Search Results (451)

Fluidized solidified soil piles combine slurry-like constructability with post-hardening strength development and provide a potential approach for soft ground improvement. This study investigated the vertical bearing behavior and load-transfer mechanism of fluidized solidified soil piles in layered soft ground through field single-pile vertical static load tests, core drilling, and three-dimensional numerical simulation. The field tests and core drilling provided experimental evidence for evaluating load–settlement behavior, pile integrity, and material strength, while the internal load-transfer mechanism and geometric parameters were mainly interpreted using the numerical model. The field results showed that the Q-s curves exhibited staged deformation characteristics, with relatively stable settlement development during the main loading stage and more pronounced nonlinearity under high load levels. The ultimate vertical bearing capacities of the 10 m and 20 m test piles were 1050 kN and 950 kN, respectively. Core drilling indicated that the two pile groups had similar material strength, suggesting that the bearing capacity difference was mainly associated with the pile toe bearing stratum rather than pile material strength. After comparison with the measured Q-s curves, the numerical analysis showed that the 20 m pile mobilized a longer shaft resistance range and a higher shaft resistance contribution, but its pile toe extended into the lower mucky soil layer, resulting in reduced pile toe resistance. Parametric analysis indicated that increasing pile length does not necessarily improve bearing performance when the pile toe bearing stratum is unfavorable, whereas increasing pile diameter more directly reduces pile head settlement under the same pile toe bearing condition. These findings highlight the need to consider both shaft resistance mobilization and pile toe bearing stratum in the design of fluidized solidified soil piles in layered soft ground. Full article

Patellofemoral pain (PFP) in athletes is associated with lower-limb kinetic-chain constraints, yet rehabilitation strategies targeting both hip and ankle mobility remain insufficiently examined. This assessor-blinded randomized controlled trial investigated the effects of a 6-week hip and ankle mobility-based rehabilitation program in male collegiate athletes with PFP. Forty-eight participants were assigned using computer-generated 1:1 randomization to an intervention group (n = 24) or a control group (n = 24). The intervention group completed supervised hip and ankle mobility rehabilitation three times weekly, whereas the control group maintained regular sport-specific training only. Co-primary outcomes were pain intensity assessed using a 10-cm visual analog scale (VAS) and knee-related function assessed using the Kujala score. Secondary outcomes included hip rotation range of motion, weight-bearing ankle dorsiflexion, vastus medialis–vastus lateralis (VM–VL) onset timing, Y-Balance Test (YBT) composite score, and countermovement jump (CMJ) height. Significant group × time interactions favored the intervention group for VAS (p < 0.0001; partial η² = 0.436; change difference: −1.54 cm; 95% CI: −2.06 to −1.02) and Kujala score (p < 0.0001; partial η² = 0.285; change difference: 8.00 points; 95% CI: 4.24 to 11.76). Significant interactions were also observed for hip internal and external rotation range of motion, weight-bearing ankle dorsiflexion, VM–VL onset timing during a controlled squat task, and YBT composite score (all p ≤ 0.0405; partial η² = 0.088–0.374). No significant group × time interaction was observed for CMJ height (p = 0.0511; partial η² = 0.080). These findings suggest that, compared with regular sport-specific training alone, adding a supervised hip and ankle mobility-based rehabilitation program may improve pain, knee-related function, targeted mobility outcomes, VM–VL onset timing during a controlled squat task, and dynamic balance in the short term. However, because the control group did not receive an active or attention-matched intervention, these findings should be interpreted as the added effect of the supervised rehabilitation program rather than as definitive evidence of mobility-specific treatment effects. In addition, because patellar tracking, knee kinematics, joint kinetics, and patellofemoral joint loading were not directly measured, the findings should be interpreted as clinical and functional outcome changes rather than direct evidence of a confirmed biomechanical mechanism. Trial registration: NCT07542236. Full article

