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This article deals with the seismic analysis of the dam-foundation coupled system considering direct coupling approach using displacement based finite element method. A cone-type local non-reflecting boundary condition (NRBC) is adopted to model the semi-infinite soil domain. The reservoir effect adjacent to dam body has also been incorporated in the analysis. The results depict the superiority of the proposed NRBC in absorbing spurious wave reflections over the traditional viscous boundary conditions. The analysis results show that the dynamic response of the dam gets highly affected due to the consideration of the elastic foundation domain at its base. [ABSTRACT FROM PUBLISHER]

The article analyzes fluid-structure systems considering the direct coupled effect of elastic dam and the fluid adjacent to it. The study considers three different modulus of elasticity of dam and compares the tip displacement of dam, maximum hydrodynamic pressure and different principal stresses. It examines the flexibility of dam to alter the behavior of dam-reservoir system, as well as the role of the elastic effect of dam structure on the analysis of fluid structure interaction problem.

The Saraighat Bridge came as a boon for the economy of the northeastern India and has strategic importance. Experts are of the opinion that a strong earthquake is overdue in this region. The enforcement of seismic code in India tries to mitigate the hazards to the population and infrastructure, but it started much later whereas saraighat bridge was conceptualized and designed in 1955-1958 when the knowledge about earthquake engineering was very little and the Indian seismic code was not available. With this in mind, this work of research has been taken up, which may probably reveal some interesting information about this infrastructure masterpiece. [ABSTRACT FROM AUTHOR]

The bioinspired synthesis of construction material, known as biocement, represents a significant advancement in addressing the environmental sustainability issues associated with traditional cement use in the built environment. Biocement is produced through the process of microbially induced bio-mineralization (MIBM), which offers a promising alternative or supplement to conventional cement, potentially reducing its consumption. Despite extensive literature on the application of biocement in construction biotechnology, the fundamental mechanisms underlying its ability to enhance concrete quality remain poorly understood. This study focuses on the kinetics of biomineral synthesis by two Bacillus species; Bacillus megaterium RB05 and Bacillus foraminis DRG5, to identify the most effective strain for biomineralization. Bioconcrete specimens were created by adding inoculum containing Bacillus megaterium RB05 cells with a nutrient solution to the concrete mixture in a layer-by-layer approach. After 28 days of water curing, nanoparticles of CaCO 3 , ranging in size from 27 to 82 nm, were produced in the bioconcrete specimens. The resulting concrete, containing nanocrystalline biogenic calcite, demonstrated significant improvements in mechanical properties. Specifically, compressive and tensile strengths of the bioconcrete, tested using a universal testing machine (UTM), increased by 7.69 ± 0.08% and 22 ± 0.1%, respectively, after 72 h of curing. Additionally, the biocement was found to exhibit an organic-inorganic hybrid nature, as identified by TEM, EDAX, FESEM, FTIR, and XRD analyses. The enhanced mechanical properties were attributed to the high surface-to-volume ratio and hybrid nature of the calcite nanoparticles. The findings of this investigation are encouraging, suggesting the potential development of future green and self-sustainable construction materials or bioconcrete., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)