Silos are engineering structures commonly used in the construction, chemical and agricultural industry for storing various types of materials. They are often built as a lightweight construction made of corrugated sheets strengthened along the silo circumference by thin-walled columns. The corrugations have a significant impact, particularly during the flow, on effective wall friction coefficient and, as a result, on loads acting on the silo walls. Generally, two types of granular material actions on silo structure can be distinguished. In the first one, bulk material, located inside the silo, acts on it in the static manner. Therefore, loads transferred from the material to the structure are easy to estimate with analytical solutions known for years. The second type of action occurs during the silo flow when granular material in motion causes dynamic and difficult to estimate loads acting on the wall. The magnitude of the transferred forces depends significantly on the complex behaviour of the interface. Current standards include a simplified approach for the description of the bulk material/corrugated surface behaviour, without taking into consideration many important parameters such as wall geometry. The purpose of the experimental-numerical research is to understand the mechanism of the bulk solid/wall interface during the granular material flow in silos with corrugated walls. To achieve our objectives, laboratory experiments and numerical analysis will be performed. The interface behaviour will be investigated at the laboratory-scale silo models with different types of wall corrugations (e.g. profile height) filled with various bulk materials. Experiments will allow to investigate the granular material flow at its structure level. Furthermore, the mechanism will be described by means of advanced numerical models based on discrete element method (DEM). This method is a suitable tool capable of reproducing the complex structure of granular materials and their mechanical behaviour on the grain scale level. Numerical tests performed in DEM will enhance research investigation of the contact zone between granulate and surface. Based on our experimental and numerical investigation, the exact mechanism of the shearing between two regimes will be defined. As a result of our research, guidelines for quantifying the loads acting on corrugated walls during the flow will be introduced.