bluuebunny/crossref_metadata_2025_split huggingface dataset:
Study on How to Determine the Methylene Blue (MB) Value of Machine-made Sand and Its Effects on Admixture Dosage and Compressive Strength of Concrete
Authors: Deng Lei , Shen Jianrong , Lu Shengjun , Wang Kongguo , Xie Dayin 
Published: March 2021

Abstract
Machine-made sand is a raw material commonly used in concrete production, and its quality has a very obvious effect on the performance of concrete. This paper conducted an experiment to determine the methylene blue (MB) value of machine-made sand, explored the effects of the value changes on the admixture dosage and compressive strength of concrete, and analyzed the mineral components of machine-made sand. The research results show that the mud dosage in machine-made green sand is relatively higher, and the admixture dosage increases along with the increasing of the MB value. The mixing of different types of machine-made sand has a certain effect on the compressive strength, which reaches the peak at a certain ratio.
Rapid Blockage Diagnosis And Early Warning of Urban Drainage Pipe Network
Authors: li Zhou , Yuhan Cheng , Mei Li , Yiwu Qian , Qingquan Wang , Chu Li , Manchun Liang 
Published: March 2021

Abstract
The core of comprehensive treatment effect of water environment in river basin lies in pipe network system. The blockage of urban drainage pipe network is one of the main reasons affecting the healthy operation of urban drainage network system. So the intelligent analysis method of urban drainage pipe network blockage diagnosis can quickly find the problems of urban drainage pipe network and improve the operation and maintenance efficiency of urban drainage pipe network. In this paper, through the analysis of rainfall data, rainfall and sewage pipe network flow variation regular pattern, the change range, the essay obtains the rain and sewage pipe network blockage diagnosis threshold. Combined with the urban intelligent drainage pipe network system, through the customized setting of pipe network blockage threshold, the rapid diagnosis and early warning of the blockage problem of the drainage pipe network are realized, and the healthy operation of the urban drainage network is guaranteed.
Construction Characteristics and Quality Control Measures Under High Altitude and Cold Conditions
Authors: Yang Junpeng , Li Minyan 
Published: March 2021

Abstract
Restricted by the natural environment factors, the high altitude and cold regions have low air pressure, low air density, large temperature difference between day and night, and long freezing and cold time. During the construction, strict requirements are put forward for the material preparation, material transportation, construction machinery, construction technology, workers’ personal safety and other aspects. Based on the engineering construction in Tibet, this paper studies the optimization scheme of concrete mix proportion and the systematic insulation measures of concrete construction in high altitude and cold regions. The influence of ultra-low temperature on metal welding process is studied. The effects of welding wire selection, welding environment guarantee and worker training on welding quality assurance are studied. The calculation method of mechanical efficiency reduction and the influence of altitude on environmental factors and quota adjustment coefficient are studied. The results of this study provide reference and technical support for the construction in high altitude and cold areas.
A Research of the Section Layout of the Second Phase of the Eastern Route of South-to-North Water Diversion Project: from Hongze Lake to Luoma Lake
Authors: Yang Wanhong , Cheng Jianhua , Li Xiaohong , Wang Kai , Qiang Chao , Yan Chunhua , Gao Zhifa 
Published: March 2021

Abstract
The south-to-north water diversion project is a major strategic project in China to construct the overall pattern of the water resources allocation according to the principle of “four horizontal and three vertical, north-south allocation and east-west mutual aid”. On the one hand, the first phase of the eastern route of the south-to-north water diversion project started construction in December 2002 and was completed in November 2013. After completion, it has played an important role in alleviating the contradiction between supply and demand of water resources due to consecutive drought years in Shandong Province, especially in the Shandong Peninsula, which has ensured the economic and social development and improved the ecological environment in recent years. On the other hand, the second phase of the eastern route will further improve the allocation of water resources in China, ensure the security of water supply in important areas such as Beijing and Tianjin, and further improve the water ecological environment along the route. While the section from Hongze Lake to Luoma Lake is listed as the second section of the eastern route of this project (among 11 sections in total), the water layout, officially approved in the early stage, contradicts the one recommended by Jiangsu Province. On this basis, the key to ensure the smooth implementation of the project of this section is to study its scheme of water distribution in combination with the regional water system, coordinate the functions of flood control, drainage, water supply, navigation and ecology, and put forward an economical, reasonable and technically feasible scheme of water distribution.
Research on Deformation Mechanism of Underground Chamber Surrounding Rock Based on the Influence of Surrounding Rock Stress Path
Authors: mingqun Guo , yongqi Liu , youyan Jing , fuzhang Yan , yanbing Wang , haining Liu 
Published: March 2021

