bluuebunny/crossref_metadata_2025 huggingface dataset:
Uniaxial Tensile Test and Numerical Simulation of Hybrid Fiber Reinforced Concrete
Authors: Yu Jing , Zhang Hui , Qi Yanglong
Published: February 2021

According to the reinforcement principle of hybrid fiber, steel fiber and PVA fiber were used to prepare hybrid fiber reinforced concrete (HyFRC) with compression strength of 120 MPa (SPHFC120). The tensile properties of SPHFC120 were studied by uniaxial tensile test, and the uniaxial tensile constitutive equation was established according to the stress-strain curve. An efficient and applicable three-dimensional mesoscale model to simulate HyFRC was developed. It consists of two components involving concrete matrix and fibers, and the bond between concrete matrix and fibers was considered indirectly by defining the fiber constitutive model. The model was validated with uniaxial tensile test. Then parametric studies were conducted to investigate the effect of fibers content on the tensile performance of HyFRC. The results show that PVA fibers obviously improve the tensile strength, peak tensile strain and tensile toughness of steel fiber reinforced concrete.
Research on Basic Mechanical Properties of Large Scale Thermal Steel Slag Cement Concrete
Authors: Yang Xingsheng , Huo Zhiqiang , Zhang Zheng , Yang Zhengxun
Published: February 2021

The basic mechanical properties of steel slag concrete with waste thermal steel slag instead of the coarse and fine aggregates in concrete are studied and compared with the mechanical properties of ordinary concrete. The test results show that the addition of steel slag as coarse aggregate will enhance the compressive strength and flexural strength of concrete, and it will improve with the increase in the steel slag content. When steel slag is used as fine aggregate, the compressive strength of the steel slag concrete subjected to first increases and then decreases with increase in the steel slag sand content. To obtain better performance for the steel slag concrete, the suggested optimum content of steel slag sand as fine aggregate is 50%. Within. The addition of steel slag as fine aggregate can improve the flexural strength of concrete, and the flexural strength increases with the increase of the addition of steel slag sand. The steel slag concrete with the highest strength can be obtained when 100% of steel slag replaces the concrete aggregate, and the steel slag has good basic mechanical properties for the application of road engineering.
A Comprehensive Evaluation Method of Safety Behavior of Concrete Face Rockfill Dam Based on Regression Relationship Method and Fuzzy Recognition Model
Authors: Wen Lifeng , Yang Ying , Li Yanlong
Published: February 2021

The concrete face rockfill dam (CFRD) generally encounters structural health problems during long-term operation. Therefore, it is necessary to study the safety evaluation of CFRDs. This paper proposes a comprehensive evaluation method for the safety behavior of CFRDs on the basis of regression relationship method and fuzzy recognition model. The method of sub-index safety evaluation is established by using regression relationship method. The multiplication scale method was adopted to determine the sub-indexes weight. In combineing of sub-index safety evaluation value and sub-indexes comprehensive weight, the fuzzy recognition model is used to determine the comprehensive evaluation grade of dam safety. Safety evaluation of several CFRDs were evaluated by the method proposed in this paper and exisiting safety evaluated method to verify reasonable and rationality of the method.
Rheology Test and Finite Element Analysis: A Case Study of a Rockfill Dam in China
Authors: Deng Chengfa , Xu Chang , Li Xuemei , Zheng Minsheng
Published: February 2021

Rheology often occurs in the dam rockfill deformation. In this paper, we carried out a large-scale triaxial rheological test for the tuff rockfill materials of a concrete faced rockfill dam in China, and then obtained the parameters of the seven parameter rheology model. Finally, we analyzed the dam rheology using the three-dimensional finite element model. The results show that the dam settlement, horizontal displacement, face deflection and the displacement of the joints around the face slab are all obviously increased when considering the rheological behavior of the rockfill. We find that the calculated settlement of the dam body is in good agreement with the filed measured value when the dam is completed, and the maximum settlement during the impoundment period is within the normal range.
Time-dependent Seismic Fragility Analysis of Buried Steel Pipes in Alkaline and Near-Neutral Soil Environments
Authors: Liu Xiaohang , Zheng Shansuo , Wu Xingxia , Zheng Yue
Published: February 2021

In alkaline and near-neutral soil environments, the mechanical and seismic performance of buried steel pipes degrades with deepening corrosion over time. To study the seismic fragility of buried steel pipes of different service ages in these environments, an incremental dynamic time history analysis of typical pipes was carried out with the time-varying constitutive model of steel. A probabilistic seismic demand model for buried steel pipes of different service ages in alkaline and near-neutral soil environments was then established, which can characterize the probability relationship between the ground motion intensity and structural response. Furthermore, on the basis of the tristate criteria, the limits of each ultimate failure state were determined. Time-varying seismic analytical fragility models of the pipes, including pipe units in two different soil environments and four service ages, were then established, which can characterize the probability of different failure states of structures under different earthquakes. The corresponding seismic fragility curves were then drawn. Seismic fragility curves were also obtained under three different diameter ranges based on seismic damage statistics. Results showed that, under the same ground motion, with increasing service time and decreasing pipe diameter, the probabilities of three failure states, namely, basically intact, moderately damaged, and severely damaged, all increased.
Comparison and analysis of dry mixed mortar and traditional shotcrete and equipment development scheme
Authors: Li Xu , Zhu Hong li , Jing Wen qing , Cheng Guo qiang
Published: February 2021

