bluuebunny/crossref_metadata_2025 huggingface dataset:
Fault Feature Vector Extraction Based on Edge Spectrum
Authors: Sheng Pei , Li Taoer , Xu Aiqiang , Li Heng
Published: March 2020

A new method of feature vector extraction is proposed. Firstly, the measured signal is decomposed by using the EMD, LMD, and improved methods to obtain some signal components of physical significance. Secondly, combined with the HHT theory, the boundary spectrum and boundary spectral energy are defined and used to find the feature vector. Finally, the fault mode is identified by BP neural network. The fault diagnosis of a certain line of analog circuit show that, this method can accurately identify the circuit degradation state without noise. Furthermore, the performance of each algorithm in the presence of noise is investigated by using the correlation number method. Two kinds of circuit states have been successfully classified, and the reason why there are many stray points in the classification result has been explained.
Analysis on Elastic Buckling of Thin Plate with Slotted Hole in Bending
Authors: Guo Yanli
Published: March 2020

Finite element was used to establish the calculation model of the thin plate with slotted holes in bending, the effect of the size, position, and space of the slotted hole on elastic buckling performance and buckling stability coefficient were analyzed. The results show that the influence of the hole size on the buckling of the bending plate increases. There is a safe distance between the holes. The position of the hole has obvious influence on the buckling of the thin plate in bending. Finally, according to the regression results of finite element analysis, the calculation formula of stability factor k for thin plate with slotted hole in bending is proposed.
Overall Buckling Performance of Cold-Formed Steel Axial Compression Lipped Channel Members with Circle Holes
Authors: Guo Yanli
Published: March 2020

The relationship between the stability coefficient φ and slenderness

λ
¯

for axial compression perforated members was studied using finite element software ABAQUS in this paper. The overall buckling of members with unperforated, circular and multi-circular holes was described. The influence on the members of hole position, hole size, hole spacing and plate size was analysis. According to the main parameters affecting the overall buckling of the perforated members, results show that φ will decrease with the increase of hole size. for multi-circular holes members, the smaller the hole spacing is, the more likely φ will be affected. When the hole spacing is wide enough, φ will become stable.
Deformation Monitoring on Jiaozhou Bay Cross-Sea Bridge Based on the Digital LVR Photogrammetric Model
Authors: Zhao Yongqian , Yu Chengxin
Published: March 2020

Being lack of the real-time dynamic deformation monitoring methods for the large span bridge recently, the paper makes application of the digital long visual range (shorted as: LVR) photogrammetric model with the uniform proportional pseudo-parallax algorithm in the bridge creatively. Under the normal operating conditions of the bridge, the instantaneous real-time dynamic deformation monitoring is conducted with sea level range exceed more than 2 kilometres and the single hole maximum span 600 meters. The experiment can obtain the instantaneous deformation information of multiple deformation monitoring points, describe the load-deformation curve timely, and can obtain the ideal accuracy measurement results. The results provide a theoretical and practical basis for the health deformation monitoring on the similar large bridges, then achieve the abnormal deformation parts of the bridge in time and make the warning.
Study on the Structure Optimization of h-Type Anti-Slide Pile
Authors: You Chen , Xing Haofeng
Published: March 2020

Compared with the traditional anti-slide pile, the h-type anti-slide pile has larger overall lateral stiffness, more reasonable structure stress, and can resist the greater landslide thrust. However, due to the short development history, there are relatively few studies on h-type anti-slide pile, and its structural design is not perfect. Numerical software Flac3d was used to optimize the structural parameters of h-type anti-slide pile, and the results showed that the optimal beam stiffness was 3 times of the front and rear piles, the optimal rear pile depth was 0.28 times of the length of the rear pile, and the front pile depth was 0.5 times of the length of the front pile.
Research on Corrosion and Defects of Hydraulic Metal Structures
Authors: Niu Limin , Yan Jing , Gao Dashui
Published: March 2020

The environmental conditions of hydraulic metal structures are complex. Analysis of the causes of corrosion and defects of hydraulic metal structures shows that the causes of corrosion and defects of metal structures mainly include corrosion, cavitation and erosion and erosion wear. According to the specific causes, the schemes and measures to prevent the corrosion and defects of metal structures are introduced; the existing methods for repairing underwater metal structures including blocking gate method, side caisson cofferdam method and steel cofferdam method are introduced; meanwhile, the methods of. The feasibility of deep-water metal structure underwater robot repair technology.
Comprehensive Control Method for Engineering Project Objectives Based on Basic Component Concept
Authors: Ding Rong , Zhou Bo , Qian Yongyuan , Han Jinglin
Published: March 2020

