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This case study aims to evaluate the impact of deep excavation on the adjacent short floating pile and lateral deformation control strategies using capsule expansion technology (CET). Two control strategies, i.e., real-time control (RTC) and one-time control (OTC), were applied to control the lateral displacement of piles. In this case, the wall lateral deflections (delta hm) range between delta hm=0.075%He and delta hm=0.11%He, which are relatively small and less than the specified protection levels. Although the wall deflection was controlled to a relatively small level through reasonable excavation and support schemes, the maximum horizontal displacement of the short floating pile reached 13.2 mm (0.054%He). Therefore, reasonable deformation control measures are necessary. After three stages of RTC treatment, the maximum lateral displacement of P2 was reduced by 49.2%, while P1 was decreased by 22.7% treated by OTC. Meanwhile, multiple RTCs can always control the pile deformation within the cracking limit, which avoids the dilemma of protecting the pile after it has been damaged. It confirms the feasibility and efficiency of CET in controlling pile deformation in real-time. In addition, RTC for pile lateral displacement mainly includes two aspects: (1) expansion directly induces lateral displacement of piles; and (2) expansion compensates for the soil stress loss in front of the pile to reduce the impact of the next excavation on the pile. Therefore, as external influence sources have long-term adverse effects on adjacent piles, RTC as an efficient control method should be given priority consideration for controlling pile lateral displacement.

期刊论文 2025-04-01 DOI: 10.1061/JGGEFK.GTENG-12740 ISSN: 1090-0241

Carbonate sand, widely distributed in coastal regions, presents challenge due to its high stress-dependent and time-dependent (creep) compressibility. While soil stabilization techniques have traditionally focused on enhancing the strength of carbonate sand, the evaluation on the compressibility performance of cemented carbonate sand remains a critical aspect for most envisaged practical applications. In light of recent developments in self-healing approaches for soil stabilization, this study investigated the potential of calcium alginate/Tung oil capsules to mitigate compressibility in carbonate sand. The encapsulated Tung oil serves as a healing agent, gradually releasing within the sand matrix when subjected to void ratio changes during compaction, hardening and bonding sand grains after a 30-day drying. Long-term stepwise one-dimensional compression tests were conducted on both clean sand and sand-capsule composite with different initial relative density and particle size. The overall and stress-dependent compressibility was reduced for fine sand-capsule composite, while capsules had adverse effect on the compressibility of medium and coarse sand-capsule composite. Capsules could not reduce the creep but increase the elastic response of all sand-capsule composites. The Tung oil bonding could reduce the compressibility by preventing particle breakage of sand during loading. The stabilization mechanism of capsules in carbonate sand with different particle size was further investigated through thermal analysis, CT scan and microscopic analysis, revealing that the compressibility mitigation by capsules depended on the amount of Tung oil release from capsule, which was controlled by the pore structure of sand-capsule composite.

期刊论文 2025-03-31 DOI: 10.1016/j.powtec.2025.120705 ISSN: 0032-5910

The study of various celestial bodies is of great interest at the present time. Soil studies are being conducted. Vibrating robots could be possible tools for implementing the missions involving moving on the surface of celestial bodies. At the same time, such missions must be safe and sustainable. Such missions are very expensive. And they require high-quality modeling. The dynamics of a vibrating robot is investigated in this work. These structures can move on the surface of various celestial bodies, such as Mars, the Moon or asteroids. Various models can be used as a model of the contact interaction of bodies with a surface, in particular the AmontonCoulomb law of friction. This paper is aimed at studying a mechanical system consisting of a rigid body (outer body) placed on a horizontal rough plane and of an internal moving mass moving inside the outer body in a circle lying in a vertical plane, so that the radius vector of the point has a constant angular velocity. Based on the general properties of the solutions, possible periodic modes and their features depending on the parameters of the problem are considered. All qualitatively different solutions in this case are described.

期刊论文 2025-01-01 DOI: 10.1016/j.actaastro.2024.11.042 ISSN: 0094-5765

Bacteria are used in a range of sectors, such as wastewater treatment, bioremediation, or as soil additives. For these applications, live bacteria are encapsulated to protect them from mechanical damage and desiccation. Unlike other types of cargo, bacteria are not always required to be released because when encapsulated, they can interface with their environment and fulfill their roles via molecular transport through the capsule walls. The aims of encapsulation are then shifted away from delaying release to making capsules that are mechanically robust while permitting sufficient diffusion to support the metabolic activity of the bacteria. Here, we produced covalent hydrogel capsules from a water-in-oil (W/O) emulsion of aqueous poly(ethylene glycol) diacrylate (PEGDA) in hexadecane containing a UV-radical initiator. Upon initiation, PEGDA polymerization begins at the W/O interface to produce hydrogel capsules. We discovered three classes of capsule microstructures with differing levels of macroporosity that could be tailored by changing the polymerization conditions. Systematic investigations showed how the UV energy input and the PEGDA macromonomer concentration can be used to selectively create honeycomb, sponge like, or dense spherical capsules. To explain the sponge-like structure, we propose a capsule formation mechanism based on diffusion-limited aggregation of PEGDA microbeads. The structures resemble random-walk simulations of sticky beads and, furthermore, satisfy the theoretical volume fractions required for percolation. We successfully encapsulated live Mycobacterium smegmatis within the sponge structures, demonstrating biocompatibility. Importantly, the internal hydrogel microstructure allows the growth of bacteria. This mechanistic understanding is paramount for designing robust covalent capsules while optimizing porosity within hydrogel structures.

