In ultraviolet cured-in-place-pipe(UV-CIPP)pipeline rehabilitation,resin performance critically determines repair effectiveness.Current UV-curable resins exhibit high volatile organic compound(VOC)emissions and inadeq...In ultraviolet cured-in-place-pipe(UV-CIPP)pipeline rehabilitation,resin performance critically determines repair effectiveness.Current UV-curable resins exhibit high volatile organic compound(VOC)emissions and inadequate post-cure toughness,which compromise fatigue resistance during service.To address these issues,we synthesized hydroxyl-terminated polyurethane acrylate prepolymers using diphenylmethane diisocyanate(MDI),polypropylene glycol(PPG),and hydroxyethyl methacrylate(HEMA).Fourier transform infrared spectroscopy(FTIR)confirmed successful prepolymer synthesis.We developed UV-curable resins by incorporating various crosslinking monomers and optimized the formulations through mechanical property analysis.Testing revealed that the polyurethane-acrylic UV-cured resin system combines polyurethane's mechanical excellence with acrylics'high UV-curing activity.The PPG200/MDI/HEMA formulation achieved superior performance,with a tensile strength of 55.31 MPa,an impact toughness of 22.7 kJ/m^(2),and a heat deflection temperature(HDT)of 132℃.The optimized system eliminates volatile components while maintaining high reactivity,addressing critical limitations in trenchless pipeline rehabilitation.The improved mechanical properties meet the operational demands of underground pipes,suggesting practical applicability in trenchless pipeline repair.展开更多
Widespread use of green hydrogen is a critical route to achieving a carbon-neutral society,but it cannot be accomplished without extensive hydrogen distribution.Hydrogen pipelines are the most energy-efficient approac...Widespread use of green hydrogen is a critical route to achieving a carbon-neutral society,but it cannot be accomplished without extensive hydrogen distribution.Hydrogen pipelines are the most energy-efficient approach to transporting hydrogen in areas with high,long-term demand for hydrogen.A well-known fact is that the properties of hydrogen differ from those of natural gas,which leads to significant variations in the pipeline transportation process.In addition,hydrogen can degrade the mechanical properties of steels,thereby affecting pipeline integrity.This situation has led to two inevitable key challenges in the current development of hydrogen-pipeline technology:economic viability and safety.Based on a review of the current state of hydrogen pipelines,including material compatibility with hydrogen,design methods,process operations,safety monitoring,and standards,this paper highlights key knowledge gaps in gaseous hydrogen pipelines.These gaps include the utilisation of high-strength materials for hydrogen pipelines,design of high-quality hydrogen pipelines,determination of hydrogen velocity,and repurposing of existing natural-gas pipelines.This review aims to identify the challenges in current hydrogen pipelines development and provide valuable suggestions for future research.展开更多
The relative stiffness between underground structures and surrounding soil may significantly influence the dynamic response of such structures.In this study,two underground pipelines were fabricated using rubber joint...The relative stiffness between underground structures and surrounding soil may significantly influence the dynamic response of such structures.In this study,two underground pipelines were fabricated using rubber joints with varying stiffness,and the corresponding dynamic response was evaluated.Model soils were prepared based on similarity ratios.Next,reduced-scale shaking table tests were conducted to investigate the impact of circular underground structures with varying stiffness joints on the amplification of ground acceleration,dynamic response,and deformation patterns of the underground pipelines.The comparative analysis showed that structures with lower stiffness exert less constraint on the surrounding soil,resulting in a higher amplification factor of ground acceleration.The seismic response of less stiff structures is generally 1.1 to 1.3 times the response of the stiffer structures.Therefore,the seismic response of the variable stiffness pipeline exhibits pronounced characteristics.Rubber joints effectively reduce the seismic response of underground structures,demonstrating favorable isolation effects.Consequently,relative stiffness plays a crucial role in the seismic design of underground structures,and the use of rubber materials in underground structures is advantageous.展开更多
Using the software ANSYS-19.2/Explicit Dynamics,this study performedfinite-element modeling of the large-diameter steel pipeline cross-section for the Beineu-Bozoy-Shymkent gas pipeline with a non-through straight crac...Using the software ANSYS-19.2/Explicit Dynamics,this study performedfinite-element modeling of the large-diameter steel pipeline cross-section for the Beineu-Bozoy-Shymkent gas pipeline with a non-through straight crack,strengthened by steel wire wrapping.The effects of the thread tensile force of the steel winding in the form of single rings at the crack edges and the wires with different winding diameters and pitches were also studied.The results showed that the strengthening was preferably executed at a minimum value of the thread tensile force,which was 6.4%more effective than that at its maximum value.The analysis of the influence of the winding dia-meters showed that the equivalent stresses increased by 32%from the beginning of the crack growth until the wire broke.The increment in winding diameter decelerated the disclosure of the edge crack and reduced its length by 8.2%.The analysis of the influence of the winding pitch showed that decreasing the distance between the winding turns also led to a 33.6%reduction in the length of the straight crack and a 7.9%reduction in the maximum stres-ses on the strengthened pipeline cross-section.The analysis of the temperature effect on the pipeline material,within a range from-40℃to+50℃,resulted in a crack length change of up to 5.8%.As the temperature dropped,the crack length decreased.Within such a temperature range,the maximum stresses were observed along the cen-tral area of the crack,which were equal to 413 MPa at+50℃and 440 MPa at-40℃.The results also showed that the presence of the steel winding in the pipeline significantly reduced the length of crack propagation up to 8.4 times,depending on the temperature effect and design parameters of prestressing.This work integrated the existing methods for crack localization along steel gas pipelines.展开更多
A numerical simulation analysis is conducted to examine the unsteady hydrodynamic characteristics of vortex-induced vibration(VIV)and the suppression effect of helical strakes on VIV in subsea pipelines.The analysis u...A numerical simulation analysis is conducted to examine the unsteady hydrodynamic characteristics of vortex-induced vibration(VIV)and the suppression effect of helical strakes on VIV in subsea pipelines.The analysis uses the standard k−εturbulence model for 4.5-and 12.75-inch pipes,and its accuracy is verified by comparing the results with large-scale hydrodynamic experiments.These experiments are designed to evaluate the suppression efficiency of VIV with and without helical strakes,focusing on displacement and drag coefficients under different flow conditions.Furthermore,the influence of important geometric parameters of the helical strakes on drag coefficients and VIV suppression efficiency at different flow rates is compared and discussed.Numerical results agree well with experimental data for drag coefficient and vortex shedding frequency.Spring-pipe self-excited vibration experimental tests reveal that the installation of helical strakes substantially reduces the drag coefficient of VIV within a certain flow rate range,achieving suppression efficiencies exceeding 90%with strake heights larger than 0.15D.Notably,the optimized parameter combination of helical strakes,with a pitch of 15D,a fin height of 0.2D,and 45°edge slopes,maintains high suppression efficiency,thereby exhibiting superior performance.This study provides a valuable reference for the design and application of helical strakes and VIV suppression in subsea engineering.展开更多