In order to carry out comprehensive control of engineering projects reasonably and effectively, based on basic component concepts a comprehensive control model of engineering project objectives is proposed. Each basic component is used as a unit to grasp the information on quality, cost, schedule and safety of each basic component. Based on the target comprehensive control model, the target values of the basic components of the project construction management are calculated and analyzed, which simplifies the current comprehensive control system and improves the efficiency and rationality of the integrated control.
Research on Construction Servitization Enterprises Based on AD-AS model and AHP Theory
Authors: Chen Jingjing , Qu Yan , He Menglin
Published: March 2020

In response to the call of the state to support the transformation and upgrading of traditional enterprises, major real estate enterprises have changed from simple suppliers of construction products to “products + services” suppliers. Construction servitization activities tend to be standardized, specialized and large-scale. This paper used probability theory to explain the inevitability and stability of construction servitization enterprises, recommended the influencing factors of construction servitization enterprises in construction industry through model, and put forward directional suggestions for the future development of construction servitization enterprises.
Overview of the Development of Ground Treatment Techniques in China
Authors: Zhang Dexiang
Published: March 2020

First, this paper briefly describes the emergence and development of ground treatment techniques in China; second, outlines various ground treatment techniques; third, points out the issues in the research and development of ground treatment techniques; and finally, makessome recommendations.
Safety Investment Analysis of Construction Enterprises Based on System Dynamics
Authors: Yu Zhihong
Published: March 2020

Combining the existing safety input data and characteristics, this paper uses the dynamic change method to solve the safety input problem. The origin, flow and characteristics of safety investment are analyzed, the skills of system dynamics modelling and the simulation modeling software Vensim are used to build the model, including models of safety precaution, safety control and accident risk transfer etc. Through simulation modeling, the configuration effects under different configuration schemes in an enterprise are completely decomposed. The results show that the effects of different configuration schemes on accident frequency, loss value and total accidents counts be obtained by applying the model built, which has great positive significance and practical value for dynamic safety investment.
Experimental Study and Numerical Simulation on Residual Welding Stress Relaxation
Authors: Wang Min , Qu Weilian , Wang Yifei
Published: March 2020

In this paper, the welding residual stress and the relaxation under static load are discussed by experimental research and numerical simulation. In order to understand relaxation of welding residual stresses caused by external static and dynamic loads, tests investigating relaxation of welding residual stresses caused by external static and dynamic loads in the Q345 plate welded specimens were carried out. The thermal-structural sequential coupling method was used to simulate the residual stresses of welded specimens. Based on the elastic-plastic finite element method, the relaxation behavior of welded specimens under static and cyclic loads was simulated respectively. The test of the residual stress relaxation by welding shows that the relaxation of the welding residual stress is caused when the external load is applied to the welded specimen in static and dynamic form. The residual stress relaxation condition is that the welding residual stress and the external load cause the stress to superimpose more than the material yield strength. Under the action of equal amplitude cyclic stress, the relaxation of welding residual stress occurs mainly at the end of the first stress cycle.
Prediction Analysis for Building Deformation Based on Multiple Linear Regression Model
Authors: Zhang Bo , Qiu Lijun , Zhou Zhanxue
Published: March 2020

The settlement deformation of high-rise buildings is related to many factors, which are mainly about floor load and time. Based on the measured data of building settlement deformation in 16 periods, in this paper, the number of floors and accumulated settlement time are selected as the independent variables, and the accumulated settlement is used as the dependent variable. The data in the previous 11 periods are used as the modeling sequence to establish a multiple linear regression model and predict the deformation in the last 5 periods. The results show that if there is no fluctuation in the original sequence, the fitting and prediction results are good and meet the actual engineering requirements. It is of practical value and significance for the prediction of building deformation.
Application of CSM Waterproof Curtain in Foundation Pit Engineering of Deep Saturated Sand Layer
Authors: Li Xuejun , Zeng Kaihua , Bai Dezhu , Chen Fangliang , Ju Haiyan , Xu Manqing
Published: March 2020

The deep foundation pit enginerring of Suning Square project in Nanchang, Jiangxi Province adopts SC50 type CSM cement mixing pile machine construction equal thick soil cement mixing wall as the anti-seepage reinforcement curtain. In order to verify the applicability of the CSM method in the deep saturated sand layer in Nanchang area, three non position test wall tests were carried out on site. The test results show that the strength, permeability and impact on the surrounding environment meet the design requirements and achieve the expected prevention. The effect of seepage reinforcement indicates that the CSM construction technology and construction parameters used in the field test are effective and applicable, and can be used as the anti-seepage reinforcement measures for the deep foundation pit engineering, and provide scientific basis and reference for the promotion and application of similar projects.
The calculation of the dynamic problem for the thin plate by method of convolution-type point collocation
Authors: Li Yongli , Zhao Zhigang , Yang Hua
Published: March 2020

Dynamic question of elastic body for plate is very important and dynamic analysis is very difficult to solute. The method of convolution-type point collocation is proposed to calculate the thin plate. And this method is applied to solve dynamic problems of thin plate with four sides simply-supported. From the conclusions of the calculation example it is shown this method is effective and has high accuracy.
As in the Western Architecture, Trapped in Western Architecture - Thinking about the Present Situation of Young Architects
Authors: Chen Changyong , Dai Mingqi
Published: March 2020

