bluuebunny/crossref_metadata_2025 huggingface dataset:
Basic characteristics and application of micro-nano bubbles in water treatment
Authors: Zhang Mengdi , Qiu Liping , Liu Guicai
Published: July 2020

Recently, micro-nano bubbles (MNBs) have been widely used as a highly efficient and environmentally friendly gas-liquid phase treatment process in sewage and wastewater treatment, aquaculture agriculture, and water ecosystem restoration. In this article, the basic characteristics of MNBs with long residence time, high zeta potential at the interface, generation of hydroxyl radicals, and high mass transfer efficiency were introduced. Firstly, the methods of generating MNBs including hydraulic cavitation, particle cavitation, sonic explanation, electrochemical cavitation were emphasized. Then, the application status of MNBs in water oxygenation, pollutant degradation, and membrane cleaning were discussed. These reviews are expected to provide guidance for the theoretical research and practical application of MNBs.
A large-scale garbage collection system with a garbage delivery mark device
Authors: Yan Qing , Cui Chengsheng , Liu Qin , Jia Lianqin
Published: July 2020

Based on the investigation of the existing garbage classification methods, a large-scale garbage recycling system with garbage dropping identification device is proposed and developed, which realizes the scientific garbage classification, improves the throwing efficiency, and ensures the accurate pricing of garbage scientific classification, so as to realize the sustainable development mode of human resources and environment.
Basic characteristics and comprehensive utilization of FGD gypsum
Authors: Yichao Zhang , Ying Wang , Jinghai Zhou , Jiaxi Liu , Tong Li
Published: July 2020

Firstly the basic characteristics of Flue-gas-desulfurization gypsum (FGD gypsum) is described in this paper. Then the research status of FGD gypsum is introduced, especially the comprehensive utilization of FGD gypsum. Finally, some suggestions are put forward to solve the problems existing in the application of FGD gypsum, which provides a reference for further research and development.
Case study on the Synchronous Swivel of Large-Weight T-rigid Frame Bridge
Authors: Wang Qinghe , Dong Guoming , Patrick Baligasima , Liu Jiaxi
Published: July 2020

Swivel technique has been vividly recognized and generally adopted for the T-rigid frame bridge in practice, and this has been achieved by tensioning the prestressed stranding via the ball hinge at the centre of the rigid frame bridge. Although the technique has been adopted and used, very limited study has been devoted to the feasibility of synchronous swivel for double-swing synchronous swivel T-rigid frame bridges to date. This study aims at analysing the construction control of a synchronous swivel T-rigid frame bridge with the self-weight of 12,000 ton for each wing, and providing simplified procedures to determine the unbalanced weight and friction coefficient of the rotating bridge. This study will provide guidance for the future similar projects.
Validation of numerical model based on large-scale shaking table test of liquefied site
Authors: Jia Kemin , Xu Chengshun , Dou Pengfei , Song Jia
Published: July 2020

Based on the completed large-scale shaking table test of liquefaction free field, the OpenSees computational platform was used to establish a numerical model of liquefiable free-field shaking table test in this study. In the numerical modeling, simulation of soil displacement and pore pressure using two-phase fully coupled u-p form. The comparison of shaking table test results shows that the established numerical model can reasonably simulate the seismic response of liquefiable soils, and further verify the reliability of the numerical model. At the same time, the distribution characteristics of soil excess pore water pressure at the critical moment were analyzed. This paper provides an effective numerical method for dynamic response analysis of liquefied soil.
Research and Finite Element Analysis of Prefabricated Concrete Box Structure System
Authors: Zhang Xiaomeng , Liu Wenting , Ren Qingying , Li Yongxin , Ding Weilun
Published: July 2020

This paper proposes a new type of assembled concrete box structure system, and proposes the relevant shear wall structure and floor structure. The finite element analysis of prefabricated wall is carried out to analyze its mechanical performance and mechanical characteristics, which can provide theoretical basis for further experimental research.
Structural analysis of a Concrete supertall buildings
Authors: Zhang Xiaomeng , Liu Wenting , Ren Haibo , Yang Songlin , Li Yongxin , Liu Xiang
Published: July 2020

A high-rise building, with a height of 146 meters, 4 floors underground and 32 floors above the ground, is a Class B limit of the specification, and belongs to an ultra-high over-limit structure. Through the selection of different structural systems, its structural system is determined as the frame core tube structure. This structure uses YJK, SATWE, PKPM-SAUSAGE for structural analysis, uses performance-based methods for seismic design, and the weak parts of the structure are strengthened accordingly. Structural analysis mainly includes elasticity analysis of small earthquakes, elastic time history analysis of small earthquakes, elastic and inflexion analysis of moderate earthquakes, inflexibility analysis of large earthquakes and elastoplastic time history analysis of large earthquakes.
Study on Fire Characteristics of Typical Atrium
Authors: Wang Yueqiang , Zhang Xuesong , Zhou Jian
Published: July 2020

