bluuebunny/crossref_metadata_2025 huggingface dataset:
The American West as a social-ecological region: drivers, dynamics and implications for nested social-ecological systems
Authors: Jones Kristal , Abrams Jesse , Belote R Travis , Beltrán Bray J , Brandt Jodi , Carter Neil , Castro Antonio J , Chaffin Brian C , Metcalf Alexander L , Roesch-McNally Gabrielle , Wallen Kenneth E , Williamson Matthew A
Published: September 2019

The American West exists in the popular imagination as a distinct region, and policies and politics often suggest that both the challenges and the opportunities for land management and human well-being across the region are relatively homogeneous. In this paper, we argue that there are key characteristics that define the West as a social-ecological region, and also that there are myriad social-ecological systems (SESs) within the region that require diverse and dynamic approaches to managing change over time. We first conceptualize aridity, topography, and a unique political economy of land as exogenous factors that persist over time and space to define the American West as a contiguous social-ecological region. We then identify a second set of characteristics that show high degrees of variation across SESs within the American West. Finally, we operationalize the relationships between regional characteristics and local dynamics through a set of case studies that exemplify specific types of SESs in the region. The results of these empirical representations of the regional and intra-regional social-ecological dynamics of the contemporary American West highlight the implications for research and management of taking a cross-scale integrated approach to address pressing social-ecological opportunities and challenges in complex adaptive systems.
The Analysis for The Importance of The Service Performance of Sluice Engineering Based on The Game Theory
Authors: Cao Qiulin , Shao Lingyu , Jiang Lulu
Published: September 2019

This paper mainly studies the importance of service performance of water brake engineering. From the technical feasibility, the effect reliability, the economic rationality, the construction convenience and the social environmental impact study the influence factor of the performance improvement measures. This paper establishes the evaluation system of the applicability evaluation sAystem of multi-level water sluice service, and puts forward the quantitative method of qualitative and quantitative indexes. Sequence relations and the variation coefficient method is used to the subjective and objective study on the importance evaluation index respectively, and put forward the subjective and objective weight fusion method based on the game theory, a more accurate service of sluice project importance evaluation index performance improvement measures are studied.
Algal Response Based on in situ Experiments of Nutrients Enrichment Bioassays in Lake Chaohu (China)
Authors: Fu Xuemei , Zheng Mingxia , Su Jing , Sun Yuanyuan , Zhang Rui , Wang Kun , Feng Xuehua , Ji Danfeng , Zhuo Feng
Published: September 2019

The algal response in relation to nutrient condition changes as well as environmental factors in Lake Chaohu (China) was investigated by in situ experiments of nutrients enrichment bioassays (NEBs) in this study. The results showed that both N and P enrichement could significantly inspire the algal growth especially in July. The highest relative algal growth coefficient compared with control obtained at TN/TP ratio of 10 reached 270% and 163% with respect to Chl-a and algal cell density, respectively. It indicated that algae blooms in Lake Chaohu are prone to occur at the TN/TP ratio around 10:1, which can be an early-warning indicator of algal blooms in Lake Chaohu. Furthermore, besides the nutrient conditions, the algal growth was significantly affected by environmental parameters such as water temperature and dissolved oxygen, which may also act as a trigger of algal blooms. This study suggested an alternative early-warning prediction method for algal blooms and provided basic information for eutrophication management scheme for Lake Chaohu.
Study on the Flow-sediment Conditions and River-bed Erosion and Deposition of Chongqing Reach after the Impoundment of Three Gorges Reservoir
Authors: Wu Huali , Jin Zhongwu , Zhou Yinjun
Published: September 2019

Chongqing city is the important node of golden waterway of Yangtze River. As the promotion of the Yangtze River economic belt strategy and normal operation of Three Gorges Reservoir (TGR), more and more attention has been paid to the sediment problem of Chongqing reach. After the experimental storage of 175m in the TGR, Chongqing reach is located in the fluctuating backwater area, with export boundary conditions and river-bed erosion and deposition changed. In recent years, with the water storage of cascade reservoirs in the lower reaches of Jinsha River, the condition of water inflow and sediment in this section has changed and the river-bed is adjusted accordingly. According to prototype observation data from 2003 to 2017, the flow-sediment conditions and river-bed erosion and deposition of Chongqing reach after the impoundment of TGR at different stages were comarred and analyzed. Results showed that during the initial storage period of TGR, from June 2003 to May 2008, sediment erosion and sediment was mainly related to water and sediment of upstream, with whole reach in a state of erosion and intensity was about 140.8 million m3 every year. After the impoundment of TGR, from September 2008 to October 2012, the condition of incoming water and sediment in Chongqing reach maintained original change trend and sediment erosion was mainly related to impoundment of TGR, with whole reach in a state of erosion, but intensity was small. From October 2012 to December 2017, sand from upstream of Chongqing reach reduced greatly, so river bed was drastically adjusted and scour intensity increased significantly, was about 312.2 million m3 every year. It concluded that decrease of upstream sediment is one of the important reasons for increased scour intensity in Chongqing reach.
Study on Water Distribution Scheme Across Regions
Authors: Zhou Jiahong , Han Haiqian
Published: September 2019

