Hongyuan Fang

Zhengzhou University | zzu · School of Water Conservancy Engineering

In this study, the uniaxial compression and cyclic loading and unloading experiments were conducted on the non-water reactive foaming polyurethane (NRFP) grouting material with a density of 0.29 g/cm3, and the microstructure was characterized using scanning electron microscope (SEM) method. Based on the uniaxial compression and SEM characterization...

Underground infrastructure (such as underground pipelines, tunnels, and pipe galleries) forms the foundation of people's lives and economic activities, and their operational and structural safety is a major concern for society and industry. This special issue aims to report the latest progress in trenchless construction and asset management of un...

The cracking of natural gas pipeline is a critical problem threat-ening its safety. A comprehensive understanding of the relevant knowledge system and research status is conducive to further re-search by scholars. This chapter comprehensively introduces the crack propagation mechanism, fracture evaluation method, crack ar-rest prediction model and...

The grouting sequence and spatial layout of grouting holes are key technical problems in the treatment of underground drainage pipeline defects. An unreasonable grouting parameter design will lead to slurry running or bulging during pipeline defect repair. In this paper, based on the discrete element particle flow numerical simulation software PFC...

Regular detection of defects in drainage pipelines is crucial. However, some problems associated with pipeline defect detection, such as data scarcity and defect counting difficulty, need to be addressed. Therefore, a Transformer‐optimized generation, detection, and counting method for drainage‐pipeline defects was established in this paper. First,...

The polymer anti-seepage wall has great application value in the reinforcement of earth dams. At present, the research on polymer anti-seepage walls is limited to the analysis of material properties and mechanical properties under static conditions. The application of polymer anti-seepage walls in earth dams in earthquake area is limited due to lac...

Conventional deep-learning-based inspection methods for sewer pipeline defects neglect the complex inner environment of pipelines (e.g., fog and motion blur) and real-time segmentation despite their high accuracy for clear images. To solve the problem of low accuracy and slow speed of fuzzy image inspection, a novel defogging, deblurring, and real-...

The regular detection of pavement cracks is critical for life and property security. However, existing deep learning-based methods of crack detection face difficulties in terms of data acquisition and defect counting. An automatic intelligent detection and tracking system for pavement cracks is proposed. Our system is formed of a pavement crack gen...

Research on pipes ringed by erosion voids is mainly concerned with circumferential mechanical behavior but ignores longitudinal bending responses induced by the relative motion of the pipe joints at voids. There has been limited innovative experimental investigation into pipe behavior that assesses the effectiveness of polyurethane (PU) grouting in...

Discovering damage in pavement videos is critical for the assessment of pavement conditions. Unfortunately, existing damage segmentation methods in pavement videos have problems of low efficiency, low accuracy, and difficulty in adapting to changes in the appearance of the damage. An automatic damage segmentation system for pavement videos is propo...

Two-component polyurethane has been widely used in various types of engineering. In this work, polyurethane samples with different foaming ratios were obtained by adjusting the ratio of each component and foaming in water. By studying the morphology and mechanical properties of these specimens, the polyurethane with foaming ratio of 16 was selected...

The non-aqueous reactive foamed polyurethane is widely used in engineering. We have observed the micromorphology of the non-aqueous reactive foamed polyurethane by field emission scanning electron microscopy. It is found that the pores are closed and the minimum pore wall thickness is only 63.5nm. Therefore, we proposed a method to construct a micr...

At present, the insufficient structural performance of pipelines leads to frequent road collapse accidents. More and more urban areas have adopted trenchless repair techniques to improve the structural performance of existing corroded pipelines and prolong their service life. The spray method has been widely used due to its advantages of convenient...

The pipeline is mainly subjected to soil load, fluid load and traffic load, the mechanical properties of corroded concrete pipes after cured-in-place-pipe (CIPP) rehabilitation under multi-field coupling have not been revealed. In this paper, a 3D numerical model of buried concrete pipes after CIPP rehabilitation under the coupled effects of the so...

