bluuebunny/crossref_metadata_2025 huggingface dataset:
Walking Time Distribution of Transfer Passengers Based on Proportional Hazard Model
Authors: Zhang Zhe , Huang Zhaohong
Published: May 2020

Walking time distribution of Transfer Passengers is the theoretical basis for studying passengers’ transfer behaviour characteristics, for specific passengers transfer, transfer distance is the main factors affecting passengers transfer walking time. The Proportional Hazard Model (PHM) is adopted to analyse the impact of transfer distance on walking time of transfer passengers. To verify the applicability of PHM in walking time distribution, the sampling method which is characterized by fixed time, sex ratio and age proportion is created to infer transfer walking time distribution. Five transfer stations of Beijing subway are selected to conduct the numerical experiment. Through the analysis of 5 channel samples, the probabilities of passenger transfer walking time follow the logarithmic normal PHM (LNPHM). It is shown by regression analysis that there is mathematical relation among the passenger flow impact level, the average passengers’ walking time and the transfer distance.
Dam breach analysis for the Hongshiyan barrier lake
Authors: Wang Lin , Xue Yifeng , Liu Lipeng
Published: May 2020

This paper presents a hyperbolic erosion rate model and a calculating circular slip surface method of lateral enlargement, and obtain a numerical analysis method of the relative stability dam-breach flood analysis. This paper develops a DB-IWHR procedure based on this principle, preparing a dam breach flood procedure is simple, easy to understand and use program in Excel 2010 spreadsheet. This improves this program, and writes a flood regulation calculation program, forming a complete program of dam breach flood and flood regulation. This paper calculates Hongshiyan barrier lake breach flood flow and the reservoirs downstream impacts.
A novel approach to investigate the network of granular material using modified 3D DEM simulation
Authors: Hu Fang , Peng Hu
Published: May 2020

Recently it is increasingly popular to draw upon concepts and tools from the network science to help with the analysis of granular material as this method is perfectly suitable for the granular system and provides new prospective into investigating the micro-macro relationship. However, 2D simulation brings insufficient and unrealistic results while 3D simulation requires huge workloads. It is of great significance to put forward a quick and accurate method to calculate the network-related indexes of a granular material. In this study, a modified open-source discrete element code, YADE is employed to simulate a series of tri-axial compression tests on specimens composed of polydisperse-sized spheres with varying particle diameter. The contact network evolution is studied real time with satisfactory calculation speed under the help of GPU and SQL Server parallel computing. The general evolution pattern of contact network during loading is illustrated from the view of network metrics. The initial void ratio, coordination number together with the clustering coefficient and the average shortest path of the system are shown. Particles with similar size tend to form a looser packing, resulting in smaller shear force and less connectivity of the whole system. The proposed approach is strong at improving the efficiency of the calculation when investigating the contact network of the granular material.
Experimental study on the sensitive parameters of non-destructive test method for the cable based on the leakage magnetic principle
Authors: Dong Zhenhua , Fan Ping , Li Pengfei , Mao Yan
Published: May 2020

The nondestructive testing (NDT) technique of steel rope based on the leakage magnetic principle has been extensively applied to the cable. In view of the difference of geometric characteristics, structures, loading between steel rope and cable, the applicability of the leakage magnetic NDT and the sensitive parameters on detection accuracy should be studied. So a cable specimen with local defects was designed and fabricated, and then the leakage magnetic testing technique was applied. The experimental electrical signal output of the cable were compared and analyzed. The results show that the accuracy of the test results is strictly related to the geometric characteristics of the test instrument, the depth of internal defects, the height of sensor removal, the sensitivity coefficient of the magnetically sensitive element, the defect spacing, etc., and the qualitative evaluation and individual quantitative index of the cable defects are proposed. The above conclusions can provide data support for the test quantitative index and the application of nondestructive testing technique.
Experimental study on the effect of sustained axial tension load at early age on the tensile strength of concrete during late splitting
Authors: Zhuang Jinping , Chen Jianxing , Cai Xuefeng , Qiu Hao
Published: May 2020

In order to study the effect of early-stage concrete loading on the tensile strength of the later splitting, a total of 7 series of specimens were designed. Through the sustained tension in early age, the effects of preloading axial tension ratio,loaded time and concrete strength on the tensile strength of concrete during splitting were discussed. A set of sustained tension device was set up by which six concrete specimens could be applied continuous pulling force together. The test results show that the sustained tension at early age has an adverse effect on the tensile strength of the late splitting. The reduction range is between 10.4% and 18.3% in the experimental parameters.
Risk assessment of safety accidents in small and medium gyms
Authors: Yin Mingyue , Li Ziqing , Dila A
Published: May 2020