For a long time, water conservancy projects across administrative region is mostly invest in the construction by superior government, each side unconditional benefit, this is difficult to arouse the enthusiasm of benefited party to investment, and makes the government faces a great financial pressure, at the same time, it is easy to produce regional imbalance and contradiction of water resources. Finally, it will affect the resource efficiency and investment efficiency of the project. The transregional water allocation is an important basis for implementing the total water use control system in drainage basin and regions and an important content for implementing tough water management measures. This article summarily analyses the typical engineering way of water allocation, and the basic principle of the water allocation, takes Qingxi Reservoir water allocation on concrete analysis, puts forward the main factors of Qingxi Reservoir water allocation, including the area of the Qingxi river basin in each administrative regions, water resources, effect of reservoir engineering constructions, the water demand and water deficit in each administrative regions, input factors, and then puts forward proposals on water allocation. Based on two water allocation proposals, this article puts forward proportion and recommended of water allocation in each administrative region. Each administrative region should own the same right to use water resources and shoulder the same responsibility based on the same proportion, same right, same profit and same responsibility. The water allocation plan can be used as reference for Qingxi Reservoir water allocation.
Study on Influences of Water Temperature on Stress Distribution for High Arch Dam in Impounding Period
Authors: Ji Shunwen , Zheng Minsheng , Zhao Zhifang
Published: September 2019

Water temperature affects not only the water quality and ecological balance of the reservoir, but the temperature and stress field distribution of the high arch dam during water storage and operation management. During low water storage and initial operation, the concrete in reservoirs over 100 m deep in particular can easily crack or expand because of low temperature reservoir water. This paper studies the water temperature distribution law of the reservoir during initial storage by establishing a three-dimensional fluid dynamics model. Based on this, this paper explores the three-dimensional temperature field and stress field of the dam body during the storage period, the causes of cracking, and stress distribution in key parts of the arch dam.
Benefit Analysis of Silt Storage Dam System for Water and Sediment Interception in the Loess Plateau of China
Authors: Zhang Pan , Sun Weiying , Sun Zhanfeng
Published: September 2019

Silt storage dam system is an integrated system with channel engineering, flood control, sediment reduction, regulation of water resources utilization and other functions. This paper selected the Chabagou watershed as the research object. Through the comparison of runoff and sediment variation before and after the formation of the silt storage dam system under the same magnitude of the flood, analyzed the effects of soil and water conservation on reduction of runoff and sediment.
Study on Influence Factors of Water Content of Expansive Soil in Canal Slope Based on Grey Correlation Model
Authors: Liu Zuqiang , Li Mingzhe , Yan Feng , Luo Hongming
Published: September 2019

The change of water content of expansive soil in canal slope is very unfavorable to the stability of the slope. In order to analyze the influencing factors and laws of water cut, the relationship between water content and voltage of expansive soil, the relationship between initial water content and expansion force, initial water content and disintegration of expansive soil were tested relationship. The gray correlation model was analyzed based on the vertical displacement, water content, suction, rainfall, soil temperature and temperature data collected on the site. It is preliminarily believed that the main influencing factors of the change of water content of expansive soil in the test section are temperature, rainfall, evaporation and suction. The mechanism analysis of the grey relational model is also obtained: due to the lag of the rainfall infiltration process, the atmospheric rainfall can only penetrate into the 1.6m deep strong expansive soil after 3d, and the influence depth is less than 6.1m. The research on the influencing factors of the change of water content of expansive soil provides the basis for the development of prevention and control measures for canal slope soil in the middle route of South-to-North Moisture Diversion Project and the safe management of channel operation.
An Application of Cluster Analysis Methods to Mine Water Monitoring Data
Authors: Shi Chen
Published: September 2019

An optimized model of multivariate classification for the mine water of Xin Shuguang coal power plant coal mine in the north of China, has been developed. Eight samples were grouped in five distinct classes by cluster techniques (CA). The chemical composition of each sample of water is plotted on the piper’s three-line and pie chart. The Hierarchical Cluster analysis method was used to analyze the water source at the coal outlet point. These jobs will help the coal mine to better control groundwater damage.
Experimental Research on Fluctuating Pressure Characteristics of “Revetment-Protected and Non-Bottom-Protected Plunge Pool” of High Arch Dam
Authors: Yingkui Wang , Qingyi Hu , Jia Zhu , Hua Zhou , Dongbin Chen
Published: September 2019

