Based on previously performed calculations of the load-bearing capacity for the ultimate and serviceability limit states, an experimental design of a rafter arch was developed. New results from experimental studies on the stress-strain state of its components were obtained, specifically for the semi-arches, ties, and struts under the influence of symmetrical and asymmetrical loads. According to the proposed methodology, a full-scale sample of a steel arch structure was studied in accordance with the loading schemes that are possible in practice. As a result, the actual stresses in all elements were determined, considering both the inclusion and exclusion of preliminary stress. The main theoretical prerequisites for the calculation of the rafter arch, proposed by the authors under the methodology, have been validated. The research objectives were formulated for the subsequent experimental and theoretical investigations of continuous perforated elements. The focus is on establishing effective structural solutions for intermediate supports based on various factors, including size, nature (static or dynamic), type (concentrated, evenly distributed, combined), load action scheme, material strength (standard or high-strength steels), span size, and geometric parameters of the section. Distinct variations are considered concerning the presence or absence of stiffeners along the axis of the intermediate support and the inclusion of welded or non-welded perforation holes on the left and right of the support. It was determined that the stress distribution in the calculation points of characteristic cross-sections with holes of the bearing part of the non-separated perforated beam near the intermediate support significantly differs from the stress distribution in the span part, since the sign of the bending moment curve changes from positive in the span to negative at the support.