This paper studies the domestic present situation of young architects, summarizes the characteristics of them, the miniaturization, individuality, independence and pioneering, branded and so on, and points out its advantages and disadvantages. This paper argues that young architects reference of the western architectural shape and ideas, to promote the development of domestic architecture, but trapped in the western architectural theory system, lack of original local architectural theory. This paper further puts forward some Suggestions for young architects.
Theoretical Study on the Mechanics of a Coiled Tubing Working within a Marine Riser
Authors: Chen Yingchun , Wang Chang , Wang Xinhua , Fan Xiaoli , Wang Wenming
Published: March 2020

Due to its unique advantages, coiled tubing is now widely used in marine oil and gas exploitation operations, while the mechanical behavior of coiled tubing working within a marine riser is still unknown. The mechanical model of this special pipe-in-pipe system was built by analyzing the force of coiled tubing and marine riser, using quasi-static method. And the model was verified by experimental study. Based on the established model, the effects of different coiled tubing dimensions and platform transversal on the axial force of coiled tubing within a marine riser were analyzed. It was found that increasing the size of the coiled tubing can improve the axial load of the coiled tubing without affecting the force of the riser. While changing the platform transversal would have less impact on the coiled tubing, and a greater impact on the riser’s force. The mechanical model built can provide theoretical guidance on coiled tubing marine operations.
Finite Element Analysis of Flexural Behaviour of Cold-formed Thin-Walled Steel Composite Wall for Building Cladding
Authors: Di Yanqiang , Zhang Yuxia , Li Guohua , Zhang Zhijie , Wang Quan , Li Mengying
Published: March 2020

In this paper, finite element software ABAQUS was used to analyze the shear performance of cold-formed thin-walled steel composite walls. In the model construction, the plastic shell element is used, and the tapping screw is coupled and bound. The correctness of the finite element model is verified by analyzing the test results of two types of composite walls: light steel keel + fiber cement slab and light steel keel + fiber cement slab + light concrete. The influence of the number of webs on the composite wall is also analyzed. The parameter analysis shows that the more webs there are, the greater the bending stiffness of the wall will be.
A Study on the Mechanical Behavior and Statistical Damage Constitutive Model of Mudstone under Low Confining Pressure
Authors: Chen Kai , Guo Zhenyu , Zhu Cunxian
Published: March 2020

Firstly, Triaxial compression test of mudstones under low confining pressure is conducted to study deformation behaviors and mechanical properties. Then, assumed that the strength of micro-elements fits power function distribution, this paper determines a damage variable and establishes a damage constitutive model which effectively reflects the residual strength in the process of rock failure. Meanwhile, using testing data is to validate the reliability of the proposed model in this paper. Finally, impacts caused by statistic parameters variation on compression strength are analyzed comprehensively. These research outcomes presented in this paper also can effectively offer significant reference for the development of rock mechanics and rock engineering.
Experimental Research on Filtration Effect of Mesh Filters in Dewatering of Silt Foundation
Authors: Zhang Canhong , Ji Enyue , Wang Baotian , Yang Zhanmin
Published: March 2020

The filtration effect of four different filter structures is studied. These four designed filters are used in three different dry densities silt sand. The four filters are: 1) without filter; 2) 80 mesh single-layer filter structure; 3) 120 mesh single-layer filter structure; 4) one 80 mesh and one layer of 120 mesh filter combination structure. The result shows that the permeability coefficient of the soil is affected by the mesh size. The smaller the pore size, the lower permeability in the soil. The effect of filter depends on the aperture. The aperture of the filter influences the quality of sand adhere to the filter, and affects the silt erosion. The result of the experiment provides a suggestion for the selection of the mesh filters in the precipitation of the two-dimensional foundation.
A review of Research on Seismic Performance of Steel Eccentrically Braced Frames in Prefabricated Buildings
Authors: Sun Haisu , Shi Qiang , Wang Xinwu , Li Tong , Zhangshuo Zhao
Published: March 2020

Prefabricated steel structure is a type of green building, which conforms to the development process of building industrialization. The hysteretic behavior, bearing capacity, rotational capacity and energy dissipation of semi-rigid joint and eccentric supports of beam and column are being summarized. At present, there are few researches on the aseismic performance and failure mechanism of beam column semi-rigid connection applied to eccentrically support steel frames.
Reliability Analysis of Loess Landslide Considering the Change of Groundwater Level
Authors: Liang Yan , He Guanghong , Huo Aidi
Published: March 2020

