Solutions for Soil-Pile-Soil Forces in Pile Stabilized Slopes

This paper introduces a mathematical procedure to analyze slope/pile systems. Limiting equilibrium method of slices is extended to account for the pile in the slope. Force and moment equilibrium for each individual slice is satisfied. The proposed procedure allows two separate predefined failure slip surfaces (one in the upslope side and the other in the downslope side) with a unique factor of safety for each slip surface. An illustrative example is presented to elucidate the use of the solution in comprehending the interrelationships among the pile location, the desired factor of safety of the slope/pile system, and the interactive soil/pile forces

Lateral Response of Drilled Shafts in A Moving Cohesive Soil

Three-dimensional finite element (FE) analysis was carried out to investigate the behavior of a single row of drilled shafts installed in an unstable slope and to determine the soil pressures acting on the shafts. ABAQUS program was used and the built-in Mohr–Coulomb constitutive model was employed to model the elastic–plastic behavior of the purely cohesive soil, while the drilled shaft was assumed to behave as linear elastic. The length of the drilled shaft is 10 m with a diameter of 1 m. The center-to-center spacing between drilled shafts was taken as 2 m. Slope movement was simulated by imposing a uniform horizontal movement of the soil adjacent to the shaft. Soil pressures along the shaft were recorded at several uniform lateral soil movements until the ultimate soil movement was reached. Cohesion of soil was varied in the FE simulations from 30 to 100 kPa to study its influence on the soil pressure profiles. The effect of shaft stiffness on soil pressures was also included in the study through the relative shaft/soil flexibility factor KR. Two cases of drilled shafts were considered: (1) stiff shaft with KR = 2.9; and (2) flexible shaft with KR = 0.00004. Soil pressures from FE analyses were idealized and simplistic equations were developed and presented which will allow prediction of soil pressures acting on flexible and stiff shafts. The computed ultimate soil pressures agreed well with those from the literature. The computed soil movement to fully mobilize the ultimate contact pressure was found to vary from 10 to 35% of drilled shaft diameter (D) for flexible shafts and from 7 to 15% of the drilled shaft diameter for stiff shafts depending on soil cohesion. The relative displacement between the moving soil and the moving drilled shaft for the contact pressure to be fully mobilized at the soil/shaft interface was found to range from 3 to 15% of the shaft diameter

Recent Advancements in Geothermal Energy Piles Performance and Design

Geothermal energy piles or ground heat exchange (GHE) systems embrace a sustainable source of energy that utilizes the geothermal energy naturally found inside the ground in order to heat and/or cool buildings. GHE is a highly innovative system that consists of energy loops within foundation elements (shallow foundations or piles) through which a heat carrier fluid circulates, enabling heat extraction or storage in the ground. Despite the innovation and potential of GHE systems, there are significant challenges in harmonizing their thermal and mechanical designs due to the complex interactions involved. This review critically examines state-of-the-art design methodologies developed to address these complexities, providing insights into the most recent advancements in GHE performance and design. Key findings include innovative techniques such as advanced numerical modeling to predict thermomechanical behavior, the use of different pipe configurations to optimize heat transfer, and strategies to minimize thermal stress on the foundation. Additionally, this review identifies research gaps, including the need for more comprehensive full-scale experimental validations, the impact of soil properties on system performance, and the long-term effects of thermal cycling on pile integrity. These insights aim to contribute to a better understanding of the thermomechanical behavior of energy piles, ultimately facilitating more accurate and effective design solutions

Managing uncertainty in multidisciplinary renal team meetings : decision-making processes and complex challenges in kidney transplant listing

Multidisciplinary team (MDT) meetings are common to many fields of medicine and widely established internationally. They are intended to ensure higher-quality decision-making and improved patient outcomes. For patients with end-stage kidney disease (ESKD), decisions on whether to place marginally suitable candidates on the kidney transplantation waiting list can be challenging and as such they are supported by MDT meetings. Uncertainty in terms of the best course of action can be linked with a dearth of knowledge or evidence on specific medical conditions and likely implications for successful transplantation, but also on unforeseen outcomes influenced by patient behaviours. In this project, we observed how MDT meetings work in practice in kidney transplant listing, unpacking issues of risk and uncertainty in transplant decision-making processes. Our findings indicate that a central value of MDT meetings is managing medical uncertainty and psychosocial risks, and distributing responsibility for complex transplant listing decisions to ensure equity of access to transplantation as well as an efficient use of scarce kidneys. This sheds light on strategies enacted to mitigate these risks and uncertainties, and the role played by different types of knowledge (experiential versus scientifically evidence-based) in the overall decision-making process

A systematic review of the prevalence and associations of limited health literacy in CKD

Background and objectives: The self-management and decision-making skills required to manage CKD successfully may be diminished in those with low health literacy. A 2012 review identified five papers reporting the prevalence of limited health literacy in CKD, largely from United States dialysis populations. The literature has expanded considerably since. Design, setting, participants, & measurements: We used systematic review, pooled prevalence analysis, metaregression, and exploration of heterogeneity in studies of patients with CKD (all stages). Results: From 433 studies, 15 new studies met the inclusion criteria and were analyzed together with five studies from the 2012 review. These included 13 cross-sectional surveys, five cohort studies (using baseline data), and two using baseline clinical trial data. Most (19 of 20) were from the United States. In total, 12,324 patients were studied (3529 nondialysis CKD, 5289 dialysis, 2560 transplant, and 946 with unspecified CKD; median =198.5; IQR, 128.5–260 per study). Median prevalence of limited health literacy within studies was 23% (IQR, 16%–33%), and pooled prevalence was 25% (95% confidence interval, 20% to 30%) with significant between-study heterogeneity (I2=97%). Pooled prevalence of limited health literacy was 25% (95% confidence interval, 16% to 33%; I2=97%) among patients with CKD not on dialysis, 27% (95% confidence interval, 19% to 35%; I2=96%) among patients on dialysis, and 14% (95% confidence interval, 7% to 21%; I2=97%) among patients with transplants. A higher proportion of nonwhite participants was associated with increased limited health literacy prevalence (P=0.04), but participant age was not (P=0.40). Within studies, nonwhite ethnicity and low socioeconomic status were consistently and independently associated with limited health literacy. Studies were of low or moderate quality. Within-study participant selection criteria had potential to introduce bias. Conclusions: Limited health literacy is common in CKD, especially among individuals with low socioeconomic status and nonwhite ethnicity. This has implications for the design of self-management and decision-making initiatives to promote equity of care and improve quality. Lower prevalence among patients with transplants may reflect selection of patients with higher health literacy for transplantation either because of less comorbidity in this group or as a direct effect of health literacy on access to transplantation