STRUCTURAL RELIABILITY ANALYSIS OF CONCRETE DAMS– GEOSTATISTICAL APPROACH TO DESCRIBE UPLIFTPRESSURES

摘要

The possibilities to use of structural reliability analysis in dam design andrnassessment is investigated in Sweden. For such analysis statistical descriptions of the loads andrnresistances are necessary. Uplift pressure has large impact on the safety and is difficult tornquantify. In this paper a geostatistical approach was used to simulate fields of hydraulicrnconductivity under theoretical concrete dams. Total uplift force and moment for the damrnsection was calculated by a Finite Element model for each realization of conductivity field. Arnnumber of different combinations of variance and spatial range (scale) was used as input in thernanalysis. The result obtained are statistical distributions of uplift force and moment (around therndam toe) for each variance/scale combination. For increasing variance and scale the uplift forcerndistribution transform from narrow and normal-like to wide and rectangular-shaped, while thernmoment distribution becomes more triangular-shaped. An example where simulation results arernused in a structural reliability analysis of a fictitious dam is given. The results are promising,rnbut to be useful the connection between assumptions in the model and reality has to bernimproved.