WATER TIGHTNESS EVALUATION METHOD OF CORE ZONE OF ROCKFILL DAM

摘要

PURPOSE: A degree evaluation method of a rockfill dam core zone is provided to pre-detect penetration into a conventional rockfill dam by analyzing a relation between a water storage level of the rockfill dam and an amount of penetration of which influence of the rain fall are corrected, and when the rockfill dam is penetrated, repair and reinforcing work is performed in advance and thus safety of the rockfill dam is secured. CONSTITUTION: A degree evaluation method of the rockfill dam comprises steps of: building a core zone in a trapezoidal shape in a center of the rockfill dam, installing an infiltration volume measurement unit in the outlet side of the rockfill dam, repetitively totalizing and storing data in a control unit, wherein the data includes a daily rain fall, a daily accumulated rainfall, or an infiltration volume at a certain period of time through a dam body. A rockfill dam infiltration prediction formula including an infiltration volume per unit depth through the core zone(qs), a saturation permeability coefficient(ks), L calculated from a maximum depth at a lower surface of the core zone(Lmax) and a depth of the core zone at a water storage level, and a depth of water( h) as variables, measuring a survey infiltration which is ejected after it is gathered in a measuring unit, calculating a correction infiltration volume of which influence of the rainfall is amended by removing infiltration of the downstream four sides due to the rain fall in a survey infiltration, reversely computing a real saturation permeability coefficient by inputting the correction infiltration to the rockfill dam infiltration prediction formula, and judging a degree nature of the core zone by comparing the reverse calculated dam design standard saturation permeability coefficient and the real saturation permeability coefficient.