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Cyclic resistance curves, derived through undrained element tests, are central to the study of liquefaction. Their use implies that water drainage is negligible during an earthquake. Nevertheless, a growing body of evidence suggests that this hypothesis is not realistic. In proximity to the interface of a liquefiable layer with an overlying lower permeability layer, upwards water flow can lead to localised, co-seismic pore volume increase. The aim of this paper is to quantify the effects of pore volume increase on cyclic resistance curves. Cyclic triaxial experiments are presented, performed under undrained conditions and under conditions of volumetric expansion. A constant inflow rate is chosen for the sake of simplicity. Results show that even small inflow rates have a detrimental effect on cyclic resistance. A simplified methodology is developed, which can estimate cyclic resistance under constant water inflow rates, by assuming a superposition of isotropic unloading and undrained cyclic shearing. The results presented add to increasing evidence on how current liquefaction susceptibility assessments might not be conservative for layered deposits. In addition, they highlight significant aspects of soil response under partially drained conditions. [ABSTRACT FROM AUTHOR]

Internal erosion by suffusion within a sand–clay mixture may occur as detachment of clay particles, which is induced by a decrease in ionic concentration (IC) along with application of a high hydraulic gradient. Through designed laboratory soil-column experiments, this study investigates the impact of the IC gradient (stepwise or gradual decrease), clay mineralogy, sand particle size and hydraulic gradient on the suffusion of a sand–clay mixture. The observed breakthrough concentration of clay particles revealed the substantial suffusion of a sand–clay mixture caused by a stepwise decrease in the IC for kaolinite and illite, while similar filtrated quantities of bentonite were observed for stepwise and gradual decreases in IC. In addition, the small-grained sand showed a relatively high susceptibility to suffusion by a stepwise decrease in IC, most likely because of the low reattachment of detached clay particles. The mass of filtrated clay particles evaluated from the area of the observed breakthrough curves in this study provides a clear insight into the need to incorporate the IC gradient when assessing the susceptibility to the suffusion of clay-containing soils. [ABSTRACT FROM AUTHOR]

This study explores the estimation of rock properties using sound levels and drilling parameters recorded during quantitative drilling. Utilizing an indoor digital drilling test system and acoustic monitoring device developed by the authors, the research involved setting varied drilling parameters for vertical drilling of various rocks and rock-like materials. The equivalent continuous A-weighted sound pressure levels were measured during the drilling process. Simultaneously, the compressive strength of the drilled rock and rock-like samples was determined in the laboratory. A regression prediction model was developed using drilling rate (V), rotational speed (N), torque (M), propulsive force (F), ground stress magnitude (σ), and equivalent continuous A-weighted sound pressure level (Leq A) as inputs and compressive strength Rc as the output. To enhance prediction accuracy, the model integrates the feature extraction capabilities of traditional random forest (RF) and deep neural network (DNN) methodologies while incorporating a genetic algorithm (GA) for feature selection and parameter optimization. Analysis of the results indicates that the prediction accuracy of the DNN–GA–RF (deep neural network–genetic algorithm–random forest) model, based on sound level and drilling parameters, significantly surpasses traditional methods such as ridge regression, support vector machine, and RF. This finding highlights the potential of the equivalent continuous A-weighted sound pressure level as an effective tool for estimating rock properties during drilling. Furthermore, the model’s integrated learning-based approach to predicting rock strength indicators offers an innovative concept and methodological basis for the nondestructive assessment of rock properties. [ABSTRACT FROM AUTHOR]

Background: Reducing low-value care (LVC) is crucial to improve the quality of patient care while increasing the efficient use of scarce healthcare resources. Recently, strategies to de-implement LVC have been mapped against the Expert Recommendation for Implementing Change (ERIC) compilation of strategies. However, such strategies' effectiveness across different healthcare practices has not been addressed. This overview of systematic reviews aimed to investigate the effectiveness of de-implementation initiatives and specific ERIC strategy clusters. Methods: We searched MEDLINE (Ovid), Epistemonikos.org and Scopus (Elsevier) from 1 January 2010 to 17 April 2023 and used additional search strategies to identify relevant systematic reviews (SRs). Two reviewers independently screened abstracts and full texts against a priori–defined criteria, assessed the SR quality and extracted pre-specified data. We created harvest plots to display the results. Results: Of 46 included SRs, 27 focused on drug treatments, such as antibiotics or opioids, twelve on laboratory tests or diagnostic imaging and seven on other healthcare practices. In categorising de-implementation strategies, SR authors applied different techniques: creating self-developed strategies (n = 12), focussing on specific de-implementation strategies (n = 14) and using published taxonomies (n = 12). Overall, 15 SRs provided evidence for the effectiveness of de-implementation interventions to reduce antibiotic and opioid utilisation. Reduced utilisation, albeit inconsistently significant, was documented in the use of antipsychotics and benzodiazepines, as well as in laboratory tests and diagnostic imaging. Strategies within the adapt and tailor to context, develop stakeholder interrelationships, and change infrastructure and workflow ERIC clusters led to a consistent reduction in LVC practices. Conclusion: De-implementation initiatives were effective in reducing medication usage, and inconsistent significant reductions were observed for LVC laboratory tests and imaging. Notably, de-implementation clusters such as change infrastructure and workflow and develop stakeholder interrelationships emerged as the most encouraging avenues. Additionally, we provided suggestions to enhance SR quality, emphasising adherence to guidelines for synthesising complex interventions, prioritising appropriateness of care outcomes, documenting the development process of de-implementation initiatives and ensuring consistent reporting of applied de-implementation strategies. Registration: OSF Open Science Framework 5ruzw. [ABSTRACT FROM AUTHOR]

Two series of experiments were carried out to examine pressurised bentonite slurry infiltration into saturated sand columns. Three types of sand were examined, and water–bentonite and water–bentonite–sand slurries were used in series 1 and 2, respectively. Series 1 investigated the effect of sand particle size and series 2 examined the effect of the fine-sand particle content in the slurry. Scanning electron microscopy (SEM) imaging was used to observe the morphological features of the dry slurry-infiltrated sand samples. A solution for the infiltration distance during mud spurt for water–bentonite–sand slurry infiltration was verified using the data from series 2. The infiltration test results showed that the hydraulic conductivity of the slurry-infiltrated coarse sand for slurry in series 2 was lower than that in series 1. Visual observations and the SEM images showed that sand particles were bound to a bentonite film, indicating that, during infiltration, the channels for fluid flow among the sand particles are blocked by the bentonite particles adhered to the sand particles. The solution for the infiltration distance during mud spurt for water–bentonite–sand slurry infiltration showed good agreement with the experimental results. [ABSTRACT FROM AUTHOR]