The reliability analysis of landslide is very important for the early warning and prevention of landslide. In this paper, Monte-Carlo method is used to analyze groundwater level, the variation coefficient of c and ϕ, and paleosol layer impact on the reliability of landslide in Jingyang South tableland. The reliability analysis results are as follows: (1) With the increase of groundwater level, the probability of landslide failure increases and the safety factor decreases. When the depth of groundwater level is 61m, the failure probability is 2.46%, and the average safety factor is 1.166; when the groundwater depth is 31.6 m, the average safety factor is 0.791, and the failure probability is 98.94%. (2) The coefficient of variation “δ” is positively related to the failure probability of landslide, and negatively related to the reliability index. When δ < 0.05, the increasing trend of failure probability and the decreasing trend of reliability index are most significant. (3) Paleosol layer has certain influence on Reliability. When the groundwater depth is less than 35.3 m, the average safety factor with paleosol layer is less than that without paleosol, but the failure probability is higher. When the groundwater depth is more than 35.3 m, it shows the opposite relationship.
A New Simplified Method for Calculating the Sliding Distance of the Rapid Long Run-out Loess Landslides
Authors: Liang Yan , Liu Shuanshuan , Huo Aidi
Published: March 2020

The area of loess in China is 640,000 km2, accounting for 6% of the total land area. Loess landslides occur frequently, causing economic losses of tens of millions of yuan per year. There is a close relationship between the hazard and the sliding distance of landslide. The study on the sliding distance of loess landslide can provide a scientific basis for the prediction of landslide risk. Based on the law of conservation of energy, a new simplified method for calculating the sliding distance of loess landslides is proposed in this paper. Based on the fact that the decrease of potential energy is equal to the energy consumed in the sliding process, the formula for calculating the sliding distance is obtained. Taking Dabuzi landslide in the Southern Jingyang Plateau (SJP) of Shaanxi Province as an example, considering the unsaturated property of soil, Morgenstern-Price method was used to calculate the slope stability of SJP and determine the most dangerous sliding surface and sliding body. According to the proposed formula, the calculated sliding distance is consistent with the actual one. The correctness of the proposed method is verified by case calculation.
Study of Dynamic Characteristics of Subgrade Soil under High Frequency Dynamic Load
Authors: Che Gaofeng , Wang Qian , Ma Jinlian , Chai Shaofeng
Published: March 2020

By Exerting high frequency dynamic load on the subgrade soil, the dynamic elastic damping ratio was tested under different dry density, with comparing and analyzing the results of dynamic triaxial tests, it presented the influence of dynamic elastic modulus and damping ratio on the development of subgrade soil. The results showed that the dynamic elastic modulus of the different dry density subgrade soil under high frequency dynamic load, which decreases with the increase of dynamic strain, the smaller the dry density is, the faster the dynamic elastic modulus decays; the dynamic shear modulus law is consistent with the development trend of elastic modulus, it decreases with the increase of dynamic shear deformation, the larger the elastic modulus of soil is, the larger the dynamic shear modulus is; although the damping ratio is discrete, with the increase of the dynamic shear stress, the damping ratio as a whole tends to increase, the higher the dry density is, the slower the damping ratio increases.
Study on Mechanical Properties and Damage Evolution Law of Granite after High Temperature Cooling
Authors: Chen Kai , Guo Zhenyu , Zhu Cunxian
Published: March 2020

In this paper, uniaxial compression test is performed on granites cooled at different temperatures to study mechanical characteristics of granites. Main conclusions are as follows: (1) the stress-strain curves of rocks after high temperature cooling show characteristics of brittle fracture, dividing into four stages: compaction stage, linear elastic stage, weakening stage and failure stage. (2) There are two temperature thresholds for the influence of temperature on the mechanical properties of rocks: mechanical properties of the rock deteriorate with increasing temperature between the room temperature and first temperature threshold; in the second temperature threshold range, The mechanical properties of the rock are gradually strengthened as the temperature rises; when the temperature exceeds the second temperature threshold, the mechanical properties of the rock gradually deteriorate. (3) Based on Weibull distribution, the damage evolution laws are proposed and the corresponding constitutive equations are derived. And the theoretical model can partially reflect the mechanical properties of the rock under different temperatures.
Risk Assessment on the Construction of Vacuum-Aided Concrete Filled Steel Tube Pouring
Authors: Wang Jianjun , He Jianqiao , Han Yu , Deng Lijian , Li Wei
Published: March 2020

The construction of concrete-filled steel tube (CFST) pouring is a key process in the building of CFST arch bridges, directly affecting engineering quality and structure safety. However, the construction of CFST pouring has complex procedures and multiple risk sources, and major engineering problems often arise from incorrect risk assessment. In order to reasonably analyze the hazards of various risk sources to engineering, avoid major engineering problems, and improve engineering quality, risk assessment is conducted on the construction of CFST pouring in this paper. First, As Low As Reasonably Practicable (ALARP) and risk assessment matrix are introduced, and statistics are made of the occurrence probability and risk loss rating of three major risks in the construction of CFST pouring, resulting in one I-level risk, two II-level risks, five III-level risks, and two IV-level risks. Finally, seven unacceptable events requiring special attention from decision-makers are obtained through ALARP. The results of risk assessment can be used as a basis for the construction management of practical projects, and major risks are strictly controlled through strengthening management and other methods, which will effectively reduce risk levels, providing a powerful guarantee for increasing the span of CFST arch bridges.
Analysis of Influencing Factors of Performance for Sandstone Asphalt Mixture
Authors: Ouyang Xianyuan , Zhao Chenxi , Gao Peng , Wang Xiao
Published: March 2020