This study presents a comprehensive investigation of residual strength in corroded pipelines within the Yichang-Qianjiang section of the Sichuan-East Gas Pipeline,integrating advanced numerical simulation with experim...This study presents a comprehensive investigation of residual strength in corroded pipelines within the Yichang-Qianjiang section of the Sichuan-East Gas Pipeline,integrating advanced numerical simulation with experimental validation.The research methodology incorporates three distinct parameter grouping approaches:a random group based on statistical analysis of 389 actual corrosion defects detected during 2023 MFL inspection,a deviation group representing historically documented failure scenarios,and a structural group examining systematic parameter variations.Using ABAQUS finite element software,we developed a dynamic implicit analysis model incorporating geometric nonlinearity and validated it through 1:12.7 scaled model testing,achieving prediction deviations consistently within 5%for standard cases.Our analysis revealed distinct failure mechanisms between large and small defects,with large defects exhibiting stress concentration at circumferential edges and small defects concentrating stress centrally.Quantitative analysis identified defect depth as themost significant factor,with every 1mmincrease reducing strength by 0.054MPa,while defect length showed moderate influence at 0.0018MPa reduction per mm.Comparative analysis demonstrated that circumferential defects exhibited 15%higher burst failure pressure compared to axial defects,though this advantage diminished significantly at depths exceeding 40%wall thickness.These findings,validated through experimental testing with deviations within 5%,provide valuable insights for pipeline integrity management,particularly emphasizing the importance of defect depth monitoring and the need for orientation-specific assessment criteria in corrosion evaluation protocols.展开更多
Hilly terrain pipeline is a common form of pipeline in oil and gas storage and transportation industry.Due to the hilly terrain influence, the liquid at the elbow of the gathering pipeline is easy to flow back and acc...Hilly terrain pipeline is a common form of pipeline in oil and gas storage and transportation industry.Due to the hilly terrain influence, the liquid at the elbow of the gathering pipeline is easy to flow back and accumulate to form slug flow, so it is necessary to remove the accumulated liquid by gas purging. In this paper, experiment is carried out in hilly terrain pipelines. Three flow patterns of stratified flow, slug flow and stratified entrained flow are observed. The process of gas purging accumulated liquid is divided into four stages, namely liquid accumulation, liquid rising, continuous outflow and tail outflow. At the same time, the flow pattern maps of each stage are drawn. The pressure drop signal is analyzed in time domain and frequency domain, and the contour map of pressure drop distribution is drawn. It is found that the ratio of range to average value can well distinguish the occurrence range of each flow pattern.Based on visualization, the transition process of slug flow to stratified flow and stratified entrained flow is studied, and the transition boundary prediction model is established. An image processing method is proposed to convert the image signal into a similarity curve, and PSD analysis is performed to calculate the slug frequency. The normal distribution is used to fit the slug frequency, and the predicted correlation is in good agreement with the experimental data.展开更多
Strong surface impact will produce strong vibration,which will pose a threat to the safety of nearby buried pipelines and other important lifeline projects.Based on the verified numerical method,a comprehensive numeri...Strong surface impact will produce strong vibration,which will pose a threat to the safety of nearby buried pipelines and other important lifeline projects.Based on the verified numerical method,a comprehensive numerical parameter analysis is conducted on the key influencing factors of the vibration isolation hole(VIH),which include hole diameter,hole net spacing,hole depth,hole number,hole arrangement,and soil parameters.The results indicate that a smaller ratio of net spacing to hole diameter,the deeper the hole,the multi-row hole,the hole adoption of staggered arrangements,and better site soil conditions can enhance the efficiency of the VIH barrier.The average maximum vibration reduction efficiency within the vibration isolation area can reach 42.2%.The vibration safety of adjacent oil pipelines during a dynamic compaction projection was evaluated according to existing standards,and the measurement of the VIH was recommended to reduce excessive vibration.The single-row vibration isolation scheme and three-row staggered arrangement with the same hole parameters are suggested according to different cases.The research findings can serve as a reference for the vibration safety analysis,assessment,and control of adjacent underground facilities under the influence of strong surface impact loads.展开更多
Deep-sea mineral resource transportation predominantly utilizes hydraulic pipeline methodology.Environmental factors induce vibrations in flexible pipelines,thereby affecting the internal flow characteristics.Therefor...Deep-sea mineral resource transportation predominantly utilizes hydraulic pipeline methodology.Environmental factors induce vibrations in flexible pipelines,thereby affecting the internal flow characteristics.Therefore,real-time monitoring of solid–liquid two-phase flow in pipelines is crucial for system maintenance.This study develops an autoencoder-based deep learning framework to reconstruct three-dimensional solid–liquid two-phase flow within flexible vibrating pipelines utilizing sparse wall information from sensors.Within this framework,separate X-model and F-model with distinct hidden-layer structures are established to reconstruct the coordinates and flow field information on the computational domain grid of the pipeline under traveling wave vibration.Following hyperparameter optimization,the models achieved high reconstruction accuracy,demonstrating R^(2)values of 0.990 and 0.945,respectively.The models’robustness is evaluated across three aspects:vibration parameters,physical fields,and vibration modes,demonstrating good reconstruction performance.Results concerning sensors show that 20 sensors(0.06%of total grids)achieve a balance between accuracy and cost,with superior accuracy obtained when arranged along the full length of the pipe compared to a dense arrangement at the front end.The models exhibited a signal-to-noise ratio tolerance of approximately 27 dB,with reconstruction accuracy being more affected by sensor failures at both ends of the pipeline.展开更多
Unmanned aerial vehicles(UAVs)technology is rapidly advancing,offering innovative solutions for various industries,including the critical task of oil and gas pipeline surveillance.However,the limited flight time of co...Unmanned aerial vehicles(UAVs)technology is rapidly advancing,offering innovative solutions for various industries,including the critical task of oil and gas pipeline surveillance.However,the limited flight time of conventional UAVs presents a significant challenge to comprehensive and continuous monitoring,which is crucial for maintaining the integrity of pipeline infrastructure.This review paper evaluates methods for extending UAV flight endurance,focusing on their potential application in pipeline inspection.Through an extensive literature review,this study identifies the latest advancements in UAV technology,evaluates their effectiveness,and highlights the existing gaps in achieving prolonged flight operations.Advanced techniques,including artificial intelligence(AI),machine learning(ML),and deep learning(DL),are reviewed for their roles in pipeline monitoring.Notably,DL algorithms like You Only Look Once(YOLO)are explored for autonomous flight in UAV-based inspections,real-time defect detection,such as cracks,corrosion,and leaks,enhancing