In the construction progress of hydropower project, the energy dissipation security was always the focus of design and research. When the river overburden and water cushion was deep enough, the deep water cushion can be used for the energy dissipation design, and a new type - “Revetment-Protected and Non-Bottom-Protected Plunge Pool” was studied and proposed, whose stabilization was directly effected by the fluctuating pressure on the plate surface and back. The experimental research of fluctuating pressure was carried out on the 1:50 hydraulic model, and characteristic of fluctuating pressure was studied and summarized in this paper.
Modeling of the Effects of Secondary Flow on Bank Failure in a Curved Channel
Authors: Deng Chun-yan , Xia Jun-qiang , Yuan Yuan , Min Wang
Published: September 2019

The secondary flow is an important factor that affects the bank stabilization and morphological evolution in meandering reaches. In order to solve the problem of the bank failure in Upper Jingjiang River, the effect of the secondary flow on the river bank, the soil composition and mechanical properties were comprehensively considered, the Delft3D model and the BSTEM model were used to analyze the bank stability of the Upper Jingjiang River, and the process of bank failure was simulated. The simulation process is divided into two modes considering the secondary flow and not considering the secondary flow, and the results of the two models are compared and analyzed. The results indicated that, in both calculation modes, the bank collapse occurred during the periods of high water level and water level recession. Moreover, considering the secondary flow, the safety factor of the river bank decreases, the total collapse volume increases, and the bank shape after collapse is more in line with the actual situation.
Gaussian Radial Basis Function for Unsteady Groundwater Flow
Authors: Zheng Kehong , Li Congcong , Wang Fuzhang
Published: September 2019

The radial basis function (RBF) collocation methods are meshless with spectrally accurate; its approximation is an extremely powerful tool for solving various types of partial differential equations (PDEs). In this paper, the Gaussian RBF (G-RBF) collocation method is applied to solving unsteady groundwater flow governed by nonlinear elliptic PDEs. During the whole solution process, no iterations are required for a kind of nonlinear PDEs. Numerical results are compared with the well-known Kansa’s method, also namely as Multiquadrics radial basis function (MQ-RBF). The results obtained show good performance of the G-RBF as solution to unsteady groundwater flow problems.
Model Test Study on Dam Failure in Tailings Pond
Authors: Qi Qinglan , Zhang Liting , Wang Xiaogang , Zhang Shaoxiong , Lv Fei
Published: September 2019

This paper establishes the physical model of the prototype tailings pond using the similarity theory by taking a heightened and expanded project of tailings reservoir in Chengde, Hebei Province as an example and studies the process and mechanism of partial failure of the tailings reservoir when the drainage system fails by adopting the model test of the dam failure. The result shows that the dam damage can be divided into three categories: soil flow damage, gully damage and collapse damage. In addition, this paper analyzes the reasons for the three categories of damages.
Fully Nonlinear Analysis of the Interaction between Water and Free Floating Ship
Authors: Ma Hongwei , Zhang Zhen , Wang Jiwei , Wang Xuan
Published: September 2019

Based on the theory of velocity potential function, the fully nonlinear interaction between water and free floating simplified ship is studied through numerical model of fluid-solid coupling of ship-lift. The nonlinear numerical analysis of the coupling model of the water and the simplified ship body with different sizes, in which the boundary conditions included the free water surface boundary condition, the non-moving boundary condition and the water-solid coupling boundary condition. The numerical results show that the size change of the floating body affected the dynamic mechanical characteristics of the fluid-solid interaction of ship lift system, and affected the stress response of the floating simplified ship body.
Effects of high river discharge on decadal morphological evolution of the inner Yangtze Estuary
Authors: Luan Hualong , Liu Tonghuan , Yao Shiming , Lu Jinyou
Published: September 2019

Morphological evolution of estuaries and deltas at the decadal timescale is becoming a global issue in recent decades due to their economic and environmental significances. Present study explores the decadal morphological evolution under high river discharge and decreasing river sediment. Quantitative analysis of bathymetric data indicates that frequent river floods in the 1990s enhanced erosion of the inner estuary superimposed with river sediment decline. A process-based modeling approach (Delft3D) is applied to investigate the physical mechanisms of river flooding on morphological change. Hydrodynamic simulations indicate that the water level gradient and residual transport in the inner estuary increase with river discharge. High water level gradient occurs simultaneously with peak ebb flow, and this status can last for about 5-6 hours. This hydrodynamic condition with sufficient long period facilitates channel erosion and sandbar incision. Morphological simulations indicate that erosion along the main channels is enhanced under higher river discharge, especially in the upstream part. The enhanced erosion can be offset by the increase in sediment load. River flooding superimposed with further decreased sediment supply in the future may induce more significant modifications of channel-shoal systems within the inner Yangtze Estuary than the present.
The centrifuge experiments on influence of inclination on bearing capacity of the suction bucket
Authors: Xie Liquan , Ji Yifan
Published: September 2019

