Abstract: A wire method of a reinforced concrete structure, and a guide pulley apparatus for the method, wherein a cutting wire 18 guided by a pair of guide pulleys 7a, 7b disposed on the same plane as a scheduled cutting surface of a reinforced concrete structure 2 is caused to endlessly circulate and travel along the surface of the reinforced concrete structure under a regulated tension and at a regulated travelling speed through an auxiliary guide pulley 8c for separating one portion of the cutting wire from the other portion thereof.

Abstract: This invention relates to a method of cutting and removing a nuclear reactor which includes the pressure-feeding of a grouting material into a pressure vessel and to peripheral members outside the pressure vessel so as to integrate and solidify them, and the cutting of the structure starting with the outer periphery of the pressure vessel. When the cutting operation is carried out, the present invention preferably uses a wire saw having diamond grains on the surface thereof, and further performs double cutting by the use of a preceding cutting edge and a cutting groove width adjustment cutting edge when the cutting operation is made. In this way, the pressure vessel of the nuclear reactor can be dismantled and removed safely and efficiently.

Abstract: A circular opening is formed in a structure by: forming through-holes 4, 3 in the structure 1 to be cut on a circular cutting line 2 and at the center of the circular cutting line; inserting a shaft 5 through the center through-hole 3; securing support arms 13, 20 to both ends of the shaft 5; passing an endless wire saw 23 through the through-holes 4 on the cutting line and around pulleys 15, 22 mounted on the support arms 13, 20; and driving the wire saw 23 by a drive unit while rotating the support arms 13, 20 about the shaft 5.The apparatus for cutting a circular opening in a structure comprises: a shaft inserted through a through-hole formed in a structure to be cut; support arms secured to both ends of the shaft; pulleys mounted to the support arms; an endless wire saw passed through through-holes formed in the structure along a line connecting the pulleys around the pulleys; a pulley drive unit; and a support arm rotating unit.

Abstract: A guide pulley base for wire saw comprising a primary support member, a secondary support member rotatably mounted on the primary support member, a primary grooved pulley rotatably supported on the primary support member in such a way that the rotational axial line of the second support member passes tangentially through the peripheral groove of the primary grooved pulley, and a secondary grooved pulley rotatably supported on the secondary support member in such a way that the rotational axial line of the second support member passes tangentially through the peripheral groove of the secondary grooved pulley.The guide pulley base for wire saw is arranged between an object to be cut and a wire drive unit for guiding a cutting wire and smoothly turning the wire travel direction when an object to be cut such as ferroconcrete structure is cut off partially.

Abstract: A wire drive apparatus for the wire saw which is favorably used, particularly for cutting the structures of reinforced concrete with the wire saw and movable on the base surface such as the surface of the road or floor without using cranes is disclosed.

Abstract: The opening method to drill openings with required largeness on thick reinforced concrete walls such as a reinforced concrete dam body is presented.This method comprises (1) the process of drilling cable penetrations in the depth direction on each corner around the opening domain on a reinforced concrete wall, (2) the process of penetrating cutting cable through cable penetrations and to carry out wire sawing with water injection, (3) the process to break and remove the separated core.According to this method, the required opening for thick reinforced concrete walls such as a reinforced concrete dam body which has been regarded as difficult if not impossible, can be safely and exactly drilled with the smallest number of processes, having no bad influence on the surrounded wall.

Abstract: A wire sawing method for cutting buildings, dams, bridge piers, foundations and other reinforced concrete structures is exhibited.This method is characterized by laying a cable on a reinforced concrete structure and using a moving type cable driving machine which pulls the cable for cutting and drives it circularly while the machine itself moves, together in series with a fixed type cable driving machine which drives the tension side part of the cable for cutting. The endless cable for cutting is circularly driven while its running speed and tension are adjusted by the cable driving system.

Abstract: A guide pulley base for wire saw having a pair of main pulleys on the same plane, a pair of guidance pulleys in parallel to each other in such a way that each outer periphery of the guidance pulley is in contact with each parallel tangent line contacting with each outer periphery of each main pulley from the opposing side of the main pulleys, and further at need, a pair of second guidance pulleys, a pair of second main pulleys and an auxiliary pulley.The guide pulley base for wire saw is arranged between a wire drive unit and an object to be cut for guiding a cutting wire and smoothly turning the wire travel direction when an object to be cut such as ferroconcrete structure in a building, a bridge, a subway, etc. is cut off partially.

Abstract: In a wire saw drive apparatus having a carriage, a wire drive pulley mounted on the carriage, pulley drive means for rotating the wire drive pulley to drive an endless cutting wire, a pair of adjust pulleys for guiding a tensile side and a loose side of the cutting wire, and carriage drive means for moving the carriage and maintaining the cutting wire under a desired tension, the improvement comprises elastic means mounted between an adjust pulley supporting body for guiding at least the tensile side of the cutting wire and the carriage, for receiving a force applied from the cutting wire to the adjust pulley, and a guide pulley mounted on the carriage near the adjust pulley for guiding the tensile side of the cutting wire, for guiding the cutting wire into S shape fashion in cooperation with the adjust pulley.