A risk assessment model for safety accidents in small and medium-sized gymnasiums is constructed by performing risk assessments on the characteristics of the events held in small and medium-sized gymnasiums, the risks of safety accidents, and the offset of accident risks. The risk index evaluation method is used to clarify the risk of security accidents in small and medium-sized gyms and the nature of the events, the scale of the events, the types of venues, the event cycle, the circulation of people, the types of people, fire risks, crowds of people, space, safe evacuation, event management and Correlation calculation method of 12 evaluation indicators for emergency management and control. According to this, the risk of safety accidents in small and medium-sized gymnasiums is classified, and the feasibility and rationality are verified.
Study on bond mechanics of antifloating anchor in red sandstone
Authors: Li Ming , Ma Pengjie , Rao Zongrun , Chen Zhuoqun
Published: May 2020

In order to study the mechanical properties of anti-floating anchor rod in medium-strong weathered red sandstone and its application in engineering examples, this paper takes the virtual university town project of Hengyang High-tech Zone of Hunan Province as the engineering background. This paper had done destructive test of anti-floating anchor rod. The effects of different parameters on the adhesion of anti-floating anchor rod were studied by test and from three aspects: drilling depth of anti-floating anchor rod,highly and intermediary weathered sandstone. At the same time, the adhesion of anti-floating anchor rod in the same type of rock but with different drilling depths is compared and analyzed. The results show that under the condition of the same drilling depth, the adhesion of anti-floating anchor rod of different lithology is different, and under the condition of the same type of rock formation, the adhesion of anti-floating anchor rod of different drilling depth is not the same. The recommended bearing capacity characteristic value of the weathering layer is 1500 KPA, which can be used as the foundation bearing layer of the proposed building.
Experimental Study on Failure Mechanism of Hierarchical Corrugated Structures with Second-order Core
Authors: Chen Zhenfu , Luo Yaoge , Fang Yaochu
Published: May 2020

Based on the sample experiment and ANSYS simulation, the experimental verification of the failure mode prediction model under compression load is completed, and the experimental results are compared with the theoretical analysis results. Among them, the sample experiment is carried out on the universal testing machine, including base metal experiment and uniaxial compression experiment. The experimental model is made of UV Curable Resin by 3D printing technology. And the buckling mode numerical simulation is completed on the ANSYS Workbench, using the plate and shell model of the pumping surface. By comparing the failure mode and yield stress of theory, experiment and simulation, the results show that the accuracy of the prediction model based on plate theory is higher. It can provide theoretical reference for structural design.
Design of Examination Management System for Engineering Management
Authors: Cai Hualong , Yao Yong , Cai Jingwen
Published: May 2020

Through the analysis of the engineering management training system, we know that the courses in the system can be divided into theoretical, practical and experimental courses. We aims to develop an examination management system by restructuring the evaluation process of the three types of courses. And the organizational structure, hardware architecture, and software architecture of the test management system are designed to be applied in the entire process of system development, operation and maintenance. Besides, under the influence of “the pneumonia caused by novel coronavirus, COVID-19” on education, we wish that the examination management system is more suitable for the needs of the macro environment, and the results can be used to the training and evaluation of other professionals.
Study on response characteristics of red clay slope under evaporation rainfall condition
Authors: Chen Kaisheng , Luo Dipu
Published: May 2020

Evaporation rainfall is one of the main causes of slope failure. Red clay belongs to special soil, and the failure mode of the slope is different from that of the general soil slope. In this paper, based on the theory of similarity simulation, a test model of red clay slope similar to the prototype is established in a certain proportion. Sensors are embedded in different positions of the slope to carry out the change rule of physical and mechanical indexes of the red clay slope under the condition of evaporation and rainfall. The results show that the water content of the slope increases during the rainfall period, the surface water content of the slope is obviously affected by the rainfall intensity, and the water content of the slope decreases in the drying period. Under the action of evaporation and rainfall, the internal temperature of slope is stable, and the surface temperature changes significantly. The pore water pressure of the top, shoulder and slope changes little with the times of evaporation and rainfall, and the pore water pressure at the foot of slope is obviously affected by evaporation and rainfall. Evaporation rainfall causes obvious horizontal displacement of red clay slope. The earth pressure increases in the rainfall period and decreases in the static and dry periods. With the increase of evaporation rainfall times, the earth pressure increases gradually.
Dynamic compression behavior of waste glass powder concrete at high strain rate
Authors: Zeng Zeqiang , Gan Yuanchu , Ma Yuang , Lei Qing , He Bin
Published: May 2020

In order to study the dynamic compression performance of waste glass powder concrete (WGPC) under high strain rate, the experiment uses the split Hopkinson pressure bar (SHPB) device with 4 increasing strain rates to test the plain concrete and WGPC block with 10% waste glass powder, the dynamic compressive strength, peak strain, stress-strain curve and other characteristics are obtained through this experiment, and the variation rules of these characteristics with the strain rate and the amount of waste glass powder are analyzed. The results show that with the increase of strain rate, the dynamic compressive strength of WGPC has significant strain rate effect; In the multi-group test, the dynamic compressive strength of WGPC reached a maximum of 58.45 MPa, compared with static compressive strength, the increase is 166%, which is close to the strength of plain concrete, indicating that the waste glass powder in concrete is a good substitute for cement under high strain rate.
Seismic performance analysis on GFRP reinforced concrete frame structure
Authors: Liu Fangzhou , Xu Xinsheng
Published: May 2020