Chemical grouting is a technique where solution-based binders are used to improve both mechanical and hydraulic properties of the soil or rocks. The following research study shows an extensive laboratory programme where a polyurethane (PU) and an acrylate (AC) were grouted in a tertiary sand under different water contents and relative density, with different gelling time and grouting conditions. Unconfined compressive strength, splitting tests, triaxial tests and creep tests on the grouted materials were conducted. A statistical interpretation considering the kernel probability density function was performed in order to understand the interdependency of the changing parameters. In general, PU-consolidated samples provide higher mechanical properties with respect to ACs; however, the effects and the dependency on the geotechnical base parameters are different. [ABSTRACT FROM AUTHOR]

Vertical drains are used widely to accelerate the consolidation of soft clay deposits when preloading is used as a ground improvement technique. One of the essential input parameters required in Barron's theory is the coefficient of horizontal consolidation, ch. The values of ch can be determined by the radial consolidation test, using either a central sand drain or a porous plastic peripheral drain. This paper presents the laboratory tests carried out to understand the reason for the difference in values of ch determined from inward and outward radial flow consolidations tests. A 150 mm wide instrumented consolidation cell was used to carry out the inward or outward radial consolidation tests. The total stress measurements during consolidation showed non-uniform stress distribution in clay with higher effective stress values close to the drainage boundary. This stiffening of the clay close to the drain retards the consolidation rate resulting in reduced values of ch. As a result, the ch values determined by radially outward consolidation tests with a larger drainage boundary area are lower to those obtained by inward radial flow tests. The pore water pressure measurements showed significantly higher undissipated pore water pressure away from the drainage boundary for the outward flow tests. [ABSTRACT FROM AUTHOR]

A team comprising nursing, medical staff, and administrative leaders at an urban academic orthopedic hospital in the northeastern United States sought to revise a preoperative laboratory testing protocol based on evidence and practice guidelines. The goal was to decrease unnecessary tests by 20% without negatively affecting patient outcomes. After adding the revised protocol to the electronic health record, audits revealed that the target goal was not met and additional strategies were implemented, including educational webinars for surgeon office personnel who ordered tests, additional webinars for advanced practice professionals, and the creation of scorecards to track surgeons' progress. Overall, a downward trend in the ordering of unnecessary laboratory tests for patients without identified risks was observed, but a 20% reduction was not achieved. Surgical complications during the project were not associated with laboratory tests. Clinicians continue to use the revised preoperative laboratory testing protocol at the facility. [ABSTRACT FROM AUTHOR]

Currently, the treatment of miscellaneous fill foundations, composed of a mixture of domestic garbage, construction solid waste, and natural soil, presents a significant challenge in urban peripheral engineering construction. This paper discusses the application of vibrating rod compaction technology for foundation treatment in Xinjiang. It evaluates the effectiveness of cross-section vibrating rod compaction equipment in reinforcing fine-grained miscellaneous fill foundations. The study analyzes the impact of construction disturbances caused by the insertion of the vibrating rod, monitoring horizontal stresses at various depths. Both laboratory and field tests show significant improvements: soil dry density increased by 8% to 18%, porosity decreased by 10% to 23%, compression modulus increased by 22% to 246%, and compression coefficient decreased by 8% to 70%. Additionally, cohesion (C) and angle of friction (ɸ) saw increases ranging from 7 to 38% and 3% to 25%, respectively. Below a depth of 3 m, cone tip resistance exceeded 10 MPa, and sidewall friction resistance increased to over 100 kPa, surpassing pre-treatment values. The standard penetration test results doubled stroke length compared to pre-treatment, indicating a substantial improvement in foundation bearing capacity. Surface wave tests before and after treatment showed a 15% increase in wave velocity, reflecting a more compact soil structure. The vibrating rod compaction method is innovative, energy-efficient, environmentally friendly, and economically beneficial, holding great potential for future miscellaneous fill treatments. [ABSTRACT FROM AUTHOR]

The epidemiological and clinical characteristics of acute poisoning with liquid laundry detergent capsules have been comprehensively reported. However, studies of laboratory test results in these exposures are uncommon. This study analyzed the impact of the ingestion of liquid laundry detergent capsules on admission laboratory tests in paediatric patients. This retrospective study was conducted in the clinical toxicology unit of a paediatric poison centre between 2015 and 2021. Paediatric patients (less than 18 years of age) who ingested liquid laundry detergent capsules were included. The relationship between the European Association of Poisons Centers and Clinical Toxicologists/European Commission/International Programme on Chemical Safety Poisoning Severity Score and admission laboratory test results was assessed using Fisher's exact test or analysis of variance. A total of 156 patients were included in the study. A considerable proportion of patients presented with leucocytosis, acidosis, hyperlactataemia or base deficit. The median values of white blood cell count (P = 0.042), pH (P = 0.022), and base excess (P = 0.013) were significantly different among the Poisoning Severity Score groups. Hyperlactataemia was strongly associated with the Poisoning Severity Score (P = 0.003). Leucocytosis is a non-specific marker of severity following ingestion of liquid laundry detergent capsules. The incidence of metabolic acidosis and hyperlactataemia was higher in this study than in previous reports, but these metabolic features were not related to the severity of exposure. The exact mechanisms of toxicity are not yet known, but the high concentration of non-ionic and anionic surfactants, as well as propylene glycol and ethanol, in the capsule are likely contributing factors. Pediatric patients who ingest liquid laundry detergent capsules may develop leucocytosis, metabolic acidosis, hyperlactataemia, and a base deficit. [ABSTRACT FROM AUTHOR]