Soil contamination by heavy metals (HMs) [or potential toxic elements (PTEs)] poses serious risks to ecosystems and human health. Metals persist in the environment and can reach groundwater and freshwater as part of the food-chain. In soils, anthropogenic inputs dominate over geogenic sources. Metal mobility is strongly controlled by factors such as pH, mineralogy, and erosion processes that transport metal-bearing clay fractions. Wind and water can transport soil, mainly clay particles that can usually bind contaminants such as HMs. Using waste material is a tool suggested from the circular economy, so waste becomes a valuable resource. This study evaluates the immobilization efficiency of several heavy metals (Cd, Co, Cr, Cu, Mn, Ni, Pb, and Zn) using phosphate amendments—synthetic hydroxyapatite, phosphatic rock from Florida and Morocco—applied to a brownfield site. Heavy metal immobilization followed a two-step mechanism: first rapid surface complexation and secondly partial dissolution of hydroxyapatite and ion exchange with Ca, leading to the precipitation of metal-substituted hydroxyapatite phases. Synthetic hydroxyapatite generally shows the best efficiency, whereas phosphatic rocks were less effective but still provided a measurable immobilization. From a circular economy perspective, however, phosphatic rocks remain attractive due to their lower cost, availability, and waste-valorization potential. Full article

The study introduces a portable sliding sand sieve, transforming traditional stationary systems into an innovative solution for sand separation in the construction industry. This innovative tool offers improved mobility, durability, and operational efficiency, particularly for construction workers, civil technology students, and educators in areas with limited access to advanced equipment. Utilizing a developmental research design, the study involved the conceptualization, fabrication, and evaluation of the prototype. The design incorporated locally available materials, including phenolic boards, mesh screens, steel tubing, and a sliding mechanism supported by bearings and brackets. The Input–Process–Output (IPO) model guided the development, ensuring focus on functionality, affordability, and user safety. To address this gap, the researchers aimed to design, develop, and evaluate a portable sliding sand sieve to enhance sand sieving in construction settings. Expert and student evaluators highly rated the portable sliding sand sieve for its design simplicity, functionality, durability, modularity, and ergonomics. It was praised for its ease of use, time-saving capability, and adaptability to various work environments. The sliding feature enabled continuous sand flow, enhancing productivity and reducing physical strain. Full article

Self-drilling hollow bar micropiles (HBMPs), which integrate drilling, grouting, and reinforcement into a single process, have broad application prospects in mountainous transmission lines and offshore wind power projects. However, existing research has focused mainly on friction piles in soil layers, and there is a lack of systematic understanding of the load-transfer mechanism and bearing capacity calculation method for rock-socketed HBMPs. Based on field static load tests of rock-socketed HBMPs, this study systematically investigates the vertical bearing behavior and capacity calculation method of single rock-socketed HBMPs through a combination of test data analysis, finite element numerical simulation, and theoretical analysis. The field test results show that the load-settlement curves of rock-socketed HBMPs are of a slowly varying type, exhibiting mixed friction-end-bearing characteristics. After data screening, the average Q-s curve of Pile No. 1 and Pile No. 5 was taken as the benchmark, and the representative ultimate bearing capacity of a single pile determined by the 40 mm settlement criterion is 5860 kN. The test data of Pile No. 3 and Pile No. 4 were retained as independent validation data. A three-dimensional finite element model considering the cohesive contact behavior at the pile–rock/soil interface was established using ABAQUS. After calibration with the test results, the error between the simulated and measured bearing capacity is −3.4%, demonstrating good model reliability. Parametric analysis indicates that the bearing capacity increases linearly with the grouting volume increase rate $V_{\mathrm{inc}}$, with the expansion effect being the main enhancement mechanism; the improvement amplitude under hard rock conditions is significantly smaller than that in cohesive soils. The effect of uniaxial compressive strength $q_u$ of hard rock on bearing capacity is negligible because the capacity is controlled by the pile–rock interface shear strength. The bearing capacity increases approximately linearly with the rock-socketed depth $L_r$, and a minimum rock-socketed depth of 1.0 m is recommended. Analysis of the load-transfer mechanism shows that rock-socketed HBMPs rely mainly on shaft resistance (accounting for 90.6%), and the axial force decays significantly along the pile length. Elastic compression of the pile accounts for 78% of the pile head settlement, and the limited displacement at the pile tip leads to insufficient mobilization of end bearing. A modified bearing capacity formula considering the grouting expansion effect is established with shaft resistance as the core. A hierarchical validation strategy is adopted to test its predictive ability: for the finite element cases not participating in parameter calibration, the prediction error is within ±2%; for the field test piles, the prediction error is +7.9%; and for Pile No. 3 and Pile No. 4, the errors are +1.7% and −2.1%, respectively. These values are significantly better than those of existing methods (errors ranging from −72.1% to +54.5%). The research results can provide a theoretical basis for the design of single HBMP bearing capacity under rock-socketed conditions. Full article