At present, the research on FRP-reinforced concrete structures mainly focused on the performance of members at home and abroad, and there is less research on the overall seismic behavior of FRP-reinforced concrete frame structures. Based on the existing related research and the shaking table test, this paper studies the overall seismic performance of GFRP reinforced concrete frames. We excited the structure by inputting seismic waves through the computer, to make the frame model go through seven-degree multiple encounters earthquake damage, seven-degree fortifications earthquake damage, seven-degree rare encounters earthquake damage, eight-degree rare earthquake damage in turn, and recorded the acceleration and displacement responses of the structure. Acceleration data was analyzed by MATLAB software. And then used these data to analyze the seismic performance of the structure.
Study on Bending-Shearing Separation Force of Reinforced Tenon Precast Shear Wall Joints
Authors: Wang Shilin , Wu Qing , Chen Wei
Published: May 2020

A new type of large-size reinforced tenon precast shear wall was proposed, which can effectively reduce the pin-key shear stress of the longitudinal connecting steel bars and improve the seismic performance of the precast shear wall. In order to study the bending-shear separation mechanism of the wall edge restraint member and the reinforcement-slotted shear, this paper first proposes the bending-shear separation mechanism of the wall edge restraint member. The concept of bending-shear separation degree was introduced, the mechanical analysis model of reinforced tenon was established, and the calculation method of horizontal relative slip of reinforced tenon interface was obtained by using Rayleigh-Ritz variational method. The relationship between horizontal relative slip of interface and shear stress of steel pin key was established, and the size of large-sized reinforced tenon to interface was studied.
The Analysis and Research on Durability of Super-high Strength Concrete Poles
Authors: Guo Ji-Yuan , Gao Fan , Yu Ren , Ren Ya-Ning , Ma Cong
Published: May 2020

Compared to ordinary concrete, super high strength concrete has the characteristics of high strength and excellent durability. But it has higher requirements for materials and conditions for maintenance, as a result, its application in actual engineering is less. Based on actual project, this paper analyzed and summarized its durability, including compressive strength, frost resistance, carbonation resistance, anti-chloride ion permeability and water resistance, so as to provide a reference for the research and development of super-high performance concrete poles.
Exploration on Control of Engineering Safety Supervision in the Framework of Fuzzy Mathematics
Authors: Li Weifeng
Published: May 2020

Carrying out effective safety supervision and control during the construction process of a construction project can greatly guarantee the construction safety of the construction project, and at the same time can improve the quality of the construction project, which is an important part of the construction process. There are still some problems in the current safety supervision of construction projects, which affect the efficiency of safety supervision. This requires analysis of the main points of safety supervision and control work, and promoting the effective application of safety supervision in the construction process of construction, so as to promote the long-term stable development of China’s construction engineering industry.
Application of Steel Sheet Pile in Deep Foundation Pit Support of Collapsible Loess Regions
Authors: Yang Yang , Liu Wanfeng , Hu Aiping , Li Fei , Yang Zhaoqian
Published: May 2020

Due to its high quality, simple construction, good durability and interchangeability, steel sheet pile can reduce the requirements of space for construction tasks and other advantages. In recent years, it has been widely used in support engineering. Taking a deep foundation pit in a collapsible loess area as an example, this paper analyzes the application and calculation of steel sheet pile support under the complex operation conditions, which is composed of many adverse factors such as the limitation of the construction work area’s narrow influence on the construction, and expounds the feasibility of steel sheet pile in the deep foundation pit support in collapsible loess area, which adds precious steel sheet pile support to the deep foundation pit in collapsible loess area The experience has a good reference and guiding significance for the use and promotion of steel sheet pile support in similar projects.
Study on the Design of the Upper Space Parking Lot of Urban Multi-layer Tunnels
Authors: Li Jian
Published: May 2020

In recent years, with the continuous acceleration of the urbanization process, underground parking lots have developed rapidly, and they are continuously moving towards intelligence. Based on the multi-layer tunnel section of the Xiamen Haicang Subsea Tunnel, this paper conducts theoretical research on the liquid analysis of the surrounding area of the tunnel area, the graphic design of the parking lot, the architectural design, the function, and the fire prevention design. The research results are of great significance to the rational use of urban underground space, increase the utilization rate of underground parking lots and ease parking difficulties.
Investigation and Analysis of Existing Housing Deterioration in Jinan
Authors: Wang Xiao , Li Bing , Zhang Xiwen
Published: May 2020

