Vízügyi Közlemények, 1971 (53. évfolyam)

4. füzet - Rövidebb közlemények és beszámolók

(67) BRIEF PUBLICATIONS AND REPORTS 1. Gál, T. and Kovács, S., Civ. Engrs.: Flood levee construction across ail abandoned bed (For the Hungarian text see pp. 397) In the construction of flood levees across abandoned former river beds the removal of I be organic sill layer encountered in these beds and often of considerable thickness tends to cause very often difficulties. A method for the removal of I his sill of low bearing capacity from Ihe foundation of the levee, applied successfully at the construction of a levee section along the Tisza River is described in this report. A fill of narrow width at the toe, consequently producing high bearing pressures has been constructed over the thick sill layer of low bearing capacity (in which the groundwater level was also high). Under the load the silL was displaced towards the two sides. The process of displacement was accelerated by blasting explosive charges in boreholes sunk in two rows along the levee loe. Blasting caused the fill to scllle as much as 1,0 to 1,2 m during 24 hours. The fill material was disrupted by this settlement, for which reason it was spread and a new levee core was placed in order to ensure watertightness. Secondary settlements averaged 1 cm during 5 months and the new levee successfully withstood the load exerted by the spring floods in Í970, during which its sealing properties proved satisfactory. 2. Mészáros, L., Civ. Engr. : Nuclear density and moisture measurements for observing flood effects (For the Hungarian text see pp. 404) In various theories the levee body is assumed to be uniform, presenting an isotropic field of seepage, in which the flow is steady and irrotational and to which Darcy's law applies. These assumptions proved to result in a very crude approximation only of the phenomena actually taking place. Nuclear density and moisture measurements offer the possibility for tracing the phenomena caused by water in flood levees. During the flood in 1970 on the Tisza River, such measurements have been conducted in bereholes of altogether round 400 m length. The cross-section of the levee studied in the vicinity of the town Csongrád is shown in Fig. I, while the distribution of moisture along a berehole sunk in the levee is exemplified in Fig. 2. Changes in Ihe moisture content along the horizontals 6,6 and 7,7 im the vicinity of the levee bottom have been compiled in Table I. The process of saturation is even better reflected in the experimental levee constructed at Porboly, where the possibility was offered for realizing artificial flood waves. BOOK REVIEW I. I)r. Itéthlv. Л ni ni : Meteorological events and elementary disasters in Hungary from 17(11 to UtlH). Reviewed by ' Dr. I.ászlnffg, Waldemar. Published in 1970, Rudapest, Publishing House of the Academy, pp. 622, 24 figs.