To analyze the performance for pavement and its influencing factors of sandstone asphalt mixture, eight kinds of asphalt mixture combination plans were designed to discuss the influences of various coarse aggregate, fine aggregate and different types of anti-stripping agents on road performance. The rutting test, beam bending test, immersion Marshall test and freeze-thaw splitting test were conducted on these samples. The results indicate that the performances of sandstone asphalt mixture can be improved by replacing coarse aggregate with sandstone and then appropriately increasing the amount of mineral filler, adding cement, slaked lime and anti-stripping agent. Moreover, the high temperature and low temperature performance is significantly enhanced than that of pure limestone mixture; The water stability can be improved by adding slurred lime, cement and anti-strapping agent, but there is no significant difference between Marshall test and freeze-thaw splitting test. As for fine aggregate, there is no significant difference between white limestone and cyan limestone.
Research on Axial Compression Performance of Waste Fiber Recycled Concrete Column
Authors: Zhou Jinghai , Zhao Li , Wang Yichen , Zhao Qi
Published: March 2020

In order to investigate the compressive performance of waste fiber recycled concrete(WFRC) columns under axial compression, this paper used ABAQUS finite element software(FEM) to establish 8 models of WFRC columns, taking the length of waste fibers, volume of waste fibers and replacement rate of recycled aggregate as variables. The lateral deformation in midspan and stiffness of specimens under axial compression were analyzed and compared with experimental data. The results showed that the strain curves of WFRC specimens analyzed by ABAQUS software were very consistent with those obtained by experiments, and the results were basically the same. The ductility was changed by the incorporation of waste fibers, and when the length of waste fibers was 19 mm and the volume of fibers was 0.12%, the ductility of WFRC column was the best.
Study on Characteristics and Application of High Plastic Clay Filling for In-service Highway
Authors: Song Changjun , Wu Lijian , Li Peng , bian Xiaolin , Li Shengting
Published: March 2020

Clearing the engineering characteristics of high plastic clay and its engineering application are the basis for rational use of high plastic clay to fill the embankment. In this study, a series of water content tests, relative density tests, liquid and plastic limit tests, the grain size analysis tests, compaction and California Bearing Ratio (CBR) tests were carried out based on high plastic clay of diseased subgrade along west-section of Hainan Beltline Freeway. The relationships between CBR and water content, coarse particle content and compaction energy were studied. The results indicated that water content, coarse particle content, and compaction energy had significant effect on CBR, and water content is the main impact factor on CBR values. The maximum CBR water content was greater than the optimal water content by 4% to 5%. The performance of CBR and dry density had obvious distinction under different consistency and compaction energy. The equilibrium water content of high plastic clay subgrade during highway running period was near the plastic limit, which is 6% to 13% higher than the optimal water content. Base on the indoor test results, the problems related to the application of high plastic clay in subgrade filling were analyzed considering the characteristics of highway engineering and climate in Hainan province. It was concluded that high plastic clay could be directly used for embankment filling when the compaction energy conducted under the maximum CBR water content.
Study on Vacuum Compaction of Asphalt Mixture and its Compaction Performance
Authors: Li Yanwei , Yao Yunshi , Shi Xin , Zhang Liangqi , Li Guanfeng , Pei Su
Published: March 2020

In order to improve compactness of asphalt mixture, a novel vacuum compaction method is proposed and its process parameters are optimized. A simple compaction cylinder with a hole adjusting air pressure was designed and fabricated based on marshal compaction cylinder design. Common compaction and vacuum compaction were conducted separately by using compaction cylinder. The experimental results demonstrate that accumulative compaction depth with vacuum compaction was deeper compared to that of common compaction in the same compaction repetitions. In vacuum compaction, the effect of compaction at -0.08 Mpa presented the best performance. Accumulative compaction depth at - 0.08 Mpa is 3.41mm deeper than that in common compaction, increased 20.53%. Meanwhile, density, porosity, voids in mineral aggregate and percentage of asphalt volume also exhibits that vacuum degree of -0.08 Mpa is most efficient pressure value. These results indicate that vacuum compaction method can effectively improve compactness of asphalt mixture, which could provide a novel method for the enhancement of road quality and road lifespan.
Study on Hear Resistance of Cold-formed Steel Composite Wall with Openings
Authors: Li Youcheng , Wang Xingxing , Pei Xingzhu
Published: March 2020