To study the mechanism of bearing capacity of a suction bucket, a series of centrifugal tests were designed to investigate the uplift bearing capacity, and the entire dynamic process of pore water pressure were monitored as well. The results show that with the increase of inclined degree of suction foundation, the bearing capacity of suction foundation decreases continuously, and the influence of inclination on the foundation bearing capacity is obvious.
Study on earthquake resistance behaviors of Taihe Palace by simulation
Authors: Zhou Qian , Weng Guoqiang , Xiaoli Cao
Published: September 2019

Taihe Palace in the Forbidden City in Beijing is the largest scale as well as highest level of Chinese ancient palace buildings. To effectively protect Chinese ancient buildings, the Taihe Palace is taken as example to study its earthquake resistance performances. Simulation means is considered for analysis. Based on typical constitutions of Taihe Palace such as freestanding column root, tenon-mortise connection between beam and column, bracket sets (tou-kung), heavy roof, filler wall and so on, its finite element model is built by ANSYS program. By modal analysis, response spectrum analysis and time-history analysis, its dynamic characteristic and seismic performances are discussed. Results show the basic frequency of Taihe Palace is 0.85 Hz, its main modes are of translation in level directions. There is little relation among main modes. Under 8 degree intensity of of frequently occurred earthquakes, internal forces of the building are within permission scopes, which means it is not destroyed. Under 8-degree intensity of rare occurred earthquakes, its maximum deformation value is within the permission scope, reflecting it does not collapse. The constitutions such as freestanding column root, tenon-mortise joint, bracket sets and so on are helpful for earthquake resistance. Thus the Taihe Palace has good aseismic performances.
Strategy research of internationalization of engineering construction standards for the Belt and Road Initiative
Authors: Chai Hua , Liu Yilin
Published: September 2019

To establish a comprehensive, multi-layer and multi-disciplinary network is the major aim of the “Belt and Road Initiative (BRI)”. Infrastructure connectivity is the main global trend and the basis of connection for trade and people communications, and it becomes the high priority of development of the BRI. Standards are the basic rules for connectivity, and engineering construction standards are also seen as the technical references for economic activities and general language worldwide, which play the important roles during development of the BRI. In order to explore the development strategy for internationalization of engineering construction standards, this paper firstly analyze the development status and demand of standardization of engineering construction of the countries and regions encompassed by the infrastructure corridors based on the investigations, and then, an in-depth analysis on internationalization of engineering construction standards in China is carried out. Finally, multi-level suggestions on internationalization of engineering construction standards promotion have been presented.
Notes on the meaning of adjoint wave equation derived via Lagrange multiplier approach
Authors: Xie Zhinan , Ma Wanjun , Zheng Yonglu , Zhang Xubin
Published: September 2019

Full-wave adjoint inversion method can be formulated via the Lagrange multiplier approach, taking the forward seismic wave equation as an additional independent constraint on synthetic wavefield. The adjoint wave equation is explained as the Lagrange multiplier where the local minimum existed, in case the model parameters are unperturbed. Such an explanation is unsatisfactory, due to the fact that the variation of synthetic wavefield equals to zero in case the model parameters are unperturbed. To avoid such a contradiction, we give a more clear explanation about the meaning of the adjoint wave equation, that it serves for converting the gradient of misfit function with respect to synthetic wavefield to the gradient of misfit function with respect to the model parameter.
Correlation between results of constant voltage RCM test and those of variable voltage RCM test
Authors: JiaQi Zhao , Yang LuFeng , Chen Zheng
Published: September 2019

Laboratory tests were performed on 74 sets of concrete specimens with the constant voltage RCM test and variable voltage RCM, respectively. Based on the regression analysis method, a computational model for transformation relation between test results of constant voltage RCM and those of variable voltage RCM was developed. The accuracy and applicability of the proposed model were validated by the tested data and existing model. Results show that the proposed model is applicable with higher accuracy.
Fuzzy Comprehensive Assessment for Impact on Ecology En-vironment of Construction of Extra-long Highway Tunnels in Mountain Area
Authors: Cao Peng , Fang Lin , Zheng Zhong , Zhang Zhe , Yang Feixiong
Published: September 2019

Construction of highway tunnels affect the original hydrogeological environment in tunnel zone, may even cause the unbalance of ecological environment, study on the influence on ecology environment of tunnels construction is therefore of great significance by adopting effective evaluation measures. Problem commonly encountered with comprehensive assessment of impact on environment is as follows, the multiple indexes, the narrow scope of application, the quantification of index with high difficult. With the support of Erlang Moutain Tunnel, six factors associated with assessment of impact on ecological environmental during tunnel construction are weighted according to the characteristic of tunnel. Determine both the subordinated function and weight of factors on the basis of fuzzy hierarchy estimation, evaluation systems on ecology environment of construction of extra-long highway tunnels in mountain area are established. Through confirmatory analysis of Erlang Moutain Tunnel, the evaluation systems obtained has good application and operability, which may provide reference to similar tunnels or underground engineering.
Research on Elevation Effect of Blasting Vibration in Step Slopes
Authors: Xiao-jun Zhang , Bao-cai Ma , Zheng Wei , Jian-jun Shi , Shao-lin Li
Published: September 2019