reliability and accuracy.A vital aspect of this research is the proposed deployment of a hybrid drone design combining lighter-than-air(LTA)and heavier-than-air(HTA)principles,achieving a balance of endurance and maneuverability.LTA vehicles utilize buoyancy to reduce energy consumption,thereby extending flight durations.The paper details the methodology for designing LTA vehicles,presenting an analysis of design parameters that align with the requirements for effective pipeline surveillance.The ongoing work is currently at Technology Readiness Level(TRL)4,where key components have been validated in laboratory conditions,with fabrication and flight testing planned for the next phase.Initial design analysis indicates that LTA configurations could offer significant advantages in flight endurance compared to traditional UAV designs.These findings lay the groundwork for future fabrication and testing phases,which will be critical in validating and assessing the proposed approach’s real-world applicability.By outlining the technical complexities and proposing specialized techniques tailored for pipeline monitoring,this paper provides a foundational framework for advancing UAV capabilities in the oil and gas sector.Researchers and industry practitioners can use this roadmap to further develop UAV-enabled surveillance solutions,aiming to improve the reliability,efficiency,and safety of pipeline monitoring.展开更多
Corrosion poses a major threat to the safety of transportation pipelines.Therefore,it is crucial to have an in-depth understanding of corrosion mechanisms in pipeline steels for the effective management of pipeline in...Corrosion poses a major threat to the safety of transportation pipelines.Therefore,it is crucial to have an in-depth understanding of corrosion mechanisms in pipeline steels for the effective management of pipeline integrity.Conducting research on corrosion mechanisms relies on the use of efficient and reliable corrosion monitoring and analysis techniques.The advancements in corrosion monitoring techniques specifically designed for the localized corrosion monitoring were aimed to be introduced,and a comprehensive overview of recent progress in understanding the localized corrosion mechanisms in pipeline steels was provided.Based on the different corrosive environments encountered,the localized corrosion issues inside pipelines are classified into two categories:localized corrosion primarily influenced by electrochemical processes and localized corrosion controlled by both electrochemical and mechanical factors.Additionally,a thorough analysis of the synergistic effects between micro-cell and macro-cell currents,as well as the interplay of mechanics and electrochemistry is presented.Finally,recommendations for future research on the mechanisms of internal localized corrosion in pipelines are provided.展开更多
Pipeline Inspection Gauge(pig)is an important equipment for oil and gas pipelines during different stages of their operations to perform functions such as dewatering,cleaning,and inspection.Owing to the hyperelasticit...Pipeline Inspection Gauge(pig)is an important equipment for oil and gas pipelines during different stages of their operations to perform functions such as dewatering,cleaning,and inspection.Owing to the hyperelasticity,time and temperature-dependent material behaviour of the sealing disc attached on the pig,the contact between the pig and the pipeline expresses complex behaviour,leading to an uncertainty in the prediction of the pig's frictional force.Knowing the deformation of the sealing discs well is essential and can be highly meaningful for predicting the pig motion,as well as reducing the pigging risks.In this study,the geometrical deformation of the sealing discs with different sizes are investigated through experiments and numerical simulations.The effects of the four nondimensionalized parameters(interference,thickness per pipeline inner diameter,and clamping ratio)of the sealing discs on the deformation behaviour were observed and discussed,and an improved mathematical model for predicting the geometrical deformation of the sealing discs was proposed and verified.With the auxiliary angleαadded in the improved mathematical model,the relative error declines to 1.87%and 3.18%respectively for predicting deformation of the sealing discs in size of 2-inch and 40-inch pig.The results of this study can help better understand the frictional force of a pig with sealing discs,as well as its motion.展开更多
Cardiolipins(CLs),the mitochondria-specific class of phospholipids,are crucial to energy metabolism,cristae structure,and cell apoptosis.CLs present significant challenges in lipidomics analysis due to their structura...Cardiolipins(CLs),the mitochondria-specific class of phospholipids,are crucial to energy metabolism,cristae structure,and cell apoptosis.CLs present significant challenges in lipidomics analysis due to their structural diversity with up to four fatty acyl side chains.In this study,we developed CLAN(Cardio Lipin ANalysis),a comprehensive computational pipeline designed to improve the accuracy and coverage of cardiolipin identification.CLAN integrates three innovative modules:A cardiolipin identification module that utilizes specific fragmentation rules for precise characterization of CLs and their acyl side chains;a false positives detection module that employs retention time(RT)criteria to reduce false positives;and a prediction module that constructs regression models to identify CLs lacking authentic MS/MS spectra.CLAN achieved better identification accuracy and the highest recall rate for potential CL identification compared to the existing lipid identification tools.Furthermore,we applied CLAN program to an intermittent fasting mouse model,delineating tissue-specific CL alterations across 10 tissues.Every-other-day fasting(EODF)can partially counteract the disruption of the CL atlas across multiple tissues caused by high-fat-high-sugar diet feeding,providing novel insights into mitochondrial lipid metabolism under dietary interventions.Taken together,this work not only advances CL identification methodology but also underscores CLAN's potential in comprehensive analysis of CL atlas in the EODF animal model.CLAN is freely accessible on Git Hub.展开更多
With the development of offshore oil and gas resources,hydrates pose a significant challenge to flow assurance.Hydrates can form,accumulate,and settle in pipelines,causing blockages,reducing transport capacity,and lea...With the development of offshore oil and gas resources,hydrates pose a significant challenge to flow assurance.Hydrates can form,accumulate,and settle in pipelines,causing blockages,reducing transport capacity,and leading to significant economic losses and fatalities.As oil and gas exploration moves deeper into the ocean,the issue of hydrate blockages has become more severe.It is essential to take adequate measures promptly to mitigate the hazards of hydrate blockages after they form.However,a prerequisite for effective mitigation is accurately detecting the location and amount of hydrate formation.This article summarizes the temperature–pressure,acoustic,electrical,instrumental–response,and flow characteristics of hydrate formation and blocking under various conditions.It also analyzes the principles,limitations,and applicability of various blockage detection methods,including acoustic,transient,and fiber-optic-based methods.Finally,it lists the results of field experiments and commercially used products.Given their advantages of accuracy and a wide detection range,acoustic pulse reflectometry and transient-based methods are considered effective for detecting hydrate blockages in future underwater pipelines.Using strict backpressure warnings combined with accurate detection via acoustic pulse reflectometry or transient-based methods,efficient and timely diagnosis of hydrate blockages can be achieved.The use of a hydrate model combined with fiber optics could prove to be an effective method for detecting blockages in newly laid pipelines in the future.展开更多
