Description
Summary: | Sand filter tests using cylindrical specimens with a circular hole and large prismatic specimens with a vertical slot were performed extensively. Results reveal that compacted sand filters which obey a conventional filter criterion, act safely to control and seal leaks through cracks in compacted impervious soils comprised of dispersive clay. The dispersive clays in the area of the Sobradinho Dam project occur predominantly in the alluvium as far as the "sodium concentration in pore water of soils" criterion is concerned. X-ray diffraction on clay minerals shows the presence of montmorillonite, common in these dispersive clays. Field and laboratory observation on properties of the soils leads to utilization of nondispersive clays at three conjunctions with concrete structures to minimize any risk of occurrence of internal erosion adjacent to them
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Physical Description: | 1 online resource (12 pages) : illustrations, figures, tables |
Bibliography: | Includes bibliographical references |
Access: | Restricted for use by site license. |