The Safety Monitoring Methods And Application Of CFRD

Dam safety monitoring is effective means and method to understand the running status and safety condition of dams, which concludes acquisition of various kinds of environment, hydrology, structure, safety information, the steps of recognition, calculation, judgment etc. and offering the process of safety degree of dams finally.It is elaborated that the monitoring disposal, instruments selection, installation and observation methods, observed results data analysis of the safety monitoring of CFRD based on the monitoring project of Shuangxikou reservoir dam in Yuyao. Main conclusions are presented:The data of strainometers keep stable before dam filling. The data vary at a certain range with the dam filling by loading influence of it. The strainometers of diaphragm wall vary to the tendency of compressive stress with the rise of reservoir’s water level after dam impounding.The stationary clinometer appears to upstream displacement status by the influence of dam loading, which the displacement is in the allowable range without abrupt change and it is steady with the variation of time. Every measure point appears to downstream displacement status with the reservoir water level rising and the maximum displacement1.7cm, which is at the normal range.The water levels of Osmometers are mainly affected by rainfall before dam impounding. The water levels and potentials of osmometers near the downstream diaphragm wall increase to a certain extent and the rest measure points’ rangeabilities are small with the water level rising by reservoir impounding; meanwhile dam foundation has no seepage stability problem by seepage calculation.The water levels of every piezometric tube are mainly influenced by rainfall and the reservoir water levels keep the same. The corresponding water levels of every piezometric tube have no rising tendency one year later.Although strain monitoring results of diaphragm wall show that the tensile stress in construction period exceeds the FEM theoretical calculation result, it is demonstrated that the anti-seepage performance is good by the monitoring data of osmometers and piezometric tubes, which don’t appear abnormal.Most of the total settlement of every water tube settlement meter appears at the construction period. The maximum value of accumulated settlement at the percentage of dam height is0.94%. The settlements of some measure points increase by the effect of water pressure and dam enrockment rheology after dam impounding, which are in a normal range. The settlements of all measure points are in a stable state currently.Tension horizontal displacement meters near upstream are moving upstream and the ones near downstream are moving downstream in construction period. Every measure points tends to move downstream after dam impounding.The displacements of three-dimensional joint meter are relevant with the reservoir water levels by the effect of reservoir water pressure, which increase at three dimension; The displacements of two-dimensional joint meter are not much relevant with the reservoir water levels with the joints affected by reservoir water pressure; The joints’ variations of one-dimensional joint meter are mainly affected by outside temperature.