Fatigue failure caused by vibration is the most common type of pipeline failure.The core of this research is to obtain the nonlinear dynamic stress of a pipeline system accurately and efficiently,a topic that needs to...Fatigue failure caused by vibration is the most common type of pipeline failure.The core of this research is to obtain the nonlinear dynamic stress of a pipeline system accurately and efficiently,a topic that needs to be explored in the existing literature.The shell theory can better simulate the circumferential stress distribution,and thus the Mindlin-Reissner shell theory is used to model the pipeline.In this paper,the continuous pipeline system is combined with clamps through modal expansion for the first time,which realizes the coupling problem between a shell and a clamp.While the Bouc-Wen model is used to simulate the nonlinear external force generated by a clamp,the nonlinear coupling characteristics of the system are effectively captured.Then,the dynamic equation of the clamp-pipeline system is established according to the Lagrange energy equation.Based on the resonance frequency and stress amplitude obtained from the experiment,the nonlinear parameters of the clamp are identified with the semi-analytical method(SAM)and particle swarm optimization(PSO)algorithm.This study provides a theoretical basis for the clamp-pipeline system and an efficient and universal solution for stress prediction and analysis of pipelines in engineering.展开更多
Water-induced disasters in long-distance pipelines are prevalent geological hazards,characterized by their frequency and widespread distribution.The complexity of factors contributing to pipeline damage in practical e...Water-induced disasters in long-distance pipelines are prevalent geological hazards,characterized by their frequency and widespread distribution.The complexity of factors contributing to pipeline damage in practical engineering poses a significant challenge for analysis using solely theoretical models.This study systematically reveals the cross-scale failure mechanism of long-distance pipelines under hydrodynamic impact through the combination of multi-scale experimental representation and theoretical modeling.Employing a combination of macroscopic measurements,advanced material testing of residual samples from failed pipelines,and consideration of operational conditions and environmental factors,the failure modes is systematically analyzed.The findings reveal that under the vibrations induced by water impulses,the pipe material exhibits a pronounced ratchet effect,leading to an 8.92%reduction in elongation at break.Furthermore,the Bauschinger effect is observed,resulting in a 2.95%decrease in yield strength.Cyclic hardening significantly diminishes the impact toughness of the weld by 22.2%.Notably,at high vibration frequencies of approximately 18.98 Hz,the stress concentration in the girth weld near the axial midpoint of the pipe section initiates cracking,ultimately leading to failure under the alternating load generated by the oscillation.This study provides valuable insights into the scientific understanding of pipeline failure mechanisms under water impact,contributing to the development ofmore robust and resilient pipeline systems.展开更多
The transportation of oil and gas through pipelines is crucial for sustaining energy supply in industrial and civil sectors.However,the issue of pitting corrosion during pipeline operation poses an important threat to...The transportation of oil and gas through pipelines is crucial for sustaining energy supply in industrial and civil sectors.However,the issue of pitting corrosion during pipeline operation poses an important threat to the structural integrity and safety of pipelines.This problem not only affects the longevity of pipelines but also has the potential to cause secondary disasters,such as oil and gas leaks,leading to environmental pollution and endangering public safety.Therefore,the development of a highly stable,accurate,and reliable model for predicting pipeline pitting corrosion is of paramount importance.In this study,a novel prediction model for pipeline pitting corrosion depth that integrates the sparrow search algorithm(SSA),regularized extreme learning machine(RELM),principal component analysis(PCA),and residual correction is proposed.Initially,RELM is utilized to forecast pipeline pitting corrosion depth,and SSA is employed for optimizing RELM’s hyperparameters to enhance the model’s predictive capabilities.Subsequently,the residuals of the SSA-RELM model are obtained by subtracting the prediction results of the model from actual measurements.Moreover,PCA is applied to reduce the dimensionality of the original 10 features,yielding 7 new features with enhanced information content.Finally,residuals are predicted by using the seven features obtained by PCA,and the prediction result is combined with the output of the SSA-RELM model to derive the predicted pipeline pitting corrosion depth by incorporating multiple feature selection and residual correction.Case study demonstrates that the proposed model reduces mean squared error,mean absolute percentage error,and mean absolute error by 66.80%,42.71%,and 42.64%,respectively,compared with the SSA-RELM model.Research findings underscore the exceptional performance of the proposed integrated approach in predicting the depth of pipeline pitting corrosion.展开更多
Suction bucket jacket foundations exhibit considerable potential for implementation in deep-sea offshore wind power projects. To address water film formation resulting from negative pressure penetration during constru...Suction bucket jacket foundations exhibit considerable potential for implementation in deep-sea offshore wind power projects. To address water film formation resulting from negative pressure penetration during construction, certain suction bucket jacket foundation projects implement grouting techniques to ensure adequate bearing capacity. This study conducted a large-scale suction bucket foundation grouting model experiment to examine grout flow characteristics and specific phenomena under various grouting pipeline configurations. Comparative analyses of grouting efficiency and quality across different pipeline layouts identified critical influencing factors and their impact on grouting performance. The results demonstrate that the number of grout outlets should be maintained within an optimal range:insufficient outlets enhance the indentation effect and decrease fill efficiency, while excessive outlets necessitate precise spacing for effective distribution. Additionally, grout outlets should be uniformly arranged to reduce segregation and enhance overall grouting quality. This study's findings provide a scientific foundation for optimizing grouting design in suction bucket jacket foundations, with substantial implications for engineering applications.展开更多
基金Funded by the National Natural Science Foundation of China(No.52473077)China Three Gorges Corporation(No.202403190)。
文摘In ultraviolet cured-in-place-pipe(UV-CIPP)pipeline rehabilitation,resin performance critically determines repair effectiveness.Current UV-curable resins exhibit high volatile organic compound(VOC)emissions and inadequate post-cure toughness,which compromise fatigue resistance during service.To address these issues,we synthesized hydroxyl-terminated polyurethane acrylate prepolymers using diphenylmethane diisocyanate(MDI),polypropylene glycol(PPG),and hydroxyethyl methacrylate(HEMA).Fourier transform infrared spectroscopy(FTIR)confirmed successful prepolymer synthesis.We developed UV-curable resins by incorporating various crosslinking monomers and optimized the formulations through mechanical property analysis.Testing revealed that the polyurethane-acrylic UV-cured resin system combines polyurethane's mechanical excellence with acrylics'high UV-curing activity.The PPG200/MDI/HEMA formulation achieved superior performance,with a tensile strength of 55.31 MPa,an impact toughness of 22.7 kJ/m^(2),and a heat deflection temperature(HDT)of 132℃.The optimized system eliminates volatile components while maintaining high reactivity,addressing critical limitations in trenchless pipeline rehabilitation.The improved mechanical properties meet the operational demands of underground pipes,suggesting practical applicability in trenchless pipeline repair.
