Daily Archives: August 11, 2026

Authors: Hari Om Dhar Badgaiyan, Assistant Professor Hariram Sahu

Abstract: The deck girder is one of the most influential components governing the structural response, stiffness, weight, durability, and overall economy of a cable-stayed bridge, and the choice between reinforced concrete (RC), structural steel, and prestressed concrete (PSC) remains a central design decision. This paper presents a structured literature review of published research relevant to this choice, covering material-specific behaviour of RC, steel, and PSC deck girders; design practice and analytical studies on tower geometry, dynamic/seismic response, and finite element modelling; direct comparative studies between deck materials and hybrid/composite systems; economic and life-cycle cost studies; construction-stage and composite-action behaviour; and studies conducted under Indian IRC loading provisions. The review finds general agreement that RC decks are economical and durable under normal service but suffer from higher self-weight and tensile cracking over longer spans; steel decks offer a superior strength-to-weight ratio and rapid erection but require sustained corrosion protection and careful fatigue design; and PSC decks combine improved stiffness and crack control with the durability of concrete, at the cost of higher initial complexity. The review further finds that although each material has been studied extensively in isolation or in pairwise comparison, very few investigations evaluate reinforced concrete, structural steel, and prestressed concrete decks together under identical bridge geometry, loading, and analytical procedure, and fewer still combine such a structural comparison with a consistent life-cycle economic evaluation. This gap is identified as the principal motivation for a unified, controlled-variable comparative investigation of the three deck systems.

DOI: https://doi.org/10.5281/zenodo.21888527

Published by: vikaspatanker

Authors: Ramanuj Singh, Assistant Professor Hariram Sahu

Abstract: Flexible pavements constructed over clay subgrades are highly susceptible to premature distress on account of the low bearing capacity and pronounced moisture sensitivity of clay soils. This paper presents an experimental investigation into the effectiveness of geosynthetic reinforcement in improving the California Bearing Ratio (CBR) of a high-plasticity clay (CH) subgrade collected from Damoh, Madhya Pradesh, India. Two commercially available geosynthetics, a Mirafi HP370 woven polyester geotextile and a Tensar BX1200 biaxial polypropylene geogrid, were evaluated at three reinforcement depths within the CBR mould, namely H/3, H/2, and 2H/3, under both soaked and unsoaked conditions. The soil was classified as CH under IS 1498, with a liquid limit of 55.36%, plasticity index of 30.03%, optimum moisture content of 19.5%, and maximum dry density of 1.69 g/cm³. The unreinforced clay exhibited unsoaked and soaked CBR values of 4.8% and 1.9%, respectively, both indicative of a very weak subgrade. Reinforcement with Tensar BX1200 at H/2 produced the greatest improvement, raising the CBR to 9.6% (unsoaked) and 4.9% (soaked), corresponding to gains of 100.0% and 157.9% over the unreinforced control. The Mirafi HP370 geotextile performed best at H/3, with improvements of 85.4% and 121.1%. The results confirm that both reinforcement type and placement depth significantly influence subgrade performance, and that biaxial geogrid reinforcement at mid-depth offers the greatest structural benefit for the clay investigated. The experimentally derived CBR values are discussed in relation to their implications for flexible pavement thickness design over weak clay subgrades.

DOI: https://doi.org/10.5281/zenodo.21887185

Published by: vikaspatanker

Authors: Prateek Anand, Assistant Professor Rishi Sharma, Assistant Professor Gaurav Morghare

Abstract: Low Earth Orbit (LEO) satellite communication has emerged as a key enabler of sixth-generation (6G) Non-Terrestrial Networks (NTNs), offering global coverage, low propagation delay, and high-capacity broadband connectivity. However, the high orbital velocity of LEO satellites introduces significant challenges, including severe Doppler frequency shifts, rapidly varying channel conditions, and frequent handovers, which adversely affect communication reliability, throughput, and Quality of Service (QoS). Existing Doppler compensation and handover mechanisms are generally treated as independent processes and often rely on static threshold-based strategies or computationally intensive artificial intelligence (AI) models, limiting their adaptability in highly dynamic satellite communication environments. This paper proposes an Adaptive AI-Assisted Doppler Compensation and Predictive Handover Optimization (AIDCPHO) framework for LEO satellite communication in 6G Non-Terrestrial Networks. The proposed framework integrates real-time Doppler estimation, AI-assisted predictive handover decision-making, adaptive beam selection, and dynamic link quality assessment into a unified optimization model. A predictive mobility module estimates future satellite-user link conditions using orbital dynamics and user mobility information, while an adaptive Doppler compensation module minimizes frequency estimation errors before communication degradation occurs. Furthermore, a multi-parameter handover decision algorithm utilizes Signal-to-Noise Ratio (SNR), Doppler shift, elevation angle, received signal strength, and predicted link quality to proactively initiate seamless handovers, thereby reducing service interruption and packet loss. The proposed framework is implemented and evaluated using MATLAB-based simulations that model realistic LEO satellite orbital movement, time-varying communication channels, and user mobility scenarios.

Published by: vikaspatanker