In order to study the advantages and disadvantages of dry mixed mortar and traditional shotcreting in underground shotcreting operation, and improve the mechanization level of underground shotcreting operation. This paper makes a statistical analysis on the use of dry mixed mortar shotcreting machines in 10 pairs of mines, such as Fucun and Tianchen of Zaokuang group. It is found that the dust content in the feeding point and the shotcreting point is higher, and the rebound is also higher. Six pairs of coal mines, such as Fucun and Tianchen, were selected to compare and analyze the shotcreting efficiency, rebound rate, dust rate and economic and technical indicators between dry mixed mortar and traditional mortar. The results showed that compared with traditional mortar, the shotcreting efficiency of dry mixed mortar was increased by 55.1%, the work efficiency was increased by 97.9%, and the rebound rate was reduced by 4.8%. Based on the above problems existing in dry mixed mortar shotcreting operation, the joint scientific research institute of Zao mining group put forward the schemes of bag feeding of finished dry mixed mortar and centralized feeding of finished dry mixed mortar, as well as the new shotcreting machine JSPB-8LX which can automatically adjust the water cement ratio, laying a foundation for the comprehensive promotion and application of dry mixed mortar under the mine.
Glacial lake outburst caused by small amplitude wave overflow
Authors: Wang Baoliang , Wang Hongfei , Yao Zhenguo
Published: February 2021

In this study, a series of glacial lake dam overflow experiments are conducted. In those experiments, the influence of surge scale on dam outburst was studied. According to the results of the experiment, the surge overflow is the direct trigger factor of the natural lake outburst, and the periodic return of the small amplitude surge is favorable to the formation of the dam outburst. The scale of the surge will affect the time required to form the break, and the shape of the outburst flood curve. The scour movement of the water in the dam back side will make the dam form a gully. The scour movement of the water in the back side will make the dam form a gully, when the gully developed to a certain extent, the interaction between the water flow and the bottom bed changed from shear action (friction resistance) to impact action, which greatly increased the erosion and destruction capacity of the water flow and formed a "headcut". The water flow constantly brushes the bottom of the "headcut" and produced retrospective erosion, make the break constantly expanded, eventually result in dam break.
Green Development Path Analysis of Small Hydropower Based on River Chief System
Authors: Zhang Xinfeng , Li Zhaoxu , Jiang Ran
Published: February 2021

River chief system is an innovative river and lake management system and model with Chinese characteristics. At present, the river chief system has achieved remarkable results in the management and protection of rivers and lakes in various regions. To promote the green development of small hydropower stations under the river chief system is not only the internal requirement of protecting water ecological environment, but also the urgent need of small hydropower stations to adapt to the green development in the new era. Based on the current situation of small hydropower development, this study establishes the evaluation system of small hydropower cleaning and rectification, evaluates the main problems existing in the green development and ecological transformation of small hydropower, and puts forward a practical development path, in order to promote the small hydropower ecological problems rectification and gradually embarking on the road of green development.
Investigation of South Korea Precipitation Variation using Empirical Orthogonal Function (EOF) and Cyclostationary EOF
Authors: Sun Mingdong , Kim Gwangseob , Xu Xiangqin , Wang Yan
Published: February 2021

The monthly precipitation data of 56 stations during 47 years (1973-2019) in South Korea are comprehensively analysed using the EOF technique and CSEOF technique respectively. The main motivation for employing this technique in the present study is to investigate the physical processes associated with the evolution of the precipitation from observation data. The first mode account for 77.07% of the total variance and exhibits annual cycle of corresponding PC time series with traditional spatial pattern, and the second mode spatial patterns account for 8.13% of the total variance and show strong north to south gradient. In CSEOF analysis, two leading modes temporal pattern of PC time series reveals the annual cycle on a monthly time scale and long-term fluctuation, the first mode temporal pattern of PC time series account for 73.55% of the total variance and shows an increasing linear trend which represents that temporal variability of first mode pattern has been strengthened. The spatial distribution corresponding to two leading modes show monthly spatial variation. Compared with the EOF analysis, the CSEOF analysis preferably exhibits the spatial distribution and temporal evolution characteristics and variability of South Korea historical precipitation.
Development status and trend of water saving agriculture in China
Authors: Li Fuqiang , Wang Yucai , Zhang Hengjia
Published: February 2021