As a new type of chemical grouting material, polymers have been widely used in fractured rock masses, but the understanding of the diffusion characteristics of polymers still needs to be further improved. Due to the expansion of polymer slurry, the change of grouting pressure is not synchronized with the time change of diffusion radius, leading to...

Prestressed concrete cylinder pipe (PCCP) makes full use of the compressive and corrosion resistance of concrete and mortar, as well as the tensile and sealing properties of steel, and has good mechanical properties. But the bell-spigot joints are the weak points of the PCCP pipeline and are easy to be damaged. In this study, a fined 3-D FEM model...

Flexural properties is one of the important parameters for the evaluation of buried pipeline ultraviolet cured-in-place pipe (UV-CIPP) rehabilitation effectiveness. The flexure failure mechanism of UV-CIPP materials under the influence of different construction parameters (curing time, UV lamp irradiation intensity, curing distance, and material th...

Polymer grouting materials are widely used in the field of trenchless rehabilitation of infrastructure, and their properties are closely related to the crosslinking process and crosslinking degree between components. In this paper, polyurethane (PU) models with different crosslinking degrees were built based on the molecular dynamics (MD) simulatio...

Leak location studies of water supply pipes are crucial to reducing water waste and eliminating potential hazards. However, for the situation where the noise intensity is much greater than the leak signal intensity, the traditional noise-reduction localization methods have become ineffective. Therefore, an adaptive time-delay estimation method base...

Wire breakage is the most prevalent type of damage to prestressed concrete cylinder pipes (PCCPs) as widely used in large-scale water supply projects. Based on the elastic mechanics theory, the distribution of deflection, bending moment, shear force, and strain along the length of PCCP after wire breakage is calculated in this work. A three-dimensi...

Two-component foaming polymer (TFPU) grouting material is increasingly used in civil engineering. Its compressive strength is key to achieving the desired enhancing effect. The constitutive model of TFPU grouting material is a theoretical basis to evaluate the strength performance, which, however, is not fully understood. Here the uniaxial compress...

The compressive mechanical properties of self-expanding grouting materials with different densities are essential in evaluating the ultimate conditions of the repaired underground infrastructure. In this study, digital imaging correlation (DIC) and acoustic emission (AE) techniques were applied to monitor the compressive damage evolution process of...

With the rapid urbanization, waterlogging losses caused by rainstorm are becoming increasingly severe. In order to reveal the correlations between rainstorm characteristic elements, and make the calculation of rainstorm return period more reasonable and objective, this study established the joint distribution models of rainstorm elements by using c...

In the present study, distribution characteristics and biodiversity of microbial communities from four real sewer pipes in urban residential area were studied. The differences of microbial community were observed in spatial distribution. The genus of Mycobacterium, Acidiphilium and Acidithiobacillus were mainly detected in the upper and middle part...

Polymer anti-seepage walls have been widely used in the anti-seepage reinforcement projects of earth dams. Dam crest is always supposed to meet the requirements of traffic load which has significant influence on the dam body and anti-seepage wall. In order to analyze the coordination characteristics of the deformation between polymer anti-seepage w...

At present, researches on urban short-duration rainstorm patterns mainly focus on single-peak rainstorm patterns, and rarely involve double-peak rainstorm patterns, or convert double-peak patterns into single-peak patterns directly, even ignore the impact of double-peak patterns, which directly affects the urban flood planning and early warning and...

Deep learning algorithms have achieved promising results in the field of pavement damage segmentation. Since the texture features of map crack damage are complex, existing segmentation methods may experience the problem of edge information loss for the damaged area. In this study, we therefore propose Road-Seg-CapsNet, a feature fusion model combin...

With the age of pipeline and increase in the volume of urban sewage, the pipeline has different degrees of defects, which can cause safety problems such as road collapse and urban flooding. The service life of drainage pipes is closely related to daily maintenance and inspection, so it is very important to inspect the defects and monitor the operat...

