Undrained bearing capacity of the cutting face for an open caisson

Large-diameter open caissons are an increasingly common means of constructing underground storage and attenuation tanks, as well launch reception shafts for tunnel-boring machines. A ‘cutting face’ at the base caisson wall, resembling inclined ring footing, is typically used to aid sinking phase. This paper describes a suite over 15 000 finite-element limit analyses exploring bearing capacity cutting face, partially or wholly embedded in undrained soil. The primary aim study assess influence face inclination angle on vertical capacity. effects roughness, internal overburden surcharge, radius also investigated. In particular, results indicate that steepening may not always reduce capacity, if rough. numerical output informs development closed-form approach application routine design. new design method shown provide excellent representation output.