Kidney stone disease is a widespread urological disorder affecting millions globally. Timely diagnosis is crucial to avoid severe complications. Traditionally, renal stones are detected using computed tomography (CT), which, despite its effectiveness, is costly, resource-intensive, exposes patients to unnecessary radiation, and often results in delays due to radiology report wait times. This study presents a novel approach leveraging machine learning to detect renal stones early using routine laboratory test results. We utilized an extensive dataset comprising 2156 patient records from a Saudi Arabian hospital, featuring 15 attributes with challenges such as missing data and class imbalance. We evaluated various machine learning algorithms and imputation methods, including single and multiple imputations, as well as oversampling and undersampling techniques. Our results demonstrate that ensemble tree-based classifiers, specifically random forest (RF) and extra tree classifiers (ETree), outperform others with remarkable accuracy rates of 99%, recall rates of 98%, and F1 scores of 99% for RF, and 92% for ETree. This study underscores the potential of non-invasive, cost-effective laboratory tests for renal stone detection, promoting prompt and improved medical support. [ABSTRACT FROM AUTHOR]

The softening effect has been widely accepted as the fundamental mechanical property of the granular materials, which underlies some specific phenomena such as fluidization during vibration. In this paper, a series of resonance column experiments are performed to observe the modulus softening of granular materials. A statistical softening model is subsequently proposed and its applicability is verified through a quantitative analysis of the variation of the normalized modulus by changing the external confining pressure. The average potential energy in grain contact has been found to be a power-law scaling with grain size. An evolution model is further implemented to account for the experimental findings on the evolution of modulus of the granular system subjected to different confining pressures. The modulus evolution, including softening and recovery, can be captured by the unified evolution model. [ABSTRACT FROM AUTHOR]

Abstract Background Reducing low-value care (LVC) is crucial to improve the quality of patient care while increasing the efficient use of scarce healthcare resources. Recently, strategies to de-implement LVC have been mapped against the Expert Recommendation for Implementing Change (ERIC) compilation of strategies. However, such strategies’ effectiveness across different healthcare practices has not been addressed. This overview of systematic reviews aimed to investigate the effectiveness of de-implementation initiatives and specific ERIC strategy clusters. Methods We searched MEDLINE (Ovid), Epistemonikos.org and Scopus (Elsevier) from 1 January 2010 to 17 April 2023 and used additional search strategies to identify relevant systematic reviews (SRs). Two reviewers independently screened abstracts and full texts against a priori–defined criteria, assessed the SR quality and extracted pre-specified data. We created harvest plots to display the results. Results Of 46 included SRs, 27 focused on drug treatments, such as antibiotics or opioids, twelve on laboratory tests or diagnostic imaging and seven on other healthcare practices. In categorising de-implementation strategies, SR authors applied different techniques: creating self-developed strategies (n = 12), focussing on specific de-implementation strategies (n = 14) and using published taxonomies (n = 12). Overall, 15 SRs provided evidence for the effectiveness of de-implementation interventions to reduce antibiotic and opioid utilisation. Reduced utilisation, albeit inconsistently significant, was documented in the use of antipsychotics and benzodiazepines, as well as in laboratory tests and diagnostic imaging. Strategies within the adapt and tailor to context, develop stakeholder interrelationships, and change infrastructure and workflow ERIC clusters led to a consistent reduction in LVC practices. Conclusion De-implementation initiatives were effective in reducing medication usage, and inconsistent significant reductions were observed for LVC laboratory tests and imaging. Notably, de-implementation clusters such as change infrastructure and workflow and develop stakeholder interrelationships emerged as the most encouraging avenues. Additionally, we provided suggestions to enhance SR quality, emphasising adherence to guidelines for synthesising complex interventions, prioritising appropriateness of care outcomes, documenting the development process of de-implementation initiatives and ensuring consistent reporting of applied de-implementation strategies. Registration OSF Open Science Framework 5ruzw.

Abstract Currently, the treatment of miscellaneous fill foundations, composed of a mixture of domestic garbage, construction solid waste, and natural soil, presents a significant challenge in urban peripheral engineering construction. This paper discusses the application of vibrating rod compaction technology for foundation treatment in Xinjiang. It evaluates the effectiveness of cross-section vibrating rod compaction equipment in reinforcing fine-grained miscellaneous fill foundations. The study analyzes the impact of construction disturbances caused by the insertion of the vibrating rod, monitoring horizontal stresses at various depths. Both laboratory and field tests show significant improvements: soil dry density increased by 8% to 18%, porosity decreased by 10% to 23%, compression modulus increased by 22% to 246%, and compression coefficient decreased by 8% to 70%. Additionally, cohesion (C) and angle of friction (ɸ) saw increases ranging from 7 to 38% and 3% to 25%, respectively. Below a depth of 3 m, cone tip resistance exceeded 10 MPa, and sidewall friction resistance increased to over 100 kPa, surpassing pre-treatment values. The standard penetration test results doubled stroke length compared to pre-treatment, indicating a substantial improvement in foundation bearing capacity. Surface wave tests before and after treatment showed a 15% increase in wave velocity, reflecting a more compact soil structure. The vibrating rod compaction method is innovative, energy-efficient, environmentally friendly, and economically beneficial, holding great potential for future miscellaneous fill treatments.

The ring penetrometer is a shallow rotational penetrometer that has been developed to characterise the mechanical behaviour of surficial marine sediments. The strain-rate dependency of soils is crucial to the design of a wide range of offshore geotechnical infrastructure founded in the upper layers of the seabed (e.g. pipelines, cables and shallow foundations). This paper explores the potential application of a ring penetrometer test to measure the strain-rate dependency of the interface friction generated in soft soils at low stresses. Large-deformation numerical models of the test are developed using an elastoplastic constitutive model and a viscoplastic variant with strain softening. Using parameters representative of kaolin clay and a calcareous silt from an offshore location, the numerical analyses demonstrate a clear and measurable influence of both the viscous and strain-softening behaviours on the device–soil interface friction. These simulations were used to design suitable experimental protocols for multi-rate ring penetrometer tests, the results of which yielded a strain-rate dependency of 9–16% and 22–26% per log cycle in the kaolin clay and calcareous silt, respectively, which compare favourably with measurements derived from T-bar twitch experiments. Finally, models are presented that can be applied in the interpretation of varying-rate ring penetrometer test data for application in practice. [ABSTRACT FROM AUTHOR]