According to the theory of architecture and fire engineering, U-shaped enclosed atrium and full enclosed atrium are selected as the research objects to understand the fire characteristics of typical atrium. The fire characteristics of the two types of atrium are quantitatively studied and the fire characteristic indexes are compared, which provides more objective data for the building fire safety assessment. Based on the research results, the fire protection design suggestions for typical atrium are proposed.
Discussion on the Displacement and Stability of The Soil Nailing
Authors: Hu Hai-ying , Zhang Yu-cheng , Chen Cai-yuan
Published: July 2020

Because of the advantages such as easy construction, low cost, short construction period and mature construction techniques, soil nailing has been widely used in engineering. However, at present there is lacks of the calculation theory of soil nailing, and shortages also exist in allowable deformation values specified by current specifications: a) the safety factor of soil nailing wall is generally calculated by conventional limit equilibrium method, which has relatively low computational accuracy for complex soil distribution and can not give the relation between deformation and stability of soil nailing structure; b) current soil nailing specifications just simply specify an allowable deformation value without considering features of foundation pit, supporting types and surroundings, and these specifications also determine the early warning value for monitoring without combining the deformation with the stability of foundation pits. Thus, these shortages lead to the downward trend of usage of soil nailing that has good performance-price ratio in fact.
Analysis of the effect of gradation and maximum nominal particle size on coarse aggregate movement
Authors: Gong X , Ai Y C , Liu W D , Ge G H
Published: July 2020

The formation of ruts is closely related to the movement of the aggregate. In order to analyze the movement law of the aggregate during compaction, this paper based on the discrete element model, the coordination number, void ratio, average contact force, and axial stress are used as indicators to investigate the effects of gradation and maximum nominal particle size on the law of aggregate movement. The influence of material parameters on aggregate movement was explored from the microscopic level so as to provide suggestions for design grading and improving rutting resistance of asphalt pavements.
The fractal characteristics of C80 high performance concrete pore structure subject to high temperatures
Authors: Fan Y N , Du H X , Shi L N
Published: July 2020

The pore structure of C80 high-performance concrete (HPC) without and with 0.2% polypropylene fiber (PPHPC) was tested by mercury intrusion porosimetry, combining with fractal theory, the high temperature, PP fiber, pore parameters and fractal dimension was discussed. Results showed that porosity, the most probable pore size, the volume intermediate pore size and the threshold pore size all increase with the rising of temperature, the deterioration of the internal pore structure becomes serious. The pore growth rate of HPC is higher than PPHPC, and the porosity of HPC is about the same as PPHPC at 600°C. With temperature gradually increased, the fractal dimension of HPC increases first and then decreases, and the PPHPC shows a decreasing trend as a whole. The incorporation of PP fibers improves the internal connectivity of materials, reduces the deterioration of micro-structure after high temperature.
Design and application of 9000KN hydraulic lifting cable-borne crane for suspension bridge steel girder erection
Authors: Deng Nianchun , Qin Zhiyong , Liuyi Wu
Published: July 2020

Based on the steel girder hoisting construction of Yangsi Port YangtzeRiver Bridge, the bearing capacity, applicability, safety and operation efficiency of 9000KN hydraulic hoisting cable-borne crane are studied. Considering the structural characteristics and parameters of the bridge, the hoisting methods of special beam segment and the construction cost and safety of double cable-borne cranes, the main parameters of the cable-borne crane of the bridge are determined. Then, the structure of cable-borne crane is checked by ANSYS. Finally, the cable-borne crane has been verified by experiment and applied in engineering. The results show that the structure of 9000KN hydraulic lifting cable-borne cranes is safe, reliable, excellent-performance, energy-saving and environmental. The whole structure of the cable-borne cranes adopts modular design and has strong versatility, which is conducive to installation, transportation and turnover utilization, and has brought better economic benefits to society.
Analysis on the causes and prevention measures of the potential safety hazard of the formwork support system
Authors: Yudian Li
Published: July 2020

In recent years, with the rapid development of urban modernization, the collapse of formwork support system occurs frequently. The erection of formwork support system has become the key control object in the current construction safety production. This paper summarizes the main reasons for the potential safety hazards of the formwork support system in four aspects. The design of formwork support scheme is lack of guidance; the material and specification of formwork support system do not meet the standard; the formwork erection personnel are not professional; the management concept of the general contractor and subcontractor is different, and the supervision implementation is not complete. In view of the above reasons for the potential safety hazards, this paper innovatively puts forward the use of three-dimensional virtualization technology to make the virtual positioning of the mold support system, increase the mold support system process (three-dimensional positioning, solid line inspection); the frame rental is suggested to be self-sufficient, customized frame materials to establish the internal material catalogue for the use of turnover; sets up a new type of work, carry out assessment and training according to the scaffolders, and understand woodworking skills, so as to promote the standard erection of formwork support system; changes the conventional quota calculation rules, and increases the lower limit usage amount (tonnage calculation) of support system materials per square meter in the subcontract management agreement, so as to limit the abuse of excessive cost control.
Influencing Factors Analysis of Ammunition Storage in Reef Environment and Countermeasures
Authors: Chao Song , Zhiqiang Li , Weichao Si
Published: July 2020

