Abstract: [PROBLEMS TO BE SOLVED] To effectively clean up lead-contaminated soil through phytoremediation aiming at decontamination with the use of a plant. [MEANS FOR SOLVING PROBLEMS] A plant species which is rich in oxalic acid is grown in soil contaminated with lead and/or a compound thereof by sowing a seed or transplanting a seedling. After the plant species rich in oxalic acid is allowed to absorb and accumulate lead and/or the compound, the plant is harvested and removed. As the plant rich in oxalic acid, any of plants belonging to the family Polygonaceae, Oxalidaceae, Chenopodiaceae, Araceae, Begoniaceae and Musaceae or a combination thereof is used.

Abstract: A cutterhead is supported at the front part of a main frame so as to incline at a specified angle with respect to a vertical plane. The main frame includes (i) a roof support disposed at a position corresponding to where a reaction force acts in the direction of the periphery of a tunnel against a force caused by rotation of the cutterhead, and (ii) a pusher for pushing the roof support toward the cutterhead resisting the reaction force.

Abstract: An electronic stereo clino-compass which can be targeted directly at the discontinuous surface of a soil layer and in particular, where the running direction (azimuth) and inclination of a target surface can be measured quickly and easily without the necessity of specialized knowledge.

Abstract: A laser positioner is located at a survey base point for projecting a geodetic design pattern depicting design working points onto a working face remote from the base point by use of a laser pattern projector, upon surveying an object route by use of a laser surveying unit. In tunneling operations for example, the design pattern is formed on the working face, so that boring of the holes for charging explosives in the working face can be performed without paint-marking on the working face.

Abstract: In laser surveying system has a laser measuring unit which is operable independently of a laser projector, a laser spot pattern is first determined by using the laser measuring unit and projected onto the working face of an object structure by driving the laser projector. While marking the working face with the laser spot pattern formed by the laser projector to execute the desired construction work, the laser measuring unit is turned toward a different measuring object so as to independently make other measurements. Thus, point marking and measurement on different objects can be rationally effected at one time.

Abstract: A tunnel driving method using a drill carriage provided with plural number of drill booms having drifters. According to a preferred embodiment, while the drill carriage is placed before a bench, the charging cages are moved to mark blasting holes and rock bolt holes for an upper portion. While the drill carriages are moved backward with a predetermined length, the charging cages are moved to insert the rock bolts for the upper portion. Simultaneously, the charging cages are operated in a lower portion to bore blasting holes for the lower portion. Then, the charging cages are operated to charge the blasting holes for the upper portion and the lower portion with dynamite for blasting so that the facing is broken and a new facing is formed. Subsequently, after first and second operation of concrete shooting, the above continuous operation is performed repeatedly.

Abstract: Directional control of a shield excavator is automatically carried out merely by inputting a direction of rotational moment to which the excavator is directed and a magnitude of the moment.

Abstract: Apparatus for safely and efficiently removing a layer of asbestos or like material from a generally planar or corrugated ceiling surface, I-beams or the like is disclosed and comprises a head assembly including an outer cover having a first open portion adapted to face the asbestos layer and a second open portion communicating with suction means through asbestos collecting means, an open ended inner wall member mounted within the outer cover to define an air passage between the inner wall member and the outer cover, and a rotary wire brush mounted within the inner wall member and adapted to engage and remove the asbestos layer from the surfaces to be stripped. The apparatus also includes adjusting means for moving the head assembly to an operative position wherein the rotary wire brush is in scraping contact with the asbestos layer with a small gap present between the peripheral edge of the first open portion of the outer cover and the surface to be stripped.

Abstract: A milling cutter for cutting the contaminated surface of concrete and used at the time of repairing and dismantling nuclear facilities. The milling cutter is characterized in that guide grooves are provided on the outer surface of a body, with their edges slanted from both sides of the body toward the center thereof, and that cutter chips are located along the stepped edge of each of the guide grooves in such a manner that the cutter chips can be easily detached and that those located along the stepped edges of the adjacent grooves are symmetrical in relation to the center line of the body.