MX80 bentonite pellet/powder mixture has been considered as a candidate sealing/filling material in geological high-level radioactive waste disposal. As a single pellet can play an important role in the global hydro-mechanical behaviour of the mixture, the compression behaviour of a single MX80 pellet was investigated by performing uniaxial compression tests on cylinder-shaped pellets at different initial suctions, imposed by the vapour equilibrium technique. Large cracks were observed at suctions ≤ 9 MPa. Results from the compression tests showed that the axial strain εaxial contributed to the contractancy, whereas the lateral strain εlateral contributed to the dilatancy. The uniaxial shear strength σa, max, the crack closure (CC) stress σcc, the crack initiation (CI) stress σci, the crack damage (CD) stress σcd and the Young's modulus E were found to decrease with decreasing suction, providing evidence of the suction effect through softening and cracking. CI was considered as the inflection point of Δεlateral and the onset of dilatancy. Because of the combined effects of suction and wetting-induced cracks, the Poisson's ratios v increased until the suction decreased to 38–25 MPa, and then decreased with further suction decrease. Loading closed the wetting-induced horizontal cracks at suctions ≤ 9 MPa, leading to a drop of εlateral before CC. [ABSTRACT FROM AUTHOR]

Abstract Lime is widely used for soft ground treatment, rendering the compressibility of lime-treated soil a crucial factor in deformation analysis in engineering applications. This study investigated the compressibility of three remoulded lime-treated slurries with high water content in Southeast China. Sixty groups of oedometer tests were conducted on lime-treated soils with an initial water content of 1 to 3 times the liquid limit and lime contents between 1 and 3%. The oedometer test results were discussed to examine the remoulded yield stress $${\upsigma }_{y}^{\prime}$$ σ y ′ of lime-treated slurry. Considering the relationships between $${\upsigma }_{y}^{\prime}$$ σ y ′ , the void ratio, lime content, and initial water content were preliminarily discussed and quantitatively established. Research on the normalised compression curve of lime-treated soil revealed that for soil samples containing a lime content of 0–%, the normalised compression curve at $${\upsigma }_{p}^{\prime}$$ σ p ′ > $${\upsigma }_{y}^{\prime}$$ σ y ′ can be represented by a unique line. Furthermore, the log(1 + e) − log $${\sigma }_{\text{v}}^{\prime}$$ σ v ′ compression curve of lime-treated slurry at pre-yield state is analysed, and a prediction method for the modified compression index is proposed.

Abstract This paper aims to estimate the permeability of concrete by replacing the laboratory tests with robust machine learning (ML)-based models. For this purpose, the potential of twelve well-known ML techniques was investigated in estimating the water penetration depth (WPD) of nano natural pozzolana (NNP)-reinforced concrete based on 840 data points. The preparation of concrete specimens was based on the different combinations of NNP content, water-to-cement (W/C) ratio, median particle size (MPS) of NNP, and curing time (CT). Comparing the results estimated by the ML models with the laboratory results revealed that the hist-gradient boosting regressor (HGBR) and K-nearest neighbors (KNN) algorithms were the most and least robust models to estimate the WPD of NNP-reinforced concrete, respectively. Both laboratory and ML results showed that the WPD of NNP-reinforced concrete decreased with the increase of the NNP content from 1 to 4%, the decrease of the W/C ratio and the MPS, and the increase of the CT. To further aid in the estimation of concrete’s WPD for engineering challenges, a graphical user interface for the ML-based models was developed. Proposing such a model may be effectively employed in the management of concrete quality.

Refractory materials containing calcium aluminate cement (CAC) are commonly used in the metallurgical and petrochemical industries due to their exceptional mechanical resistance, even at temperatures exceeding 1000 °C, and do not require additional reinforcement. This study seeks to advance this practice by developing ultra-high-performance structures that offer building protection against fire and explosions. Such structures require bar reinforcement to withstand accidental tension stresses, and the bond performance becomes crucial. However, the compressive strength of these materials may not correlate with their bond resistance under high-temperature conditions. This study investigates the bond behavior of ribbed stainless austenitic steel bars in refractory materials typical for structural projects. The analysis considers three chamotte-based compositions, i.e., a conventional castable (CC) with 25 wt% CAC, a medium-cement castable (MCC) with 12 wt% CAC, a low-cement castable (LCC), and a low-cement bauxite-based castable (LCB); the LCC and LCB castables contain 7 wt% CAC. The first three refractory compositions were designed to achieve a cold compressive strength (CCS) of 100 MPa, while the LCB mix proportions were set to reach a CCS of 150 MPa. Mechanical and pull-out tests were conducted after treatment at 400 °C, 600 °C, 800 °C, and 1000 °C; reference specimens were not subjected to additional temperature treatment. This study used X-ray fluorescence (XRF), X-ray diffraction (XRD), and scanning electron microscopy (SEM) methods to capture the material alterations. The test results indicated that the bonding resistance, expressed in terms of the pull-out deformation energy, did not directly correlate with the compressive strength, supporting the research hypothesis. [ABSTRACT FROM AUTHOR]

The soil is in a small strain state in most areas during the shield construction process, which is different from the soil properties of the commonly used intrinsic model. Therefore, in order to study the static-dynamic behaviour and engineering applicability of typical silty clay in the area of Jinan Jinluo Road Tunnel passing under Yellow River, the basic physical property parameters of silty clay and tangential stiffness Eref oed, natural stiffness Eref 50, unloading / reloading reference stiffness Eref ur were determined by laboratory soil tests, confined consolidation tests, standard triaxial consolidation tests, and dynamic triaxial tests. Then the obtained parameters were applied in the settlement analysis of the north bank embankment under the tunnel project of Jinan Tunnel through Yellow River. The obtained parameters were applied to the settlement analysis of the Jinan Jinluo Road Tunnel Project passing under the north bank embankment, and the accuracy of the HSS principal model in the deformation analysis of the area was verified by comparing the simulation results of the hardening soil model with small strain stiffness( HSS) model and the Mohr-Coulomb( M-C) model with the field measurement results. The results show that when the perimeter pressure is certain, the vertical strain of the silty clay specimens in this area is dominated by plastic strain, and with the increase of dynamic stress, the longer time is needed for the soil to reach the stability. When the cyclic load is certain, increasing the perimeter pressure of the soil could improve the stability of the soil. The deformation of the ground layer of the Jinan Jinluo Road Tunnel through the Yellow River Tunnel Project passing under the embankment, which is simulated based on the parameters of the HSS model obtained from laboratory experiments, is in good agreement with the measured values in the field. The research results could enrich the study of the stratigraphic parameters of silty clay in Jinan Yellow River area, and provide reference for the selection of the soil model and stratigraphic parameters for the numerical simulation and analysis of geotechnical engineering in this area. [ABSTRACT FROM AUTHOR]