As an agricultural country, the shortage and waste of water resources seriously restrict the rapid development of agriculture in China, so how to realize water-saving agriculture is imminent. This paper expounds the current situation and existing problems of water-saving agriculture in China, studies and discusses the development trend of water-saving agriculture in the future, which provides a certain theoretical basis for the rapid development of China’s agriculture.
Effects of different irrigation quotas on growth characteristics and yield of seed maize in Hexi Corridor
Authors: Xiao Rang , He Zhibin , Zhang Yongling , Xiao Zhanwen , Cheng Hongyu , Liang Chao
Published: February 2021

In order to find out the optimal scheme of irrigation quota for seed corn in Zhangye, field experiments were carried out to study the effects of different irrigation quotas on the growth and yield of seed corn. Seed corn was used as test crop, drip irrigation under plastic film was used as water supply mode different irrigation quota treatment T1(4200m3/ha), T2(4650m3/ha), T3(5250m3/ha), T4(5400m3/ha), CK(5850m3/ha) were set up.The results showed that the plant height of T2 was the highest, reaching 154.6 cm,and the ear height of T4 was the highest, reaching 74.8cm.There was a significant difference in the double ear rate among different treatments, among which the double ear rate of T4 was the highest, reaching 19.12%, followed by T3(17.86%) and CK(15.12%), and the double ear rate of T1 was the lowest, reaching 12.98%. The empty stalk rate of T2 was the largest(7.72%), followed by T3 and T4, and the empty stalk rate of T5 was the smallest. The ear of T3 was the longest(14.74cm), and the invalid ear length of T4 was the largest(1.64cm). The grain number per ear of T4 was the largest, followed by T2, CK and T3, and CK was the smallest. Compared with T2 and T3, T4 increased by 0.23% and 4.32%(P>0.05), respectively, and significantly increased by 16.56% compared with T1.Different treatments have different responses to the yield of seed production. Among them, the T4 treatment has the largest yield, reaching 6655.8kg/hm2, followed by T2 and T3, which are 5853.6 and 5661.9kg/hm2, respectively.The T1 yield is the smallest, only 5362.2kg/hm2,T4,T2 increased by 24.12% and 9.15% respectively compared with CK, significant difference. Comprehensive consideration of agronomic traits, ear economic traits, crop yield and yield increase rate and other indicators show that the optimal irrigation quota for corn planting areas in the Hexi Corridor is 5400m3/ha The irrigation quotas for each growth period are 825m3/ha at the jointing stage, 825 m3/ha at the big bell mouth stage, 975m3/ha at the tasseling stage, 975 m3/ha at the flowering stage, 975m3/ha at the filling stage, and 825 m3 at the milking stage/ha. This research can provide theoretical and technical reference for realizing high-efficiency water-saving cultivation and industrialization development of maize seed production in the oasis irrigation area of the Hexi Corridor.
Mechanical properties of corroded stainless steel rebars under marine environment
Authors: Zhao Zi-Xiang , Gui Shi-Jie , Tang Peng , Wang Xiao-Hui
Published: February 2021

Under the marine environment, the durability of the reinforced concrete (RC) infrastructures is greatly influenced by the chloride-induced corrosion of the ordinary reinforcing bars. In order to prolong the service life of the RC infrastructures, stainless steel rebars (SSRs) are gradually used in marine infrastructures due to their better corrosion resistance. However, research on the corrosion and mechanical properties of the SSR under marine environmental attack is quite limited. In this paper, tensile tests at room temperature were carried out on corroded SSR samples with different types and diameters. Results show that, no obvious yielding plateaus can be observed in the stress-strain relation curves of the SSRs when compared with those of the ordinary carbon steel bars; the yielding strength and ultimate strength of the corroded ordinary carbon steel bars and SSRs decrease with the increased average cross-sectional loss while the elongation change of the corroded SSRs with the average cross-sectional loss is variable. Basing on the constitutive model of uncorroded SSR proposed by Ramberg and Osgood and considering the influence of the average and maximum cross-sectional loss on the strengths of corroded SSRs, stress-strain constitutive models of the corroded SSRs were proposed.
Research on Regional Planning of Trans-provincial Flood Control River
Authors: Piao Xitong
Published: February 2021

Aiming at the problem of the integrity of the regional flood control planning with the division of administrative boundaries in the coordinated development of the region, the typical inter-provincial basin of Beijing, Tianjin and Hebei is selected as the research object, and the numerical coupling model of flood control and drainage based on MIKE11, MIKEurban and MIKE21 is constructed to identify the regional problems of river flood control, to reveal the systemicity, linkage and synergy of flood control and drainage planning under the background of regional coordinated governance, and to explore the planning ideas for linkage planning of regional flood control and drainage projects.
Corrosion resistance of two types of stainless steel reinforcements under the simulated seawater wetting-drying cycle attack
Authors: Qi Lu-lu , Gui Shi-Jie , Tang Peng , Wang Xiao-Hui
Published: February 2021

