The water pressure test and several important aspects of test execution and evaluation were treated in Chap. 4. The current method of judging rock permeability has also been discussed. In Chap. 6.3.4, the results of the model tests established that small water takes provide unequivocal evidence of the type and scope of the permeability and the hydraulic routing, but that intermediate and larger takes are ambiguous. Even in view of possible misinterpretations of the test results, it is in the author’s opinion more important to investigate the pressure-dependent permeability behaviour rather than to determine only the WPT rates. This is particularly important, because the grouting behaviour, decisively influencing the economy of a grouting programme, can then be studied. Water pressure tests can also be valuable for this, if they are carefully executed and evaluated; whereby, above all, the course of the test has to be considered, because this illuminates also the grouting behaviour. The execution and evaluation of the water pressure tests were dealt with in Chap. 4. Now, after the execution of simulated water pressure tests, whose results are very helpful because they allow a better understanding of the actual tests, the theme of Chap. 4 can be supplemented. In the following the results of actual tests will be interpreted with the aim of finding a way for a better judgement of the scope of the permeability as well as of the pressure-dependent behaviour during testing and grouting.
Weitere Kapitel dieses Buchs durch Wischen aufrufen
- Practical Field Investigations on Permeability by Means of Water Pressure Tests
Professor Dr. Friedrich-Karl Ewert
- Springer Berlin Heidelberg