Abstract: To study the optimized design of the anti-slide caissons, this paper presents the case history of the Baiguoshu landslide. Based on the soil arch effect and combined with the shear strength index of the soil behind the caisson, the optimized caisson spacing of the anti-slide caisson is selected. Based on determining the caisson spacing, the mechanical analysis of the anti-slide caisson structure is carried out by using the the design bending moment of the positive section of the anti-slide caisson and the design shear force of the oblique section. The design optimization of the retaining structure is carried out, which shows that increasing of the cross-section of the anti-slide caisson can effectively reduce the amount of the longitudinal steel bars within a certain range, and on the premise of satisfying the estimation of the bending bearing capacity of the positive section of the anti-slide caisson, the height of the concrete compression zone is close to the height of the compression zone of the structural boundary as far as possible so that the compressive strength of the concrete can be fully utilized.

Key words: Anti-Slide Caisson, Caisson Spacing, Soil Arching Effect, Appropriately Reinforced Beam, Compression Zone Limits