In order to study the corrosion resistance of the stainless steel bars under marine environmental attack, simulated seawater drying and wetting test on the two types of the stainless steel bars (SSRs), 304 and 316L austenitic SSRs as well as S32304 and S32205 duplex SSRs, was carried out in the laboratory. Electrochemical monitoring of open-circuit potential, linear polarization and electrochemical impedance spectroscopy (EIS) was carried out via CS310H electrochemical potentiostat. Zview software was used to discuss the measured data. Results show that the Stern-Genry coefficient B of the ordinary carbon steel bar is about 20mV, while those values of the duplex SSRs and austenitic SSRs are in the range of 14∼16mV and 15∼17mV, respectively. For the above-listed reinforcement, better corrosion resistance is shown in the duplex SSRs with the best behaviour observed in S32304 duplex SSRs; the corrosion resistance of the austenitic SSRs 304 and 316L is good and similar, while poor corrosion resistance is shown in the ordinary carbon steel bar as expected.
Application Progress of Comprehensive Evaluation Model in Irrigation District Water-Saving Reform
Authors: Wang Zeyi , Wang Yingying , Zhang Hengjia
Published: February 2021

Water-saving reform in irrigated districts is of great significance to agricultural water-saving and production increase, and to promote economic development. Hence, a reasonable evaluation of the comprehensive benefits of irrigation district water-saving reform is conducive to the planning and management of the water, and to the modernization of irrigation districts. Through the collation of relevant literature, the necessity and feasibility of water-saving reform in irrigation districts were briefly described, and the application progress of different evaluation models in the benefit evaluation of water-saving reform in irrigation districts was clarified. The problems and development trends of benefit evaluation of water-saving reform in irrigation districts are put forward, and the benefit evaluation model widely used at present is described. Benefit evaluation has involved all aspects of human life, and its application fields have become wider and wider, and more and more methods have been adopted. Therefore, it is of great importance to summarize the evaluation methods and theories.
Research on a Method for Simulating Hydrodynamic Pressure of Two-way Water Retaining Thin Plate
Authors: Bi Zhonghui , Huang Weiyang , Yang Wenyun , Liu Fanghong
Published: February 2021

Under the action of an earthquake, the interaction between water bodies and solids is an important part of analyzing the stability of water retaining structures. This paper proposes the use of shell elements to simulate two-way water retaining thin plates, and the correctness of the method is verified by ANSYS fluid-solid coupling plate; then the new method is used to simulate the impact of the water on the thin plate under the action of earthquakes. Earthquake water pressure is used to analyze the seismic response law of the two-way water retaining plate. The research results show that: the hydrodynamic pressure of the two-way water-retaining sheet is greater than that of the one-way water-retaining, and is approximately equal to the sum of the dynamic pressures of the two-way water-retaining.
Research Status and Prospect of Fish Habitat
Authors: Liu Ya , Tong Sichen , Xiong Yongfeng
Published: February 2021

The impact of habitat changes on fish has become increasingly prominent, leading to the decline of fish population in varying degrees. Therefore, the study of fish habitat is an important means to protect fish resources. This article introduces the current status of fish habitat research at home and abroad. Overseas fish habitats are more comprehensive. Domestic fish habitat research mainly focuses on fish reproduction hydrology research, fish reproduction hydrodynamics research, and fish habitat suitability. The purpose of this study is to provide a systematic scientific basis for the protection of fish key habitats, and to protect the sustainable utilization of fish germplasm resources and the sustainable development of fisheries.
A Study of Water Quality Safety of Rural Water Supply Projects in the Pearl River Basin
Authors: Jiang Ran , Zhu Xiaoping , He Rui , Chang Ze
Published: February 2021

In order to know the water quality of rural water supply projects, the water samples are collected from finished water and tap water of administrative villages in some counties and districts of the Pearl River Basin for sampling inspection in 2019. The water quality indexes and limits in Table 1 and Table 4 are taken from Standards for Drinking Water Quality for evaluation. The detection results showed that the water quality of finished water and the water source area was completely up to the standard. For 71 water samples collected from the finished water of the water treatment factory detected, except for some parameters that slightly exceeded the limits, the rate of reaching the standard is up to 97.2%. It can thus be seen that the water quality safety of the rural water supply projects in the Pearl River Basin area is highly reliable.
Channel regulation engineering plan for Reach in Xijiang River
Authors: Li Shaoxi
Published: February 2021

In the reach from Jieshou to Ducheng of the Xijiang River, the flow and sediment conditions are complex, the shallows are linked together and the rocks are densely covered. With the promotion of waterway classification, the navigation-obstructing phenomenon appears in some shoal reaches due to insufficient depth. There are some safety hazards for ship navigation due to the distribution of rocks in channel or on both sides of channel. Based on the navigation-obstructing characteristic, the channel regulation principles mainly in dredging and rock blasting and secondly by damming were put forward. And according to the concrete condition of different shallow reaches, different channel regulation methods were proposed. By fixed and movable bed physical model test, the variations of the water level along the reach and the velocity in channel before and after different engineering plans were studied. The results show that the dredged channel will be stable and the water depth in channel will meet the demands of design depth after the recommended plan implementation.
Research and application of numerical simulation of ship maneuvering under non-uniform wind
Authors: Wang Chuanai , Tong Sichen , Diao Mingjun
Published: February 2021

