Jul 2026· Herald of Polotsk State University. Series F. Civil engineering. Applied sciences· 0 citations· 15 references
Abstract
Currently, increasing attention is being paid to the development of analytical methods for verifying the robustness of structural systems in accidental design situations, the use of which is particularly effective at the preliminary design stage. Studies of multi-story buildings subject to sudden column removal have shown that, instead of considering the entire frame, it is entirely acceptable to discretize the design model by identifying the damaged floor for which verification calculations are performed. Unlike existing analytical approaches, which focus primarily on the flexural resistance of beams and slabs, the proposed method takes into account the additional influence of the membrane effect in monolithic slabs surrounded by beams. It is shown that taking the membrane effect into account in slabs can increase the load-bearing capacity of beam-slab floors (in some cases, by up to 30%). It was established that the membrane effect should be considered primarily when the central (inner) column is removed, whereas when the outer and corner columns are removed, it is recommended to consider only the bending effects (due to the uncertainties of providing anchorage for horizontal ties). The comparison showed good agreement between the calculation results, taking into account the membrane effect in slabs, and the experimental data obtained during tests of floor sections.
The design of coal room and pillar panels has traditionally focused primarily on pillar behaviour. However, if the design process were approached from first principles, one would start with the design of the rooms and first look at the redistribution of the stresses around the rooms. Numerical simulations (elastic and elasto-plastic behaviour) clearly demonstrate the development of relaxed zones in both the roof and floor strata, as well as along the sidewalls in the pillars. The extent of these relaxed zones is governed by factors such as excavation geometry and the ratio of vertical-to-horizontal in situ stresses. A second concern is the widespread tendency to approximate in situ pillar behaviour through vertically loading experiments, such as uniaxial compression tests. These experiments would only be representative if pillars were constructed structures. More complex stress paths develop within the coal pillars during mining, and the load is far from uniform. The current design practices are based on the average pillar load, while the rock behaviour is not determined by average stresses but by local stresses. This paper concludes by proposing directions for future research and by identifying opportunities to improve current understanding and design methodologies for coal room and pillar workings.
This article examines the theoretical prerequisites for establishing quantitative limits for the technical condition of reinforced concrete structures (limited serviceability and emergency), expressed as fractions of the design bearing capacity. It is noted that current regulatory documents, including GOST 31937, lack direct recommendations on the permissible reduction in bearing capacity due to defects.
The results of a summary of experimental data are presented, confirming the presence of a safety margin of up to 30% and a deformability margin of up to 50%, provided that regulatory design requirements are met. An analytical justification for the technical condition limits is provided based on a comparison of the calculated bending moment according to SP 63.13330 and the ultimate actual moment achieved with full realization of the curvilinear stress diagram in the compressed zone of concrete. A ratio in the range of 0.7–0.77 was obtained for a rectangular diagram and 0.55–0.77 for a triangular diagram. An analysis is provided of the reserves incorporated in the reliability factors for materials, operating conditions, and responsibility, as well as the performance characteristics of bending reinforced concrete elements in the ultimate limit state. Practical limit values were proposed: 0.9 for a limited serviceability condition (a 10% reduction in bearing capacity from the design value); and 0.75 for an emergency condition (a 25% reduction), which is consistent with the analysis of experimental and theoretical data.
V. S. Fedorov, I. A. Terekhov, D. P. Leletko· Building and reconstruction· 0 citations
In order to facilitate the possibility of air rights development, a suitable type of structural form is needed to build over certain existing infrastructure or township.
The structural challenges of the mega-truss structure including the choice of an appropriate structural system, the appropriate practice of peripheral post-tensioning to simplify the stack-up staged structure and vibration mitigation required for structural response to exterior loadings including construction and expressway-induced vibration and wind are carefully studied.
Natural frequencies in the lateral transverse and vertical directions need to be raised to meet Eurocode specifications. Vibration study is important to the project because the vertical fundamental frequency of the functional bridging building is around 2Hz, which falls below the requirement of 5Hz stated in British Standard European Norm 1990. This implies that further comfort criteria verification due to potential vibration is required. Using validated finite element models using a theoretical solution from a simplified case, vibration analyses were performed on the whole mega truss including the stack-up building. The current research to date has focused on the basic structural form of the mega-truss. Future research will focus on resolving the above two major challenges.