To explore the characteristics of ammunition storage environment in islands of West China Sea and South China Sea and the mechanism of environmental factors affecting ammunition quality change and propose countermeasures, the characteristics of high temperature and humidity, high salt spray and ammunition storage in the sand islands and reefs in southwest China were analysed. During the process of ammunition storage in the west and south China sea islands environment, its quality is affected by many complex factors, among which temperature, humidity and salt fog are the most important factors that result in the change of ammunition quality. For the environment characteristic and the actual situation of the reef storage, some measures are put forward by increasing environmental monitoring equipment and accurately recording the environment parameter, improving the ammunition storage surrounding natural environment, strengthening warehouse construction to improve the heat insulation and moisture proof ability, and strictly implementing the storage environment inspection. The countermeasures proposed can effectively improve the quality of ammunition storage, prolong the life of ammunition and ensure the reliability of ammunition.
Dynamic Cooling Load Calculation of Heat Transfer through the Envelope for Cold Storage
Authors: Xuejin Wang , Yujing Zhang , Jing Hong
Published: July 2020

The dynamic heat transfer method is adopted, the mathematical model of reaction coefficient method is established and programmed, and a very practical dynamic load engineering algorithm for the wall of cold storage is obtained, which will provide reliable basic data for the continuous automatic regulation and energy saving control of the whole system dynamic real-time load of the cold storage. The calculated heat flow is much smaller than the current heat flow calculated according to the code insulation, and the maximum heat flow is much smaller than the current heat flow calculated according to the code insulation. The method presented in this paper can also be applied to the design and check of the thickness of the insulation layer and the analysis of the wall condensation in the wall system of the cold storage.
Dynamic Load Calculation of Solar Radiation Heat Gain for Energy-saving Buildings Envelope in Winter
Authors: Xuejin Wang , Yujing Zhang , Jing Hong
Published: July 2020

The paper analyzes the influence of solar radiation load for energy-saving building in winter, considering the thermal inertia of building envelope, a mathematical model of unsteady heat transfer is established, and a program is compiled to calculate the dynamic solar radiation load of building envelope in winter, which is a very practical calculation of solar radiation dynamic load. It not only changes the current situation that the calculation of solar radiation load in winter for energy-saving buildings can only use the steady-state algorithm, but also provides scientific and reliable data support for thermal comfort and the dynamic analysis of heating energy consumption for energy-saving buildings.
Study on human responses under different CO2 concentration and illuminance in underground refuge chamber
Authors: Tu Zhijun , Geng Shibin , Li Yong
Published: July 2020

Due to insufficient ventilation and absence of daylight, underground confined environment will be dim and occurred with high CO2 concentration. It is essential to clarify the combined effects of high CO2 concentration and illuminance on human responses in confined spaces. Twenty-four subjects were exposed to different combinations of illuminance and CO2 concentrations in an underground climate chamber, with thermal responses, physiological responses and acute health symptoms being investigated. Results show that: at CO2 level of 12,000ppm, heart rate (HR), diastolic blood pressure (DBP) and ratings of acute health symptoms (dizziness, agitation and depression) increased significantly when illuminance level was up to 500 lux. However, no similar results were observed at a CO2 concentration of 8000 ppm. Additionally, thermal sensation votes (TSV) increased significant with increasing illuminance level, regardless of CO2 concentration being 8000 or 12,000 ppm. Similar result was obtained for the change of thermal comfort votes (TCV) at CO2 level of 12,000 ppm. However, TCV result for illuminance level of 100 and 500 lux did not show a significant difference at CO2 concentration of 8000 ppm. This indicated that the combined effects of illuminance and high CO2 concentration lead to different human responses.
Experimental study of post-fire mechanical properties of a light prefabricated composite slabs
Authors: Qi Shen , Zhiheng Meng , Xintang Wang
Published: July 2020

The post-fire mechanical performance of a prefabricated composite slabs consisting of thin-walled steel beams with opening in web and lightweight aggregate concrete was experimentally studied, and the displacements of the composite floor specimens was discussed. The experimental results showed that the composite floors after fire had better plastic deformation capacity and greater residual bearing capacity. Type of the shearing keys, pull pieces between the precast concrete panels and the connection way of shearing keys to pull pieces had greater effect on the post-fire mechanical property of the composite slabs.
Study of post-fire mechanical behaviours of the light prefabricated composite floors after fire
Authors: Zhengguo Pan , Zhiheng Meng , Xintang Wang
Published: July 2020