Taking Fortran language as the platform, a depth-integrated two-dimensional non-uniform flow mathematical model and a ship maneuvering mathematical model were developed from the bottom layer. By further coupling the influence of wind, the mathematical model of ship maneuvering motion based on wind and current effects was constructed. Taking a typical river section in the Three Gorges Reservoir area as an example, the numerical simulation of ship maneuvering motion under still wind and non-uniform wind effect was carried out. Results show that the ships are obviously affected by wind in this river section. With the increasing change frequency of wind speed and direction, the difficulty of ship control increases correspondingly. In order to avoid the average accident, the ship must change its steer in time accordingly. This model can simulate the ship maneuvering motion and navigation status under wind effect quite well, which can provide some references for the ship’s navigation and maneuvering in inland rivers.
The characteristics of sediments in the middle and lower Yangtze River influenced by dam operation
Authors: Guo Anan , He Li
Published: February 2021

Since the Three Gorges Dam (TGD) was operated, the sediment characteristics in the downstream river have changed significantly. The characteristics of sediments can be partly reflected by the critical diameter to distinguish wash load and bed material load (WAB) and the ratio of wash load to suspended sediment (WTS). However, the WAB and WTS of the Yangtze River(YR) have not been fully investigated. In this study, data of sized suspended sediment and bed material at four stations in the middle and lower YR were collected to calculate the WAB and WTS, using the most-curvature method. The variations were then analyzed. The results suggest that the WAB and WTS of Yichang station varied greatly before the impoundment, while that of other stations were in small fluctuations. After the impoundment, the WAB of Yichang station increased dramatically to 1.856 mm, and the growth rate of the WAB at Jianli and Hankou stations were 1.0% and 4.1%, respectively (compared with WAB in 2002), while that of Datong station was -8.4%. Comparing with the rising WAB, the WTS of Yichang station continued to rise until it was close to 100%. However, the WTS of other stations decreased overall (30%-40% in Jianli and Hankou, and 8% in Datong).
Research and Calculation on the Optimization of Hydraulic Lifting Mechanism for New Steel Gate
Authors: Kaixuan Li , Yehan Geng , Zhan Wang , Yongsheng Yan
Published: February 2021

The steel gate based on the principle of hydraulic lifting mechanism has been widely used in urban water ecological construction, but the retaining height of this kind of gate is mostly l-5m at present. With the development of water conservancy engineering and the deepening of the application research of steel gate, the retaining height gradually grows to 6-8m. However, at present, there are few researches on hydraulic lifting mechanism in the case of large retaining height. In this paper, Inventor is used to firstly establish three-dimensional visual entity models of the direct push type, Booster type and Maleli type hydraulic lifting mechanism. Then, the changing rules and relations among hydraulic cylinder diameter, stroke and stability safety factor of the three hydraulic lifting mechanisms are calculated and analyzed by changing the constraint conditions in the case of large retaining height (4m, 5m, 6m, 7m, 8m) and different opening and closing angles. It is aimed at providing a scientific basis for the optimization of hydraulic lifting mechanism of steel gate under the condition of large retaining height.
Construction of risk diagnosis mode database for South to North Water Transfer Project
Authors: Zhou Ning , He Yongjun , Wang Fang , Li Hongen
Published: February 2021

There are complex and diverse engineering structures in the Middle Route Project of South to North Water Transfer. In order to ensure the normal operation of the project during the operation period. By analysing and summarizing the possible dangerous situations, it can effectively improve the emergency response ability of relevant management departments. In this paper, typical structures and risk databases are built based on the method of entity relationship graph. Using the related factors in the history risk databases, the engineering factors, environmental factors and human factors are sorted out to subdivide the entities. The relationship between risk factors and typical structures is carried out by risk codes, so as to build a complete engineering risk database.
Dynamic Simulation Research on Operation Safety of Main Canal of South-to-North Water Transfer Based on Risk Input
Authors: Wang Fang , Zhou Ning , He Yongjun , Li Hongen
Published: February 2021

The South-to-North Water Diversion Project will pose a great threat to the lives and property safety of people along the route once a dangerous situation occurs. Therefore, this paper analyzes the historical risk data of the South-to-North Water Transfer Project to identify risk sources, combs the actual risk occurrence process with the basic structure of "Risk Factor→Destruction Link→Destruction Mode", and builds a main canal system risk interpretation model. At the same time, taking the typical high-fill section of the main canal of the South-to-North Water Transfer Project as an example, a typical failure evolution process is selected to construct a dynamic simulation model based on system dynamics to simulate the failure process of the canal embankment under three kinds of manual intervention, as the channel operation under risk input scheduling decisions provides new ideas.
Research on the Recycle of Different Materials from Demolition Waste
Authors: Chengdu CHEN
Published: February 2021