期刊论文 2024-09-10 DOI: 10.1021/acsapm.4c02458 ISSN: 2637-6105

Self-healing approaches are increasingly being explored in various fields as a potential method to recover damaged material properties. By self-recovering without external intervention, self-healing techniques emerge as a potential solution to arrest or prevent the development of large strains problems in soils (e.g., landslides) and other ground effects that influence the serviceability of structures (e.g., differential settlement). In this study, a microcapsule-based self-healing sand was developed, and its performance during mixing and compaction, shearing, and recovery of shear strength was demonstrated. The cargo used for sand improvement, a hardening oil, tung oil, was encapsulated in calcium alginate capsules by the ionic gelation method. The surface properties, internal structure, thermal stability and molecular structure of the capsules were evaluated by advanced material characterization techniques. The survivability of capsules during mixing and compaction was assessed by measuring the content of tung oil released into the sand, while their influence on sand shear strength and its recovery was assessed with shear box tests. The results showed that the capsules could rupture due to movement of the sand particles, releasing the tung oil cargo, leading to its hardening and minimizing its strain-softening response and enhancing up to 76% of the sand shear strength (at a normal stress of 10 kPa and capsules content of 4%). This study demonstrates the potential of a capsules-based self-healing system to provide 'smart' autonomous soil strength recovery and thus with potential to actively control the large strain behavior of soils.

期刊论文 2024-08-01 DOI: 10.1007/s11440-024-02270-7 ISSN: 1861-1125

In order to attenuate the pollution problem caused by low fertilizer utilization, a biodegradable urea slow-release capsule was prepared in this study using gelatin as the main material. Glycerol was added to the gelatin solution as a plasticizer, and the mechanical properties and water resistance of the gelatin film were enhanced by crosslinking with glutaraldehyde. The addition of nano-SiO2 (nSiO2) and calcium magnesium phosphate fertilizer power (CaMgP) enhanced the hydrophobicity and tensile strength of the gelatin film. X-ray diffractometer confirmed that the nSiO2 could make the gelatin molecular chains more tightly entangled. Scanning electron microscope indicated that the addition contents of nSiO2 and CaMgP was optimal at 2 wt% and 40 wt%, respectively. The gelatin capsules were loaded with urea particles for slow-release experiments, the results of soil column drenching showed that the release rates of urea from nSiO2-modified and CaMgP-modified cross-linked gelatin capsules were 4.1 % and 5 % after 24 h, respectively, and 78.8 % and 75.2 % after 28 d, respectively.

期刊论文 2024-05-01 DOI: 10.1016/j.polymertesting.2024.108427 ISSN: 0142-9418

Background: Heavy elements such as antimony greatly affect the environment and living organisms. Antimony is discharged into the environment by mining and industries that use it as pesticides and flame retardants. This activity can lead to environmental pollution, water and soil contamination. Antimony can also accumulate in living organisms and cause negative health effects, such as damage to the respiratory system and skin, and growth abnormalities of animals and plants. Methods : The primary objective of this investigation was to explore the teratogenic impact of the antimony heavy metal on histological structure of the liver in adult rabbits ( Oryctolagus cuniculus ). The study included adult white rabbits divided into several groups: the first one is the control group injected with physiological saline (0.09% NaCl), the other group injected with 20 mg/kg antimony, and the last injected with 30 mg/kg antimony over a 30 -day period. Following this, postmortem procedures were conducted to extract and fix the liver organ, and tissue sections were prepared. Result : The results revealed significant histological changes, including distortion and rupture in Glisson's Capsule, leading to the formation of a sub -capsular space due to its separation from hepatocytes. Additionally, alterations in the radial organization of hepatocytes and pyknosis in the nuclei were observed, characterized by a dark color and reduced size. Karyolysis, where nuclei completely disappeared, and hydropic degeneration in hepatocytes with swollen appearance and dark nuclei due to fluid accumulation were noted. Moreover, an increase in Kupffer cells and blood congestion in the central vein, resulting in dilation compared to the control group, were observed. Conclusion : Overall, the treatment with antimony at 20 and 30 mg/g doses for 30 days show profound teratogenic effects on the histological structure of the liver in adult rabbits. These effects are represented by the destruction of various parts of liver, in addition to changes in arrangement, and distortion and rupture of the cells. Furthermore, an increase in Kupffer cells and blood congestion were also recorded.

期刊论文 2024-05-01 ISSN: 2310-5380

The capsule expansion technique (CET) is a novel active measure to control the deformation of subsurface structures induced by underground engineering construction. CET has been applied to tunnel deformation control, but its application in pile foundations is rarely reported. In this paper, a field trial and three-dimensional coupled consolidation finite-element analysis were performed to study the interaction of capsule-soil-pile and control efficiency of CET. Field trial results verify the feasibility of CET in controlling pile horizontal deformation, and the control efficiency is 60% higher than that of Tube-a-Manchette grouting with 40%. Numerical back analyses indicate that the pile maximum displacement increases almost linearly with the expansion diameter, while the control efficiency of CET hardly changes. The total stress of the soil in front of the pile is significantly reduced by 20.3% due to the dissipation of excess pore-water pressure, resulting in the reverse displacement of the pile. High excess pore pressure induced by CET would cause the soil to bear additional stress after dissipating, leading to the reverse displacement of the soil and further diminishing the control efficiency. Moreover, control efficiency can be improved by reducing the surrounding excess pore-water pressure induced by expansion and increasing the excess pore-water pressure at the back side of the pile.

期刊论文 2024-01-01 DOI: 10.1061/IJGNAI.GMENG-8985 ISSN: 1532-3641
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