This article takes existing houses in Jinan as a research object, focuses on the outer walls of the houses, and conducts field surveys and collections of the existing housing deterioration phenomena. Based on a large amount of survey data, the existing housing deterioration phenomena and the distribution characteristics are analyzed, and combined with the research of previous literature, the reasons for the deterioration phenomenon were discussed from the four aspects of design and construction, construction quality, materials selection, and maintenance.
Whether the degree of industrial agglomeration affects the discharge of industrial pollution in China
Authors: Liang Yinuo , Ding Jiaqi , Kang Xiaotong
Published: May 2020

This paper discusses the influence of industrial agglomeration on industrial pollution emission in China. Based on the data of several industrial sectors in China from 2005 to 2015, the panel model is adopted for empirical analysis. Industrial agglomeration significantly affects the discharge of industrial waste water, so2 and industrial dust, and the effects are all positively correlated. This shows that in the process of industrial development, enterprises’ geographic spatial aggregation will increase industrial pollution emissions to a certain extent, which is not conducive to easing the contradiction between industrial development and ecological environment.
River Classification in Line with China’s New Requirements of Water Resources Management
Authors: Huang Huojian , Yuan Yong , Xing Ziqiang , Wang Ding
Published: May 2020

River classification facilitates efficient management of rivers. Due to the complexity and variety of river morphology in China, classification of Chinese rivers has never developed maturely. The current river classification system used in China becomes even less qualified for new management requirements aiming to environmental protection and restoration as a response to the worsening environmental conditions represented by the deterioration of river functions and the scarcity of water resources, which have been greatly exacerbated by the impressive growth of Chinese economy. Moreover, some well-known classification methods discussed internationally cannot adapt to Chinese specific conditions appropriately, although they have been developed beyond the Chinese ones. This thus highlights the necessity to establish an updated classification system that is adequate for the emerging river management requirements of China. In these circumstances, this paper summarizes the currently representative river classification methods and proposes a pathway to improve river classification methodology for China.
Risk Assessment of Debris Flow in Ya’an City Based on BP Neural Network
Authors: Liu Xiaoyu , Shu Xiaolong , Liu Xing , Duan Zhe , Ran Zhiyi
Published: May 2020

Since the occurrence of debris flow hazards is related to many factors, this paper selects five evaluation indicators: rainfall, lithology level, slope gradient, undulation degree and distance from faultages based on the three scopes of geomorphology, meteorology and geology. In this paper, the data extracted from the occurrence point of historical debris flow disaster is used, and BP neural network is used for training, then the weights of evaluation indicators are obtained. Finally, the GIS software is used to superimpose and analyze these indicators, and the risk of debris flow in Ya’an city is divided into five levels, thus the danger distribution map of debris flow in Ya’an city is obtained. And the map is compared with historical debris flow disaster occurrence points, the results show that, three districts of Tiancheng County, Lushan County and Baoxing County have the highest overall risk; the overall risk of Yingjing County, Yucheng District and Shimian County is high; and the overall risk of Hanyuan County and Mingshan District is relatively low. The evaluation results reflect the actual situation of the spatial distribution of debris flow in Ya’an city, which can provide a scientific basis for the development of reasonable flood control and disaster against planning in Ya’an city.
Spatial downscaling of monthly precipitation based on TRMM satellite in Ya’an
Authors: Chen Ting , Liu Xiaoyu , Liu Xing , Li Xiaodong , Liu Jie
Published: May 2020

In the study of precipitation in ya’an with complex terrain, a statistical downscaling algorithm based on the monthly precipitation data of TRMM 3B43 from 2000 to 2008, digital elevation model (DEM) and normalized difference vegetation index (NDVI) was presented. The precipitation fields from TRMM 3B43 were downscaled to l km × l km resolution simulated precipitation by constructing multiple linear regression equation and using regression model and residuals method. Combined with the observation values obtained from 8 weather stations in the study area, the downscaled precipitation was tested in the two aspects of overall accuracy and singel station. On this basis, the spatial and temporal distribution characteristics of monthly precipitation in recent 9 years in the study area were analyzed. The results showed that: The correlation coefficients of TRMM before and after downscaling and observation values were 0.863 and 0.854, and the biases were -0.08 and -0.12. The correlation and accuracy of the two types of data were basically consistent on the whole. 75% of the stations had a high correlation with the downscaling results, and the absolute value of the bias of each station was no more than 0.35, which showed that the data accuracy was high, the data was suitable for the precipitation analysis in the research area. The distribution of monthly precipitation in 8 stations over the years showed that the precipitation in the middle of ya’an was concentrated in January and November to December. From February to April and July to August the north received more precipitation than the south, while the opposite was true from May to June and September to October, and the August in the main flood season reached the heaviest rainfall of the year.
Accuracy and Grade Demonstration and Research of Elevation Control Network for Long distance Water Diversion Projects in Plateau
Authors: Zhang Xin , Yang Zhe , He Muxia
Published: May 2020