In order to study the shear resistance of cold-formed steel wall with openings, a numerical model of the specimen for cold-formed steel wall with openings shear test was established using Opensees software, which was used to simulate its shear resistance under cyclic loading. On this basis, the parameters of the factors affecting the shear resistance of cold-formed steel wall with openings were analyzed. The results show that the contribution of the coupling beam to the shear performance of the whole wall is reduced with the increase of the span-depth ratio of coupling beam. When span-depth ratio of the coupling beam is greater than 5, the contribution of the coupling beam to the shear resistance of the wall is ignored. The ratio of opening to wall and the ratio of window to wall have a great influence on the shear resistance of cold-formed steel wall with openings, and the influence of each factor on the shear performance of the cold-formed steel wall with traditional side column is greater than that of the cold-formed steel wall with reinforced end studs. The stiffness of the side column has little effect on the shear resistance of the cold-formed steel wall with openings.
Experimental Study on Model of Red Mud Duncan-Zhang Model of an Aluminum Company in Shanxi
Authors: Zhang Liting , Liu Hongbo , Zhang Shaoxiong , Teng Zhiguo , Wang Shu
Published: March 2020

This paper takes the red mud, an auxiliary product of aluminum smelting industry in an aluminum factory in Shanxi Jinzhong as the research object, and tests the basic physical and mechanical parameters and Duncan-Zhang model parameters of red mud. According to the geotechnical test procedure, the parameters such as particle size gradation and liquid plastic limit of red mud were obtained. The stress-strain relationship curve of the red mud material was obtained by the triaxial consolidation compression test. The Duncan-Zhang model parameters of the red mud material were obtained according to the experimental data, which provided a reference for the stability analysis and calculation of the red mud yard in the future.
Study on the Reinforcement of Existing Slab Culverts by Corrugated Steel in Permafrost Regions
Authors: Guo Changzhi , Chen Hongyu , Wang Hanwen
Published: March 2020

Through the field detection and numerical simulation methods of existing culvert structures, the stress state of the corrugated steel structure strengthened with the slab culvert is studied, the reinforcement effect and stress state of the slab culvert structure in the unfavorable state, the corrosion of the corrugated steel and the change of the fill height are analyzed. Numerical simulation results show: Corrugated steel structure can significantly improve the internal force of the slab culvert structure and the degree of flexural deformation, and the reinforcement effect of the culvert structure under live load is more obvious. Corrugated steel structure can effectively reinforce the existing cover culvert structure when subjected to corrosion and the wall thickness becomes small, and its reinforcement performance decreases slowly with the decrease of wall thickness. When the original cover culvert structure loses its bearing capacity, the corrugated steel structure can still effectively exert the function of the original cover culvert structure. When the top fill height of the slab-culvert is between 1 m and 4 m, the reinforcement effect of the corrugated steel structure is relatively stable.
Undrained Shearing Behaviour of Kaolin after Undrained Heating
Authors: Wang Kuanjun , Shan Zhigang , Wang Mingyuan
Published: March 2020

With the rapid development of energy engineering, such as energy pile and gas or oil pipeline are widely used in geotechnical engineering, which will elevate the temperature of the surrounding soil. In previous researchers’ opinion, the most unfavourable case scenario occurred in practical engineering is under undrained condition, owing to the large excess pore water pressure caused by undrained heating. However, the experiments of the undrained shearing behaviour of fine-grained soil after undrained heating are rarely seen in previous researches. For this reason, series of triaxial compression tests under 20 °C, 40 °C, 45 °C and 55 °C are carried out on kaolin. The results show that critical state stress ratio M rises after undrained heating, which are consistent with the theoretical-empirical relationship of M-T. Meanwhile, the undrained shearing behaviour results are different from the previous researches, where the undrained shear strength does not decrease with the rise of temperature (undrained heating). A viscoplastic model is introduced to simulate the undrained shearing behaviour of kaolin after undrained heating, the predicted results are generally matched with the test results. The measured and predicted results show that the undrained shear strength remains nearly unchanged as temperature varies (undrained heating). The excess pore pressures of specimens under high temperature are almost the same, and greater than the one under room temperature. The measured stress paths of kaolin after undrained heating are performed as overconsolidated soil, not normal consolidated instead, which hasn’t been discovered before.
Effect of Tension Sequence of Transverse and Longitudinal Prestressed Tendons on Performance of Prestressed Concrete Reaction Wall
Authors: Zuo Yuan , Li Weibing , Chen Yunmang
Published: March 2020

In this paper, five different tensioning schemes for transverse and vertical prestressed tendons are proposed respectively. The numerical simulation and analysis was carried out by the finite element software Midas Fea to evaluate this interactive effect. The optimal scheme is that transverse tendons are firstly tensioned from the bottom to the top and then vertical tendons are tensioned from the middle to the side symmetrically.
Study on Flexural Bearing Capacity of Reinforced Concrete Beams with Artificial Shell Aggregate
Authors: Yang Xiuli , Zhu Renmiao , Xu Bin
Published: March 2020