Cement-based grouting materials have high compressive strengths, but they are brittle. The low strain burden limits their rehabilitation application in the high compressive strain engineering. A new cleaner polyurethane elastomer (PUE) grouting material with high hardening strain is proposed in this work to provide a better choice for the fundament...

Polyurethane grouting materials are increasingly used in the non-excavation rehabilitation of roadbeds. The compressive strength of roadbed rehabilitation polyurethane (RHPU) grouting materials is the key to achieving the desirable repair effect, whereas the constitutive model of RHPU grouting materials is not yet understood. Here, the mechanical p...

Urban waterlogging becomes a challenge with the higher urbanization. This paper aims to assess waterlogging risk in the high-tech district of Zhengzhou city in China by coupling land surface hazard-pregnant (LSHP) features and underground pipe network operation (UPNO) characteristics. The LSHP risk is assessed according to the regional surface feat...

To understand the runoff-sediment discharge relationship , this study examined the annual runoff and sediment discharge data obtained from the Tangnaihai hydrometric station. The data were decomposed into multiple time scales through Complete Ensemble Empirical Mode Decomposition with adaptive noise (CEEMDAN). Furthermore, double cumulative curves...

Improving the accuracy of hydrological prediction for long-term annual runoff series is important for water resources management and planning. In this study, the complementary ensemble empirical mode decomposition with adaptive noise (CEEMDAN) is used to decompose the runoff time series of the Tangnaihai hydrological station in the source area of t...

This letter proposes a method based on deep learning for the automatic recognition and localization of underground pipelines using the ground penetrating radar (GPR). First, an automatic recognition model with an average precision (AP) of 0.9256 is proposed and trained based on Faster R-CNN. The feature extraction is optimized by the Attention-guid...

In order to reveal the correlations between rainstorm characteristics variables, and make the return period of rainstorm more reasonable and objective, in this study, the joint distribution models of rainstorm elements are established by using copula theory based on the rainfall data in a Chinese megacity, Zhengzhou. Then their combined design valu...

With the development of deep learning, convolutional neural networks (CNN) have been gradually used in pipeline defeats detection. However, due to the complex environment inside the pipeline, few defeat images are not enough for the training of CNN. A multi-defect detection system based on StyleGAN-SDM and fusion CNN for sewer pipelines is proposed...

The stability of an arch dam can be significantly damaged by an extreme underwater explosion. This study proposed a damage index for assessing the degree of local damage of an arch dam after the dam was subjected to an underwater explosion. The damage index was applied to assess local damage at the middle part of the dam, surcharge holes, and abutm...

Polymer is a kind of high molecular elastic material. The polymer cement mortar composite material formed by mixing it with cement mortar has the advantages of light weight, high strength, and good durability compared with traditional mortar materials. The effect of polyurethane polymer content on mechanical properties and microstructure of polyvin...

Cured-in-place pipe (CIPP), the most common approach employed in trenchless sewer rehabilitation technology, has been increasingly used in recent years. To examine the mechanical characteristics of corroded buried concrete pipes after semi-structural rehabilitation of CIPP, a series of full-scale tests was performed. The influence of traffic, surch...

Under the coupling effect of the defects inside and around pipes, the shear displacement of the joints of old concrete pipes fallen into disrepair usually shows an accelerated deterioration trend, and its excessive value can lead to structural damage or fluid leakage. Therefore, developing a prediction model for the maximum shear displacement of co...

The present work numerically studies the dynamics of a droplet impact on solid spheres with different sizes and surface wettability. Different initial impact velocities are also set to the droplet to consider the velocity effect. A particle-based numerical method, many-body dissipative particle dynamics (MDPD), is employed to perform the simulation...

Wire breakage in prestressed concrete cylinder pipe (PCCP) is the most common type of damage. A theoretical model for calculating the stress distribution of steel wire is proposed, by assuming a linear distributed pattern of bond stress. The theoretical model is evaluated by comparing the shrinkage value from an experiment on a PCCP with broken wir...

