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Povzetek: Each year, over one billion cubic meters of sediments are dredged from ports and inland water bodies to maintain navigability and ensure infrastructure safety, creating significant landfill and environmental challenges. Dredged sediments are typically characterized by high moisture content, low bearing capacity, and limited shear strength. Their sustainable reuse requires effective stabilization and remediation strategies. Recent advancements in soil stabilization have increasingly focused on sustainable bio-binders, particularly biopolymers, due to their ecofriendly properties. This study evaluates the effectiveness of four biopolymers, namely calcium alginate (AL), chitosan (CH), xanthan gum (XA), and guar gum (GG) as sustainable bio-binders for improving dredged sediments from the Port of Koper, Slovenia. Mechanical testing demonstrated that 1 wt% XA, AL, and CH increased unconfined compressive strength by 40 %, 29 %, and 10 %, respectively. Direct shear tests revealed that AL and XA increased cohesion by 52 % and 104 %, respectively, while reducing the friction angle by 4◦ In contrast, CH and GG enhanced both cohesion (by 81 % and 37 %, respectively) and the friction angle (by 1◦ in each case). Consolidation characteristics were also improved, with reduced settlement under normal load. Microstructural analysis identified the formation of biopolymer matrices including fibrous networks, gel films, and particle clusters that explain the mechanical improvements. The findings confirm that biopolymer stabilization is a viable technique to convert dredged marine sediments into engineered materials, minimizing landfill disposal, and supporting the transition to more sustainable construction practices.
Ključne besede: dredged sediment, biopolymer, stabilization, mechanical characterization
Objavljeno v DiRROS: 13.01.2026; Ogledov: 204; Prenosov: 113
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Povzetek: Seepage during the first filling of a reservoir is a critical aspect for earth dams and embankments safety, which requires precise monitoring. The thermometric method has demonstrated significant potential for detecting seepage anomalies through continuous temperature measurements using optical fiber distributed temperature sensing (DTS). However, most previous research has primarily focused on thermal monitoring when seepage flow reached a steady-state condition, which highlights the need for more research on seepage and heat transfer in transient state, particularly in unsaturated soils during the reservoir’s first filling. This paper addresses the transient seepage flow and heat transfer during the first filling of a laboratory sand model. Temperature variations within the sand were recorded using an optical fiber DTS, while seepage progression was tracked through digital imaging at regular intervals, followed by image processing. A coupled hydrothermal numerical model was also developed to simulate transient seepage flow and heat transfer within the unsaturated and variably saturated sand. In numerical modeling, heat dispersion and the thermal conductivity of sand were investigated through parameter calibration. Results indicate that thermal monitoring using optical fiber DTS is an effective method for estimating the development of the phreatic line during the first filling of the reservoir. Numerical simulations further revealed that seepage velocity plays a key role in the heat transfer process during transient seepage. Additionally, the results highlight that heat dispersion significantly influences heat transfer, particularly during transient seepage flow, whereas the effect of thermal conductivity is relatively minor as seepage progresses.
Ključne besede: seepage, phreatic line, temperature, heat dispersion, optical fiber DTS
Objavljeno v DiRROS: 09.05.2025; Ogledov: 576; Prenosov: 337
Celotno besedilo (16,17 MB)
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