Hidrológiai Közlöny 1966 (46. évfolyam)

10. szám - Dr. Öllős Géza–Dávidné Deli Matild–Szolnoky Csaba: A nyomás alatti réteget megcsapoló kutak tervezésének hidraulikai kérdései

Dr. öllős G.—Dávidné, Deli Matild—Szolnoky Cs.: A nyomás alatti réteg Hidrológiai Közlöny 1966. 10. sz. 459 [13] BiesTce, E.: Bohrbrunnen. Verlag von R. Oldenbourg München. 1953. [14] Öllős Géza: Talajvizek hidromechanikája. Alapozás szakmérnök ágazati jegyzet. Budapest 1966. [15] Juhász József: Gyakorlati összefüggés kútellenállás meghatározására. Hidrológiai Közlöny, 1966. 5. [16] Öllős Géza: Well hydraulics. Budapest. 1966. International Post-Graduate Course on Hydrological Methods for Developing Water Resources Management. Number 11. [17] Todd D. K.: Ground Water Hydrology. NewYork. 1959. [18] Schultze, J.: Reichweite und Ergibigkeit einer Grundwasserabsenkung in Abhangigkeit von der Betriebsdauer. Bautechnik. H. 43. 1923. [19] Prinz, E.: Handbuch der Hydrologie. 1919. nWABJlHMECKHE BOnPOCbl ÜPOEKTHPOBAHMfl K0J10Í1UEB, ílEnPECCHPY ÍOIIIMX CJ10H, HAXOÍlfllUHECfl no^ HAnOPOM JJ-p SAASW r. Kandudam mexHuiecKux nayK fl. ílejiH, M.-COJIHOKH, M. HHweHepbi, 3aHiiMaioinnecH c npoeKTHpoBaHHeM K0Ji0fli;eB Bee MeHbine H MeHbrne MOTYT O6OHTHCI> 6e3 3HaHHH paCMeTHOÍÍ KpHTHieCKOil CKOpOCTH, KOTOpaH MO>KeT SbiTb flonycTHMa Ha HapyjKHOÍi CTeHe Kojio^ua, H KOTopan HBnnercH BawHoii c TOMKH 3peHHji oueHKH 3anjieHHH, HO H oflHOBpeMeHHO TeopeTimecKH flOKa3aHa. OnbiTbi npaKTHKH nocjieflHHx neT Bee öojiee «0Ka3biBa.nn, ITO ypaBHeHne 3nxap«Ta (2) H aHanonmHbie (HaxoflaujHec5i B jiHTepaType 3aBiicMM0cra) ypaBHeHHH ne flaioT jyiH npoeKTHpoBmnKa 0flH03Ha

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A H rpaHynoMeTpHMeCKOTO COCTaBa rpyHTOB. OCHOBHajI MbICJIb CTaTbH, 1TO pflflOM TeOpeTHHeCKHX H JiaÖOpaTOpHblX HCCJieflOBaHiiil e 6ydyu{eM ece öoAbuie 3HaneHUH npuoőpemawm onumbi, noAyteHHbie Ha Mecme 3KcnAoamaquu cpaKmunecKU deücmeywu}ux KOAOöifee. Hydraulic Problems in the Design of Wells Drawing on Artesian Aquifers By Dr. G. Öllős Candidate of Technical Sciences Mrs. M. D. Dávid and Cs. Szolnoky The permissible seepage velocity on the outer well mantle assumes increasing importance in the design of wells and the knowledge of the critical value, which is the highest that causes no sand clogging, beeomes essential for the designer. This value must be based on sound theoretical considerations. From practical experience gained during recent years it became increasingly apparent that the equation of Sichardt — Eq.(2) — as well as other similar relations found in the literature — fail to yield a unique solution for the designer. It is demonstrated that instead of the hyperbola represented by Eq.(l), a set of hyperbolas should be used (Fig. 1). The curves should be plotted in terms of drawdown s in the well. The solution offered by this approach is, however, still unsatisfactory, since wells are in practice operated frequently at drawdowns attaining 15—30 metres and the critical seepage velocity is considerably exceeded without operational troubles. In the paper an attempt is made to answer this problem on the basis of laboratory experiments. In Chapter 4 generál trends are outlined for the future development of well hydraulics. Seepage parameters of wells drawing on artesian layers are considered hereafter in detail. Referring on artesian layers are considered herafter in detail. Referring to the example of Wen-Hsiung IÁ it is pointed out that seepage around the well and the flow of water in the well — as a structure — should be treated as a single system — Eqs. (12) to (15). Hereafter the seepage flow pattern around fully and partially penetrating wells (Figs. 4 to 6) is studied in the light of experimentál evidence and a relationship is developed between potential distribution on the mantle, they yield of fully and partially penetrating wells (Fig. 10), the hydraulic gradient along the mantle (i) and drawdown in the well. Relying on Fig. 12 and Eq. (23) it is demonstrated that troublefree operation of the well is indeed possible even at gradients considerably steeper than that indicated by Eq. (1), provided that the grain-size distribution of the soil is favourable for the development of a filter layer (111. 1). A review is then given on seepage conditions pertaining to entrance through the well bottom (Figs. 13 to 20). From among investigations aiming at the selection of the preferable gravel filter the approach developed by Professor A. Kézdi is described, who by introducing the concept of autó-filtering capacity of soils, contributed greatly to our knowledge of filter layers. In conclusion an example is given for the preferable combination of grain-size distributions of the gravel filter in a given soil (Fig. 21), on the basis of current investigations. As far as future progress is concerned it is suggested that besides theoretical and laboratory studies experiences gained during the practical operation of existing wells will gain increasing significance.