Prestressed concrete cylinder pipe (PCCP) is widely used in large-scale water supply projects. The most common damage mode of PCCP is caused by rupture of prestressed wires. To strengthen a damaged PCCP, the technology of wrapping prestressed carbon fiber reinforced polymer (CFRP) externally is proposed. A full-scale test on a PCCP with an inside d...

In recent years, the dispersion characteristics of materials are not considered in the numerical simulation of underground structure damages by ground penetrating radar, which leads to errors in the numerical simulation. To solve this proplem, a novel first-order explicit symplectic Euler method with debye model is provided for the electromagnetic...

The mechanical properties of the roadbed rehabilitation polyurethane (PU) grouting materials subjected to different chemical corrosion are the theoretical basis for evaluating the long-term performance, which, however, is not clear yet. Here, the PU grouting materials with different densities were immersed in water, H2SO4, HCl, and NaOH solutions f...

Polymer-modified cement mortar (PMCM) composite materials have drawn the attention of researchers worldwide because of their excellent capabilities such as crack resistance, durability, simple construction process, and cost-effectiveness. This paper investigates current research on the enhancement effect of adding polymers in ordinary cement mortar...

In recent years, polymer grouting material has been applied to engineering combined with the development of grouting technology. Two-component foaming polyurethane is one type of water insensitive polymer grouting material, in which the cell structure plays a key role on its physical properties. To explore the impact of the microstructure of the po...

Antiknock research of reinforced concrete (RC) slabs is often carried out with spherical or nearly spherical explosives, although many explosives used in engineering and military are cylinder shaped. It is known that the shock wave caused by cylindrical explosives varies in different directions, which is quite different from the spherical charge. I...

As a new antiseepage reinforcement material, polyurethane grouting material has been widely studied in terms of its static mechanical properties. However, research on its dynamic mechanical properties is relatively rare. In this research, considering the influence of the explosive charge weight, the air contact and close-in explosion experiments of...

In order to study the damage characteristics of polymer plates under the impact of the underwater explosion, the underwater contact and near-field explosion tests of polymer plates were conducted using different explosive quantities. In this paper, eight polymer plates with the size of 500 mm × 500 mm × 60 mm were made, and eight groups of explosio...

Microbial-induced carbonate precipitation (MICP) is a promising technique to reinforcconclusione soils utilizing the metabolic process of bacteria. MICP can be utilized in coarse-grained soil and result in calcium carbonate precipitation among soil particles, thus improving the mechanical properties. However, the reinforcement efficiency decreases...

Conventional algorithms are not sensitive to small objects like pavement cracks. We developed a pavement crack detection method based on a convolutional neural network (CNN) with multiple feature layers. The model extracts multi-scale features to increase the accuracy of pavement crack recognition. After hyperparameters tuning, the model accuracy r...

Broken prestressing wires in prestressed concrete cylinder pipe (PCCP) can cause incident of pipe burst. A method was proposed to repair damaged PCCP with broken wires by externally bonding carbon fiber reinforced polymer (CFRP). A finite element model was established and calibrated against the data from a prototype-scale laboratory test. Upon cali...

At present, researches on urban short-duration rainstorm patterns mainly focus on single-peak rainstorm patterns, and rarely involve double-peak rainstorm patterns, or convert double-peak patterns into single-peak patterns directly, even ignore the impact of double-peak patterns, which directly affects the urban flood planning and early warning and...

For old pipes that have been in service for a long time in disrepair conditions, it is common to find internal and external defects in the pipelines. The repair technologies for internal defects inside the pipes are well-established, but these technologies for the defects around the pipe are still in the early stage. In this study, an innovative tr...

This paper presents a rapid detection and pixel size measurement method for airport pavement apparent disease and Foreign Object Debris. Firstly, MobileNet-SSD algorithm is used for object identification. Then Mask R-CNN algorithm is used to segment the target image and measure the pixel size of the target object. Finally, the detailed information...