Vibration caused by blasting is an important factor affecting the safety of blasting production and the stability of slope rock mass. This paper conducts on-site blasting vibration measurement and concrete model blasting vibration test. It is concluded that the elevation has both amplification and attenuation effects on blasting vibration. And the attenuation effect is dominant, and the amplification effect is supplemented. In the region where the elevation amplification effect appears obvious, the magnification increases with the increase of the elevation. The law of change is first increased and then decreased.
An improved analysis model for cantilever failure of composite riverbanks and collapse simulation
Authors: Tao Guilan , Chen Jie , Pan Yuepeng
Published: September 2019

The riverbanks in the Lower Jingjiang Reach are mostly composite ones with fine sand overlain by cohesive clay, thus when the sandy layer is undermined due to rapid erosion, the cohesive upper layer generates a cantilever and is prone to beam failure. In this study, the formula of critical width of cantilever failure was improved considering the hydraulic effects. The formula of accumulated width of failed blocks at bank foot was deduced. A collapse analysis model of composite banks was subsequently proposed, and the collapse process of a typical bank slope was simulated using the model. The conclusions include: The cantilever failure of composite riverbanks is more prone to occur during the period of water level decline than that of water level rise. The critical width of cantilever decreases with the dropping of river level, the weakening of the supporting role of river water and the enhancement of the overturning effect of groundwater. The thicker the cohesive layer is, the greater the decrement of its critical overhang width is as river level decline. The protective effect of failed blocks accumulated at bank foot reduces its erosion distance, the more times the bank collapse takes place, the greater the impact is.
Deformation analysis of retaining structure of deep foundation pit in soft soil under over-excavation
Authors: Wang-Yan  , Zhang-Fei
Published: September 2019

In the construction of deep foundation pits in soft soil areas, over-excavation of foundation pits and failure to set up support in a timely manner often occur. Due to the creep properties of soft soil, the envelope structure will be sharply deformed and cause engineering accidents. With the secondary development program of the elastic-viscose-plastic constructive model, simulate the conditions of normal construction and over-excavation of foundation pit in Soft clay area, analyze the time change regulation of retaining structures and safety state of foundation pit, in order to achieve effective control of the deformation and protect the buildings adjacent to foundation pit.
The Method of Diagnosis for Corrosion Hydraulic Gate Based on Strain Mode and Frequency
Authors: Dong Xian , Li Yunan , Yu Zewen
Published: September 2019

The gate is important equipment of hydraulic structures. However, the special underwater working environment of the gate would cause corrosion of the in-service gate inevitably. The corrosion of steel would lead to the decrease of static bearing capacity and the instability of dynamic performance of gate structure. Therefore, in recent years, more and more studies on gate corrosion have been carried out. The hydrodynamic effect has an important influence on the dynamic performance of the gates under water operation, which include natural frequencies and modes. It is worth noting that the variation of the natural frequency and the mode have been used as the overall indexes of the steel gate in the structural inspection. These indexes are insensitivity to the detection of local pitting corrosion, and strain mode is better than these overall indexes. In this paper, the finite element dynamic analysis of the radial gate has been carried out by considering the fluid-solid coupling effect, and the arm has been taken for the corrosion simulation. It is found that under the condition of small area corrosion, the natural frequency of the steel gate did not change significantly. The local evaluation index of the strain mode (the change of the strain mode around the corrosion was obvious) could clearly determine the corrosion position of the steel gate.
The Indoor Model Test on the Characteristic of Expansive Soil Slope under Climatic Conditions
Authors: Zhai Ju-yun , Ma Ming-jiang , Hao Xiao , Zhao Jin , Zhao Yu , Yang Qi-qi
Published: September 2019

An indoor model of expansive soil filling slope is tested in Pingdingshan city, Henan province, China. Using temperature and humidity detectors, earth pressure cells and so on, the static evaporation - rainfall infiltration cycles are tracked and monitored in the climate condition. The study suggests that atmospheric temperature is the direct cause of soil temperature. Due to the convection heat transfers, the surface temperature of the soil changes rapidly, and the temperature change of the heat transfer to the interior has a hysteresis phenomenon. Under surface evaporation conditions, the greater the depth is, the smaller the change range is in water content. Water loss rate is related to soil, air flow, temperature and humidity, cracks, soil water holding capacity, permeability and other factors. The change of stress in the expansive soil slope is the result of the joint action of soil water content, nature and climatic conditions. Due to the early erosion of rainfall, soil pressure is obviously attenuated. The soil pressure is on the rise due to the effects of rainfall infiltration and expansion force in the late rainfall. In the engineering, the key to prevent and cure engineering disaster of expansive soil is to improve the deformation characteristics and reasonable drainage of expansive soil.
Simulation of Two-Dimensional Temperature Field via Kriging Method Based on Limited Conditioning Points in an Arc Dam
Authors: Zheng Dong , Du Ze-Kuai , Peng Shao-Cai
Published: September 2019

