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筛选条件 : 土木工程学院
Lu Ren; Xingyu Yan; Juan Liu; Yu Shi; Xinluan Wang; Zhihai Gao
Applied Surface Science, 2025 687 - EI SCIE

摘要 : In the photocatalysis process, TiO 2 necessarily requires light, and this light requirement restricts the application scenarios, such as TiO 2 -modified building materials. We fabricated the novel MnO x -TiO 2 nanocomposites through the recombination of amorphous manganese oxide with {001} facets anatase TiO 2 . The MnO x -TiO 2 nanocomposites not only possess efficient water purification capacity in the absence of light, but also can handle various pollutants efficiently. Notably, the sample of MTO-20 exhibits the highest specific rates, being 3.04, 2.04, and 6.80 times higher than that of pure TiO 2 under irradiation, in the dark, and at 90 °C for the purification of crystal violet (CV), respectively. Besides the highly efficient purification of cationic dye CV in the dark, the MnO x -TiO 2 nanocomposites can remarkably and efficiently enhance the purification performance for anionic dyes, nonionic organic pollutants, arsenic, and antibiotics. It is evidenced that the purification of pollutants by the MnO x -TiO 2 nanocomposites is a process of oxidative degradation. The optimal sample MTO-20 was applied to coat on the ceramsite, which presents a CV degradation as high as 72.6 %, while the blank ceramsite is only 32.6 %. We may provide a novel nano-modified material to application in building materials in more scenarios without light limitations.

Saeed Sarajpoor; Yumin Chen; Yi Han; Runze Chen; Zhongling Fu; Ke Ma
Soil Dynamics and Earthquake Engineering, 2025 190 - EI SCIE

摘要 : The air injection method has been identified as a promising liquefaction mitigation technique to enhance the liquefaction resistance of sand. This innovative approach involves reducing the saturation degree of sand by injecting air, ultimately mitigating the generation of excess pore pressure during seismic events. This paper thoroughly investigates the potential of sandy soil to entrap air bubbles to reduce saturation degree. Fujian silica sand and the South China Sea calcareous sand, with varying gradation curves, were selected to evaluate the influence of key parameters such as uniformity coefficient, void ratio, and relative density on the air entrapment capacity. Box model experiments utilizing the air injection method were performed to evaluate the air entrapment capacity of sands. The findings reveal that the physical properties of sand can influence both the air distribution pattern and the air entrapment capacity. Finally, two additional tests were performed on transparent fused quartz sand to further examine the air injection process. The ability to observe air bubble distribution within the pore structure of the transparent sand enabled a qualitative comparison, facilitating the analysis of results obtained from experiments on natural sand samples.

Xianzhi Luo; Sumei Zhang; Yuchen Zhang; Yuexin Jiang
Thin-Walled Structures, 2025 208 - EI SCIE

摘要 : Ultra-High Performance Concrete (UHPC) exhibits better cracking behavior and durability compared to Normal Concrete (NC). UHPC-NC composite members utilize reinforced UHPC as a protective layer only on the side with a higher risk of corrosion, aiming to improve the service performance of the members while reducing the usage of this costly material. To investigate the drift capability and cracking behavior of UHPC-NC composite members, eight UHPC-NC composite members and one NC member were loaded to failure under bending moment. The results show that UHPC-NC composite members with reinforcement ratios between 0.7 % and 1.5 % exhibit ductile failure, avoiding the crack localization failure seen in UHPC members. Members with 0.5 % and 2.0 % fiber contents can limit maximum crack widths to 0.20 mm and 0.10 mm, respectively, during service. Flexural capacity predictions based on UHPC's tensile strength overestimate the capacity, but introducing a reduction factor α improves prediction accuracy. The cracking behavior of members is highly sensitive to deformation localization, and a reinforcement ratio sufficient to avoid failure after crack localization can still induce severe degradation in cracking behavior. Using a UHPC layer without rebars as a protective layer for reinforced concrete bending members is not recommended.