Lime is widely used for soft ground treatment, rendering the compressibility of lime-treated soil a crucial factor in deformation analysis in engineering applications. This study investigated the compressibility of three remoulded lime-treated slurries with high water content in Southeast China. Sixty groups of oedometer tests were conducted on lime-treated soils with an initial water content of 1 to 3 times the liquid limit and lime contents between 1 and 3%. The oedometer test results were discussed to examine the remoulded yield stress σ y ′ of lime-treated slurry. Considering the relationships between σ y ′ , the void ratio, lime content, and initial water content were preliminarily discussed and quantitatively established. Research on the normalised compression curve of lime-treated soil revealed that for soil samples containing a lime content of 0–%, the normalised compression curve at σ p ′ > σ y ′ can be represented by a unique line. Furthermore, the log(1 + e) − log σ v ′ compression curve of lime-treated slurry at pre-yield state is analysed, and a prediction method for the modified compression index is proposed. [ABSTRACT FROM AUTHOR]

Visco‐hypoplastic material model for tertiary soils in Frankfurt am Main The subsoil conditions in the city centre of Frankfurt am Main are characterized by tertiary over‐consolidated clays and clayey marls with embedded limestone banks and sand layers, whose thickness varies considerably depending on the location. In a research project, the time‐dependent material response of these tertiary clays, which significantly influence the deformation behaviour of buildings, was investigated with a comprehensive laboratory test program and a set of parameters for the visco‐hypoplastic AVISA model was determined. This article summarizes the findings obtained for the tertiary Frankfurt clays. In addition, a concept is proposed with which the system permeability and the system stiffness of the heterogeneous tertiary layers taking into account embedded limestone banks and sand layers can be realistically modelled in 3D coupled pore pressure‐displacement analyses with the finite element method. [ABSTRACT FROM AUTHOR]

This paper presents measurements of total pressures and pore pressures in the mixing chamber, the pore pressures in the soil in front of an earth pressure balance (EPB) at the Botlek Rail tunnel, as well as laboratory tests on foam infiltration behavior from foam–sand mixture to saturated sand. It shows that the plastering effect at the tunnel face is less effective for an EPB shield than for a slurry shield, as the pressure fluctuations are greater in the mixing chamber for an EPB shield, suggesting a higher water leakage at the tunnel face. The difference in the development of excess pore pressure at two different locations of the EPB shield suggests the influence of the soil permeability. Foam infiltration at the tunnel face can result in a low permeable layer that restricts the ground water flow. Results from laboratory tests suggest that foam infiltration will be influenced by foam injection ratio and soil permeability. As the foam infiltration length is only limited, no low permeable layer can be formed during drilling for fine sand conditions. While a larger foam infiltration length can be expected for medium sand condition. Field measurements on the development of pore pressures in the soils at the two different locations show agreement with the conclusions from laboratory tests. [ABSTRACT FROM AUTHOR]

Patients treated for systemic urinary tract infections commonly have nonspecific presentations, and the specificity of the results of the urinalysis and urine cultures is low. In the following narrative review, we will describe the widespread misuse of urine testing, and consider how to limit testing, the disutility of urine cultures, and the use of antibiotics in hospitalized adult patients. Automated dipstick testing is more precise and sensitive than the microscopic urinalysis which will result in false negative test results if ordered to confirm a positive dipstick test result. There is evidence that canceling urine cultures if the dipstick is negative (negative leukocyte esterase, and nitrite) is safe and helps prevent the overuse of urine cultures. Because of the side effects of introducing a urine catheter, for patients who cannot provide a urine sample, empiric antibiotic treatment should be considered as an alternative to culturing the urine if a trial of withholding antibiotic therapy is not an option. Treatment options that will decrease both narrower and wider spectrum antibiotic use include a period of watching and waiting before antibiotic therapy and empiric treatment with antibiotics that have resistance rates > 10%. Further studies are warranted to show the option that maximizes patient comfort and safety. [ABSTRACT FROM AUTHOR]

The objective of this study was to explore the higher-order turbulence statistics of flow and turbulent length scales around a complex pier (CP) and compare the results with those for a simple pier (SP). The velocity data were recorded in a laboratory flume using particle image velocimetry (PIV). The PIV data were analysed to estimate the velocity fluctuations of third order, turbulence production and dissipation rates, turbulent length scales and the contributions of burst–sweep events to the total Reynolds shear stress around the piers mounted on a rigid flat surface. The skewness and advection coefficients indicated a more asymmetric distribution of velocity fluctuations for the SP than for the CP. Ejection and sweep events illustrated the dominance of similar strengths for an extended period, downstream of the piers. The upstream turbulent kinetic energy production was similar for both piers, while the upstream dissipation rate was higher for the CP. The length scales were greater at the upstream for the case of the SP while, downstream, they were greater for the CP. The findings of this work demonstrate the importance of a pile cap in restricting downward-moving flow by showing a lower magnitude of scour-inducing turbulence parameters for the CP as compared with the SP. [ABSTRACT FROM AUTHOR]

Anibi S, Ellouze S, Zairi M. 2024. Reservoir siltation and sediment characterization for reuse as construction material in a semi-arid area. Lake Reserv Manage. 40:159–176. In this study, we investigated the siltation rate, evolution, and spatial distribution of sediments within the Siliana Dam reservoir, north-west Tunisia. We analyzed the geotechnical, chemical, mineralogical, and trace metal content properties of sediment samples collected from the reservoir. Additionally, we examined the potential valorization of reservoir sediments in road construction and the effects of hydrated lime treatment on their bearing characteristics. The Siliana dam reservoir is currently 50% silted up, and the sedimentation rate is approximately 1.52% per year. The sediments are mainly fine-grained, low organic with medium to high plasticity and high content of calcium carbonate. The sediments consist of calcite and quartz, with minor amounts of dolomite, hematite, and phyllosilicate minerals. Chromium, zinc, and copper contents in the sediments exceed environmental standards. The lime treatment improved the materials bearing capacity. Adding lime (5% by weight) resulted in an immediate bearing ratio of 26%, a higher ratio compared to the raw sediments. The study of the spatial and temporal evolution of sediment accumulation provides information to develop strategies for mitigating the accumulation of sediments. The sediment characterization evaluated the suitability of sediments to be used as construction materials, offering potential cost savings and contributing to informed decision-making for reservoir management. [ABSTRACT FROM AUTHOR]