According to the characteristics of the Water Diversion Project in Central Yunnan, the application of error theory analysis and simulation calculation method, the influence value of the elevation error of the channel line on the longitudinal slope is obtained. It is deduced that the first-level elevation control network of the project should use the second-level level control network. Combined with the analysis and calculation of the error in the weakest point elevation, it is analyzed that the project should use the third-level encryption high-speed control network. Finally, through the valuation calculation, it is determined that the Water Diversion Project in Central Yunnan does not need to correct the lunisolar attraction in the elevation control network.
Analysis on Feature of Soil_River_Ground_Plants Water Based on Stable Oxygen Isotope in Poyang Lake Wetland
Authors: Lin Yuru , Deng Zhimin , Xiong Ying , Xu Jijun
Published: May 2020

Poyang Lake is the largest freshwater lake in China, the water level of Poyang Lake was declined continuous, and extreme droughts have frequently occurred in recent years, the structure and function of the wetland ecosystem were destroyed. In this paper, Stable oxygen isotopes was used as a tracer to identify composition of soil water, river water, ground water, and plants water. The focus was on characterize the variation with depth of the stable oxygen isotope composition and identifying the main sources of oxygen in soil water, ground water, river water and plants water, understanding the mechanisms of water movement among them. Soil water sampled at 10 cm intervals over the top 100 cm at two sections in the Poyang Lake wetland, and water samples collected from the plants, river water and ground water, were analysed for stable oxygen isotope composition, exploring the recharge and discharge of relationship between them. The results shown that the values of δ18O at depth of 0∼30cm at section I were declined with increasing soil depth, the value of δ18O at depth of 0∼40cm at section II had rare variation with increasing soil depth. The groundwater supply at section I was mainly influenced by precipitation, at section II was by precipitation and river water. The average value of δ18O in the domain species plants leaves of phalaris arundinacea, crex cinerascens, and phragmites communis was -0.9%º, -4.23%º, -5.25%º respectively.
Development of Tianwan river system and characteristics of river geomorphology
Authors: Di Tang , Long Tan , Xuefeng Wu , Lijiang Qi
Published: May 2020

The uplift of Gongga Mountain has greatly affected the development of water system and topography of Tianwan River Basin. In this paper, ArcGIS software is used to extract the water system and main channel profile of Tianwan River Basin, and Horton theory is used to analyze the water system development and river network characteristics of Tianwan River Basin. The results show that the water system development of Tianwan River Basin basically conforms to Horton’s law, but the Horton ratio is larger at some levels, and the Horton ratio of the right bank is larger than that on the left bank. There are many river fissures in the basin, the largest of which are the Bawanghai Sea, which raises the river erosion benchmark and effectively suppresses the upstream disasters.
Monthly runoff forecasting via an improved extreme learning machine
Authors: Niu Wen-jing , Chen Yu-bin , Min Yao-wu , Li Yu-rong , Zhang Xiao , Feng Zhong-kai
Published: May 2020

Generally, monthly runoff prediction is of great importance for effective water resource planning and management. Extreme learning machine (ELM) is a novel training tool for the famous single layer feed-forward neural network. Due to the satisfying performance, ELM is chosen for monthly runoff forecasting in this research. Nevertheless, it is unfortunately found that ELM easily falls into local optima in practice because the randomly-determined computational parameters remain unchanged during the learning process. Thus, this paper tries to develop an improved extreme learning algorithm (IELM) where the evolutionary algorithm is used to search for satisfying computational parameters while the Moore-Penrose generalized inverse method is used to determine the output weights. The IELM method is applied to forecast the monthly runoff of Hongjiadu reservoir in southwest China. The results show that the proposed method outperforms several traditional algorithms with respect to the performance indicators. Thus, this paper provides a new and effective artificial intelligence approach for the monthly runoff forecasting.
Study of the Thickness of Curtain Grouting Ring for the life-cycle of Tunnel in Water-rich Fault Fracture Zone
Authors: Jia Yanling , Lu Ouyang , Zhou Shaowen , Wang Gang
Published: May 2020

Junchang Tunnel passes through fault fracture zone where joints and fracture developed, the water-rich zone is wide and the geological condition is extremely complex, which is likely to induce the water gushing and mud gushing. Based on the project, the proper thickness of curtain grouting ring for the life-cycle of tunnel in water-rich fault fracture zone is analyzed, and the main conclusions are as follows: (1) Comprehensive advance geological forecast including ultra-high density resistance method, land sonar method, transient electromagnetic method and drilling method are adopted to achieve good prediction results in the fault fracture zone of DK7+812 to DK7+862; (2) The full-face curtain grouting method can effectively reduce the formation deformation caused by tunnel excavation in the tunnel construction in water-rich fault fracture zone, and the effect of water plugging is great; (3) According to the formula of thick wall tube, the experience of grouting and water plugging in existing tunnels, and the comparison of finite element method, the thickness of curtain grouting ring should be greater than 5m to meet the safety requirements. Considering the safety requirements and the reduction of curtain grouting ring in the operation period, the thickness of curtain grouting ring needs to be increased to 7m.
Determination Method for Conversion Sampling Frequency of Structural Deflection Monitoring of Small-and Medium-Span Bridges
Authors: Hua Wenlong , Wang Runjian , Hu Jianming , Li Haiguang , Sun Xiaohong
Published: May 2020

