Construction of inverted filters, made from mineral fibrous materials, in hydraulic structures

Abstract

1. The use of artificial mineral-fibrous materials and products made from basaltic or glass fibers to construct filters does not complicate the design of earth dams, since the physical-mechanical properties of these filters practically do not differ from those of rubble filters. 2. The techniques for placing such filters on the slopes of earth structures are considerably simplified, inasmuch as some operations required in the construction of rubble filters are eliminated (control of grain size distribution, thickness, etc.), while constant parameters of the inverted filter are conserved for the entire structure. 3. In the concreting process, the continuous penetration of the cement mortar into the filter fibers amounts to not more than 2–3 mm, forming a transition layer between the concrete and the filter. 4. Further study of the thermal conductivity properties of mineral-fibrous filters will probably permit reducing the thickness of the sand blankets used at the present time for protecting the slopes of loam dams against swelling. 5. The use of filters made from glass felt or mats permits reducing by 30–50% the cost of drains in hydraulic structures.