The post-fire mechanical properties of a prefabricated composite slabs consisting of thin-walled steel members and lightweight aggregate concrete was experimentally studied, and the displacements of the composite floor specimens was discussed. The experimental results showed that the ultimate load of the composite slab specimens after fire with using the stud shearing connectors was greater than that with using the new type shear keys made with thin-walled steel plate. The global stiffness and load-bearing capacity of the composite slabs after suffering hydrocarbon fire can be effectively improved by increasing the wall thickness of transverse sub-members appropriately.
Study of post-fire mechanical properties of the light composite slabs after suffering hydrocarbon fire
Authors: Yixiang Hao , Zhiheng Meng , Xintang Wang
Published: July 2020

The post-fire mechanical behaviours of the composite floors consisting of lightweight aggregate concrete and thin-walled steel members were experimentally studied, and the test result of the composite floor specimens was discussed. The experimental results showed that the residual load-bearing capacity of the composite slabs after suffering hydrocarbon fire can be effectively improved by increasing the wall thickness of transverse sub-members appropriately. The ultimate load of the composite slab specimens after fire with using the commonly used stud shearing connectors was larger than that with using the shear keys made with thin-walled steel plate.
Study on early dynamic mechanical properties of inorganic polymer based fast hardening concrete
Authors: Zhang Hengbo , Xu Jinyu , Luo Xin , Nie Liangxue , Wang Yanan
Published: July 2020

For the purpose of explore the early dynamic mechanical properties of inorganic polymer based fast hardening concrete (IPFC), two groups of IPFC specimens were prepared with slag and silica fume as the main raw materials, flake alkali and water glass as alkali activators: slag based fast-hardening concrete (SFC) and silica fume-slag based fast-hardening concrete (SSFC). The dynamic mechanical properties of specimens at the age of 3 hours were studied by Φ 100 mm split Hopkinson pressure bar (SHPB) test device. The results show that, the dynamic compressive strength and peak toughness of SFC and SSFC both have obvious strain-rate sensitivity, and the peak stress of SSFC is higher than that of SFC, while the peak toughness is lower than that of SFC overall; The peak strain of SFC and SSFC shows no rate dependence, and the peak stress changes little with strain rate in the range of 30 to100 s−1, the peak strain of SFC is generally higher than that of SSFC.
Study on mechanism of electromagnetic shielding effectiveness of carbon nanofibers reinforced cement concrete
Authors: Zhang Hengbo , Xu Jinyu , Wang Han , Nie Liangxue
Published: July 2020

In this paper, five groups of cement concrete specimens reinforced by carbon nanofibers (CNFs) were prepared with different fiber content of 0%, 0.1%, 0.2%, 0.3% and 0.5%, the electromagnetic shielding effectiveness (SE) and the mechanism of shielding were analyzed. The results show that, when the frequency of electromagnetic wave is higher than 2 GHz, with the increase of frequency, the improvement gradually increases; When the frequency is 18 GHz, the SE reaches the maximum; CNFs can improve the SE of concrete material by improving its conductivity and the loss of electromagnetic wave.
Analytical Method for Local Damage of Beams under Moving Vehicle Loading
Authors: Wang Guizhong
Published: July 2020

In order to accurately identify damage of bridge under natural excitation, an analytical solution of local stiffness of simply supported beam structure is established by using structural mechanics method through establishing the moving load model of simply supported beam. On this basis, an accurate identification method of local damage of beam structure under vehicle load is proposed. Firstly, the local bending stiffness is described in terms of equal length intervals. Secondly, the corresponding loading methods are established for single concentrated load and two-axle vehicle respectively, and the local bending stiffness values of each interval are solved by analytic equation established by node displacement. Damage information can be identified by comparing the flexural stiffness values of simply supported beams before and after damage. Based on the discreteness of local bending stiffness of simply supported beams and the change of local bending stiffness caused by damage, the location and degree of local damage of beams can be accurately identified.
Correction and Regularity of Influence Coefficient for Double-Line Tunnel Settling
Authors: Shang Yanliang , Dang Hongqian , Zhang Yunxia , Li Qiang
Published: July 2020

In the construction of most double-tunnel subways and postexcavation tunnels, settlement deformation is an important problem. In this study, we analyzed the problem using monitoring data from the Huai’anqiao-Xisanjiao section (an anhydrous sand layer) of the first phase of China’s Shijiazhuang Rail Transit Line 3 project. First, FLAC3D software was used to establish a numerical model. Grouting pressure was assumed to be uniformly distributed. The settlement value of a measured point was calculated as the test data, and the range of the correction factor was obtained by an influence coefficient formula. The correction factor was revised in accordance with the measured data, and the correction factors for the properties of Shijiazhuang sand were obtained. For the first tunnel measuring point, the correction factor was –0.2; for the rear of the tunnel point the correction factor was 0.2. Finally, different numerical models were established, and the influence on the correction factor of such factors as tunnel depth and horizontal spacing, slope ratio, and tunnel spacing were established by using a control variable method.
Free vibration analysis of shield cutter head using element-free method
Authors: Shang Yanliang , Dang Hongqian , Zhang Yunxia , Li Qiang
Published: July 2020

