Vorlicek, è gia stato fatto; più volte, solo che si perdono queste informazioni. Secondo me ripeto, sono i costruttori che devono mantenerne memoria e aggiornarle, come o già ricordato qualche posta fa. Putroppo anche nell'era di internet bisogna aver tempo di cercare (a scapito del tempo dedicato al lavoro).
Proceedings ISC 2 (Porto,2004)
Experimental In Situ Test Sites
Gianni Togliani
Senior Geologist Consultant
Giorgio Beatrizotti
Senior Geologist, IST-SUPSI (Institute of Earth Science – University of Applied Science of Southern Switzerland)
Keywords: CPTU, CPT, DMT, DPL/M, DPSH.
ABSTRACT: The IST-SUPSI has promoted the construction of two experimental test sites in the southern part of Switzerland in order to compare the results of the most commonly used in situ tests. The Gordola site is characterized by alluvial and deltaic deposits while the Stabio site presents alternating fluvial and lacustrine deposits, both recent and of glacial origin. Even though the program is still in its initial phases and the results obtained remain to be confirmed and eventually adapted to the various regional situations, the developments of the DPSH with casing seem promising, especially for lithological and geotechnical interpretation of the soils encountered. Hopefully this will encourage greater use. Similar considerations can be made for a proposed non-conventional SPT.
6 CONCLUSIONS
The results obtained at Gordola and Stabio sites confirm the necessity to execute in situ test as CPTU and DMT, if one wants to obtain a reliable stratigraphic and geotechnical characterization of the fine grained soils.
The most important lesson learned however, is the capacity of DPSH with cased rods to provide, elaborating the dynamic penetration resistance of both, qc and fs equivalent values comparable with that measured by CPTU.
This means that everywhere we have coarse soils with variable amount of gravel, able to obstruct or prevent the execution of CPTU and DMT, DPSH with casings become the recommended equipment (compared to CPT also has a much more extensive application field).
Assuming that each investigation requires at least a borehole with continuous core recovery not only to obtain undisturbed samples or to place a piezometer, but especially to have an interpretation key for all in situ tests, the use in coarse soils of the non-traditional proposed SPT, once more allow to obtain in a simple, rapid and inexpensive manner, elaborated reliable values of qc, exploitable for a corrected geotechnical characterization.
Concerning the DPL/M we suggest using them (better with casings), only in cases of impossible access for others equipment and when the investigation does not exceed depths of 10-12 m.
Finally, the common habit of passing from DPL/M to DPSH by the application of a simple correlation coefficient is unadvisable even modifying it with the soil characteristics encountered.
ACKNOWLEDGEMENTS
Special thanks go to IST-SUPSI (Institute of Earth Science-University of Applied Sciences of Southern Switzerland) to have promoted the research, DPT (Roadway Administration) and SSIC (Swiss Building Enterprises Association) for providing the test sites, INJECTOSOND S.A., PALER S.A. and PAGANI GEOTECHNICAL EQUIPMENT for the execution of boreholes and in-situ tests.
L'unica osservazione che mi permetto di fare a questo lavoro è che trovo difficile correlare la resistenza alla infissione del rivestimento DPSH(sforzo totale) con l'attrito locale di CPT.
Spero di aver fatto cosa grata agli Autori pubblicizzando il loro lavoro in abstract.