基金supported by the National Key Research and Development Program of China(No.2022YFB4003400)the Key Research and Development Program of Zhejiang Province of China(No.2023C01225)the State Key Laboratory of Clean Energy Utilization,China。
文摘Widespread use of green hydrogen is a critical route to achieving a carbon-neutral society,but it cannot be accomplished without extensive hydrogen distribution.Hydrogen pipelines are the most energy-efficient approach to transporting hydrogen in areas with high,long-term demand for hydrogen.A well-known fact is that the properties of hydrogen differ from those of natural gas,which leads to significant variations in the pipeline transportation process.In addition,hydrogen can degrade the mechanical properties of steels,thereby affecting pipeline integrity.This situation has led to two inevitable key challenges in the current development of hydrogen-pipeline technology:economic viability and safety.Based on a review of the current state of hydrogen pipelines,including material compatibility with hydrogen,design methods,process operations,safety monitoring,and standards,this paper highlights key knowledge gaps in gaseous hydrogen pipelines.These gaps include the utilisation of high-strength materials for hydrogen pipelines,design of high-quality hydrogen pipelines,determination of hydrogen velocity,and repurposing of existing natural-gas pipelines.This review aims to identify the challenges in current hydrogen pipelines development and provide valuable suggestions for future research.
基金Key International(Regional)Joint Research Project under Grant No.52020105002National Natural Science Foundation of China under Grant No.51991393。
文摘The relative stiffness between underground structures and surrounding soil may significantly influence the dynamic response of such structures.In this study,two underground pipelines were fabricated using rubber joints with varying stiffness,and the corresponding dynamic response was evaluated.Model soils were prepared based on similarity ratios.Next,reduced-scale shaking table tests were conducted to investigate the impact of circular underground structures with varying stiffness joints on the amplification of ground acceleration,dynamic response,and deformation patterns of the underground pipelines.The comparative analysis showed that structures with lower stiffness exert less constraint on the surrounding soil,resulting in a higher amplification factor of ground acceleration.The seismic response of less stiff structures is generally 1.1 to 1.3 times the response of the stiffer structures.Therefore,the seismic response of the variable stiffness pipeline exhibits pronounced characteristics.Rubber joints effectively reduce the seismic response of underground structures,demonstrating favorable isolation effects.Consequently,relative stiffness plays a crucial role in the seismic design of underground structures,and the use of rubber materials in underground structures is advantageous.
基金funded by the Science Committee of the Ministry of Science and Higher Education of the Republic of Kazakhstan(Grant No.AP19680589).
文摘Using the software ANSYS-19.2/Explicit Dynamics,this study performedfinite-element modeling of the large-diameter steel pipeline cross-section for the Beineu-Bozoy-Shymkent gas pipeline with a non-through straight crack,strengthened by steel wire wrapping.The effects of the thread tensile force of the steel winding in the form of single rings at the crack edges and the wires with different winding diameters and pitches were also studied.The results showed that the strengthening was preferably executed at a minimum value of the thread tensile force,which was 6.4%more effective than that at its maximum value.The analysis of the influence of the winding dia-meters showed that the equivalent stresses increased by 32%from the beginning of the crack growth until the wire broke.The increment in winding diameter decelerated the disclosure of the edge crack and reduced its length by 8.2%.The analysis of the influence of the winding pitch showed that decreasing the distance between the winding turns also led to a 33.6%reduction in the length of the straight crack and a 7.9%reduction in the maximum stres-ses on the strengthened pipeline cross-section.The analysis of the temperature effect on the pipeline material,within a range from-40℃to+50℃,resulted in a crack length change of up to 5.8%.As the temperature dropped,the crack length decreased.Within such a temperature range,the maximum stresses were observed along the cen-tral area of the crack,which were equal to 413 MPa at+50℃and 440 MPa at-40℃.The results also showed that the presence of the steel winding in the pipeline significantly reduced the length of crack propagation up to 8.4 times,depending on the temperature effect and design parameters of prestressing.This work integrated the existing methods for crack localization along steel gas pipelines.
基金Supported by the National Natural Science Foundation of China (Grant No. 52222111)the National Science and Technology Major Project of China “Key Technologies and Equipment for Deepwater Dry Oil and Gas Production and Processing Platforms”(No. 2024ZD1403300)+1 种基金Subproject 5 “Research on Safety Risk Assessment Technology System for Deepwater Dry Oil and Gas Production and Processing Platforms”(No. 2024ZD1403305)the China Scholarship Council (202306440019)。
文摘A numerical simulation analysis is conducted to examine the unsteady hydrodynamic characteristics of vortex-induced vibration(VIV)and the suppression effect of helical strakes on VIV in subsea pipelines.The analysis uses the standard k−εturbulence model for 4.5-and 12.75-inch pipes,and its accuracy is verified by comparing the results with large-scale hydrodynamic experiments.These experiments are designed to evaluate the suppression efficiency of VIV with and without helical strakes,focusing on displacement and drag coefficients under different flow conditions.Furthermore,the influence of important geometric parameters of the helical strakes on drag coefficients and VIV suppression efficiency at different flow rates is compared and discussed.Numerical results agree well with experimental data for drag coefficient and vortex shedding frequency.Spring-pipe self-excited vibration experimental tests reveal that the installation of helical strakes substantially reduces the drag coefficient of VIV within a certain flow rate range,achieving suppression efficiencies exceeding 90%with strake heights larger than 0.15D.Notably,the optimized parameter combination of helical strakes,with a pitch of 15D,a fin height of 0.2D,and 45°edge slopes,maintains high suppression efficiency,thereby exhibiting superior performance.This study provides a valuable reference for the design and application of helical strakes and VIV suppression in subsea engineering.