Temperature in an arc dam is a critical quantity of interest in safety monitoring. How to estimate a temper-ature field for an arc dam has been a challenging task, particularly when only a limited number of ther-mometers are arranged. This paper proposes to use the ordinary Kriging to estimate the two-dimensional temperature fields based on limited monitored temperature data from thermometers in an arc dam. The Kriging method interpolates the temperature field between spatially distributed values of temperature. The effects of scale of fluctuation (δ) and correlation structure on the estimated temperature fields are examined. The results indicate that the Kriging method can estimate the temperatures at locations where the thermometers are not arranged. The estimated temperatures near the measuring points have higher accuracy. The estimated variances near the thermometers are lower than the variances far away from the thermometers regardless of the δ. When the δ is high, the data from conditioning (known) points can reduce the uncertainties of estimated temperatures near the known points. The distributions of tempera-tures using different correlation structures are quite similar. The δ has obvious effects on the smoothness of the temperature fields, contours and variances.
Study on crack propagation based on extended finite element and optimized adhesion structure
Authors: Qi Xili , Song Shuai , peng Yujie , Wang Daihua , Wu Haike , Xu Yi , Wang Shiyang
Published: September 2019

The basis of numerical simulation in this paper is discontinuous finite element analysis named extended finite element method. The description of the theory is helpful to understand the basis for the realization of cohesive constitutive relation in software. The characteristics of linear cohesive constitutive relation, bilinear cohesive constitutive relation, turning point and implicit function cohesive constitutive relation are studied. A new cohesive constitutive relation is optimized with analysing the advantages and disadvantages of each cohesive constitutive relation. Comparing the experimental results of classical mode I crack propagation with the numerical simulation of the cohesive constitutive relationship, show that the simulation results of the optimized constitutive relationship are closer to the experimental structure than those of the bilinear constitutive relationship. Optimized cohesive constitutive model is used to simulate an asymmetric four-point bending beam with a single notch. The results show that the crack propagation trajectory is highly consistent with the experimental structure. The rationality of optimizing the cohesive constitutive relation is verified by comparing two experiments.
Short-term Vehicle Speed Prediction by Time Series Neural Network in High Altitude Areas
Authors: Shi Feng , Wang Yong , Chen Jun , Wang Jian , Hao Yanjun , He Yulong
Published: September 2019

Vehicle driving conditions at high altitudes are quite different from those in plain areas. Accurately predicting the speed of vehicles traveling at high altitudes is of great significance for the development of vehicle safety assisted driving. In order to study the vehicles’ speed of highways in high-altitude areas, and predict the speed of vehicles accurately, more than 30 000 data were collected by a medium-sized SUV in Qinghai under typical adverse environmental conditions. The real-time vehicle status data (engine speed, engine torque, transmission gear, throttle opening), road alignment data, and historical vehicle speed data was denoised by wavelet method. The collecting data is time-varying and nonlinear characteristics. A nonlinear auto-regression with exogenous inputs (NARX) dynamic neural network prediction model was established in this paper to fit travel speed. The network model after training has small error and high fitting degree. The accuracy of vehicle speed prediction in the next five seconds is 96.01%. The root mean square error of prediction is less than 2.21 km/h, which can achieve better prediction effect. At the same time, the transplantability of the model is enhanced by taking altitude and road alignment as variables.
Study on Residual Displacement of FPB bearing in Long-span Continuous Girder Bridge
Authors: Song Shuai , Qi Xili , Qian Yousheng , Tan Liangliang , Zhou Lvyang , Peng Yujie
Published: September 2019

Based on the principle of mechanical equilibrium, the theory of FPB with residual displacement is analyzed. This analysis derives the stiffness and equivalent damping ratio of FPB with residual displacement, and constructes the hysteretic model with residual displacement according to the existing hysteretic model of FPB. Through midas/civil modeling and analysis, the influence of different friction coefficients on the residual displacement of FPB is studied. When the friction coefficient is small, the distribution of residual displacement of FPB bearings is directional; the positive residual displacement is positively correlated with the friction coefficient, and the negative residual displacement gradually changes to the direction of seismic wave input with the increase of friction coefficient, first decreases and then increases. The positive and negative residual displacements after aftershocks are the same as those after main shocks, and their variation with friction coefficient is related to aftershocks intensity. By analyzing the hysteretic curves of different residual displacement bearings, the correctness of theoretical analysis is proved. At the same time, it is concluded that the larger the residual displacement, the more vulnerable the bearings are to instability, which leads to the failure of the main beam. The study of residual displacement can provide theoretical basis for selecting friction coefficient and controlling residual displacement in FPB design.
Parameters sensitivity Analysis of the Duncan-Chang Model Based on Orthogonal Test
Authors: zhiyu Song , lili Dong , zhengxiong Bai , bin Li
Published: September 2019