This paper proposes a method for determining the frequency of interest of static and dynamic deflection responses based on the analysis of components of the deflection deformation of small-and medium-span bridges in service. By analyzing the impact of sampling frequency on the time-domain signal amplitude, this paper determines the maximum sampling frequency limit of undistorted signals, thereby providing reference for the determination of the sampling frequency for the real-time monitoring of the deflection of small-and medium-span bridges.
Calculation and test on the construction support deformation for the viaduct of the subway Line 1 of Changzhou
Authors: Weixing Wang , Teng Liu , Darong Pan , Longlong Niu , Tianjiao Dai
Published: May 2020

When the high formwork support collapses during construction, the bars present obvious deformations that exceed the normal limit. The deformation characteristics of the high formwork support were calculated and analyzed by nonlinear buckling finite element method, and the deformation test was carried out by using the automatic deformation monitoring system based on machine vision. The results show that the FE results are in good agreement with the tested results, and the FE calculation can predict the deformation behavior of the structure relatively well.
Dynamic Centrifuge Modelling Tests for Asphalt Concrete Core Dam
Authors: Ren Guofeng , Gu Xingwen , Wang Nianxiang
Published: May 2020

Dynamic centrifuge modelling tests are carried out to study the seismic behaviour of a sand-gravel dam with asphalt concrete core wall. The acceleration response, deformation, core wall stress and stability are analysed under design and check seismic intensity. The crest acceleration amplification factor is 2.7~3.0. The crest settlement rate is 0.442% and 0.481%, respectively under design and check intensity. Maximum seismic stress is recorded in core wall of 2/3~4/5 dam height. Under design intensity, failure cracks appear in crest and upstream dam revetment at water level. Under check intensity, more cracks are found. Furthermore, landslide occurs in upstream slope above 2/3 dam height under check intensity. Downstream slope is stable. No evident separation is observed between dam shell materials and core wall. The dam is unstable under design and check earthquake. Aseismic measures are necessary according to test results.
Seismic liquefaction evaluation of deposit soils under engineering loading or unloading conditions
Authors: Yang Yusheng , Liu Xiaosheng , Zhao Jianming , Zhou Jie , He Bing , Wang Long
Published: May 2020

Engineering activities such as water conservancy and hydropower, water transportation and harbor and navigation often lead to loading or unloading conditions, which makes the stress state of overlay different before and after construction. Relevant codes in the field of water conservancy and hydropower projects recommend the linearization correction method based on stress equivalence expressed by buried depth, considering the influence of stress state of overlying soil on its liquefaction resistance under loading and unloading conditions. On the basis of demonstration and analysis, this paper points out that the linearization correction method based on stress equivalence expressed by buried depth will overestimate the anti-liquefaction ability of soil under engineering loading conditions, and the liquefied layer may be evaluated as non-liquefaction, which brings potential risks to the project. Under unloading conditions, the anti-liquefaction capacity of soil will be underestimated, and the non-liquefied layer may be evaluated as liquefaction, which will lead to the increase of foundation treatment cost. Aiming at the defect of linearization correction method based on stress equivalence expressed by buried depth, a new non-linearization correction method is proposed, which takes into account the influence of the stress state of overburden soil caused by loading and unloading of dams and other projects on its liquefaction resistance. This method can effectively avoid the potential danger or waste of investment caused by the miscalculation of the original formula.
Particle breakage of coral sand in direct shear test
Authors: Wang Weiguang , Li Wan
Published: May 2020

Due to its unique development environment and historical origin, coral sand often breaks up in the process of loading, which is quite different from ordinary siliceous land-based sand in mechanical properties. Therefore, it is of great significance to study coral sand. A particle analysis testwas conducted on the coral sand from a reef in the South China Sea to study its particle size distribution, and then direct shear tests were conducted to study the influence of two factors, namely relative compactness and vertical normal stress, on the crushing of coral sand particles. The results show that when the vertical normal stress is constant, the particle breakage rate increases with the increase of the relative compactness, and when the relative compactness is the same, the increase of the vertical normal stress level can further increase the crushing of coral sand particles.
Modalidentifícation of a building structure by frequency domain decomposition
Authors: Ma Jun , Luan Wei
Published: May 2020

Frequency domain decomposition (FDD) and Enhanced frequency domain decomposition(EFDD) methods were adopted to estimate modal parameters of an18-story reinforced concrete building. Ambient vibration test was conducted on the 18-story reinforced concrete building and the two modal identification methods above were applied. The results show that FDD and EFDD methods can estimate modal parameters accurately and effectively from ambient vibration data.
Statistical Analysis of Temporal Characteristics of Natural Runoff in Golmud River Basin
Authors: Zhen Yiwei , Liu Shuguang , Hu Zichen , Liang Jiyu
Published: May 2020