文摘This study presents a comprehensive investigation of residual strength in corroded pipelines within the Yichang-Qianjiang section of the Sichuan-East Gas Pipeline,integrating advanced numerical simulation with experimental validation.The research methodology incorporates three distinct parameter grouping approaches:a random group based on statistical analysis of 389 actual corrosion defects detected during 2023 MFL inspection,a deviation group representing historically documented failure scenarios,and a structural group examining systematic parameter variations.Using ABAQUS finite element software,we developed a dynamic implicit analysis model incorporating geometric nonlinearity and validated it through 1:12.7 scaled model testing,achieving prediction deviations consistently within 5%for standard cases.Our analysis revealed distinct failure mechanisms between large and small defects,with large defects exhibiting stress concentration at circumferential edges and small defects concentrating stress centrally.Quantitative analysis identified defect depth as themost significant factor,with every 1mmincrease reducing strength by 0.054MPa,while defect length showed moderate influence at 0.0018MPa reduction per mm.Comparative analysis demonstrated that circumferential defects exhibited 15%higher burst failure pressure compared to axial defects,though this advantage diminished significantly at depths exceeding 40%wall thickness.These findings,validated through experimental testing with deviations within 5%,provide valuable insights for pipeline integrity management,particularly emphasizing the importance of defect depth monitoring and the need for orientation-specific assessment criteria in corrosion evaluation protocols.
基金supported by the Basic Science Center Program for Ordered Energy Conversion of the National Natural Science Foundation of China(No.52488201)the National Natural Science Foundation of China(No.52422606).
文摘Hilly terrain pipeline is a common form of pipeline in oil and gas storage and transportation industry.Due to the hilly terrain influence, the liquid at the elbow of the gathering pipeline is easy to flow back and accumulate to form slug flow, so it is necessary to remove the accumulated liquid by gas purging. In this paper, experiment is carried out in hilly terrain pipelines. Three flow patterns of stratified flow, slug flow and stratified entrained flow are observed. The process of gas purging accumulated liquid is divided into four stages, namely liquid accumulation, liquid rising, continuous outflow and tail outflow. At the same time, the flow pattern maps of each stage are drawn. The pressure drop signal is analyzed in time domain and frequency domain, and the contour map of pressure drop distribution is drawn. It is found that the ratio of range to average value can well distinguish the occurrence range of each flow pattern.Based on visualization, the transition process of slug flow to stratified flow and stratified entrained flow is studied, and the transition boundary prediction model is established. An image processing method is proposed to convert the image signal into a similarity curve, and PSD analysis is performed to calculate the slug frequency. The normal distribution is used to fit the slug frequency, and the predicted correlation is in good agreement with the experimental data.
基金National Natural Science Foundation of China under Grant Nos.52078386 and 52308496SINOMACH Youth Science and Technology Fund under Grant No.QNJJ-PY-2022-02+2 种基金Young Elite Scientists Sponsorship Program under Grant No.BYESS2023432Fund of State Key Laboratory of Precision Blasting and Hubei Key Laboratory of Blasting Engineering,Jianghan University under Grant No.PBSKL2023A9Fund of China Railway Construction Group Co.,Ltd.under Grant No.LX19-04b。
文摘Strong surface impact will produce strong vibration,which will pose a threat to the safety of nearby buried pipelines and other important lifeline projects.Based on the verified numerical method,a comprehensive numerical parameter analysis is conducted on the key influencing factors of the vibration isolation hole(VIH),which include hole diameter,hole net spacing,hole depth,hole number,hole arrangement,and soil parameters.The results indicate that a smaller ratio of net spacing to hole diameter,the deeper the hole,the multi-row hole,the hole adoption of staggered arrangements,and better site soil conditions can enhance the efficiency of the VIH barrier.The average maximum vibration reduction efficiency within the vibration isolation area can reach 42.2%.The vibration safety of adjacent oil pipelines during a dynamic compaction projection was evaluated according to existing standards,and the measurement of the VIH was recommended to reduce excessive vibration.The single-row vibration isolation scheme and three-row staggered arrangement with the same hole parameters are suggested according to different cases.The research findings can serve as a reference for the vibration safety analysis,assessment,and control of adjacent underground facilities under the influence of strong surface impact loads.
基金financial support by the National Natural Science Foundation of China (Nos.52471293 and 12372270)the National Youth Science Foundation of China (Nos.52101322 and 52108375)+3 种基金the Program for Intergovernmental International S&T Cooperation Projects of Shanghai Municipality, China (Nos.24510711100 and 22160710200)The Oceanic Interdisciplinary Program of Shanghai Jiao Tong University (No.SL2022PT101)funded by the Open Fund of the State Key Laboratory of Coastal and Offshore Engineering of Dalian University of Technology (No.LP2415)National Key R&D Program of China (No.2023YFC2811600)
文摘Deep-sea mineral resource transportation predominantly utilizes hydraulic pipeline methodology.Environmental factors induce vibrations in flexible pipelines,thereby affecting the internal flow characteristics.Therefore,real-time monitoring of solid–liquid two-phase flow in pipelines is crucial for system maintenance.This study develops an autoencoder-based deep learning framework to reconstruct three-dimensional solid–liquid two-phase flow within flexible vibrating pipelines utilizing sparse wall information from sensors.Within this framework,separate X-model and F-model with distinct hidden-layer structures are established to reconstruct the coordinates and flow field information on the computational domain grid of the pipeline under traveling wave vibration.Following hyperparameter optimization,the models achieved high reconstruction accuracy,demonstrating R^(2)values of 0.990 and 0.945,respectively.The models’robustness is evaluated across three aspects:vibration parameters,physical fields,and vibration modes,demonstrating good reconstruction performance.Results concerning sensors show that 20 sensors(0.06%of total grids)achieve a balance between accuracy and cost,with superior accuracy obtained when arranged along the full length of the pipe compared to a dense arrangement at the front end.The models exhibited a signal-to-noise ratio tolerance of approximately 27 dB,with reconstruction accuracy being more affected by sensor failures at both ends of the pipeline.
基金supported by the Yayasan Universiti Teknologi PETRONAS(YUTP)under Cost Center 015LC0-485.