This paper aimed at the problems of huge computation burdens and poor accuracy because of too many parameters in the embankment dam’s inversion. Authors designed a mixed-level test for eight parameters of the Duncan-Chang Model: K, n, Rf
, Kb
, m, c, φ
0, and Δφ through an orthogonal test method and numerical analysis with FEM. Using the different directional displacement of two nodes and principal stress of element as the test index and through variance analysis, we can conclude that K, Kb
and φ
0 are sensitive parameters which control the strain and stress of dam, and which should be accurately obtained by back-analysis.
Landscape planning and design of tourist highway service area under the background of all-for-one tourism system
Authors: Yang Zhihua , Jin Fei , Shou Jiaojiao , Yang Yunxing
Published: September 2019

Nowadays, service areas are increasingly difficult to meet the demand of high quality services. According to the characteristics of tourist highway service area demand, and analyzed the concept of all-for-one tourism system, the paper expounded the classification of tourist highway service area and key points of layout, summarized the functions and facilities of different service area, putted forward the service area of landscape planning and design requirements. It can provide a reference for other tourist highway service area landscape planning and design.
Research on the mechanism and testing technology of dynamic compaction of high-filled gravel soil roadbed
Authors: Zhang Lu , Yang Guangqing , Zhang Dongliang , Hou Licheng , Jin Jing
Published: September 2019

The dynamic compaction method is an important method for roadbed compaction treatment. Due to its simple procedure, quick construction speed, material saving, low cost, and excellent effect, it is an extremely important procedure in the roadbed construction with gravel soil. By analyzing the structure of the embankment, structural characteristics of the gravel fill and the the engineering stress characteristics of the subgrade in the mountainous area, the macroscopic and microscopic reinforcement mechanisms of the dynamic compaction is analyzed by using three waves transfer procedure. The results show that the various waves do positive to the gravel-filled foundation in the mountainous area. However, the way of contribution is different. The analysis should be focus on the effect of dynamic consolidation, which is the result of the synergistic action of three waves. Based on the Ping-zan highway project, the details of the test and the operating process have been introduced. Also, references for roadbed dynamic compaction reinforcement construction under similar conditions have been provided.
Research on Cost Management of International Contracting Enterprises under the Background of “Belt and Road”—— Based on Value Chain Perspective
Authors: Zhou Wenwen , Yang Yi
Published: September 2019

Under the “Belt and Road” strategy, there are more and more foreign contracted projects in China, so the requirements for cost management of international contracting enterprises are getting higher and higher. This paper provided new ideas for the cost management of international contracting enterprises based on the perspective of value chain. Firstly, the value chain and cost management theory of international contracting enterprise were deeply analyzed, and then the cost management model for international contracting enterprise based on the value chain perspective was constructed. The value chain optimization method was also proposed to realize the goal of international contracting enterprises to enhance the market competitiveness.
Rationality Analysis of Continual Improvement of a Simply Supported T Beam Bridge
Authors: Yalin Yang , li Dai , Xianglin Jiang
Published: September 2019

A 40m prestressed concrete simply supported T beam in continuous transformation and reinforcement, because the T beams is thin, and there is no suitable T concrete diaphragm that can share the anchorage force, can not guarantee the reliability of prestressed anchoring system. This paper puts forward a new method to construct the pier top continuous transformation, and analyzes and discusses the rationality of the two construction schemes. Midspan construction loading and bearing pre-top construction reformation have not improved the T beam bearing capacity, which can improve the force of the structure, the calculation results show that the bending moment is close to the bending capacity of the middle span after the continuous transformation., and improve the effect is not obvious. In addition, the continuous structure and a new type of pier top continuous structure can not prevent the cracking of the pier top, and there is a risk of increasing the midspan deflection of T beams in the construction
Profit Distribution Strategy of Cooperation Construction Supply Chain under Carbon Tax Policy
Authors: Jiang Wen , Wei Manke , Wu Wenjing
Published: September 2019

Based on the background of carbon tax policy, this paper studies the optimal emission reduction decision and profit distribution strategy of the secondary construction supply chain composed of a general contractor and a subcontractor. By establishing the profit distribution model of the construction supply chain, the optimal emission reduction, the construction supply chain and the maximum profits of enterprises under the two conditions of decentralization and centralization are obtained, and then the comparative analysis of the two is conducted to obtain the reasonable range of the profit distribution proportion of the construction supply chain under the centralized situation. The results show that the full partnership has a positive effect on enterprises to take action to reduce emissions, and the reasonable profit distribution proportion is helpful to the construction of supply chain profit and the improvement of enterprises’ profit.
Compressive characteristics of geogrid-reinforced steel slag
Authors: Wang Liyan , Li Jinsong , Tao Yunxiang , Wang Qi
Published: September 2019

