Comparison between baseline technique design and partial factor design in slope engineering

In slope engineering, the allowable safety factor design (ASFD) is widely used. However, it includes all sources of uncertainties and does not truly account for risk. Therefore, a more robust design method is required. This study compares the actual reliability levels that ASFD, PFD (partial factor design), and BTD (baseline technique design) provide. The results indicate BTD provides the most stable reliability levels. The major findings are as follows. (1) A sampling strategy is provided to evaluate the performance that ASFD, PFD, and BTD achieve specific target reliability indexes. It provides reliability-based calibration and evaluation. (2) BTD provides more stable reliability levels, especially when the target reliability index is high. (3) The performance of PFD is influenced by the selection of quantile; BTD uses optimal quantiles and achieves the most stable reliability levels. This study provides a numerical investigation of design factors for shear strength parameters, and it uses a sampling strategy considering typical soils from sand to clay. Preliminary results show that BTD is attractive in numerical aspects.