Two reinforced concrete beams with different reinforcement ratios are designed by using the formulas and assumptions of normal section flexural bearing capacity of ordinary concrete, and the static flexural tests are carried out. The coarse aggregate used in the reinforced concrete beam is artificial shell aggregate. The strain curves of concrete with different cross-section heights prove that the RC test beam accords with the assumption of plane cross-section in the bending process. The crack distribution and mid-span deflection curve trend of the test beam show that the crack develops rapidly and the deflection of the beam increases sharply before the reinforced concrete beam with artificial shell aggregate is destroyed completely, which gives obvious damage omen and is consistent with that of the ordinary reinforced concrete beam. The strain curve of the mid-span steel bar shows that the shell aggregate above the steel bar is crushed under a certain load after the mid-span longitudinal tension steel bar is yielded, the stress of the steel bar is released, the phenomenon of strain retraction occurs, and the possibility of the mid-span steel bar being pulled off is reduced. The results show that the mechanical properties of reinforced concrete of artificial shell aggregate used as coarse aggregate of structural concrete are similar to those of ordinary concrete and it is possible to use artificial shell aggregate in structural components.
Experimental Study on Resistivity Characteristics of Compacted Loess
Authors: Li Xiangning , Ni Wankui , Zhu Min , Wang Haiman
Published: March 2020

In order to study the resistivity characteristics of compacted loess, the resistivity values of 36 groups of samples were measured under six different dry densities. It was found that there was a good exponential relationship between resistivity ρ and water content w. At the same time, the SWCC and Fredlund curve equation of soil water in the process of soil moisture increasing are obtained by using the self-designed loess moisture increasing and decreasing device. The results show that, for compacted loess, the resistivity and suction ψ of soil are closely related to its water content. By comparing the ρ - w curve and SWCC, It is found that the relationship between soil resistivity and suction satisfies the expression ψ = u · ρ λ, u, λ are fitting coefficients. The formula shows that the suction value can be obtained indirectly by measuring the soil resistivity, which avoids the difficulty of suction test and has good applicability.
Study on the Supporting Features of Composite Soil Nailing Wall
Authors: Wang Bo , Jiang Xiaoming , Liu Qilu
Published: March 2020

This paper was based on a deep foundation pit support project in Beijing. FLAC3D software was used to simulate the excavation and support process of the foundation pit in detail according to design parameters and geological conditions. The experiment data of the horizontal and vertical displacements of walls, the axial forces of soil nailing and prestressed anchor cables during excavation and support process of the foundation pit provided a technical reference for the site construction and ensured the safety of the whole project.
Experimental Study on Shear Resistance of Rubber Concrete Brick Masonry
Authors: Wang Fengchi , Chong Bowen , Ding Junsheng
Published: March 2020

In this paper, the shear properties of two kinds of brick masonry specimens are studied, including rubber concrete brick masonry (RBM) and common fired brick masonry (CBM). The specimen is a double shear specimen composed of three layers of nine bricks, with the size of 179 mm × 240 mm × 365 mm. Through the shear strength test, the failure forms of masonry are obtained, and the failure types are classified. According to the experimental data, the shear strength of RBM and CBM are compared, and the factors that affect the shear strength are analyzed. The influence of mortar on the shear strength of rubber concrete brick masonry is obtained. Through regression analysis, the recommended equation of RBM shear strength average value, RBM shear strength standard value and RBM shear strength design value are obtained.
Study on Disintegration Characteristics of Improved Ancient Site Soil by Sticky Rice Solution
Authors: Niu B , Liao H J , Lv J , Wu J , Dong Y D
Published: March 2020

Some ancient sites in northwest China are exposed outdoors and damaged by rainwater erosion. To reduce the damage rate of the earthen sites, based on the principle of minimal intervention, the disintegration characteristics of compacted loess samples were improved by sticky rice solution. To analyze the effect of different concentrations of sticky rice solution on the disintegration characteristics of compacted samples, a series of disintegration experiments were carried out. The experiments results showed that the disintegration phenomenon had a significant inhibition in improved loess samples. The disintegration volume of unimproved samples was more lager than improved samples under the same time. The initial disintegration rate of improved samples was greatly reduced because of hydrophobic film formed by sticky rice solution in the surface. This paper showed that it was feasible to improve the disintegration characteristics of ancient site soil with sticky rice solution, which provided a theoretical basis for the application of sticky rice solution in the protection of earthen sites.
The Research on Bridge Engineering Risk Management and Assessment Model Based on BP Neural Network
Authors: Wang Xin , Wang Yilin
Published: March 2020