Nowadays, with the reduction of energy sources and deterioration of the natural environment, people pay more and more attention to infrastructure sustainability. It is because a large part of the pollution comes from the construction industry. There are lots of construction and demolition (C&D) waste produced every year. This paper analyzes the recycle of aggregates, asphalt, plastic, glass, ferrous metal, and wood and discusses and compares the future of recycling these materials.
A Two-Step Damage Identification Based on Cross-Model Modal Strain Energy and Simultaneous Optimization
Authors: Fan Qin
Published: February 2021

Aiming at the problem of the effect on damage identification caused by noise and modal incompleteness, a two-stage damage identification method based on cross-model modal strain energy and simultaneous optimization was proposed. This paper proposed an improved damage index (Modified Index of Cross-model Modal Strain Energy, MICMSE) based on cross-model modal strain energy. This method first locates the damaged elements by MICMSE, and introduces simultaneous optimization to quantify the damage ratios of damaged elements. The two-step method avoids the calculation of the sensitivity of the modal parameters and the reanalysis of the characteristic equation, speeds up the convergence speed, and guarantees the recognition accuracy. The results of the numerical example show that the method proposed in this paper can effectively locate the damage elements and identify the damage ratios under different damage cases and noise levels.
Analysis on Seepage Flow and Dam Stability of Ecological Permeable Dam
Authors: Ma Xiaotang , Jiang Linlin , Zhao Chuan
Published: February 2021

In this paper, the Geo-studio finite element analysis software is used to establish a variety of dam models to analyze the seepage of permeable dam and the slope stability, the results of seepage data are compared by hydraulic physical model experiment. The results show that the single width seepage flow of the permeable dam is 0.0017398m2/s, which meets the design permeability; the XY rate of seepage of the dam meets the law of permeability coefficient mutation. The minimum safety factor is 1.0388, the most likely slip surface appears in the middle and lower part of the dam body facing the water surface, and the leakage point is above the reservoir in the dam, reinforce this area in advance to prevent seepage damage; the simulation process also showed that dams with similar permeability coefficients are safer and more reliable. These research results have certain reference value for the design and research of permeable dams in the future.
Research on Construction Sequence and Line Network Structure of Urban Rail Transit
Authors: Jinghui Liu , Qiuping Wang
Published: February 2021

With the construction of urban subway lines, the network characteristics of subways have begun to appear. Under certain objective conditions such as capital, manpower, and material resources, the construction sequence of subway lines ought to be different, so that priority construction of lines can maximize network benefits. In order to study the time sequence of urban subway line construction and the network effect of the line, the evaluation index of urban rail transit construction time sequence based on the complex network theory is constructed. The catastrophe progression theory is applied to avoid the subjectivity of the weighting of the primary indicators. The existing lines of Xi’an Metro are transformed into the L-space topology, and the relevant network indicators are calculated to judge the network characteristics of the subway. Through the calculation of the membership degree, the construction priority of each line is finally determined. The route planned for the third phase of the Xi’an Metro is taken as an example, the calculation results show that the small-world characteristics of the Xi’an Metro network are emerging and the network is in its infancy. The calculation results of the priority of the planned line construction sequence indicate that large-scale sports meeting and events have a decisive influence on the construction sequence of the subway line.
Comparative analysis of accuracy and efficiency of different contact algorithms
Authors: Zhang Hong , Xue Binghan , Fang Hongyuan , Chen Jianguo , Yu Xiang , Du Mingrui
Published: February 2021

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, augmented lagrange method and L&P method, which are commonly used in ANSYS. Then, different examples are used to compare the four contact algorithms in terms of accuracy, convergence and efficiency. Finally, considering the accuracy, convergence and efficiency, it is suggested to adopt L&P method in hydraulic structure contact analysis.
Study on Stability of Surrounding Rock of Mechanized Construction in Tunnel Entrance Section
Authors: Guo Hongyan , Chen Shuang , Zhu Guanyu , Li Ke
Published: February 2021

With the development of tunnel construction technology and mechanical equipment, the mechanized drilling and blasting construction of mountain tunnels has gradually developed, but there are still certain problems in the mechanized tunnel entry. Relying on a tunnel project in Yunnan, this article uses FLAC3D software to study the stability of surrounding rock under the condition of mechanized large-section construction of shallow buried section of the tunnel entrance. When the shallow buried section of the cave entrance is constructed by the micro-step method, the surrounding rock displacement and plastic zone changes of the surrounding rock before and after the use of different cyclic footage and the tunnel face reinforcement when the tunnel face is used are compared and analyzed. The results of the study show that when the tunnel face is not reinforced, in order to ensure the safety of construction, the mechanized excavation cycle footage of the tunnel entrance section should be controlled within 1.2m, and the overlap length of the leading pipe shed should be greater than 5m; if the circulation is to be increased for footage, the tunnel face must be reinforced. Under the condition that the tunnel face is reinforced with glass fiber anchors with a length of 10m and a pitch of 1.5m, the cycle footage can be increased to 1.8m at most.
Advances in the identification of reservoir-induced earthquakes
Authors: Di Liu , Bo Jin , Shiliang Zhang
Published: February 2021