Free vibration of cutter head is very important to the shield tunneling machine in design, manufacture and construction. It is a free vibration problem of simply-connected circular plates with clamped supported boundary. In this paper, a element-free key to solve the problems of cutter head vibration by the Radial Basis Function is put forward. In order to save the computational time, the real-part MFS is used to carry out the mathematical analysis which is different from the previous complex value calculation. For the cutter head, the eigenequations were obtained by analytic deduction using the discrete element-free model. It is found that the spurious eigenequation relies on the equations employed, but the true eigenequation is related to the boundary conditions. By using Burton & Miller methods, the true eigenequation was extracted. A numerical case of clamped cutter head was adopted to valid the effectiveness of the present method.
Experimental study on bearing capacity of single steel pipe column for fully united framework
Authors: Zhang Wenwen , Liu Ping , Liu Liangliang , Yang Jianjiang
Published: July 2020

It is analyzed and tested the substitution of triangular section columns for single steel outgoing line columns in the 500kV fully united framework based on the design, test and analysis with 18 specimens of single steel pipe. The theoretical calculation method of bearing capacity is put forward by analyzing the design theory. Through the experimental analysis and research, the computational model with bottom fixed, middle hinged and top hinged is obtained, which is consistent with theoretical values, thus providing valuable reference conclusions for the revision of the specification. It provides meaningful theoretical and experimental data for the analysis and calculation of substitution of single steel pipe outgoing line column for the original triangular section outgoing line column for the 500kV fully united framework.
Experimental Research on Temperature Field of Large Diameter Concrete-Filled Steel Tube Section
Authors: Liu Dianyuan , Qi Tiedong
Published: July 2020

In order to research the influence of solar radiation on temperature field of large diameter concrete-filled steel tube (CFST) section, the field test of temperature field of CFST section was carried out based on the reconstruction project of Huaihe River Bridge in Xi County, Xinyang City, Henan Province. For the asymmetric temperature distribution of concrete-filled steel tube sections caused by sunlight, considering the environmental factors and the actual position, temperature field of CFST section under sunshine was analyzed by finite element method, and the results are compared with the field test results to verify the reliability of the model. The analysis results show that the non-uniform distribution of the CFST with large diameter appears due to the sunlight effect; the larger the size of core concrete, the slower the change of central temperature, and the greater the temperature difference between the core and the boundary. Therefore, the influence of sunshine effect should be considered in the actual engineering.
A review of researches on lighting energy saving technology methods for highway tunnels
Authors: Chen Mingyang , Wang Qianyue , Zhen Jiangming , Xie Wenjing , Li Qi , Wu Yue
Published: July 2020

Lighting accounts for a large proportion of energy consumption in highway tunnels. In the context of the “low-carbon economy” and “energy conservation and emission reduction” strategies, this article starts from designing energy conservation, and discusses energy saving of light sources, lamp arrangement, control system, and auxiliary lighting. It summarizes the related research results, and puts forward some insights on the future energy saving design of highway tunnel lighting in China, and provides a reference for highway tunnel lighting design.
Comparative analysis of bearing characteristics between triangular columns and variable-section columns
Authors: Zhang Wenwen , Zhang Lianli , Liu Liangliang , Yang Jianjiang
Published: July 2020

Fengnan 500KV substation fully united framework was taken as the engineering background for analyzing the effect of load on the bearing characteristics of triangular frame columns and variable-section steel columns under different working conditions. Through ANSYS simulation, the bearing characteristics of the two structures under the same working conditions were obtained. The possibility of replacing the original triangular frame column with a variable-section frame column in a 500kV fully united substation frame was analyzed.
Considering the stress deflection of foundation pit unloading soft soil study on deformation characteristics
Authors: Qiujuan Zhou , Zhongxiang Liu , Xiaoping Chen , Siyan Fang , Lijia Ma
Published: July 2020

The deflection of the main stress caused by the unloading of the foundation pit is bound to change the stress state of the surrounding soil and produce deformation. By analyzing the stress state of the surrounding soil after the foundation pit excavation and introducing the stress ratio vector, the soil constitutive model considering the stress deflection is derived. The constitutive model shows that: After excavation and unloading of foundation pit, the strain of surrounding soil is not only affected by the change of stress, but also closely related to the deflection of principal stress axis, and then the influence of different azimuth on the deformation characteristics of unloading soil is discussed by static shear test with different azimuth of principal stress axis. The test results show that: When the azimuth Angle of the principal stress is between 0° and 45°, the shear strength of the soil sample decreases with the increase, and the strain increases with the increase. At 45°∼75°, the shear strength of soil samples increases with the increase, and the strain decreases with the increase. The variation of the deformation modulus of the soil samples under different azimuths of the principal stress is like a “scoop” curve, which is mainly the reflection of the anisotropy of the soil, and shows strong anisotropy at 0°∼15°. By normalizing the stress-strain relationship curves of soil under different azimuth of principal stress, it is found that the strain of soil is not only related to stress, but also affected by the change of principal stress direction. The experimental results are in good agreement with the constitutive model proposed in this paper.
Leakage Detection of CFRDs Based on a Multi-source Information Fusion Method
Authors: Tian Jinzhang , Gao Dashui , Xu Yi , Zhu Yantao , Huang Lixian
Published: July 2020