Bridge engineering risk research is an important part of bridge engineering management. This paper establishes the risk indicators system of bridge project, and then introduces BP neural network theory into bridge risk evaluation. By using the neural network toolbox of MATLAB, a risk assessment model of BP neural network is bulit. The validity and feasiblility of the risk evaluation model is verified by a practical example.
Study on Influence of Vertical Position of Steel Bracing in Foundation Pit of Open Cut Railway on Deformation of Envelope Structure
Authors: Wang Qingbiao , Ma Pengcheng , Shi Zhenyue
Published: March 2020

The influence of different vertical position of steel support on the retaining structure of deep foundation pit is studied, and the deformation and deformation of retaining pile under multi-supported support conditions are revealed, which provides support design and excavation optimization design for deep foundation pit engineering. in accordance with. Through the calculation of the rational deep foundation pit calculation software and FLAC3D numerical simulation software, the deformation law of the retaining structure under different vertical position of steel support is studied. The research results are as follows: (1) Different vertical positions of the steel support to the retaining pile the deep horizontal displacement of the pile has a great influence. Appropriate encryption of the lower steel support is conducive to the stability of the retaining structure. (2) The influence of the vertical position change of the steel support on the horizontal displacement of the pile top is limited, but the first two supports are vertical. When the position is unchanged, the third steel support is moved down by 1m, which can effectively limit the horizontal displacement of the pile top, which is beneficial to the stability of the retaining structure.
Research on Guarantee Technology of Measuring Accuracy of Highway Bridge Expansion and Contraction Installation Test System
Authors: Liu Lu , Wang Shuai , Liu Jing
Published: March 2020

The highway bridge expansion and contraction installation is the guarantee for the stability of the bridge structure, using a reasonable detection methods is the key to ensure the accuracy of the test of highway bridge expansion and contraction installation. This paper through the investigation and summary of the status quo of the use and measurement of the highway bridge expansion and contraction installation test system, the accuracy of the measurement results of the highway bridge expansion and contraction installation test system is tested and determined, the measurement technical parameters are determined. Through the establishment of the “highway bridge expansion and contraction installation-highway bridge expansion and contraction installation test system standard dynamometer-national force measurement standard” traceability chain, it can meet the needs of calibration of highway bridge expansion and contraction installation test system.
Research on Selection of Prefabricated Lining Design for Single-Track Tunnel of High Speed Railway
Authors: Zhang Shenglong , Wang Zhiwei , Chang Kai , Zhao Peng , Wang Zihong , Tang Qichao
Published: March 2020

Research on selection of prefabricated lining design for 350 km/h single-track tunnel of high-speed railway was carried out. The finite element calculation software was used to analyze the internal force characteristics of the whole lining under different surrounding rock pressure conditions based on the “load-structure” model. On this basis, consider reducing the original lining stress forms as much as possible, and dividing the lining structure into 8 parts at the small bending moment corresponding to the overall lining, and analyzing the surrounding rock pressure under the surrounding rock loads of III, IV and V and the force and deformation characteristics of the block assembly structure under joint stiffness. Compared with the overall lining structure, the prefabricated lining structure increases the maximum axial force by 0.3%, 1.6% and 2.4% respectively, increases the maximum bending moment by 16.8%, 11.1% and 0.9% respectively, increases the maximum lateral displacement by 143.1%, 129.2% and 101.1% respectively, and increases the maximum vertical displacement by 14.3%, 17.7%, 8.3% respectively. The safety coefficients of the assembled lining all meet the requirements of the specification, and the joint stiffness has little effect on the lining safety factor.
Experimental Study on Smoke Exhaust of Circular Fire Lane in Underground Vehicle Base of Urban Railway
Authors: Liu Xin , Lu Shichang , Huang Yiliang
Published: March 2020

To discuss the natural ventilation design parameters of fire lane for underground car parking, a full scale experiment is adopted in this study to analyse the heat release rate and minimum clear height of underground fire lane. As a supplement, FDS numerical simulations are carried out to further study the smoke exhaust effect of natural ventilation under different external wind speed. Analytical results of full scale experiment and FDS numerical simulations show that the natural ventilation of underground circular fire lane of this case can effectively discharge the flue gas due to combustion. Through the results of this study, the natural ventilation design parameters of fire lane for underground car parking are determined primarily, which will provide reference for the fire protection design and approval of the underground car parking in the future.
Finite element analysis on the support system of cast-in-place continuous box girders for high-speed railways
Authors: Lu Mingqi , Yan Yu
Published: March 2020

Continuous box girders of high-speed railways are constructed by the cast-in-place method, which often need to provide a supporting structural system to bear the upper construction loads. Therefore, it is necessary to ensure the structural safety of the supporting system during the construction. In the past, the calculation of supporting structures was usually only analyzed on a single member, and the method cannot take into account both the overall structure and partial members. In this paper a finite element analysis method for the overall calculation of the supporting structure was proposed and was applied in a practical project. It can be seen from the case analysis in practical engineering that the proposed method can not only consider the overall stability of the supporting structure system comprehensively, but also be used for the calculations of the deformation and stress of specific members. That indicates the method is feasible.