Steel slag is a solid waste from industrial recycling that is granular and has similar characteristics as those of soils. Geogrids could improve the stability of the granular steel slag, and the technology of geogrid-reinforced steel slag (GRSS) is proposed here. To understand the engineering behaviours of geogrid-reinforced steel slag (GRSS) as a foundation treatment method, it is first important to consider its compressive deformation behaviour. The compression deformation behaviours of GRSS were investigated by carrying out uniaxial compression tests. Furthermore, the compressive moduli of the GRSS were compared with those of traditional soils. The comparisons indicated that the reinforced effect of embedding a two-layer geogrid in the steel slag was the best, which was consistent with the conclusions of other studies. The comparisons also indicated that GRSS had a good compression resistance and had potential as a geotechnical backfill technology.
Embankment dam leakage detection by joint use of Magnetic Resonance Sounding and Electrical Resistivity Imaging
Authors: Hongen Li , Zheng Li , Haifeng Xu , Ning Zhou , Yongjun He
Published: September 2019

Embankment dam leakage may cause devastating consequences and its early detection plays a significant role in the stability of embankment dam. Conventional dam leakage detection methods, such as piezometric tube or osmometer, are restricted by limitations of spatial distribution and high costs of instruments. This paper introduces the method of joint use of Magnetic Resonance Sounding(MRS) and Electrical Resistivity Imaging(ERI) to investigate embankment dam leakage. MRS and ERI are carried out to reveal embankment dam leakage in the same site and the stratigraphy of electrical conductivity obtained by ERI is carefully used for the inversion process of MRS data. And then the amount of groundwater in the subsurface can be directly determined by the technique of MRS. The MRS and ERI results show good consistency with yield data obtained by geological survey. Finally, the detecting capability of joint use of MRS and ERI is verified.
Sediment-carrying capacity prediction using extreme learning machine
Authors: Wei Xianglong , Li Chang , Huang Wei , Gu Jiyi , liu Jing , Zhu Mingcheng
Published: September 2019

Sediment-carrying capacity prediction is an important part in the river sediments movement simulation. In this paper, a novel machine learning approach was proposed to predict the sediment-carrying capacity by using the Extreme Learning Machine (ELM). The evaluation indexes and the average errors of these prediction models were analysed in detail. The result shows that the ELM model has a good generalization performance for the sediment-carrying capacity prediction, and the ELM approach could be an effective tool for the sediment movement simulation.
Earthquake-induced landslide susceptibility mapping: Application and Comparison of Frequency Ratio, Logistic Regression, Weight of Evidence and Support Vector Machine
Authors: Zhou Suhua , Zhang Yunqiang , Xing Jingkang , Chen Changfu , Fang Ligang
Published: September 2019

This study seeks to use the following GIS-based (Geographic Information System) models for earthquake-triggered landslides susceptibility mapping: frequency ratio (FR), logistic regression (LR), weight of evidence (WE) and support vector machine (SVM). The case of April 20th, 2013 Lushan earthquake in China was employed and analysed by using these GIS-based models to produce landslide susceptibility maps. An inventory containing 1289 landslides related to this earthquake was randomly divided into two parts: 70% for training and the rest 30% for testing. Seven thematic layers representing landslide predictive factors were used in the models to produce the landslide susceptibility maps. The results are validated using two indexes: the relative landslide density (RLI) and area under the receiving operating characteristic (ROC) curves (AUC). Results of RIL showed that in general, all six models were reasonably accurate and the SVM models relatively performed better in earthquake-triggered landslide susceptibility mapping. The AUC values showed that the SVM (RBF) model provided the highest success rate (91.2%) and the second highest prediction rate (79.4%), while the SVM (polynomial) generated the second highest success rate (87.6%) and the highest prediction rate (82.0%). Results using FR model gave the lowest AUC values of 0.727 in success rate and 0.734 in prediction rate. The LR and WE model produced approximate values in success and prediction rate. The resultant landslide susceptibility maps would be helpful for regional planning and reconstruction in this earthquake-prone area.
Research on safety impact analysis and Countermeasures of geological Disaster for China-Pakistan Karakorum Highway
Authors: Tian Jian , Li Zhiqiang , Luo Zhigang , Shao Hui
Published: September 2019

Safety problem of highway construction is serious because China-Pakistan Karakorum Highway is located in the mountains, deep valleys, steep terrain, and variety of geological disaster types are widely distributed. On the basis of analysis of geological disaster types and consequences, researching the influence of the geological hazards for construction of bridge, tunnel and etc., corresponding risk control measures are put forward.