The specific objective of this study was to solve the problem of high risk and low efficiency of manual inspection of airport road surface. This paper describes the design of an Airport Road Surface Intelligent Inspection System Based on machine vision and deep learning. The system completes the airport pavement inspection through autonomous naviga...

Self-expansion polymer grouting technology is a new rapid trenchless method for repairing leakage and subsidence of underground concrete structures. The bond between polymer and concrete is critical to determine the ultimate conditions of repaired concrete. In this paper, a series of direct shear tests were performed to investigate the influence of...

In order to forecast flood accurately and reveal the relationship between rainstorm and flood at the micro level, a model which combines wavelet analysis, GM (1,2) and fuzzy weighted Markov is built. Taking the Jialu River of Zhengzhou City in China as study area, the GM (1,2) model is constructed between the components of rainfall and flood volume...

Understanding mechanical behavior at the soil–structure interface is fundamental for safety in engineering and is therefore an important consideration in structural design. Buildings can be deformed or severely damaged by shear forces from the action of earthquakes, waves, or winds. It is therefore necessary to understand the conditions which lead...

Cured-in-place pipe (CIPP) has become one of the most widely used pipeline trenchless rehabilitation technologies because it has the advantages of needing no grouting, rapid curing, and short construction time. However, previous research has not yet revealed the mechanical sensitivity of pipe-liner composite structures. In this paper, a numerical m...

In order to reveal the multi-time scale of rainfall, runoff and sediment in the source area of the Yellow River and improve the accuracy of annual runoff forecast, the Complete Ensemble Empirical Mode Decomposition with Adaptive Noise (CEEMDAN) method is introduced to decompose the measured rainfall, runoff and sediment data series of the Tangnahai...

In order to solve contact problems, ANSYS provides a variety of contact algorithms. However, there is no basis for how to select the contact algorithm when solving the contact problem in hydraulic structure engineering. Therefore, this paper introduces the basic concepts of contact algorithms briefly, such as penalty method, lagrange method, augmen...

The geopolymerization process affects the mechanical properties and chemical durability of geopolymer cement by forming alkali aluminosilicate gels of varying degrees of polymerization. An integrated and accurate analysis of geopolymerization process cannot be easily achieved due to the restriction of in-situ detection. In this work, vacuum dehydra...

This letter presents a ground-penetrating radar (GPR) forward model on dispersive media based on parallel conformal symplectic Euler algorithm. We developed a symplectic Euler algorithm combined with conformal meshes and graphics processing unit (GPU) acceleration technology, which proved to be an accurate and effective method to simulating GPR ele...

Nowadays, asphalt road has dominated highways around the world. Among various defects of asphalt road, cracks have been paid more attention, since cracks often cause major engineering and personnel safety incidents. Current manual crack inspection methods are time-consuming and labor-intensive, and most segmentation methods cannot detect cracks at...

Prestressed concrete cylinder pipe (PCCP) is widely used in hydraulic engineering. The bell‐and‐spigot joint is a weak point along a PCCP pipeline, since damage of joint can affect the operation of the whole pipeline. In this paper, a three‐dimensional numerical model of buried PCCP, considering the simulation of rubber gasket in bell‐and‐spigot jo...

A three dimensional elasticity analysis for the transverse free vibration characteristics of functionally graded magneto-electro-elastic plates based on the scaled boundary finite element method (SBFEM) incorporated with the precise integration algorithm (PIA) is presented. The material properties of magneto-electro-elastic plates are changing alon...

Concrete drainage pipelines built in early China are seriously aged and in disrepair. Therefore, the methods that can be directly used to evaluate the service performances of such pipelines are urgently needed. In this study, 100 three-dimensional (3-D) refined finite element (FE) models of concrete drainage pipelines subjected to corrosion and voi...

Developing an accurate and efficient forward model of the dynamic response of pavement structure is of great significance for obtaining the design parameters of the layered pavement structure through inverse calculation based on the measured pavement data. Based on the spectral element method, this study proposes an accurate and efficient numerical...