Based on the 45-year natural runoff time series from 1956 to 2000 of Golmud hydrological station, the control station of Golmud River basin, the inter-annual variation characteristics involving tendency, periodicity and abrupt change and intra-annual distribution of runoff were researched by using the linear tendency estimate method, cumulative departure method, Mann-Kendall method, Morlet wavelet analysis method, Yamamoto method and Pettitt method, combined with the analysis of annual average distribution process and complete adjustment coefficient. The results indicate that the overall inter-annual fluctuations of the runoff in the Golmud Basin are relatively small, and the overall annual runoff shows a significant increasing trend. After the abrupt change occurred in 1966, the runoff increased significantly. The variation of runoff has 3-year, 6-year and 18-year periods, and the 6-year period is especially obvious. Furthermore, there is a change rule of wet and dry with an 8-year alternation in the 18 years periodic variation. The intra-annual distribution of runoff is uneven, showing a “single peak” distribution, and the degree of unevenness tends to more concentrated.
Three-dimensional geonet ecological slope protection technology and its engineering application
Authors: De-yong Wang , Qing-jun Zun , Jing Wang , Wei-yuan Huang
Published: May 2020

A protective structure system for slope with combination of vegetation and 3D geonet network was established. First the mechanism and ecological effects of slope protection with vegetation technology in slope engineering were discussed. Then specific implementation steps were proposed. Taking a slope ecological restoration project as an example, herbaceous plants suitable for slope protection were compared and tested, long term monitoring shows that the slope plants grow well, the protection effect of the new branches and roots were obvious, the stability of the slope was enhanced under comprehensive protection measures.
Semi-analytical solutions to consolidation for unsaturated soils by vertical drains under arbitrary time-dependent loading
Authors: Qin Aifang , Jiang Lianghua , Li Tianyi , Xu Weifang
Published: May 2020

This paper presents general semi-analytical solutions to equal strain consolidation for unsaturated soil layer by vertical drains, and the well resistance is considered. Firstly, the coupled governing equations are transformed into ordinary differential equations (ODEs) by Laplace transform and introducing two new variables, and combined with boundary conditions to obtain solutions. On this basis, the semi-analytical solutions in the time domain are achieved by performing inverse Laplace transform with Crump’s method. Secondly, the correctness of the semi-analytical solutions are verified by comparison with the existing analytical solutions of radial consolidation for unsaturated soils under constant loading. Finally, the effect of well resistance factor, permeability coefficient ratio ka/kw
and load parameter on the average degree of consolidation was analyzed under exponential loading.
The statistical distribution of curvatures of natural rivers meanders
Authors: Feng Jun , Li Kai , Ma Liang , Tian Yu
Published: May 2020

The rivers meanders are the most common form of natural rivers. In this paper, the shapes of meanders may be characterized in terms of the statistical distribution of curvatures measured along their contours. Deviation degree and span are proposed, in which deviation degree represents the closure degree of the bend and span represents the roundness degree or even degree of curvature distribution of the bend. Using these two indicators, we can effectively distinguish the state of the development of the river bend and thus determine different river regulation schemes. Finally, the method of deducing the reliable curvature of the bend from the satellite pictures of the river is discussed.
Study on Seismic Behaviour of Cold Formed Steel Structure Based on Simplified Mechanical Model
Authors: Liu Lei , Yao Yong , Chu Yunpeng , Liu Jiqiang
Published: May 2020

Cold-formed thin-walled steel buildings adopt the process of layered assembly, which is easy to disassemble and assemble and conforms to the requirements of industrial construction. But there is no clear method of seismic design. Taking a cold-formed thin-walled light steel structure house in Dazhou city as an example, the Pivot connection unit that can characterize the structural damage and the finite element software SAP2000 are used to establish a model, then this model is used to analyse the basic dynamic characteristics of structures and to analyze the time-history response of structures under seismic action. The results show that the simplified modeling analysis of the structure has a strong feasibility, and the lateral stiffness of the structure can resist the action of multiple earthquakes. Under the action of rare earthquake, the displacement between the layers of the structure is lower than the limit of the code, and the hysteretic performance of the structure is good, which can ensure the safety and reliability of the structure.
Analysis of slope stability considering the mechanism of the bolt-beam-root pile composite retaining structure
Authors: Hong Zhang Yan , Bin Sun , Chavez Torres Jose Luis
Published: May 2020

This project focuses on the development of a new type of retaining structure, namely Bolt-Beam-Pile Composite Retaining Structure. The proposed structure is a technical and economically feasible method enhancing the slope stability. A parameter sensitivity analysis carried out to evaluate the behavior of the structure under different scenarios, and the variation of the soil parameters. Finite element method was utilized to stimulate the model and perform the analyses. The results demonstrated that, compared with other three typical retaining structures the new Composite Retaining Structure has larger safety factor and smaller displacement.
Research Status of 1-D Soil Layers Seismic Response
Authors: Bingbing Liu , Haiyun Wang , Weiping Jiang , Xu Zhang
Published: May 2020