Dam leakage is one of the most important failure causes of concrete face rockfill dams (CFRDs). Causes of dam leakage problems are various and hard to target due to the non-homogeneity of dam materials and the multi-dimensional deformation of CFRDs. This paper effectively performs multi-source information fusion of the safety monitoring, underwater sonar scanning, underwater high-definition cameras, and connection tests to propose a method for seepage detections of concrete face rockfill dams. The proposed method has been successfully applied in the seepage detection of a CFRD.
Time-varying Flexural Reliability Analysis of RC Beams Strengthened with SNSM CFRP under Environment Effects
Authors: Zewen Zhu , Li Dai , Lin Mao
Published: July 2020

In order to evaluate the influences of environmental effects on the reliability of reinforced concrete (RC) beams strengthened with side near surface mounted (SNSM) carbon fibre-reinforced polymer (CFRP), combined with the relevant research results and the actual parameters of strengthened beams, the time-varying functions of the flexural capacity of the strengthened beams considering environmental effect was established. Then, based on the JC methods, the time-varying flexural reliability of RC strengthened beams under different ratios of standard values of dead load and live load was calculated. The results showed that the flexural reliability of RC beams decreased slowly with service time in the early period, and decreased rapidly in the later period. Compared with unstrengthened beams, the reliability of strengthened beams had been improved to a certain extent. When the unstrengthened beams were serviced 70% of the base period T, and then it could continue to be serviced about 16% of the base period T after been strengthened with SNSM CFRP. In general, the SNSM CFRP technique could improve the service time of RC beams. According to the analysis results, it was recommended that the RC beams should be strengthened in the early period to better improve the service time.
Influence of High Damping Rubber Bearing on Seismic Performance of The Bridge
Authors: Yan Yang
Published: July 2020

Based on the qingyijiang bridge of ya’an-kangding expressway in Sichuan province, the influence of high damping rubber bearing on the seismic performance of the bridge is analyzed from the aspects of structural natural vibration period, internal force at the bottom of the pier, displacement at the top of the pier, displacement at the end of the beam and shear displacement of the bearing. The results are compared with those of ordinary rubber bearing. Some suggestions are put forward for its applicability on conventional highway bridges.
Discussion on The Design of Water Blocking and Drainage Limit of Water-rich Mountain Tunnel in Ecologically Fragile Area
Authors: Zhang Zhien , Huang Mingli , Huang Jiefang
Published: July 2020

In mountainous areas with abundant groundwater and high water pressure, the design of waterproof and drainage is the most important part of the whole tunnel construction process. Improper treatment of groundwater will not only damage the local ecological environment, but also bring hidden danger to the safety of tunnel structure, especially in the ecologically fragile area. The tunnel project under construction in the East Tianshan Mountain is located in the high-altitude mountain area. The surface is the national forest protection area, and the vegetation is perennial. Once a large amount of groundwater is lost, the surface ecology will be damaged and hard to recover in a short time. In this paper, the existing design of mountain tunnel waterproof and drainage is summarized, and its advantages and disadvantages are analyzed. Based on the previous research, the concept of waterproof and drainage design suitable for the East Tianshan tunnel is proposed: “one block, two rows and Three Preventions”. “One block” is a circle of grouting outside the tunnel to block most of the groundwater. “Two rows” is to set two layers of drainage pipe network between shotcrete and waterproof layer and between waterproof layer and lining. “Three proofing” is to use three layers of water proofing: shotcrete layer, special waterproof layer and lining concrete. Layers of fortification can minimize the interference to groundwater and ensure the safety of tunnel structure.
Life Cycle Cost Analysis of Medium and Small Span Steel-Concrete Composite Bridges in Jiangxi Province
Authors: Li Dai , Zewen Zhu , Xianglin Jiang
Published: July 2020

This paper investigates the structural form, scope of application, construction technology, management and maintenance measures of steel-concrete composite bridges. Then based on the construction conditions of highway bridges in Jiangxi Province, life cycle cost of steel-concrete composite bridges is analyzed. The economics of short and medium and span steel-concrete composite bridges and concrete bridges are compared from the perspective of life-cycle cost.
Application of Premixed Solidified Soil in Backfilling of Foundation Trench
Authors: Huang Mingli , Sun Tong , Wang Linghai
Published: July 2020