The suction caisson foundation has been extensively adopted for offshore wind turbine infrastructure owing to its adaptability to deep-water environments, cost-effectiveness, and convenient construction. However, such foundations suffer from relatively low horizontal and vertical bearing capacities when embedded in soft clay deposits. To address this limitation, this study proposes a novel mobile jet-reinforcement technique and the corresponding composite suction caisson configuration. Physical model tests are conducted to investigate the soil fracturing-erosion mechanism induced by jet injection and the bearing performance of the reinforced composite foundations. Test results reveal that the soil breaking depth increases with injection pressure and injector diameter, whereas the soil breaking width increases with jet angle. Larger breaking depth and width contribute to an expanded horizontal–vertical bearing capacity failure envelope. The ultimate bearing capacity of the composite caisson increases with greater soil breaking depth, and a larger number of circumferentially arranged jet pipes enables more uniform cement–soil cladding around the caisson body. Overall, the reinforced foundations achieve a bearing capacity 3.0–5.0 times that of conventional unreinforced suction caissons. Furthermore, a time-dependent hyperbolic model for soil breaking depth prediction and a bearing capacity failure envelope method are established for the reinforced composite suction caissons. The outcomes of this study can provide a reference for the engineering design of jet-reinforced suction caisson foundations in offshore areas with soft clay. Full article

Background: Acute compartment syndrome (ACS) is a limb-threatening surgical emergency most commonly associated with fractures or high-energy trauma. Non-fracture-related ACS in athletes is uncommon and may lead to delayed diagnosis. Repetitive blunt trauma during combat sports has rarely been described as a potential mechanism. Case Methods: The case concerns a 21-year-old elite-level kickboxing athlete who developed acute compartment syndrome of the left lower leg following repeated calf kicks sustained during sparring. The patient presented with rapidly progressive calf pain, swelling, compartment firmness, paresthesias and weight bearing difficulties. CT angiography demonstrated diffuse edema of the posterior compartments associated with a large intramuscular soleus hematoma without active arterial bleeding. Results: In view of the severity of the symptoms and the characteristic clinical presentation, an emergency fasciotomy was performed in operating room. Progressive closure was achieved using the vessel loop shoelace technique, allowing gradual tension-free closure. Wound healing progressed without infection, and physiotherapy was introduced with joint mobilization. The patient achieved full functional recovery after 6 months. Conclusions: This case illustrates an atypical etiology of ACS—repetitive targeted calf strikes—and underscores the importance of early recognition even in the absence of fracture or major trauma. Clinical vigilance remains paramount, and prompt surgical intervention is critical to prevent irreversible muscle and nerve damage. Awareness of such mechanisms is particularly relevant for clinicians managing athletes in combat sports. To our knowledge, this is the first documented case of ACS secondary to repeated calf kicks in kickboxing. Full article

