The article presents the results of the analysis of the stress-strain state of the developed jointing node of construction scaffolding (spatial rod temporary structures), since nodal connections are often the weakest elements of such temporary structures. The analysis of the stress-strain state of the node was performed on the basis of a full-scale experiment. The study revealed the most stressed zones in the node structure, as well as the causes of node destruction. Nodes are well known to be the weakest elements of scaffolding. It often happens that structural elements are more stable than the connections between them. Mobile spatial rod structures are very popular in construction at the present time. These structures are used for the construction of ski jumps, stands, stages and scaffolding. They are also used as support scaffolding to support the formwork of floorings. Therefore, the development of new nodal solutions, increasing the bearing capacity of nodal joints and studying their stress-strain state under various loads is a very important task.

This article deals with the issue of calculating combined plywood-metal flooring as a horizontal disk of stiffness, taking into account the structural non-linearity. An analytically obtained method calculating the shear stiffness of the flooring under the action of horizontal loads is proposed. The task was to derive a three-line correlation - relationship for the fictitious connection operation, based on the constructively nonlinear operation of the flooring. Based on the proposed analytical method of calculating the shear stiffness of the flooring under the influence of horizontal loads, the work of the flooring is modeled as part of the design scheme shown in the figure. The resulting diagram of fictitious relationships was introduced as a characteristic of nonlinear work. In manual calculation in the derivation of the analytical formulas, the compound was considered as a pure hinge. We can conclude that the proposed analytical method of calculating the shear stiffness of the flooring when it is working on a horizontal load, taking into account the structural non-linearity.

This article discusses the design of pedestrian bridges. When designing pedestrian bridges, engineers are guided mainly by the static characteristics of the types of spans under consideration. If you want to build a load-bearing beam structure of a large span, you cannot lose sight of their relatively large mass and low stiffness due to the length of the bridge. These factors lead to a low natural frequency close to the frequency of pedestrian load, in the form of people passing through this structure, which, in turn, act as recipients of vibrations. The structure is a metal span restructure with two I-beam main beams with a solid sloping wall, an orthotropic plate of the passer-by part below, a calculated width of 44.0 m, a total length of 44.6 m and a pedestrian dimension of 3.25 m. In the course of dynamic tests of the pedestrian bridge span, experimental values of the natural vertical vibration frequencies were determined, followed by the determination of the attenuation decrement. The natural oscillation frequency was 2.0 Hz, which corresponds to a period of 0.5 s oscillation.

Mobile spatial bar designs are widely used in the construction of temporary buildings and structures, such as scenes, stands, awnings, pavilions, etc. Such structures are statically indefinable and have gaps in the nodes of the connection. To study the actual work of such systems, an experimental study of the construction of the stage was carried out and a comparative analysis of the results of testing and calculation was performed.

No abstract