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The accurate quantification of the temporal changes in seabed strength allows for more reliable and less conservative geotechnical design. A recently developed effective stress framework, established within a one-dimensional computational domain to quantify changes in soil strength due to pore pressure generation and dissipation, has been extended to a two-dimensional (2D) computational domain to allow for consideration of boundary value problems that are too complex to be simplified to one-dimensional conditions. The work to implement the 2D framework is reported across two companion papers. The first of the two papers utilises large deformation finite element analyses to quantify the spatial distribution of accumulated plastic shear strain. These distributions are encapsulated within a strain influence function that is used within the new 2D framework in this paper to calculate the extent and magnitude of excess pore pressure, and in turn the mobilised soil strength for a number of boundary value problems that represent typical offshore geotechnical processes. The merit of the new 2D framework is explored via retrospective simulations of existing experimental and numerical data. The resulting comparisons demonstrate the potential of the new framework, which is in quantifying the reliability of a range of geotechnical structures under complex loading conditions. [ABSTRACT FROM AUTHOR]

With more and more loss caused by forest biological disasters (FBDs) in China, forest farmers, as one of the most important stakeholders, are participating in the control. In this study, the ordinary least squares model, simultaneous equation model, and propensity score matching method were used with the data from 818 surveys conducted in the typical FBD outbreak provinces, to reveal the FBD control behaviors of forest farmers and their differences between western and eastern regions of China. The results indicated the following. (1) Household factors: forest farmers could timely take control measures. An increase of 1 ha in the area of occurrence would increase the control measures by 3.26 ha. However, the control measures can only reduce 50% of the economic loss caused by FBDs and cannot effectively control the spread trend of FBDs. There are issues, including an insufficient and old labor force, insufficient technology support, and low consciousness of ecology protection. (2) External factors: forest farmers would increase control when the temperature rises, and reduce control when rainfall increases. After village committees unify organizing the control, their participation enthusiasm would increase, which would have a substitution relationship with the household investment. (3) Regional difference: the eastern region of China has higher figures than the western in terms of outbreak area, economic losses, control measures, and pesticide cost. If the western forest farmers have the control funds as the eastern forest farmers have, and the eastern forest farmers have the control intensity as the western forest farmers have, the overall FBD control effect would be better. [ABSTRACT FROM AUTHOR]

Marine soft clays are prevalent in coastal regions of China, giving rise to engineering challenges such as salt swelling, corrosion, and load bearing in foundations with soft soil. This study is dedicated to enhancing the mechanical properties of fiber-reinforced cement-stabilized soft clay (FCSSC) and revealing its strengthening mechanism. Uniaxial compression tests are performed to explore the impact of fiber length, fiber amount, and curing ages on mechanical behavior. The stabilization mechanisms of cement and glass fibers are explored through damage analyses and microscopy. Based on the experimental results, a damage constitutive model is formulated for FCSSC, and its validity is established by comparing fitting curves with testing curves. The results demonstrate a significant improvement in the mechanical properties of the stabilized soil, attributed to the synergistic effects of the cement and glass fibers. The growth rate of the unconfined compressive strength decreased with increasing curing ages. Notably, the fiber length significantly impacted the strength index, with short-chopped fibers playing a crucial role in strength enhancement. The compressive strength exhibited an initial increase followed by a decrease with rising fiber content, reaching a maximum between 0.3% and 0.4%. The bridging effect of the glass fibers proved effective in inhibiting compression crack expansion and mitigating structural damage of the soil sample. However, excessive fiber content or length led to improved local porosity, resulting in the deterioration of strength and deformation properties. The stress–strain curves fitted using the proposed damage constitutive model accurately reflected the stress–strain relationship and deformation characteristics of the FCSSC. [ABSTRACT FROM AUTHOR]

Forest biological disaster control (FBDC) is appealing the attention in China and even across the world, while the control system plays a pivotal role in the entire control work. The survey-based comprehensive indicators system was developed to evaluate the perceived effectiveness of the entropy weight model and the perceived responsibilities of the FBDC system of China from the perspective of government administrators at the province-, prefecture-, and county- levels. Ordinary Least Square (OLS) and Simultaneous Equations Models (SEM) were further developed to quantitatively analyze the affecting factors of the perceived effectiveness. The results indicated that the perceived effectiveness of the FBDC system in China was relatively low, with a value of 47.18 (the range is 0–100). In specific, the county level has the highest value of 48.85, while the province level has the lowest value of 42.99. The major limiting factors perceived are the insufficiency of the funds and employees. In addition, the intelligentization level, the implementation of the quarantine enforcement, the infrastructure construction, and the involvement of the local communities also need to be further improved. The salary does not positively affect the perceived effectiveness, while administrators with higher education levels and ages usually have higher salaries. Furthermore, compared with the province- and prefecture-level agencies, the county-level agencies have higher perceived effectiveness and more perceived responsibilities with higher workloads. Thus, future policies are suggested to focus on diversifying the investment sources, refining the employee recruitment and promotion system, and paying more attention to the county-level agencies. The results of this study could help to enhance the understanding of the FBDC system of China, hence improving the control efficiency and reducing the economic loss caused by forest biological disasters in China. [ABSTRACT FROM AUTHOR]