Ge Song
Soil Dynamics and Earthquake Engineering, 2025 189 - EI SCIE

摘要 : This study investigates and quantifies the energy-dissipating capacity of self-centering shear walls (SCSW) based on the degradation observed under variable loading sequences. 14 SCSWs with diverse structural features are designed and subjected to numerical simulations under cyclic loads with varying amplitudes and loading sequences. An exponential model is employed to evaluate the deterioration of energy-dissipating capacity in SCSWs, accounting for variations in loading sequences and structural features. This model is then utilized to estimate the energy-dissipating capacity for SCSWs. Results show that nonlinear deformation histories have significant impacts on the hysteretic responses and the deterioration of energy-dissipating capacity in SCSWs. SCSWs with higher stirrup reinforcement ratios and concrete strength exhibit less deterioration in energy-dissipating capacity, especially under ultimate conditions. Conversely, a larger self-centering parameter reduces the energy-dissipating capacity under loading sequences with amplitudes smaller than ultimate deformations. The proposed approach can provide reliable estimation of energy-dissipating capacity for SCSWs considering both loading sequences and structural features.

Yutang Chen; Jun Yang
Engineering Geology, 2025 345 - EI SCIE

摘要 : In slopes and embankments, soil elements are often anisotropically loaded and the sustained stress ratio SR may vary a lot. The understanding of the influence of SR on the small-strain shear modulus G 0 of sands prior to failure is a practical concern that remains inadequately understood in the existing literature. This study aims to address this knowledge gap through a meticulously designed experimental program. The testing program encompasses three quartz sands with differing particle shapes and a diverse set of principal stress ratios produced via drained triaxial compression. By employing bender elements embedded within the apparatus, elastic shear waves are generated, enabling the measurement of G 0 from isotropic stress states to anisotropic stress states. A careful evaluation and comparison of existing anisotropic G 0 models in the literature is also conducted, and the potential limitations when subjected to elevated SR levels are noted. A new, unified model is proposed to effectively characterize G 0 of different sands subjected to a wide range of triaxial compression states and it is validated using literature data.

Xudong Zhang; Mingjing Jiang; Zhenyu Yin; An Zhang
Computers and Geotechnics, 2025 178 - EI SCIE

摘要 : The mechanical behavior of Methane Hydrate-Bearing Sediment (MHBS) is essential for the safe exploitation of Methane Hydrate (MH). In particular, the pore size and physicochemical characteristics of MHBS significantly influence its mechanical behavior, especially in clayey grain-cementing type MHBS. This study employs the Distinct Element Method (DEM) to investigate both the macroscopic and microscopic mechanical behavior of clayey grain-cementing type MHBS, focusing on variations in pore size and physicochemical characteristics. To accomplish this, we propose a Thermo-Hydro-Mechanical-Chemical-Soil Characteristics (THMCS) DEM contact model that incorporates the effects of pore size and physicochemical characteristics on the strength and modulus of MH. This THMCS model is validated using experimental data available in the literature. Using the proposed contact model, we conducted a series of investigations to explore the mechanical behavior of MHBS under conventional loading paths, including isotropic and drained triaxial tests using the DEM. The numerical results indicate that smaller pore sizes and lower water content—key physicochemical characteristics resulting from variations in electrochemical properties and the intensity of the electric field—can lead to reduced shear strength and stiffness due to the increased breakage of aggregates and weakened cementation. Additionally, heating was found to further accelerate the process of structural damage in MHBS.

Xingchen Jia; Huaning Wang; Fei Song; Alfonso Rodriguez-Dono
Transportation Geotechnics, 2025 50 - SCIE

摘要 : The main objective of this study is to establish a general analytical model for investigating the hydro-mechanical problems of twin tunnels excavated in elastic saturated ground, taking into account the influence of seepage flow on the mechanical responses. All hydro-mechanical (HM) boundary conditions are satisfied to derive the analytical solutions. An innovative analytical complex function in the HM coupled framework, integrating complex variable theory and the Schwarz alternating method, has been developed with the consideration of arbitrary sizes and arrangements of twin tunnels. The convergence speed of the alternating method is quite fast, generally achieving enough accuracy within three iteration steps in the solving procedure, guaranteeing the application of the developed solutions in geotechnical engineering. The results obtained from these solutions match well with those of the numerical predictions, verifying the proposed analytical theory and the developed analytical solutions. Additionally, sensitivity analyses are performed to investigate mechanical responses of stresses and displacements of host rocks subjected to different engineering cases, including geometry and boundary conditions of twin tunnels. Results indicate a significant increase in the major principal stresses and deformations with rising seepage forces, suggesting that seepage flow can pose underground structures to dangerous conditions. Consequently, the influence of seepage flow plays a significant role in the stability analysis of tunnelling in water-rich geological areas. The proposed analytical approach offers an innovative and efficient alternative for the preliminary design of twin tunnels excavated in saturated ground, providing valuable insights for engineering applications.