文摘Unmanned aerial vehicles(UAVs)technology is rapidly advancing,offering innovative solutions for various industries,including the critical task of oil and gas pipeline surveillance.However,the limited flight time of conventional UAVs presents a significant challenge to comprehensive and continuous monitoring,which is crucial for maintaining the integrity of pipeline infrastructure.This review paper evaluates methods for extending UAV flight endurance,focusing on their potential application in pipeline inspection.Through an extensive literature review,this study identifies the latest advancements in UAV technology,evaluates their effectiveness,and highlights the existing gaps in achieving prolonged flight operations.Advanced techniques,including artificial intelligence(AI),machine learning(ML),and deep learning(DL),are reviewed for their roles in pipeline monitoring.Notably,DL algorithms like You Only Look Once(YOLO)are explored for autonomous flight in UAV-based inspections,real-time defect detection,such as cracks,corrosion,and leaks,enhancing reliability and accuracy.A vital aspect of this research is the proposed deployment of a hybrid drone design combining lighter-than-air(LTA)and heavier-than-air(HTA)principles,achieving a balance of endurance and maneuverability.LTA vehicles utilize buoyancy to reduce energy consumption,thereby extending flight durations.The paper details the methodology for designing LTA vehicles,presenting an analysis of design parameters that align with the requirements for effective pipeline surveillance.The ongoing work is currently at Technology Readiness Level(TRL)4,where key components have been validated in laboratory conditions,with fabrication and flight testing planned for the next phase.Initial design analysis indicates that LTA configurations could offer significant advantages in flight endurance compared to traditional UAV designs.These findings lay the groundwork for future fabrication and testing phases,which will be critical in validating and assessing the proposed approach’s real-world applicability.By outlining the technical complexities and proposing specialized techniques tailored for pipeline monitoring,this paper provides a foundational framework for advancing UAV capabilities in the oil and gas sector.Researchers and industry practitioners can use this roadmap to further develop UAV-enabled surveillance solutions,aiming to improve the reliability,efficiency,and safety of pipeline monitoring.
基金sponsored by the National Key R&D Program of China(No.2022YFC2806200)the National Natural Science Foundation of China(No.52001055)the Open Foundation of State Key Laboratory of Structural Analysis for Industrial Equipment(GZ22118).
文摘Corrosion poses a major threat to the safety of transportation pipelines.Therefore,it is crucial to have an in-depth understanding of corrosion mechanisms in pipeline steels for the effective management of pipeline integrity.Conducting research on corrosion mechanisms relies on the use of efficient and reliable corrosion monitoring and analysis techniques.The advancements in corrosion monitoring techniques specifically designed for the localized corrosion monitoring were aimed to be introduced,and a comprehensive overview of recent progress in understanding the localized corrosion mechanisms in pipeline steels was provided.Based on the different corrosive environments encountered,the localized corrosion issues inside pipelines are classified into two categories:localized corrosion primarily influenced by electrochemical processes and localized corrosion controlled by both electrochemical and mechanical factors.Additionally,a thorough analysis of the synergistic effects between micro-cell and macro-cell currents,as well as the interplay of mechanics and electrochemistry is presented.Finally,recommendations for future research on the mechanisms of internal localized corrosion in pipelines are provided.
基金supported by Key Technologies Research and Development Program(Grant No.SQ2022YFC2806103)and the National Natural Science Foundation of China(Grant No.51509259).
文摘Pipeline Inspection Gauge(pig)is an important equipment for oil and gas pipelines during different stages of their operations to perform functions such as dewatering,cleaning,and inspection.Owing to the hyperelasticity,time and temperature-dependent material behaviour of the sealing disc attached on the pig,the contact between the pig and the pipeline expresses complex behaviour,leading to an uncertainty in the prediction of the pig's frictional force.Knowing the deformation of the sealing discs well is essential and can be highly meaningful for predicting the pig motion,as well as reducing the pigging risks.In this study,the geometrical deformation of the sealing discs with different sizes are investigated through experiments and numerical simulations.The effects of the four nondimensionalized parameters(interference,thickness per pipeline inner diameter,and clamping ratio)of the sealing discs on the deformation behaviour were observed and discussed,and an improved mathematical model for predicting the geometrical deformation of the sealing discs was proposed and verified.With the auxiliary angleαadded in the improved mathematical model,the relative error declines to 1.87%and 3.18%respectively for predicting deformation of the sealing discs in size of 2-inch and 40-inch pig.The results of this study can help better understand the frictional force of a pig with sealing discs,as well as its motion.
基金supported by grants from the National Key Research and Development Program of China(No.2022YFE0205800)the National Natural Science Foundation of China(No.21974114)+5 种基金Major Science and Technology Special Project of Fujian Province(No.2022YZ036012)the Fundamental Research Funds for the Central Universities(No.20720220003)Project“111”sponsored by the State Bureau of Foreign Experts and Ministry of Education of China(No.BP0618017)to S.-H.LinNatural Science Foundation of Fujian Province of China(No.2022J01330)Natural Science Foundation of Xiamen City of China(No.3502Z20227208)the China Scholarship Council(No.202308350047)to J.Zeng。
文摘Cardiolipins(CLs),the mitochondria-specific class of phospholipids,are crucial to energy metabolism,cristae structure,and cell apoptosis.CLs present significant challenges in lipidomics analysis due to their structural diversity with up to four fatty acyl side chains.In this study,we developed CLAN(Cardio Lipin ANalysis),a comprehensive computational pipeline designed to improve the accuracy and coverage of cardiolipin identification.CLAN integrates three innovative modules:A cardiolipin identification module that utilizes specific fragmentation rules for precise characterization of CLs and their acyl side chains;a false positives detection module that employs retention time(RT)criteria to reduce false positives;and a prediction module that constructs regression models to identify CLs lacking authentic MS/MS spectra.CLAN achieved better identification accuracy and the highest recall rate for potential CL identification compared to the existing lipid identification tools.Furthermore,we applied CLAN program to an intermittent fasting mouse model,delineating tissue-specific CL alterations across 10 tissues.Every-other-day fasting(EODF)can partially counteract the disruption of the CL atlas across multiple tissues caused by high-fat-high-sugar diet feeding,providing novel insights into mitochondrial lipid metabolism under dietary interventions.Taken together,this work not only advances CL identification methodology but also underscores CLAN's potential in comprehensive analysis of CL atlas in the EODF animal model.CLAN is freely accessible on Git Hub.
基金supported by the National Natural Science Foundation of China(52476058,U21B2065,52006024,and 52306188)the National Key Research and Development(2022YFC2806200).
