The analysis of various regulatory methods for calculating reinforced concrete slabs for pushing and comparing with experiment results is made. The tested sample, measuring equipment and test bench are described. Sizes and materials for experimental prototype were chosen by existing beamless and capless slabs of monolithic reinforced concrete superstructures with column grid from 8×8 to 9×9 m. Experimental research results of reinforcing concrete plate structure are presented for study purpose of stress-strain state when punching shear collapse occurring. Various aspects and observations obtained during the test are given. The comparison of the tested slab fragment with the complete response of slab structure is performed. Analysis of tested sample stress-strain state and punching bearing capacity calculations results in according to existing regular standards were made. Main criterias of punching shear collapse were determined and new procedure for punching calculation of RC concrete slabs was offered basing on significantly new approach in punching bearing capacity defining.

The article analyzed the results of the calculation of the monolithic trench “wall in soil” (WIS) with fastening attachment anchors without the use of distribution beams based on solving a spatial problem with the different topology of the fence elements. In practice, when solving such problems in a flat arrangement, it is assumed that the WIS is a solid construction in the longitudinal direction, vertical concreting joints are not taken into account, formed between grabs, rupture along horizontal longitudinal reinforcement between adjacent spatial frames, reduction of the rigidity of the WIS structure due to the formation and opening cracks in two directions, as well as inelastic operation of the compressed zone concrete. Analysis of stress-strain state (SSS) of the fence construction structure based on the results of spatial calculation with different topology (flat and volumetric) of finite elements (FE) showed the need to correct the calculation methodology. Based on the results of the calculations, it was found that the values of internal forces in the design obtained using flat FE are significantly overestimated. Based on the numerical method of studies, recommendations on the selection of the design scheme of the monolithic reinforced concrete structure of the pit’s fence are proposed and the calculation methodology is corrected. The subject of the study, the results of which are presented in this article, was the specifics of the operation and calculation of the WIS with anchor attachment without distribution beams and the analysis of the calculation results based on the solution of the spatial problem with different topology (flat and volume) of the FE structure of the fence.

The article describes the features of modeling monolithic trench “diaphragm wall” with ground anchors without the use of distribution beams on the progressive collapse caused by the failure of one of the anchors. In the simulation of the above calculation case, in the flat formulation commonly used in practice, it is assumed that the “diaphragm wall” is a continuous structure in the longitudinal direction, without taking into account the presence of vertical joints formed between the grippers when concreting the fence and the lack of connection between the longitudinal reinforcement of adjacent reinforcement spatial frameworks. The performed calculations show that the failure to take into account these circumstances leads to a significant reassessment of the ability of the “diaphragm wall” to redistribute the load from the broken anchor to the neighboring anchor and can lead to an incorrect assessment of the results of the calculation for a progressive collapse. The need to take into account the reduction of structural rigidity of the “diaphragm wall” due to the formation of cracks in two directions is also shown.

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