Observations Analysis And Safety Evaluation Of Renzonghai Rock-fill Dam

The thickness of river bed cover at Renzonghai Rock-fill Dam is 130~148m, which have complex structure-level, and dam foundation seepage control by suspended concrete cutoff wall which maximum depth is 82m. The rock mass at two banks abutment is strongly unloading , and the seepage control by curtain grouting. The dam is complex geomembrane prevented-seepage face rock-fill dam; the maximum height is about 56m. As the dam structure and the foundation treatment works is more complex, and less instances of similar projects at home and abroad, then the seepage and the deformation of the dam are particularly important during its initial impoundment period. This paper flow through the analysis of the results of seepage flow,seepage force and dam deformation monitoring and numerical simulation of the three seepage, draw the conclusions as follow:(1) There is reservoir water to the lower penetration around the bottom of the wall, and the left bank more significant than the right. The seepage pressure at 1-1,2-2 and 3-3 monitor profile of rock-fill dam have changed, and leak the left bank of the lower level grouting hole and the slope of loading platform, which is mainly used by the reservoir water to the lower penetration around the bottom of the wall and the rising of groundwater level of dam foundation.(2) The seepage effect of curtain grouting is better on the left bank; there is no obvious infiltration around abutment. The leak at the right bank of the lower level grouting holes,around the penetration hole and the toe slope of right bank, which is mainly used by the reservoir water around the bottom of grouting curtain and discharge to the downstream at grouting curtain end, of which the former dominant.(3)Through on-site inspection, the analysis of the results of seepage flow, seepage force, the seepage of Renzhonghai rock-fill dam in a abnormal state on comprehensive Judgment.(4) Dam settlement affect by downing or rising of water level, most monitoring points appear 2 ~ 8mm value uplift phenomena during the water rising, and then each monitoring points was significantly increased subsidence during the water downing. The maximum settlement amount is 50.1mm on the dam surface during initial impoundment period, the amount of uneven settlement is less than 1%.(5) Horizontal displacement of dam affect less by reservoir water level change, the horizontal displacement of the surface point to the downstream direction, and the amount is less than 33mm. In addition to monitoring point VE7 which deformation is to the upstream on 2-2 monitoring section, the deflection of the other inclinometer holes is to the downstream direction. The maximum deflection on the 1-1,2-2,3-3 and 4-4 monitoring sections of rock-fill dam are 99.76mm,-143.66mm,123.47mm and 16.06mm.(6) Through on-site inspection, the analysis of the results of dam deformation, the deformation of Renzhonghai rock-fill dam is stability wholly, but the trend of local deformation that is 2-2 monitoring section on upstream slope have not stabilized.