Guofu Zhao; Jun Lu; Kai Su; Junmiao Xiao; Jie Li; Pan Ming
Engineering Failure Analysis, 2025 167 - EI SCIE

摘要 : This study investigates the effects of irregular holes on the load-bearing mechanism and capacity of prestressed concrete cylinder pipes (PCCP). An internal pressure test was performed on a PCCP specimen containing multiple irregular holes, and a finite element numerical simulation was conducted to explore the impact of these holes. The results indicated that the presence of irregular holes caused significant anisotropic stress distribution, particularly at the inner wall of the concrete core, with stress concentrations around the holes. Cracks were initiated near the spigot end and propagated axially as the internal pressure increased. The load-bearing process of the PCCP evolved in three stages: (1) the prestressed wires bore the majority of the load, (2) the concrete began sustaining a portion of the load as it experienced tensile stress, and (3) the concrete underwent plastic damage, transferring the load to the steel cylinder and prestressed wires. The internal pressure of PCCP model with multiple irregular holes associated with the serviceability limit-states was 0.23 MPa, representing only 26.4 % of the intact model, which was 0.87 MPa. However, the difference in ultimate load-bearing capacity between the two models was minimal. These findings underscore the necessity of timely repairs to prevent the worsening of erosion in PCCPs with irregular holes.

Zhiwu Bie; Xuefeng Liu; Yajie Deng; Xian Shi; Xiaoqiao He
Nanomaterials, 2025 15 (2) - SCIE

摘要 : Helical carbon nanotubes (HCNTs) with different geometrical properties were constructed and incorporated into nanocomposites for the investigation of the anti-crack mechanism. The interfacial mechanical properties of the nanocomposites reinforced with straight carbon nanotubes and various types of HCNTs were investigated through the pullout of HCNTs in the crack propagation using molecular dynamics (MD). The results show that the pullout force of HCNTs is much higher than that of CNTs because the physical interlock between HCNTs and matrices is much stronger than the van der Waals (vdW) interactions between CNTs and matrices. Remarkably, HCNTs with a large pitch length can not only effectively prevent the initiation of breakages but also hinder the growth of cracks, while HCNTs with a small diameter and tube radius cannot even effectively prevent the initiation of cracks, which is similar to straight CNTs. Moreover, the shear resistance of HCNTs increases with the increase in the helix angle, which remains at a high level when the helix angle reaches the critical value. However, HCNTs with a small helix angle and large diameter can carry out more polymer chains, while snake-like HCNTs and HCNTs with a small diameter and helix angle can hardly carry out any polymer chain during the pullout process and show similar interfacial properties to the straight CNTs.

Fang Yuan; Zhiyuan Xia; Baijian Tang; Zhuoyi Yin; Xinxing Shao; Xiaoyuan He
Measurement, 2025 242 - EI SCIE

摘要 : To address the limitations of Digital Image Correlation (DIC) technology in terms of single-view and resolution capabilities, multi-camera systems have emerged, expanding the measurement area by increasing the number of cameras. However, traditional multi-camera systems continue to face challenges in the calibration of global external parameters and error control, particularly when uniform calibration between camera subsystems is not achieved, making the calibration results difficult to evaluate and analyze. In response, this paper systematically investigates the sources of error in multi-camera system calibration and proposes a novel precision evaluation method. This method qualitatively analyzes the registration results of subsystems by examining the determinant of the rotation matrix used to transform local coordinate systems to the global coordinate system and quantitatively assesses the registration accuracy based on the alignment error of targets after registration. Furthermore, a series of experiments were conducted to validate the proposed evaluation method, with results demonstrating that the method not only offers high effectiveness in precision evaluation but also provides reliable technical support in complex engineering measurements.