The local site effect of vibration propagation during earthquakes is usually considered by one-dimensional site response analysis, while the ground motion of the site is the result of the combined effect of the source, the propagation path and the local site conditions. In the study, the influence of ground motion input, soil layer properties and analysis methods need to be considered. Based on a large number of related literatures, this paper briefly summarizes the research status of seismic response of one-dimensional soil layer sites through the determination of bedrock ground motions, soil dynamic constitutive models, and analysis methods. In the future, the development of seismic response of soil sites is prospected and summarized.
Study on strength and durability of fair-faced concrete in underground station of urban rail transit
Authors: Ding Sheng , Wang Weixing , Yang Xuanming , Wang Shuxian , Chen Li
Published: May 2020

Concrete is still in the developing stage in China, only some design and construction units can master its construction technology. The side walls and middle columns of underground station of Changzhou Metro Line 2 are made of fair-faced concrete. In this paper, the material properties of the underground station are studied based on the project. In this paper, the working performance, compressive strength, impermeability, sulfate corrosion and carbonization resistance of fair-faced concrete are mainly studied by drawing up the base mix ratio. The research results have reference value for the future development of fair-faced concrete engineering.
Research on optimal operation of Chaohu Lake Based on the Particle Swarm Optimization algorithm
Authors: Li Kai , Xun Jijun , Wang Yongqiang
Published: May 2020

There is a shortage of water resources in the Huaihe River area. With the development of the economy and society, the shortage of water resources is becoming more and more serious. Among them, the Yangtze to Hauihe Water Division is a strategic backbone project to solve the contradiction between water supply and demand in the Huaihe River Basin and the Jianghuai Water Shortage Area, which can improve the water resources allocation capacity in the basin. Chaohu Lake is an important storage place for the Yangtze to Hauihe Water Division. This paper takes the Chaohu optimal operation of the Yangtze to Hauihe Water Division as an example and uses the partical swarm optimization algorithm to solve the problem. When P=95%, through the comparison of conventional operation, after the optimal operation, the water diversion was reduced by 0.071 billion m3. When P=50%, through the comparison of conventional operation, after the optimal operation, the water diversion was reduced by 0.03 billion m3. The results show that the optimal operation can reduce the water diversion of the Yangtze to Hauihe Water Division River project more effectively.
Investigation on an application of emergency rescue in the initial natural earthquake by wavelet analysis
Authors: Peng Majun , Wei Cheng
Published: May 2020

Earthquake brings great harm to humans. In order to achieve the desired effect and mitigation effectiveness of early warning, it must reduce the time of rapidly assessing earthquake location and processing seismic and other data. Seismic phase identification based on the wavelet analysis is a powerful and widely spread method in identifying the initial earthquakes. We can get the signals’ recognition factor of S wave and P wave in different scale. Then according to these recognition factors, we can determine the positioning function of primary earthquake of S wave and P wave. Next through the positioning function, we can easily pick up the first arrival of P wave and S wave. The wavelet packet analysis is a more precise analysis method of signal, which makes the frequency band multi-level division, and further decomposes the high-frequency part. Also, the wavelet analysis does not subdivide, and according to the characteristics of analysis-signal, the adaptive-select the corresponding frequency band is matched by the frequency spectrum of the signal, improving the time-frequency resolution. This paper mainly investigated the applications of initial earthquakes identification on emergency rescue, and it can be a useful theoretical reference for further relevant research.
An In Silico Exploration of the Factors That Affect the Precision of the Bethesda Assay
Authors: Seheult Jansen N , Cardel Laynalee , Tange Julie I , Ashrani Aneel , Nichols William L , Heikal Nahla , Chen Dong
Published: May 2020

Objectives

Despite more than 40 years of experience performing the Bethesda assay (BA), poor intra- and interlaboratory precision remains the biggest laboratory challenge to date.

Methods

The BA procedure was modeled using stochastic simulation techniques to determine the precision of the BA up to dilutions of 1:4,096, to estimate the minimum significant relative change at various inhibitor titers, and to understand the laboratory procedural variables that could significantly affect the performance of the BA at high dilutions.

Results

Selecting the lowest dilution tube with a residual activity closest to 25% for calculating the reported Bethesda titer (BT), using a factor activity assay with a coefficient of variation less than or equal to 7.5% in the range of 15% to 50% factor activity level, performing the factor activity measurement in replicates, and minimizing pipette volumetric error resulted in the lowest imprecision in the reported BT. The factor neutralization kinetics of the inhibitor appear to have little impact on the precision of the assay if the incubation time is greater than 90 minutes.

Conclusions

This in silico model will assist future laboratory efforts in standardizing the quantification of specific coagulation factor inhibitors and improving the precision of the reported results.