This study investigates the influence of inside-trapped water and remedial grouting on the vertical bearing behaviour of suction bucket foundations in sand through 1 g laboratory model tests. The tests were designed to compare the relative responses of different trapped-water and grouting conditions under the same model scale, sand preparation procedure, and loading protocol. Two target trapped-water conditions were considered: a condition without an observable continuous water layer beneath the bucket lid and a condition with an initial trapped-water thickness of approximately 2 cm. These conditions were controlled and verified before loading using the scale attached to the transparent bucket wall and the underwater camera monitoring system. The results show that inside-trapped water modifies the vertical load-transfer path between the bucket lid and the internal soil plug. When a water layer exists beneath the lid, direct lid–soil plug contact is weakened, and the foundation resistance relies more strongly on skirt-side resistance and the resistance mobilized near the bucket rim. Under cyclic vertical loading, the trapped-water case exhibited larger cumulative displacement and a lower post-cyclic bearing response than the no-trapped-water case. The secant cyclic stiffness showed a continuous increase in the no-trapped-water case, whereas a rise-then-fall trend was observed in the trapped-water case, which may be associated with cyclic densification, soil plug disturbance, changes in lid–soil plug contact, and possible local pore pressure development. Remedial grouting filled the trapped-water space beneath the bucket lid and partially restored the lid–soil plug load-transfer path. Under the present model test conditions, the post-cyclic dimensionless bearing capacity of the grouted cases increased by approximately 13–16% relative to the ungrouted trapped-water case. The grouting cases with different bentonite contents showed similar recovery trends within the limited dataset, suggesting that the improvement was mainly related to filling and sealing the trapped-water space rather than to the intrinsic strength of the grout material. Full article

Planetary exploration has increasingly relied on mobile robots known as rovers to support space development. Among various locomotion systems, legged mechanisms have attracted attention as a promising approach for achieving high mobility on rough terrain. However, the surfaces of extraterrestrial bodies such as the Moon and Mars are covered with loose regolith that easily deforms under external forces. As a result, legged rovers tend to disturb the ground surface and experience slippage due to leg-induced loading. To address this issue, a previous study proposed a novel walking method in which the rover’s leg applies vibration to the soil before stepping to compact it. Experiments confirmed that this vibration increases the soil’s bearing capacity, defined as its resistance to vertical loading. This increase is attributed to improvements in soil density and particle interconnectivity, which enhance soil shear strength. In this study, the relationship between the bearing capacity of vibration-compacted soil and its shear strength is investigated through experiments. The results reveal a clear correlation between these parameters, indicating that the bearing capacity of vibration-compacted soil can be estimated from shear strength measurements. Full article

Low-permeability reservoirs at the high-water-cut stage commonly suffer from dominant water channel development, poor sweep of weakly connected zones, and inefficient mobilization of remaining oil. Existing profile control or oil displacement agents can improve either flow diversion or microscopic oil displacement, but their single-agent evaluation does not fully explain the coupled process of sweep expansion and remaining oil mobilization. To address this issue, this study focuses on a previously optimized HK-0417/ALT-603 composite system and investigates its synergistic behavior at pore, core, and well group scales. Microscopic visualization displacement experiments were used to identify streamline redistribution and remaining oil evolution. Natural core experiments were conducted to evaluate injectivity adaptability and plugging persistence. Under slug injection conditions, the Box–Behnken design was employed to optimize the injection parameters. Finally, the field pilot response was analyzed based on production data from test wells in the Changqing Oilfield. The results show that the combination system simultaneously achieves streamline expansion and residual oil reduction: the injected fluid is redistributed toward weakly swept zones, large continuous oil bodies are fragmented and dispersed, and both sweep efficiency and oil displacement efficiency are superior to those of individual agents. Natural core experiments indicate that the injection pressure difference is generally controllable in cores with permeabilities ranging from 1.76 to 7.02 mD, and the plugging rate during subsequent water flooding reaches 75.47–80.54%. Response surface optimization yields the following optimal parameter combination: profile control slug volume = 0.41 pore volume (PV), oil displacement slug volume = 0.61 PV, injection rate = 0.19 mL/min, with a corresponding predicted enhanced oil recovery (EOR) of 18.52%. In the field pilot, the cumulative injection volumes of the two injectors are 41,898 kg and 61,472 kg, respectively. The injection pressure in the well group increases from 5.8 MPa to 7.0 MPa, the comprehensive water cut decreases from 90.6% to 85.3%, and the monthly decline rate is reduced from 0.5% to 0.2%. The proposed system mainly acts by increasing flow resistance and redirecting flow in high-water-cut channels, while it enhances oil detachment through interfacial tension reduction in oil-bearing pores. After optimizing the slug parameters, the field pilot exhibits a clear phased response and promising application potential. Full article

