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Saline soil is composed of abundant soluble salts, exhibiting undesirable properties when used in backfill projects. To address the mentioned problem, a hydrophobic polymer with an active ingredient of hydrosiloxane-containing siloxane was evaluated as a soil additive in this paper. Five groups of specimens were solidified with a fixed dosage of polymer, with initial water contents (IWCs) ranging from 12.8% to 20.8%, to determine the effectiveness of polymer treatment and the effect of IWC. Natural specimens were also prepared to serve as a control condition. Results showed that the polymer formed a hydrophobic interface on the surface of soil particles, causing the shrinkage of the diffuse double layer (DDL) and the flocculation of clay particles. Therefore, the plasticity index reduced, and the fine particles transformed into coarser particles after polymer treatment. Furthermore, the polymer-solidified soil exhibited a significant enhancement in unconfined compressive strength, characterized by an agglomerated microstructure that possessed a high cementing ability. Nevertheless, increasing IWCs continuously induced a decrease in the strength of the solidified soil, especially when the IWC was greater than the optimum water content. The maximum strength increase rate could be up to 98.2%. However, at an IWC of 20.8%, the strength increase rate could still reach approximately 72%. Correlation analysis showed that the solidification mechanism of the hydrophobic polymer was mainly electrostatic interactions. Variable water contents mainly affected the formation of polymer bonding and thickness of DDL. The utilization of hydrophobic polymer for soil improvement in backfill projects shows great potential in light of these findings. [ABSTRACT FROM AUTHOR]

Tunneling in sandy dolomite strata often faces hazards such as collapse, water inrush, and water-sand inrush, seriously threatening the safety of tunnel construction. There are currently limited studies on the mechanical behaviors of sandy dolomite tunnels. In view of this, an analytical solution for tunneling in sandy dolomite strata is derived in this study, and then parametric analysis is performed to analyze the mechanical response of rock mass in sandy dolomite tunnels. The results demonstrate five tunnel sidewall stress scenarios according to the different lateral pressure coefficients (λ). Varying λ values impact stress distribution and tunnel stability, with extreme values posing risks of instability. Tunnel safety is greatly reduced when rock stress approaches the plastic limit. At different internal friction angles, cohesion, and initial rock stresses, radial stress decreases gradually as the radius increases. The stress values under different conditions tend to be similar, while the effects of internal friction angle, cohesion, and initial rock stress on stress in the elastic zone decrease with increasing distance from the center of the tunnel. Under different internal friction angles and cohesion, the plastic zone radius increases with increasing distance from the excavation surface, and a larger internal friction angle and cohesion lead to an increase in stress. The stress and cohesion of a rock mass significantly affect the plastic zone radius, and an increase in tunnel excavation radius also leads to an increase in the radius of plastic zone. These findings provide a reference and insight for similar geotechnical engineering practices in the future. [ABSTRACT FROM AUTHOR]

Objective: We summarize the global, regional, and national burden of inflammatory bowel disease (IBD) in children and adolescents from 1990 to 2019., Methods: Based on the Global Burden of Disease Study 2019, the data of IBD in children and adolescents were analyzed by sex, age, year, and location. Joinpoint analysis was applied to assess the temporal trend of the disease burden., Results: From 1990 to 2019, the incidence of IBD in children and adolescents increased by 22.8%, from 20,897.42 to 25,658.55 cases, especially in high SDI region. During the same period, the DALY numbers decreased by 53.5%, from 243,081.06 to 113,119.86, with all SDI regions experiencing a clear drop in DALYs except high SDI regions. In 2019, early-onset IBD incidence and DALY numbers were reported at 2,053.52 (95% UI: 1,575.62 to 2,677.49) and 73,797.46 (95% UI: 43,655.86 to 105,998.63), respectively., Conclusion: Early-onset IBD in children and adolescents remains a significant global health concern. The disease burden has not improved in developed countries over the past 30 years, highlighting the need for targeted interventions., Competing Interests: The authors declare that they do not have any conflicts of interest., (Copyright © 2024 Chen, Xiang, Fan, Xia, Xiao, Wang, Ye, Kang, Jing, Wu and Chen.)