Nodular diaphragm wall (NDW) is a novel foundation type with favorable engineering characteristics. In contrast to traditional diaphragm walls

the vertical bearing capacity of NDW is significantly enhanced by the existence of nodular sections. Currently

the application and research of NDW are limited

and further clarification is needed regarding its deformation properties and failure modes. This study employs particle image velocimetry (PIV) technology to analyze the displacement and failure mechanisms of the foundation under vertical uplift. The findings indicate that positioning end and middle nodular sections extend the influence range to both deep and shallow soil layers

while multiple nodular sections facilitate in mobilizing broader spectrum of soil. The failure pattens of NDW involve interconnected sliding planes

including vertical sliding planes

inverted pyramid-shaped

or tangent curves

and vase-shaped curves (referred to as curve sliding planes). Overall

compared to pile foundations

the failure surfaces of the retaining wall exhibit complexity

influenced by the number and arrangement of sections

with certain sliding plane orientations correlated with the soil’s internal friction angle.