Background/Objectives: The preliminary experience with new dual-mobility system for small Japanese patients was introduced in this paper. Methods: Twenty-nine hips which underwent primary THA were retrospectively reviewed. All cups were inserted via Hardinge lateral approach. The ability to perform formal Japanese sitting in a kneeling position (Seiza in Japanese) and bowing while sitting (Zarei in Japanese) was evaluated. The mean follow-up was 6 months. Results: The mean age at surgery was 70 years, mean height was 156 cm, mean weight was 58 kg, and mean body mass index was 23.6. The acetabular cups utilized were a hemispherical hydroxy-apatite coated cup (25 hips) and a hemispherical trabecular titanium cup (4 hips), with diameters of 46 mm in 5, 48 mm in 15, 50 mm in 3, 52 mm in 1, 54 mm in 3, 56 mm in 1, and 62 mm in 1; mean diameter was 49.4 mm. No postoperative dislocations including intraprosthetic dislocation or metal allergy were observed. The mean Harris hip score improved significantly from 39 points preoperatively to 89 points postoperatively (p < 0.05). Radiographic evaluation demonstrated bone ingrowth stability in all cases according to Engh’s criteria and no aseptic loosening of the implants. Mean hip flexion increased from 75° preoperatively to 90° postoperatively (p < 0.05). The ability to perform Seiza increased from 8 patients preoperatively to 23 patients postoperatively (p < 0.05). The ability to perform Zarei (deep bowing) increased from 7 patients preoperatively to 20 patients postoperatively (p < 0.05). Conclusions: This novel dual-mobility system designed for smaller Japanese patients offers three distinct advantages: (1) availability of 42, 44, 46 and 48–66 mm outer diameter cups, (2) 1 mm deeper center of rotation, providing increased jumping distance compared to other designs, and (3) improved assembly instrumentation (cement-gun-type bearing press). Early clinical results suggest that this newly developed dual-mobility THA system is well-suited to the lifestyle and anatomical characteristics of Japanese patients. Full article

Background: Total knee arthroplasty (TKA) is a common procedure aimed at alleviating knee pain and restoring function in patients with degenerative joint diseases. Traditional implants are typically designed to restore mechanical knee alignment, but personalized implants have shown promise in improving clinical outcomes. The Origin^® individualized TKA system provides a tailored approach to knee reconstruction by utilizing preoperative 3D planning to create individualized implants and cutting guides based on each patient’s unique anatomy. Surgical Technique: The Origin^® system employs a preoperative computed tomography (CT) scan and Knee-Plan^® software to design individualized implants that optimize alignment and joint anatomy. The surgical technique involves the use of patient-specific cutting guides for precise bone resections and the insertion of either cruciate-retaining (CR) or posterior-stabilized (PS) implants, depending on individual patient needs. This process aims to replicate the pre-arthritic alignment and kinematics of the pre-arthritic knee. Postoperative Protocol: The postoperative protocol allows for immediate weight-bearing, and patients are guided through a structured rehabilitation program to ensure optimal recovery. Full range-of-motion exercises begin early to promote knee mobility and strength. Discussion: The individualized TKA system offers several advantages, including precise restoration of pre-arthritic anatomy, reduced bone resection, and improved implant fit. These benefits are particularly valuable in patients with unique anatomical challenges, such as deformities or previous surgeries. Despite the potential advantages, challenges remain, including the costs and time associated with individualized manufacturing, as well as increased radiation exposure from the required CT scans. Conclusions: The Origin^® individualized TKA system represents a significant advancement in knee arthroplasty by providing a tailored approach to patient care. Future studies are needed to further evaluate the long-term outcomes and cost-effectiveness of this personalized system compared to conventional TKA approaches. Full article