Due to the construction of large hydropower stations and the impoundment of reservoirs, the earthquakes occurred in or around the reservoir area are called reservoir-induced earthquakes, which have the characteristics of low magnitude, shallow source and high intensity. The construction of large reservoirs plays an important role in promoting the local economic development, improving the water conditions of the people and affecting people’s life and property. Therefore, the identification, prediction and judgment of reservoir induced earthquake is an important technical support to ensure the construction and operation safety of hydropower stations. Over the years, many scientific and technological personnel have carried out active and large amount of research. This paper reviews and sorts out the macroscopic identification of reservoir induced earthquakes, including the mechanism of reservoir induced earthquakes, the cases of reservoir induced earthquakes, and the identification of reservoir induced earthquakes. Some problems and future research directions of reservoir induced earthquakes are discussed.
Experimental study on anti-collapse performance of beam-column assembly considering surrounding constraints
Authors: Weihui Zhong , Di Gao , Zheng Tan
Published: February 2021

Due to the uncertainty of the position of the failure column in the building structure, the surrounding constraints of the beam-column substructure are different after the local failure. Three-column and two-beam substructures with two different boundary conditions are taken as the research object (overall constrained and partially constrained), the failure mode, mechanical form and anti-collapse mechanism of the beam-column substructures are investigated by static loading tests. Tests show that the deformed forms of the two specimens are similar, the development process of the resistance mechanism follows the beam mechanism stage, the mixing stage of beam mechanism and catenary mechanism, and the catenary mechanism stage, however, boundary conditions have a significant influence on the development of catenary mechanism of beam-column substructure, the catenary mechanism of overall constraint specimens accounts for 30% of the total resistance, while the ultimate deformation capacity of partial constraint specimens is weak, and the catenary mechanism resistance only accounts for 15%.
Earthquake risk and damage assessment for airport transportation system
Authors: Yang Ying , Wang Xiao , Deng Nan
Published: February 2021

Taking airport transportation system as the main research object, this paper studies the potential danger and direct economic loss of earthquake. Based on the structural response and damage characteristics of airport transportation system under earthquake action, the framework and theoretical model of HAZUS disaster assessment and direct economic loss developed by FMEA are introduced. This paper focuses on the application of vulnerability curve and capacity curve in airport transportation system risk assessment and economic loss assessment. Taking an airport terminal suffering from a magnitude 8 earthquake as an example, the potential damage degree, probability and direct economic loss of the earthquake are quantitatively calculated, and the property loss is given, thus explaining the importance of the seismic risk assessment framework and method to the safety assessment of China.
Experimental study on flocculation-Vacuum-Electroosmosis method for strengthening soft soil foundation in coastal area
Authors: Hu Zhen
Published: February 2021

In view of the traditional vacuum preloading method to reinforce soft soil foundation, puts forward a new method of foundation reinforcement: flocculation - vacuum - electroosmosis method, and indoor test, the test shows that flocculation - the vacuum - electroosmosis method can greatly reduce the moisture content of reinforced soil, enhance the vane shear strength, and the reinforcement effect was homogeneous.
Construction Site Safety Management Research Based on SEM
Authors: Huang Ying , Wei Jinguo , Liu Mengru , Xiong Wenwen
Published: February 2021

The construction project provides a large number of employment opportunities for the construction workers, and the health of the construction workers is closely related to the safety management of the construction site. This paper first designs construction workers’ health and construction site safety management measurement scale by using literature analysis and group interview. After that, through the structural equation model(SEM), the author reveals the path between the construction workers’ health and construction site safety management of the labors and contractors. According to the results of the discussion, the construction workers’ physical health and the safety technology management are the core of construction site safety management.
Safety Assessment of Gas Pipeline Body and Weld Stress in High Fill Area
Authors: Wang Dongyuan , Zhang Zhenyong , Yang Jian , Zhao Zifeng
Published: February 2021

Gas pipeline is occupied by high-filled soil and a large amount of soil has caused long-lasting additional stress on the pipeline. Under the action of the additional stress of the high fill soil, the pipeline may undergo relatively large displacement and deformation, which will cause harm to the safe operation of the pipeline. In order to clarify the stress and deformation state of gas pipeline body and weld in the high fill area, this paper preliminarily calculated the radial stability of gas pipeline under the action of the high-fill soil and the stress state of the weld under the ovality deformation. According to the actual parameters, boundary conditions and deformation of pipeline, a finite element model is established to calculate and check the stress state of the pipeline in the high fill area. Analyzed the serviceability of the pipeline according to the requirements of gas pipeline integrity management specification. Finally, according to the analysis results, a comprehensive assessment of the high fill area of the pipeline is carried out, and recommendations for the next treatment measures are put forward.
Research on Parsing and Storage of BIM Information Based on IFC Standard
Authors: Wang Ruoxiao , Tang Yongjing
Published: February 2021