This paper aims to estimate the permeability of concrete by replacing the laboratory tests with robust machine learning (ML)-based models. For this purpose, the potential of twelve well-known ML techniques was investigated in estimating the water penetration depth (WPD) of nano natural pozzolana (NNP)-reinforced concrete based on 840 data points. The preparation of concrete specimens was based on the different combinations of NNP content, water-to-cement (W/C) ratio, median particle size (MPS) of NNP, and curing time (CT). Comparing the results estimated by the ML models with the laboratory results revealed that the hist-gradient boosting regressor (HGBR) and K-nearest neighbors (KNN) algorithms were the most and least robust models to estimate the WPD of NNP-reinforced concrete, respectively. Both laboratory and ML results showed that the WPD of NNP-reinforced concrete decreased with the increase of the NNP content from 1 to 4%, the decrease of the W/C ratio and the MPS, and the increase of the CT. To further aid in the estimation of concrete's WPD for engineering challenges, a graphical user interface for the ML-based models was developed. Proposing such a model may be effectively employed in the management of concrete quality. [ABSTRACT FROM AUTHOR]

The simple shear test has been an important tool in practical geotechnical engineering and the study of soil behaviour. The attractiveness of the simple shear test is founded in its relative ease of specimen preparation, similarity to at-rest conditions during consolidation and rotation of principal stresses during shear. Despite this test's attractive qualities, there are significant deficiencies in the interpretation of standard test results: horizontal normal stresses are not known and excess pore pressures are often interpreted from assumptions about constant-volume tests without saturation. To address this problem, a set of monotonic tests were performed on a sand, during which horizontal normal stresses were measured in the central portion of specimens. Based on the measurements, the full state of stress was defined, stress paths were drawn and directions of the principal stresses were determined. Outcomes showed that the conventional approach of estimating excess pore pressures as the change in vertical pressure to maintain constant volume in response to shear is problematic, and friction angles interpreted from conventionally measured shear and vertical stresses may be grossly underestimated in some cases. [ABSTRACT FROM AUTHOR]

There are relatively few experimental studies on the hydromechanical and critical state behaviours of unsaturated silty sand. In this paper, suction-controlled, consolidated, drained triaxial shear tests were conducted on silty sand under saturated (net confining pressures of 100, 200, 300 and 400 kPa) and unsaturated (suctions of 30, 100 and 200 kPa and net confining pressures of 100, 200 and 300 kPa) conditions. For unsaturated silty sand, the effects of dry density, matric suction and net confining pressure on the hydromechanical and critical state behaviour were investigated, and the critical state parameters were obtained. The main findings for unsaturated silty sand included shear shrinkage at low dry density (1·6 g/cm3) and dilatancy at higher density (1·96 g/cm3). The peak shear strength was positively correlated with dry density, matric suction and net confining pressure. The critical state volumetric strain and critical state degree of saturation were negatively correlated with dry density and matric suction but positively correlated with net confining pressure. A new dilatancy equation that includes the state parameter for unsaturated silty sand was established. A unique critical state line passes through the origin in the effective stress p ∗ –deviator q plane, and its slope is the saturated critical state stress ratio M s . In the lnp*–v plane ( v is the specific volume), the critical state lines corresponding to different matric suctions are parallel. [ABSTRACT FROM AUTHOR]

This study solves the following tasks: a comparative analysis of theoretical, computer, and experimental data on the bending of experimental beams is given, the influence of various forms of reinforcement on the strength and stability of beams with a corrugated web is determined; the deformability of a beam with a corrugated web with perforations and without perforations in the elastic and elastic-plastic stage is studied. Experimental studies of models have allowed establishing the main characteristics of the load-bearing capacity, the features of the loss of stability of shelves and corrugated webs with various methods of reinforcing perforations. The given test results showed the necessity and economic feasibility of the work carried out to identify the optimal ways of reinforcing perforations, to meet the requirements of technologists for passing equipment within the construction height of the beams, reducing the consumption of steel for their reinforcement and reducing the complexity of production. The conducted mathematical modeling, laboratory tests, and the performed dispersion analysis allow the study to draw conclusions about the effectiveness of the improved BGS-3 and BGS-5 models and about the need to develop recommendations for introducing two proposed options for reinforcing the perforations of the BGS-3 and BGS-5 models. [ABSTRACT FROM AUTHOR]

To investigate the settlement behaviour under alternate vacuum preloading, a series of laboratory tests considering different influencing factors, such as vacuum pressure and alternating criterion, were conducted. Based on experimental data, a new settlement prediction model, which can synthetically reflect the effects of vacuum pressure, alternating criterion, and improvement time, was proposed. The prediction model took into account the influence of improvement depth and variations in vacuum pressure. The model was validated using several case studies and laboratory tests. Comparisons between the proposed model and layer-wise summation method results indicate that the calculated results of the proposed model are closer to the actual settlement with errors consistently less than 10%. The proposed model can conveniently and accurately predict the ultimate settlement of high water content dredger fill improved by vacuum preloading method. [ABSTRACT FROM AUTHOR]

The durability of concrete structures, which are designed for long- -term use is predominantly determined by the resistance to chemical influences, i.e., the concrete's ability to protect the reinforcement steel. The carbonation and the chloride ingress into concrete are the most significant causes of steel corrosion and the potential failure of the structure. The primary goal is to ensure that any significant damage does not occur during the structure's service life, primarily achieved by selecting an adequate thickness of the concrete cover. The issue is approached through calculations based on performance analyses, and the use of appropriate models for these chemical phenomena. The paper provides a brief overview and the methodology for analysing the impact on the durability of concrete structures in accordance with the leading international normative documents. The emphasis is on the recent changes introduced in second generation of European Eurocode standards. The consequences of the analysed phenomena are presented through the results of field tests conducted at salt factories, coke industries, and thermal power plants, and through laboratory tests. The tests were performed in order to develop a rapid prediction method for the measure of chloride ingress into concrete without the stimulating chloride ion migration by electricity, as an alternative to standardized tests. [ABSTRACT FROM AUTHOR]