Return-type cable suspension bridges transfer the main-cable force to the anchorage predominantly in the horizontal direction, which may induce coupled sliding–overturning instability of the anchorage–foundation system. This study examines the stability of return-type cable gravity anchorage using the composite anchorage of the Jixin Expressway Yellow River Three Gorges Bridge as the prototype. A 1:100 laboratory specimen was designed based on similarity theory and tested under incremental loading until failure. Four configurations were considered by combining two embedment ratios (1/4 and 1/2) with two base types (flat-base and shear-keyed). Horizontal displacement, overturning angle, interface contact stress, and foundation strain were monitored throughout loading. Because the return-type cable transmits a predominantly horizontal force, the anchorage–foundation contact stress exhibits pronounced asymmetry between the toe and heel regions, and this stress asymmetry governs the coupled sliding–overturning instability mode. The shallow flat-base case exhibited a distinct displacement and contact stress jump at high load levels, followed by rapid rotation, indicating slip–tilt coupled instability. Increasing embedment improved confinement and delayed the onset of nonlinear deformation, but the flat-base configuration still showed pronounced toe stress concentration. By contrast, the shear-keyed base mobilized cooperative bearing of the surrounding foundation, producing smoother stress–strain evolution and higher ultimate capacity. Moreover, the shear-keyed base mitigates the stress asymmetry at the anchorage–foundation interface, leading to a more symmetric distribution of contact pressure and improved overall stability. Three-dimensional finite-element simulations reproduced the measured trends in displacement, stress concentration near the toe, and strain development, providing independent verification. The results clarify the dominant instability mechanism of return-type cable gravity anchors and offer design implications for embedment depth and shear-keyed base detailing. Full article

Uranium exploration in southeastern Mongolia remains constrained by fragmented Soviet-era datasets and limited modern synthesis. This study addresses the problem of integrating historical geological records with contemporary exploration methods to evaluate uranium mineralization potential. A comprehensive GIS-based database was compiled from Soviet reports legally acquired from the Mineral Resources Authority of Mongolia and expanded with geological, geophysical, and drilling data collected between 2006 and 2011. Methodological advances included remote sensing detection of anomalous radioactivity in arid environments, stratigraphic modeling, and hydrogeochemical surveys. The dataset encompasses more than 1100 radioactive anomalies and approximately 300 mineralized zones, with emphasis on the Han Bogd granite massif, Ail Bayan coal deposit, Suujin Tal structural system, Zuunbayan depression, and Naarst structural complex. Results indicate that most anomalous zones are sub-economic, commonly associated with organic-rich facies such as coal seams, while the continuity of mineralized bodies remains uncertain. Nevertheless, the dual consideration of granitic source terrains and coal-bearing sedimentary traps provides new insights into uranium mobility and deposition. The significance of this work lies in its systematic integration of historical and modern data, offering a refined geological framework and highlighting key areas for future investigation, thereby contributing to ongoing discussions on sedimentary uranium resources in Mongolia. Results indicate that most anomalous zones are sub-economic, commonly associated with organic-rich facies such as coal seams, while the continuity of mineralized bodies remains uncertain. Importantly, the study highlights granitic intrusions and volcanic complexes as the primary uranium sources, with coal-bearing and sedimentary basins acting as secondary depositional environments. The dual consideration of source terrains and depositional traps provides new insights into uranium mobility and deposition. Full article

Children’s scooters, as products integrating mobility, safety, and developmental functions, require systematic and reliable design decision-making approaches. However, existing processes often suffer from unsystematic user demand extraction, strong subjectivity in weight determination, and insufficient quantitative support for evaluating alternative schemes. To address these issues, this study proposes an integrated AHP–CRITIC–VIKOR framework for engineering-oriented design optimization. User requirements are identified through field investigation, questionnaires, and affinity diagram analysis, and a multi-level evaluation indicator system is constructed. AHP is applied to determine subjective weights, while CRITIC incorporates objective data characteristics, enabling balanced weighting. VIKOR is then used to evaluate design schemes and obtain compromise solutions under multi-criteria conflicts. The results show that safety-related factors, including material safety, braking performance, and load-bearing capacity, dominate the decision process. The optimal scheme demonstrates the closest proximity to the ideal solution. Sensitivity analysis confirms the robustness of the model, and comparison with TOPSIS shows consistent results and improved compromise decision capability. The proposed framework enhances decision reliability and provides an effective quantitative tool for multi-criteria product design optimization. Full article