Taking integrated pipe gallery of Tongzhou City Sub-center in Beijing as studied project, the research on the formulation of solidified soil and its preparation process were carried out for the silty clay and sandy soil samples on the site. The parameters were analyzed by finite element software simulation, which in results show that the ready-mixed fluidized solidified soil is characterized by high strength, self-compacting performance, impermeability, water stability, construction performance, and economic performance. It is in advanced compared with the traditional backfill materials. The application of solidified soil technology needs to be developed to adapt special equipment. After 7 days of placing the concrete structure, in view of factors of construction quality and construction period, the concrete structure is selected to be demolished for backfilling of the pre-mixed fluidized solidified soil, with single backfilling 0.5 meters and 1 meter respectively. The impermeability and water stability of the ready-mixed fluidized solidified soil are qualified. but the resistance to freezing and thawing is unacceptable. The mixed fluidized solidified soil should be backfilled in the area below the frozen soil layer.
Analysis of Behaviour for Bolt Joint of Corrugated Plate Subjected to Bending Moment
Authors: Guo Qi , Wu Meng , Pu Guangning , Guo Kun
Published: July 2020

In this paper, the stress distribution of corrugated plate and bolt is obtained by numerical simulation of single row screw connection of corrugated plate with different side distance. The position of rotation axis and suitable side distance of single row bolt under the action of moment are determined, and the calculation formula of single row bolt connection of corrugated plate under the action of moment is given by referring to the calculation formula of steel structure bolt connection.
Research on the Difficulties and Countermeasures of Super High-rise Steel Structure Construction
Authors: Yin Yong , Zeng Hong
Published: July 2020

Steel structures are increasingly used in super high-rise buildings. The construction of super high-rise steel structure projects has many characteristics that are different from conventional steel structure construction. Combined with the actual engineering case, some of the key points, difficulties and countermeasures that may be encountered in the construction of super high-rise steel structure engineering are discussed, which is intended to provide referencefor future engineering.
Strain Data Analysis of Small and Medium Bridge Structures Based on Finite Element
Authors: Lin Mao , Xu Lin , Li Dai
Published: July 2020

Structural health monitoring technology is increasingly used in the operation and management of small and medium span bridge structures, which also brings the problem that it is difficult to fully interpret and utilize the mass monitoring data. In this paper, the Sanyang Bridge is used as the engineering background, based on the strain monitoring data, combined with the finite element calculation software MIDAS/civil, to evaluate and analyze the operating state of the bridge structure. The results show that the overall operation status of Sanyang Bridge is good, the evaluation method combining finite element calculation and monitoring data is reasonable, this method can be applied to data processing and condition assessment of small and medium span bridges.
Research On Control Of Precast Alignment Of Short-line Method Precast Segmental Concrete Bridges Based On The Theory Of Four-point Distance
Authors: Qi Tiedong , Yuan Qin , Guan Jinbao , Liu Dianyuan , Wang Xiaolei
Published: July 2020

The short-line precast segmental concrete bridge is a concrete bridge which assembles the concrete segments made in advance by the factory through reliable connection, the key of its construction is the linear control in the prefabrication stage, generally, six point coordinate control system is used in cooperation with total station. In this paper, a new four-point distance control system is proposed to coordinate with the level gauge and steel tape for the linear control in the prefabrication stage, which has the advantages of high efficiency, simple operation and no need of measuring tower and target tower, etc. It has been successfully applied in the prefabrication stage of the main beam of the non navigable span bridge of Yueqingwan bridge, which can be used for reference in related projects.
Study on the Influence of Buried Depth on Seismic Performance of Underground Structure
Authors: Zheng Guodong , Sheng Anxiang , Zhang Qishuo , Ma Chengxiang
Published: July 2020

With the large-scale construction of urban rail transit in China, subways often cross the bottom of surface buildings or are located near them. In order to study the complex catastrophic correlation effects of the underground structure of the subway, the soil and the adjacent existing structures under earthquakes, we performed numerical simulation calculations based on ANSYS to conduct research on the effects of underground structures and adjacent existing structures under earthquakes. The interaction law of nearby existing buildings, the influence mechanism of the neighboring building’s depth factors on the seismic response of the complex system, and the system’s seismic response law were determined.
Research and Application of BIM Cloud Monitoring System for Open Caisson Construction of Super Large Bridge
Authors: Zhu Sanping , Nan Hang , Zheng Yi
Published: July 2020

Application of monitoring and BIM Technology in open caisson construction of super large bridge is analyzed. Monitoring method of open caisson construction is analyzed. Using BIM Technology to assist the monitoring of open caisson construction is studied. 2D monitoring system of open caisson based on mobile internet is studied. Monitoring system based on BIM, Internet and cloud platform is studied. Research achievements in this paper have been verified in engineering practice.
Mechanical response of buried polyethylene pipeline beneath the roadway and its influential factors
Authors: Li Liang , Wenjin Gou , Dalang Tian , Renjun Tian
Published: July 2020

