This study was started to improve the boring capacity of the blind raise boring machine. The theoretical examination on the basis of the in-situ measurement preliminarily conducted indicates that an additional stabilizer is necessary to prevent the buckling of drill rod, otherwise boring capacity may be limited to 30m. After the comprehensive study including experimental work by a model rig to certify the safety of the new system, two test borings, where upper and middle stabilizers were used, were carried out to complete 39 and 43m raises. Though the depth of 43m is a new record for this machine, high increase rate of segment jacking force encountered at the depth more than 30m was found to be a new source of trouble remained for future research.
Nous avons commence cette etude pour ameliorer la capacite d'une foreuse montante de cheminee. L'examen theorique sur les donnees prealablement mesuree aux chantiers montre que l'eguipement d'un stabilisateur supplementaire est necessaire pour prevenir la flexion des tiges, autrement la capacite de foration peut être limitee à trentaine mètres. Après l'etude complète y compris les essais dans un laboratoire par une foreuse modèle reduit pour attester la sûrete de ce nouveau système, nous avons execute deux test forages en utilisant des stabilisateurs superieur et central, et pu aboutir à 39 et 43 metres de foration. La force necessaire pour fourrer des tubes dans un trou a augmente rapidement au delà de trentaine mètres, bien que la foration de 43 mètres soit un nouveau record pour cette foreuse, ce qui est une difficulte nouvelle à resoudre par des recherches à venir.
Die Verbesserung der Bohrfahigkeiten einer mit Schildmantel ausgeruestet Blindschachtbohrmaschinen ist das Ziel dieser Forschung. Durch theoretischen Untersuchungen auf Basis der vorlaufig durchgefuehrt Feldmessungen ist es gezeigt dass ist ein zusatzlich mittel Quertrager notwendig vor dem Knick des Bohrgestange zu beschuetzen und die Bohrfahigkeiten ueber 30m zu erhöhen. Auf Basis der verschiedenen theoretischen Berechnungen und Modelversuchen wird eine verbesserte Bohrmaschine die ist mit dem Oberen und mittelen Quertrager ausgeruestet entwicket und in einem Zeche eingesetzet. Der Erfolge dieser Verbesserungen ist mit dem leistungsfahigen Aufbrechungen der 39m und 43m hohe Blindschachte bestatigt. Die Steigerung der Bohrfahigkeit von 30m auf 43m i.e. Erhöhung um rund 50% ist beachtbar, aber doch wird die bemerkenswuerdigen Aufsteigung der Vorschubkraft des Schildmantel im ueber 30m hohe Aufbruch bemessen. Es ist ein nachste Problem das muss auf kuenftigen Untersuchungen gelösen sein.
The development of the blind raise boring machine was a joint undertaking by the Dowa Mining Co. Ltd. and the Koken Boring Machine Co. Ltd.. This machine was built when it became apparent that the conventional shaft raising methods were not only uneconomical but also dangerous in difficult ground conditions frequently encountered in black ore mines such as Matsumine mine of Dowa Mining Co. Ltd. The first unit was introduced into Matsumine mine in 1976 and more than 30 raises had been successfully completed at the end of 1981. Basically the unit consists of a boring machine and a segment erection component. The segments of the shield frame are installed and jacked upward to keep the wall stable immediately after each boring cycle is over. Boring capacity of this machine was limited to 30m, and within this limit drill rods are strong enough with only one stabilizer located just beneath the cutter head. This study was started to improve the boring capacity up to the depth of 60m. This improvement is necessary for extensive use of this machine in the boring of ventilation shaft, chute, pipe and cable leading pit in mines, tunnels and underground power stations. First of all, the data was collected in-situ, such as thrust torque and horizontal load to the stabilizer. The theoretical examination on the basis of the in-situ measurement indicates that an additional stabilizer is necessary to prevent the buckling of the drill rod. After the comprehensive study including experimental work by a 1/40-scale model rig to certify the safety of the new system test borings, where upper and middle stabilizer were used, were carried out.
In Figure 1, schematic drawing of the unit is shown and main feature are summarized in Table 1. The detail of the unit can be found in the previous work (Jinno et al. 1979). Operational procedure is as follows: At the end of the boring stroke the chute and conveyer which discharges the cuttings are disconnected and removed. A new drill rod is brought in by the drill rod positioner and connected. The drill rod holder is loosened and the segment jack-up saddle is lowered for the connection of another segment piece. After a complete ring of segments has been jacked up, the chute and conveyer are reconnected and a new boring cycle commences.