Bentonite slurry is frequently used to temporarily stabilize the excavation for slurry tunnel boring machines (TBMs) driving in permeable soils, such as sand and gravel. In this study, two types of bentonite slurries (BS1 and BS2) were subjected to a series of infiltration column tests and modified fluid-loss tests under various pressure levels. Monitoring of water discharge and pore pressures at different depths of the sand bed enabled the identification of two effective sealing patterns during infiltration: the formation of a filter cake and rheological blocking. BS1 exhibited a tendency to form a filter cake, which played a vital role in effectively transferring the applied pressure to the underlying soil skeleton. The application of higher pressure facilitated the rapid formation of a filter cake, resulting in a shorter time span for slurry invasion and minimizing fluid loss. On the other hand, rheological blocking was dominant when using BS2, and the maximum infiltration distance was found to linearly increase with the applied pressure. A comparison between the measurement and a simple prediction model derived from Darcy's law revealed an overestimation of the infiltration distance during slurry invasion. Furthermore, based on the modified fluid-loss test, higher pressure was found to densify the filter cake and result in lower hydraulic conductivity. [ABSTRACT FROM AUTHOR]

AbstractPost-piled offshore jacket foundations usually temporarily rest on mudmats, which may have shear keys or skirts for increased sliding capacity. Scour protection may also be required. Therefore, the skirts or plates should fully penetrate into the scour protection. While current standards offer analytical solutions for penetration resistance in sandy or clayey soils, they may underestimate resistance when soil grain size is comparable to plate thickness. Here, small-scale laboratory tests examine this grain size effect during skirt penetration into granular soils, varying skirt thicknesses and using a sand and a gravel, with plate thickness to grain size ratios ranging from 0.4 to 63. A total of 30 penetration tests were conducted, along with triaxial and direct shear tests. Results show increased penetration load with thicker skirts and higher soil friction angles. Furthermore, the penetration load increased with the grain size to skirt thickness ratio. An alternative equivalent thickness using d99 to account for the soil grain size is proposed and validated against the conducted experimental tests. The new equivalent thickness enhances the theoretical interpretation because it reduces the range of back-fitted values for the soil friction angle to 4° in the studied cases, instead of 8° with the actual plate thickness. [ABSTRACT FROM AUTHOR]

Macroprolactinemia is one of the major causes of hyperprolactinemia. The aim of this study was to clarify the origin of macroprolactin (macro-PRL).We examined macro-PRL in the sera of 826 pregnant women and in those of their babies’ umbilical cords at delivery. Macro-PRL was evaluated by precipitation with polyethylene glycol (PEG), gel filtration chromatography (GFC), and absorption with protein G (PG).We detected macro-PRL in 16 out of the 826 pregnant women (1.94 %) and in 14 of their babies, which may indicate the possibility of hereditary origin of macro-PRL. However, the macro-PRL ratios of the babies correlated positively with those of their mothers (r=0.72 for GFC, p<0.001 and r=0.77 for PG, p<0.001), suggesting that the immunoglobulin (Ig)G-type anti-PRL autoantibodies might be actively transferred to babies via the placenta and form macro-PRL by binding to their babies’ PRL or PRL-IgG complexes may possibly pass through the placenta. There were two cases in which only mothers had macro-PRL, indicating that the mothers had autoantibodies that did not pass through the placenta, such as IgA, PRL bound to the other proteins or PRL aggregates. No cases were found in which only the babies had macro-PRL and their mothers did not, suggesting that macro-PRL might not arise by non-hereditary congenital causes.Macro-PRL in women of reproductive age might be mostly IgG-type anti-PRL autoantibody-bound PRL. The likely origin of macro-PRL in babies is the transplacental transfer of IgG-type anti-PRL autoantibodies or PRL-IgG complexes from the mothers to their babies. [ABSTRACT FROM AUTHOR]

High-quality rotary core samples of natural London Clay were taken during installation of subsurface instrumentation to monitor the ground response at Hyde Park, London, to the construction of Crossrail tunnels. An extensive programme of advanced triaxial tests was performed on specimens from London Clay divisions A3 to C. Detailed analysis of their response to undrained shearing in compression from their estimated in situ stress state provides new insights into the magnitude of and changes in stiffness at small- and medium-strain levels. A consistent trend in the variation of small-strain stiffness with depth and lithological division is established for the Hyde Park research site. Differences between the stiffness magnitudes from this investigation and those reported earlier by others are shown to be a result of the conditions before and during undrained shearing, particularly the ratio of shearing axial strain rate to the preceding creep strain rate. This provides an explanation for significant discrepancies in small-strain stiffness values reported in recent years, which have led to uncertainties regarding which values to adopt, particularly for numerical analysis applications. Understanding the relevance of the axial shearing to creep rate ratio allows for improved triaxial testing techniques and the subsequent interpretation of the test data. [ABSTRACT FROM AUTHOR]

The migration of gases is crucial to ensure the long-term feasibility of argillaceous formations for the deep disposal of radioactive waste. This paper presents an experimental investigation with a multi-scale perspective on the response to gas transport of initially saturated Boom Clay (Belgium). Gas injection tests have been performed under oedometer conditions at different controlled-volume rates, constant total vertical stress and different sample orientations (flow orthogonal or parallel to bedding planes). The results confirm soil expansion and consequent degradation during injection that has a significant impact on the aperture of localised gas pathways (fissures) and increases intrinsic permeability during the gas pressure dissipation stage. The analyses with complementary techniques (mercury intrusion porosimetry, field-emission scanning electron microscopy and X-ray micro-tomography) confirm the opening of fissures with different apertures and separations at the microstructural scale. Large-aperture fissures develop along the weaker bedding planes. These techniques allow the volume of fissures to be quantified, which does not significantly depend on gas flow direction, as also measured in the isotropic response of the gas effective permeability. A scalar damage variable derived from the fissured fraction has been used to assess the gas-entry pressure reduction and the intrinsic permeability increase after the gas tests in both directions. [ABSTRACT FROM AUTHOR]

