Vízügyi Közlemények, 1935 (17. évfolyam)

Kivonatok, mellékletek - Kivonat a 2. számhoz

19 in the Great Plains have sunk at different rate during the last 40 years, and it can be stated that the rate of sinking has been greater in the middle of the lowland basin of the Zagyva river than on its borders. The middle part of this basin is a pronounced seismic territory, where several earthquakes, have occurred since the eighteenth century. On the other hand, data of deep borings also show that the same strata are found lower in the middle than in the borders of the basin. The hydrographie situation reconstructed on the basis of maps of the eighteenth century supports the supposition that here the hydrographie conditions have been changed in such a way that all the rivers have been turned from the borders to the middle of the basin. Results of investigation : 1. All appearances show that a young basin is being formed in the lowland watershed of the Zagyva river. 2. This process was going on in historical periods, and is still advancing in the present time. 3. The longitudinal axis of the recent formation runs north and south. 4. The local sinking seems to be most pronounced between Jászberény and Jákóhalma. 5. The process of sinking is in perfect conformity with the alteration in the hydrographie conditions. 6. The proofs of a local sinking are not only the observed lowering of the fixed points of the levelling survey, and the hydrographie alterations, but also the seismic data, the position of fracture-lines in the earth-crust, and the data of deep borings. 7. The vast marshes existing in the basin prior to the completion of the draining works were caused by a continuously advancing process. V. THE RISK TO SLUICES AND PUMPING PLANTS BUILT ON BAD SUBSOIL AND UNDER TRYING CONDITIONS, AND THEIR EXAMINATION AS TO FLOOD PROTECTION. By H. LAMPL. (Pages 238—240.) The article calls attention to the risk to sluices and pumping plants built into flood control levees on bad subsoil. The danger may arise from the fact that at flood time the ground-water streaming towards the protected side washes out the fine soil particles, and thus these constructions may be undermined. The author describes a new patent procedure serving to determine the presence, the exact situation, and the extent of such underminings. The essentials of this procedure are as follows. The foundation plate of the building is bored through at places 2—3 metres apart, forming a system of holes. Then iron pipes reaching to the bottom of the foundation plate are placed in the holes and fixed with concrete, and the pipes are 2*