The Influence of Water Level Fluctuation Reservoir Stability of the Earth Dam

摘要

A large dam construction failure which caused in reservoir by ground water level fluctuations very extreme.Construction of earth dam failures can be avoided if the conditions of the dam slopes are in stable condition.This research discusses the influence of reservoir water level fluctuations on the stability of the earth dam models in the laboratory by analyzing the stress-strain and deformation using PLAXIS program version 8.2.Implementation of the research done in stages which include testing properties of the building blocks of the model earth dam and physical modelling in laboratory experiments with variations in soil types,namely: a mixture of 90% sand-silt 10%,and 80% sand-silt 20% and 100% soil.The slope of the model on the upstream 1: 1 and 1: 1.5,while in the downstream dam slope was maintained constant 1:1.Instrumentation used includes 6 soil moisture sensors with three accuracy of 2%,1 deformation pressure sensor with detection range,3 dial gauges,capacity level 1 meter with accuracy 2%.Furthermore,analysis on the stability of the earth dam modelling in laboratory tests using PLAXIS version 8.2.The results of this analysis are total displacement Plaids,total stress,total strain,pour water pressure and the safe rate(safety factor).Based on the review of the three nodal,at upstream slope of the dam are same,the effective value of the largest stresses occur in the model 10% soil 90% sand with the upstream slope 1:1,that is equal to-16.52 kN/m~2 lowering phase.Total value of largest stresses occur in the model 20% soil 80% sand with the upstream slope 1:1,that is equal to-12.89kN/m~2 phase rising 3 phase displacement(vertical displacements,the total displacements,the total incremental displacements and incremental strains),the largest value occurs in the model 100% of the land,the vertical displacements 8.12 × 10~(-6)m,the total large displacements 3.92 x 10~(-5)m,1.43 × 10~(-5)m total incremental displacements and incremental strains for-1.75 × 10~(-2).Lowest safety factor(critical condition)due to raising and lowering of water level in the upstream occurred at a slope 1:1 at 1.4710.