 12, 2013.BACKGROUND OF THE INVENTION[0002]1. Field of the Invention[0003]The present invention relates generally to the excavation of solid substrates, and particularly to a method for wire saw excavation wherein a single downhole is formed into the substrate and a wire saw is used to cut a core from the substrate from the single downhole.[0004]2. Description of the Related Art[0005]A number of different methods have been developed in the past for earth excavation and tunneling. While the earliest tunnels and excavations were carried out using hand tools, a more practicable approach is by means of mechanized tools and equipment and / or the use of explosives. However, explosives can be difficult to control accurately, and not only destroy the core material being removed, but may also fracture and weaken the surrounding substrate. T...

AI Technical Summary

Benefits of technology

The wire saw excavation method described in this patent reduces the time, effort, and expense of conventional methods by requiring the drilling of only one downhole in the substrate. This downhole acts as a guide for the wire saw to cut the desired excavation shape. The wire saw passes through robotic guide pulleys positioned at the bottom of the downhole and cuts in a plane across the substrate. No cutting of the peripheral shape of the core is accomplished at this point. Once the bottom cut is completed, the wire saw is positioned at the surface and a mechanism is sent down the hole to push the core from the completed hole. The method allows for easier removal of the core and sectioning into multiple pieces.

Problems solved by technology

However, explosives can be difficult to control accurately, and not only destroy the core material being removed, but may also fracture and weaken the surrounding substrate.

This requires considerably more time, effort, and cost to reinforce the weakened substrate around the hole formed by the detonated explosive charge.

While mechanized equipment does not generally cause so much damage to the surrounding substrate, it generally results in the destruction of the core material.

The need for the formation of multiple downholes in the substrate requires significantly more time and effort than would otherwise be required if only a single downhole were needed.

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