To investigate the 2D mechanical response of flexible buried pipelines beneath roadway under static loads, taken high-density polyethylene (PE) as an object, ANSYS finite element commercial software is employed to construct pipe-soil interacting coupled model. The influence of burial depth, the diameter of the pipe, and modulus of backfilled earth on the deformation of the pipe are studied with the newly developed model. These results indicate that: (1) the maximum vertical displacement and Von Mises stress appear at the top of pipe and side of the internal surface of the pipe, respectively; (2) even if burial depth does not have a significant effect on mechanical characteristics of pipe, there is optimal burial depth; (3) the higher the diameter of conduits, the larger modulus backfilled earth, the more difficult it is to destroy pipe breaks.
Study on Method for Controlling Opening and Closing Mechanism of Transverse Joint of Super-high Arch Dam
Authors: Youzhi Liu , Guoxin Zhang , Qixiang Fan , Wenfu Chen , jintao Li
Published: July 2020

The high-efficiency transverse joint simulation and analysis technique was developed based on the discontinuous deformation theory. This technique developed was used to realize the simulation of the overall construction and concreting process of the 300m super-high arch dam by the 3D finite element method, simulate the actual dam inside and transverse joint working behaviors throughout the process, analyze the temperature, stress and aperture change process in the inside and transverse joint face of the dam, discuss the opening and closing mechanism and crucial influencing factors of the transverse joint of super-high arch dam. Based on the feedback and analysis of field monitored data, the causes for the relatively small aperture in the foundation restraint zone of the arch dam were further analyzed, and the later aperture was predicted. The measures and proposals for effectively increasing transverse joint aperture and enhancing the groutability were further put forward, to provide important guarantee for ensuring the transverse grouting effect of the arch dam and the overall safety of the dam.
Numerical Analysis of Force and Deformation Characteristics of Reinforced Steel Corrugated Sheet Retaining Wall
Authors: Ji Xiaolei , Liang Junwei , Guo Kun
Published: July 2020

Reinforced corrugated Steel retaining wall is a kind of retaining wall structure that can realize rapid construction. It has the characteristics of large strength, high rigidity, fast construction speed and small environmental disturbance. In this paper, the finite element model is established by using ABAQUS software. With the load of 80Kpa and 120Kpa at the top of the fill, the mechanical and deformation characteristics of the steel corrugated board are studied under the coupling of steel corrugated board and fill soil. The Horizontal deformation of corrugated panel and soil of different depths are analysed. Then the stability of the retaining wall structure are analysed. The research shows that the steel corrugated retaining wall presents a reverse “S” shape under the action of filling, the upper part presents an outward deformation, and the lower part presents an inward deformation extrusion soil; under the up load, the middle part of the retaining wall produces protrusions. As the load increases, the bulge increases with the tendency of the outward inclination. The stability analysis shows that the safety factor of the retaining wall structure under the load meets the requirements of relevant specifications.
Rating the Crack-Resistance effect for a Steel Truss Bridge Based on 3D Fracture Mechanics Model
Authors: Liu Qiang , Li Dai , Tan Jinhua
Published: July 2020

A 3D fracture mechanics model for a 2 × 162m continuous steel truss bridge is modelled by mixing two different element types together, while the cracked cross-beam is meshed as solid elements and 3D-beam elements for the other truss bridge members. The static analysis result show the truss system model works well.
Experimental study on grout defects detection in precast shell wall based on wavelet packet analysis
Authors: Zhang X , Tang H S , Zhou D Y , Zhang C X
Published: July 2020

Due to construction problems, grout defects always exist in precast structure with rebars spliced by sleeves. However, research on grout defects detection faces great challenges owing to the complexity of the problem. This study presents a nondestructive grout defects detection method based on wavelet packet analysis. First, experiment is carried out on two precast shell walls, then, acceleration responses are analyzed, and defects detection indexes ERVD and ERVDs are proposed. The results show that ERVDs is more sensitive to the grout defects than ERVD, and can be used as a good defect detection index in prefabricated shear wall.
Research on Construction of Highway Bridge Quality Engineering Based on BIM Technology
Authors: Zhang Kechao , Wang Chen , Liu Xiangsheng
Published: July 2020

At present, the construction of large domestic bridges is responding to the guidance of the Ministry of Transport on building quality projects, and exploring the construction model of quality projects. This research is based on fully investigating the experience of domestic large-scale bridge quality engineering construction, combining the engineering characteristics of highways, and proposing the application of BIM technology to achieve information sharing and collaborative operations between all aspects of project management.
Discussion on the Research Status of New Epoxy Resin Concrete Assembled Truss Joints
Authors: Xie Xinying , Xu Mingyuan , Jin Yujie , Zhang Xuan
Published: July 2020

The new epoxy resin concrete has the advantages of high strength, good durability, fast strength growth, good toughness, short molding time, and easy construction. It is widely used in the field of materials. This paper summarizes the research and application status of epoxy resin concrete, the principle and development of truss structure, and the research status of truss joints at home and abroad, and discusses the prospects and prospects of new epoxy resin concrete in the field of assembled truss joints.