Industry Foundation Classes(IFC) defines the standard exchange data format of building information model. For making it possible to serve the whole life cycle of structure, it is necessary to parse and save BIM information based on IFC Standard into database. The research is implemented by Java language and MySQL database. The whole project is called IFCParser and consists of three modules: IFC Entity Module, IFCFile Parser Module and Persistence Module. IFCFile Parser Module uses lexical analyzer and syntax analyzer to decompose IFC files based on EXPRESS language into entity classes, which is called the IFC entity. Persistence Module establishes the mapping relationship between Java class and MySQL database, and uses MyBatis framework to save information into relational database.
A Simplified Calculation Model for the Rail Layer in Harbinxi Railway Station
Authors: Biyu Bao
Published: February 2021

Considering the particularity of the station house withstanding dynamic load as well as the characteristics of frame structure, the discrete analysis was used to study the finite element structure of the station house. By comparative analysis on various element simulation approaches, this paper studied the rational approach to simplify the model so as to achieve a more realistic stress status for computation results.
Campus Planning and Design of Nantong Institute of Technology Under the Background of Green and Development
Authors: Huang Wenjuan
Published: February 2021

Green and development have important guiding significance for campus planning and design. The article analyzes the campus planning and design project of the Hai’an campus of Nantong Institute of Technology as an example, and explains that campus planning and design are the basis and norms for the construction of universities and the guarantee for the sustainable development of the school. Taking the green concept as the center, reasonable campus planning and design can comprehensively reflect the characteristic concept of the school, interpret the cultural vision of the campus, and meet the diverse functional needs of teachers and students’ research-practice-humanistic spirit. It can enhance the centripetal force of students, play an imperceptibly important role in enhancing the sense of identity and belonging of the campus image, and can promote the overall, coordinated and ecological development of university campus construction, and thus better exert the ability and role of applied universities. It is the source of the intention to create planning and design, and the core idea of campus design.
Quantitative settlement hazard assessment for a permafrost embankment based on distributed optical fiber monitoring
Authors: Li Zhen , Wang Shuangjie , Zhang Juan , Yuan Kun
Published: February 2021

Quantitative assessment of the highway settlement hazard in permafrost regions is urgently needed for maintaining the performance of highway service. This study firstly conducted a field monitoring of an embankment located in the permafrost region by performing the distributed fiber optic monitoring. Subsequently, a novel indicator named embankment disease indicator(EDI
ε) was developed based on strain gradient calculated through the monitoring results to build a permafrost embankment settlement hazard quantitative assessment framework. The results indicate that, (1) the distributed fiber optic monitoring can reflect the uneven settlement distribution of permafrost embankment over a wide range and long distance; (2) 0.152% is suggested as the strain gradient criterion to calculate EDI
ε, EDI
ε can quantitatively indicate differential settlement disease rate in permafrost embankment; (3) the model implementation results have a dynamic quantity consistent with the actual situation, the assessment framework is particularly useful for large regional uneven settlement assessment of permafrost embankment.
A novel AC Protection Scheme in electronic power system
Authors: Shen Hongming , Liu Peng , wang Ziqi , Liu Min , Du Na , Jiang Jing
Published: February 2021

The application of a large number of power electronic devices has caused great changes in the fault characteristics of the AC system, and the existing protection schemes are facing great challenges. This paper first analyzes the transient current waveform characteristics of AC line faults in different scenarios such as pure AC system, DC transmission system, and new energy grid connection, and then uses the correlation coefficient to identify the transient current waveform, and a new protection principle is proposed. Finally, the new protection scheme requirements on the transformer, sampling frequency and data window length are analyzed. The correctness of the analysis conclusion is verified based on EMTDC / PSCAD simulation.
New Energy Station Monitoring Equipment Rule Verification Model Based on Data Envelopment Analysis
Authors: Zhu Dongge , Ma Yiming , Li Yongliang , Yan Zhenhua , Liu Jia , Ma Rui
Published: February 2021

According to the functional and performance requirements of the new energy station monitoring equipment, an operating rule verification model based on data envelopment analysis is proposed, and the online automatic discovery of equipment and safe operation rules for key links are designed. The equipment adopts data envelopment analysis method to read real-time data of new energy station monitoring equipment, optimizes the automatic discovery function of key sections, and tests the operating parameters of wind turbines and wind farms online through remote testers, formulates monitoring rules, and forms data requirements, Use algorithms to acquire and process data, and build models. Realize the discrete processing and rule mining of key links and safety operating procedures to ensure the safe operation of new energy station monitoring equipment. Finally, the experimental results show that the equipment can quickly and automatically generate new energy station monitoring equipment safe operation knowledge and improve new energy Safety of station monitoring equipment.