This research delivers distinct academic originality and practical engineering value for sky-bridging mega-truss structures serving air-rights development above existing urban infrastructure. The primary novelty lies in the innovative Warren truss configuration integrated with internal bottom-chord post-tensioned cables, specially proposed to resolve the mid-span deflection bottleneck that dominates the design of long-span bridging mega-trusses—a critical limitation rarely systematically targeted in prior comparative studies of long-span structural systems. Differing from conventional internal prestressing or isolated external tendon reinforcement schemes, this work establishes a holistic design methodology combining peripheral external post-tensioning, which efficiently mitigates deflection, streamlines staged assembly construction sequences, and suppresses multi-source dynamic excitations including construction vibration, highway traffic vibration and wind loads simultaneously, filling the research gap of multi-performance coordinated control for overhead mega-truss skybridges. Additionally, the preliminary modal and frequency analysis of the post-tensioned mega-truss provides original dynamic characteristic data for vibration mitigation design of air-rights crossing structures. Practically, the proposed integrated external post-tensioning framework offers a replicable design reference for architects and structural engineers to implement horizontal connectivity above operational roads and urban zones, reducing material consumption, simplifying segmented construction, and improving structural robustness under combined static and dynamic actions, which carries tangible application value for high-density urban air-right exploitation and long-span overhead bridge structural optimisation.
Jin Jiang, Ming Wu, S. Chiew et al.· Engineering computations· 0 citations
Slab systems happen to be the most material-demanding parts in a reinforced concrete building and their proper functioning is
important for the structural safety, serviceability, and cost, and energy efficiency. Though widely considered and the solid
conventional reinforced concrete slabs have consumed big amounts of concrete and steel, heavier dead loads are their outcome
and there is an increased load on the beams, columns, and foundations as well. Over the last few decades, hollow and voided
slab systems, such as hollow-core slabs, bubble deck slabs, and voided flat slabs, have been viewed as sustainable solutions
because they need less material and their structural efficiency is better. This review paper provides a thorough synthesis of recent
research on hollow slab technologies focussing on structural behaviour, flexural and punching shear performance, deflection
features, construction methods, strengthening techniques, and economic viability. The literature's experimental, numerical, and
analytical studies are rigorously analyzed to discern the advantages, limitations, and performance trends of the different hollow
slab systems. Furthermore, the paper indicates the present research gaps concerning code provisions, long-term behavior, and
system-level cost evaluation. By reviewing the literature, the authors want to provide support for engineers and researchers in
their endeavors to choose and optimize hollow slab systems for constructing safe, cost-effective, and energy-efficient buildings.
Shital Dnyaneshwar Pakhare, Divyani Harpal, Nayana Sangole· International Journal of Dru...· 0 citations
Abstract This study evaluates the structural implications of adopting lightweight concrete (LC) in multistory buildings, with emphasis on columns – a configuration seldom examined. Three models of the same fourstory building – (i) all conventional concrete (CC), (ii) LC in slabs and beams (CLC), and (iii) LC in slabs, beams, and columns (LC) – were analyzed in AltoQi Eberick V10. Verifications followed NBR 6118 (ABNT 2023a); where NBR 6118 does not prescribe LC material properties, ACI 318-19 (ACI 2019) was used for the elastic modulus and EN 199211 (CEN 2004) for the densitybased tensile adjustment. Results show foundation loads decreased by up to 12.8% and total steel consumption by up to 13.7% with LC, while lateral displacements remained within code limits. Applying LC in columns increased the global instability index to γz = 1.10 yet retained a nonsway classification. The column case clarifies the tradeoff between weight reduction and increased deformability and provides codeanchored guidance for safe adoption in Brazilian practice. Overall, the findings indicate that LC is structurally viable and materially efficient for multistory buildings under NBR-based design, and highlight priorities for detailing and stiffness control when columns are also cast with LC.
Edmilson Roque da Silva, I. V. Fernandes, Marcos David dos Santos et al.· Anais da Academia Brasileira...· 0 citations
This paper examines the problem of assessing the survivability of precast-monolithic reinforced concrete frames and frame structures in buildings under special accident loads. Survivability is defined as the system’s ability to redistribute the load between load-bearing elements after the failure of one of the elements in the structural system without causing any change in its geometry. The methodology is based on a two-level calculation scheme: first, the spatial frame of the entire building is considered as a whole, then a section of the frame in the zone of possible local failure. The calculation involves determining the stress-strain state under service loads, assessing dynamic post-loadings following the removal of an element, and calculating the structural system’s resilience parameter. Three-line deformation diagrams—‘moment–curvature’ and ‘shear force–shear angle’—are used, taking into account the formation of flexural and shift cracks, as well as the ductility of the joint between the precast and monolithic layers of the beams. The influence of the spacing of transverse reinforcement in the bearing zone of the beam was investigated. It has been established that, prior to the formation of shift cracks between the precast and monolithic layers of the beams, the beam cross-section behaves as a monolithic structure; once shift crack have formed, it behaves as a composite structure.
P. Kaydas· Building and reconstruction· 0 citations