This paper investigates the response of finned piles in sand subjected to static lateral load through laboratory tests and full-scale field tests. Firstly, model tests were carried out on free headed single piles of different shaft diameters with and without fins in sand to explore the performance of the piles under lateral loading. The results obtained from monotonic loading tests on three series of piles of three different combination of fins and pile shaft diameters were presented. The effect of fins on improving the stiffness and ultimate lateral capacity of the piles was discussed. An equivalent diameter was proposed for a finned pile, which enabled the experimental results to be back calculated using an available elasto-plastic solution for laterally loaded piles in sand. Secondly, field tests were conducted on laterally loaded Starfin screw piles in loose to medium dense sand. The proposed approach was then used for the analysis of the measured response of Starfin screw piles and further validated against measured test results from fully instrumented finned piles in overconsolidated dense sand. The results show that the proposed equivalent diameter and approach for the analysis of finned piles provided the most satisfactory match to the measured data, ranging from the initial elastic state to the ultimate limit state. [ABSTRACT FROM AUTHOR]

Purpose: Our study aimed to investigate the effectiveness of laboratory tests in predicting clinically significant pathologies (CSPs) on abdominal computed tomography (CT) in geriatric patients with abdominal pain. Materials and Methods: Our study is a retrospective case-control study. All patients who were admitted to the emergency department due to abdominal pain had an abdominal CT scan and were 65 years of age or older were included in the study. Laboratory test results were obtained from blood tests taken at the time of admission. According to CT results, patients were grouped into two groups: "CSPs (+)" or "CSPs (-)". The relationship between laboratory results and CSPs was analyzed statistically. Results: Five hundred eighteen patients were included in the study. CSPs (+) were detected on CT in 72.4% of the patients. Alkaline phosphatase (ALP), C-reactive protein (CRP), white blood cells (WBC), platelet, neutrophil, and neutrophil-lymphocyte ratio (NLR) values were statistically significantly higher in CSPs (+) patients. The optimal cut-off values of the tests were WBC>10.75 (x10^3/µL), CRP >150.5 (mg/L), NLR>4.4, ALP >92 (U/L). The area under the receiver operating characteristic curve of all of these tests was below 0.6 and was not sufficiently effective for diagnostic use. Conclusion: Our study showed that using laboratory parameters alone would not be sufficient to predict CSPs on CT in geriatric patients with abdominal pain. [ABSTRACT FROM AUTHOR]

A limit plasticity solution for evaluating the effective stress friction angle in clays from piezocone tests was assessed and compared with the popular notion of using laboratory Atterberg limits on remoulded specimens. The results showed that the in situ piezocone-based method provided a far more accurate and robust interpretation of the friction angle values of 155 separate clays than empirical correlations with plasticity index when compared with laboratory benchmark values obtained from triaxial compression tests. For illustration, the piezocone-based method was shown successfully to capture the effective stress parameter of four clays with friction angles of 20–37°: normally consolidated kaolin clay in chamber tests; natural soft clay deposit located at Bothkennar, UK; Troll offshore clay in the North Sea; and soft plastic lacustrine deposits in Bogota, Colombia. [ABSTRACT FROM AUTHOR]

Residual soils are found all around the world. Their behaviour is different from 'classic' soils due to the structure resulting from the geological formation processes, which can eventually undergo degradation under static and cyclic loads, with a decrease in both stiffness and strength. In this context, the aim of the present study was to evaluate the behaviour of weakly bonded residual soil in the face of loading and unloading cycles using field plate load tests. Preliminary field and laboratory tests were carried out to characterise the residual soil at the experimental site. Monotonic and cyclic plate load tests – with circular and square plates – were performed under three different load amplitudes. The results showed no shape effect of the loaded area for both monotonic and cyclic loading, considering the same loading pattern. Also, there is a threshold load, which indicates a yielding point and a change in soil behaviour and can be estimated from simple laboratory tests. Below this load, the residual soil presented a rigid behaviour even when subjected to cyclic loads. [ABSTRACT FROM AUTHOR]

Comprehensive study of local stresses at transverse stiffeners of crane runway girders based on tests and numerical calculations In practice, welded crane runway girders with greater web heights are usually designed with additional transverse stiffeners between the supports. This increases the buckling resistance of the web and limits the torsion of the top flange due to eccentric wheel load application. However, this creates additional critical design details near the welded connections between top flange and stiffeners with regard to wheel load introduction into the girder web. These details have to be accounted for in the verification against fatigue failure. Furthermore, the current version of DIN EN 1993‐6 does not contain any rules for calculating the local stresses in the web and in the transverse stiffeners for wheel load introduction near transverse stiffeners. This article therefore presents both laboratory tests and FE‐calculations that investigate the local stresses in the vicinity of transverse stiffeners in detail. Subsequently, the determined stresses are used for comparative fatigue design checks at the relevant constructional details in relation to corresponding design checks without taking the influence of the transverse stiffeners into account. Finally, deficits in the current procedure are highlighted and recommendations for design practice are derived on the basis of the results obtained. [ABSTRACT FROM AUTHOR]

Quality control of riverbank roads is a vital part of the road construction and maintenance process and aims to ensure infrastructure quality, safety, and sustainability. This requires adherence to technical standards, constant auditing, and regular maintenance to maintain the condition of the roads and avoid potential problems. The first step in the quality control of roads is to test the efficiency of the subgrade soil. A geotechnical investigation of subgrade soil under river bank roads is carried out to evaluate the engineering properties of the soil and determine the soil’s ability to bear the loads resulting from vehicle movement and road traffic. This investigation includes analyzing soil samples and laboratory tests to determine soil properties and determine any improvements the soil needs to bear the loads. Soil samples were collected from Al-Kadhimiya Corniche Street. It was dried and subjected to laboratory tests, the soil in this study is classified as poorly graded sand (SP), GS 2.589, the shear strength parameters an internal friction angle of 33 degrees and cohesion of 0.5 kN/m2, and the results of the compaction test indicated that the optimal moisture content was 8.1%, with a maximum dry density was 18.24 kN/m3, CBR 26.04%, and chemical tests (SO3 0.222, pH 8.55, T.SS 0.891, CL 0.085). Software FAARFIELD was used to check pavement design, the thickness design was executed utilising a subgrade CBR value of 26.04%. The subgrade pavement thickness was determined to be 304mm in total. The results agree with the actual design of Al-Kadhimiya Corniche Street, which was recently maintained during the field investigation in 2023.