Study On Criteria For Judging The Safety Of Apron Slabs In Plunge Pool

The safety of the protective structure in the plunge pool is the key to theachievements of energy dissipation and erosion protection. It is vital to the safety ofthe riverbed and the dam. How to judge the safety of apron slabs is one of theproblems that need to be solved in practice and also one of the subjects that manyresearchers have studied for years. According to this, a model experiment is designed.The relationship between the uplift loads and the resisting forces of apron slabs andthe safe water-cushion depth are studied in this paper. Based on the researches above,the criteria for judging the safety of apron slabs is put forward. The main researchwork details are as follows: 1.The process and the mode of the destabilization of the apron slabs underdifferent unit discharge, water-cushion depth and etc are analyzed. 2.The relationship between the maximum of uplift loads and the resisting forcesof apron slabs is analyzed. 3. The regression analysis on the maximum of uplift loads is conducted. Basedon the control criterion for the stabilization of apron slabs, the formula of the safewater-cushion depth is deduced. 4.Using probabilistic method, signals of uplift loads are analyzed and theprobability that uplift loads are greater than the resisting forces of apron slabs isobtained. 5.The regression analysis on the time average and standard deviation of upliftloads is conducted. Under the assumption that uplift loads are subject to normaldistribution, the formula of the safe water-cushion depth is deduced. Wavelet analysis, a new analysis method, has good local properties in both timeand frequency domains. A wavelet analysis method, which is applied to analysis onflow fluctuating pressure, is put forward. The impact of the sampling time andfrequency on this method is studied.