The CSIR "doorstopper" rock stress measuring equipment was developed five years ago and during the past three years has been commercially available. "Doorstoppers" have, as a result, been used in Australia, Canada, Ghana, Germany, Italy, Spain, Sweden. Norway, Britain, Rhodesia, South Africa, United States and Zambia and probably in other countries as well. An instrument using the same principle has, in fact, also been used in Poland. An assessment is made of the published results obtained with "doorstoppers" throughout the world in many types of rock and under varied field conditions. The versatility and the potential of the "doorstopper" equipment is evident from this assessment.
The "doorstopper" rock stress measuring equipment was developed by the C.S.I.R.* five years ago for its own research activities in the field of rock mechanics. So great was the interest by other research workers in this equipment that the C.S.I.R soon found itself inundated with requests for it. Being a research organisation it was not inclined to manufacture the equipment for any other than its own research requirements and during 1966 commissioned a firm of scientific instrument makers to undertake this. It is now three years that "doorstoppers" have been generally available and they have been used all over the world.
It is not surprising therefore that the results of rock stress measurements using "doorstoppers" are appearing in the literature and from them it should now be possible to make an appraisal of the practical usefulness of this equipment as a means for measuring stress in rock. An attempt to do this, with the published material at present available, is made in the following paper.
The name "doorstopper" possesses no scientific connotation and results from the resemblance in colour, shape and size of the first prototypes to the red rubber cylindrical blocks used as doorstops in most South African homes.
Le "butoir de porte" du CSIR, appareillage pour mesurer les contraintes existant dans les roches, a été développé il y a cinq ans. On le trouve dans le commerce depuis trois ans. Ces "butoirs de porte" on été utilisés en Australie, Allemagne, Espagne, Grande-Bretagne, Italie, Norvège, Rhodésie, Suède, Afrique du Sud, Zambie, au Canada, Ghana et aux États-Unis, et sans doute encore dans d’autres pays. En fait, la Pologne a employé un instrument fondé sur le même principe.
Cet exposé donne une estimation des résultats déjà publiés, obtenus à l’aide des "butoirs de porte", dans le monde entier, dans plusieurs types de roches et dans diverses conditions sur chantiers. Cet exposé fait ressortir également la diversité et le nombre des possibilités d’emploi du "butoir de porte".
Die CSIR „Türstoppersonde" zur Spannungsmessung im Gebirge wurde vor fünf Jahren entwickelt und war in den Ietzten drei Jahren frei im Handel erhältlich. „Türstoppersonden" wurden in Australien, Kanada, Ghana, Deutschland, Italien, Spanien, Norwegen, Grossbritannien, Rhodesien, Südafrika, den Vereinigten Staaten, Zambia und wahrscheinlich auch in anderen Ländern verwendet. In der Tat wurde ein auf dem gleichen Prinzip beruhendes Gerät auch in Polen verwendet. Besprochen werden veröffentlichte Messresultate, die mit „Türstoppersonden" in der ganzen Welt in vielen Gebirgstypen und unter sehr verschiedenen Feldbedingungen erhalten wurden. Die Vielseitigkeit und Leistungsfähigkeit der „Türstoppersonde" gehen aus dieser Besprechung klar hervor.