文摘With the development of offshore oil and gas resources,hydrates pose a significant challenge to flow assurance.Hydrates can form,accumulate,and settle in pipelines,causing blockages,reducing transport capacity,and leading to significant economic losses and fatalities.As oil and gas exploration moves deeper into the ocean,the issue of hydrate blockages has become more severe.It is essential to take adequate measures promptly to mitigate the hazards of hydrate blockages after they form.However,a prerequisite for effective mitigation is accurately detecting the location and amount of hydrate formation.This article summarizes the temperature–pressure,acoustic,electrical,instrumental–response,and flow characteristics of hydrate formation and blocking under various conditions.It also analyzes the principles,limitations,and applicability of various blockage detection methods,including acoustic,transient,and fiber-optic-based methods.Finally,it lists the results of field experiments and commercially used products.Given their advantages of accuracy and a wide detection range,acoustic pulse reflectometry and transient-based methods are considered effective for detecting hydrate blockages in future underwater pipelines.Using strict backpressure warnings combined with accurate detection via acoustic pulse reflectometry or transient-based methods,efficient and timely diagnosis of hydrate blockages can be achieved.The use of a hydrate model combined with fiber optics could prove to be an effective method for detecting blockages in newly laid pipelines in the future.
基金Project supported by the National Science and Technology Major Project(No.J2019-I-0008-0008)the National Natural Science Foundation of China(No.52305096)the Chinese Postdoctoral Science Foundation(No.GZB20230117)。
文摘Fatigue failure caused by vibration is the most common type of pipeline failure.The core of this research is to obtain the nonlinear dynamic stress of a pipeline system accurately and efficiently,a topic that needs to be explored in the existing literature.The shell theory can better simulate the circumferential stress distribution,and thus the Mindlin-Reissner shell theory is used to model the pipeline.In this paper,the continuous pipeline system is combined with clamps through modal expansion for the first time,which realizes the coupling problem between a shell and a clamp.While the Bouc-Wen model is used to simulate the nonlinear external force generated by a clamp,the nonlinear coupling characteristics of the system are effectively captured.Then,the dynamic equation of the clamp-pipeline system is established according to the Lagrange energy equation.Based on the resonance frequency and stress amplitude obtained from the experiment,the nonlinear parameters of the clamp are identified with the semi-analytical method(SAM)and particle swarm optimization(PSO)algorithm.This study provides a theoretical basis for the clamp-pipeline system and an efficient and universal solution for stress prediction and analysis of pipelines in engineering.
基金supported by the Youth Science and Technology New Star Project of Shaanxi Province(grants Nos.2024ZC-KjXX-002,2021KJXX65 and 2023KJXX-092)the Natural Science Foundation of Shaanxi Province(grant No.2021JQ-947)the Basic Research and Strategic Reserve Technology Research Fund of the China National Petroleum Corporation(projects Nos.2022DQ03-05 and 2023DQ03-07).
文摘Water-induced disasters in long-distance pipelines are prevalent geological hazards,characterized by their frequency and widespread distribution.The complexity of factors contributing to pipeline damage in practical engineering poses a significant challenge for analysis using solely theoretical models.This study systematically reveals the cross-scale failure mechanism of long-distance pipelines under hydrodynamic impact through the combination of multi-scale experimental representation and theoretical modeling.Employing a combination of macroscopic measurements,advanced material testing of residual samples from failed pipelines,and consideration of operational conditions and environmental factors,the failure modes is systematically analyzed.The findings reveal that under the vibrations induced by water impulses,the pipe material exhibits a pronounced ratchet effect,leading to an 8.92%reduction in elongation at break.Furthermore,the Bauschinger effect is observed,resulting in a 2.95%decrease in yield strength.Cyclic hardening significantly diminishes the impact toughness of the weld by 22.2%.Notably,at high vibration frequencies of approximately 18.98 Hz,the stress concentration in the girth weld near the axial midpoint of the pipe section initiates cracking,ultimately leading to failure under the alternating load generated by the oscillation.This study provides valuable insights into the scientific understanding of pipeline failure mechanisms under water impact,contributing to the development ofmore robust and resilient pipeline systems.
基金Supported by the Natural Science Foundation of Shandong Province of China(ZR2022QE091)the Special fund for Taishan Industry Leading Talent Project(tsls20230605)Key R&D Program of Shandong Province,China(2023CXGC010407).
文摘The transportation of oil and gas through pipelines is crucial for sustaining energy supply in industrial and civil sectors.However,the issue of pitting corrosion during pipeline operation poses an important threat to the structural integrity and safety of pipelines.This problem not only affects the longevity of pipelines but also has the potential to cause secondary disasters,such as oil and gas leaks,leading to environmental pollution and endangering public safety.Therefore,the development of a highly stable,accurate,and reliable model for predicting pipeline pitting corrosion is of paramount importance.In this study,a novel prediction model for pipeline pitting corrosion depth that integrates the sparrow search algorithm(SSA),regularized extreme learning machine(RELM),principal component analysis(PCA),and residual correction is proposed.Initially,RELM is utilized to forecast pipeline pitting corrosion depth,and SSA is employed for optimizing RELM’s hyperparameters to enhance the model’s predictive capabilities.Subsequently,the residuals of the SSA-RELM model are obtained by subtracting the prediction results of the model from actual measurements.Moreover,PCA is applied to reduce the dimensionality of the original 10 features,yielding 7 new features with enhanced information content.Finally,residuals are predicted by using the seven features obtained by PCA,and the prediction result is combined with the output of the SSA-RELM model to derive the predicted pipeline pitting corrosion depth by incorporating multiple feature selection and residual correction.Case study demonstrates that the proposed model reduces mean squared error,mean absolute percentage error,and mean absolute error by 66.80%,42.71%,and 42.64%,respectively,compared with the SSA-RELM model.Research findings underscore the exceptional performance of the proposed integrated approach in predicting the depth of pipeline pitting corrosion.
文摘Suction bucket jacket foundations exhibit considerable potential for implementation in deep-sea offshore wind power projects. To address water film formation resulting from negative pressure penetration during construction, certain suction bucket jacket foundation projects implement grouting techniques to ensure adequate bearing capacity. This study conducted a large-scale suction bucket foundation grouting model experiment to examine grout flow characteristics and specific phenomena under various grouting pipeline configurations. Comparative analyses of grouting efficiency and quality across different pipeline layouts identified critical influencing factors and their impact on grouting performance. The results demonstrate that the number of grout outlets should be maintained within an optimal range:insufficient outlets enhance the indentation effect and decrease fill efficiency, while excessive outlets necessitate precise spacing for effective distribution. Additionally, grout outlets should be uniformly arranged to reduce segregation and enhance overall grouting quality. This study's findings provide a scientific foundation for optimizing grouting design in suction bucket jacket foundations, with substantial implications for engineering applications.