Abstract
During the construction of the pumped-storage power station, problems such as the stability of the surrounding rock of the underground chamber of the powerhouse appeared, which put forward higher requirements for the safety of the construction of the project. How to reasonably analyze and evaluate the stability of the surrounding rock of the underground chamber became a constraint to the smooth construction of the project Obstacles to progress. In response to this problem, a typical underground powerhouse chamber of a pumped storage power station was selected, and for the problems caused by the stress unloading of the surrounding rock during the excavation of the powerhouse chamber, field sampling, indoor triaxial unloading test, and numerical analysis were adopted. The stress path test results are applied to the numerical simulation analysis of different types of surrounding rock and different excavation conditions. The calculation analysis shows that the types of surrounding rock and the excavation conditions affect the arches, arch abutments and spans of underground chambers. Key positions such as the intersection of the arch bottom and the side wall have a significant impact. When the surrounding rock grade is the same, the displacement field distribution characteristics and maximum displacement of the two step-by-step excavation schemes are not much different; when the surrounding rock grade changes from type II to type III, the maximum displacements of the arch top and the bottom of the surrounding rock increase doubled.
A method of determining monitoring indexes for spatial deformation of super high arch dam based on extreme value theory
Authors: Zhang Zhiduan , Li Bo 
Published: March 2021

Abstract
In the long service of arch dam, deformation is one of the main performance parameters which can directly reflect the working behavior of the dam. In order to effectively monitor the safety of dam operation, it is necessary to determine the monitoring control value of deformation. The traditional dam deformation monitoring control values only consider the single point, ignoring the spatial correlation between the measurement points. In order to overcome this limitation, this paper focuses on the spatial distribution characteristics of deformation measuring points of the arch dam, then by building dam deformation field and using the Projection Pursuit Analysis (PPA) project high-dimensional data to low dimensional space. On this basis, the POT model proposed to determine the monitoring control values. The PPA-POT model is applied to practical engineering, and the feasibility and applicability of the method in this paper are tested by comparing with the traditional methods, so as to provide a new analysis technique for the long-term service status safety evaluation of arch dams.
Research on the Current Situation and Countermeasures of Civil Construction Site Management
Authors: Zhao Benyu 
Published: March 2021

Abstract
With the rapid development of modern society and national economy, China’s construction industry has achieved remarkable development, and various management problems have gradually emerged. As the core work of the construction industry, civil construction site management has become a topic of widespread concern in modern society. The civil construction site is a comprehensive management work, which will directly affect the safety of the civil construction site and the normal implementation of the project. It mainly includes the control of cost, material, process and completion. Only the effective interaction of multiple departments can promote the construction of civil construction activities, lay a supporting role for the long-term development of construction enterprises, and improve the timeliness and stability of management work. However, from the current point of view, there are still corresponding problems in the management of some civil construction sites in China, and such problems will greatly affect the overall construction quality. This article will mainly analyze the corresponding status quo and countermeasures in order to provide reference for relevant units.
An optimization model for joint power generation dispatching of the cascade hydropower stations on the lower reaches of Jinsha River and the Yangtze River
Authors: Zhang Song , Zhou Man , Hu Ting 
Published: March 2021

Abstract
The Xiluodu, Xiangjiaba, Three Gorges and Gezhouba cascade hydropower stations, which located at the lower reaches of Jinsha River and the upper reaches of Yangtze River, plays a very important role in the electrical power system in China. To optimize and solve the joint power generation problem of the cascade system with highly complex constraints, hydraulic relationship and multiple dispatching objectives, this research focus on: (1) a mid-and-long term power generation optimization model for the cascade system is established, considering hydraulic and electricty connections, as well as the flood control, water supply and ecology objectives; (2) an improved LSSDC-DDDP hybrid optimization framework, based on the theory of large-scale system decomposition coordination (LSSDC) and the discrete differential dynamic programming (DDDP), is designed to well solving the proposed optimization model. In the optimization framework, a relative coefficient is used to calculate the coordination factor among subsystems (a single hydropower station); meanwhile, an adaptive corridor and a bias corridor are adopted to enhance convergence speed of DDDP. The optimization model is applied in the dispatching calculation of the cascade system using the 2015-2017 actual runoff conditions, respectively. The results indicate that joint optimal dispatching of the cascade system can theoretically increase its yearly total power generation benefit about 2.73 billion yuan on average, simultaneously satisfying the requirements of downstream water supply and improving the total firm output guarantee rate of the system.
Dynamic shear band evolution by the numerical manifold method and the Drucker Prager model
Authors: Fan Zibo , Zheng Hong , Wu Wenan , Zhang Ning , Wang Yichen 
Published: March 2021

Abstract
To simulate the dynamic evolution of shear band in soil, the numerical manifold method (NMM) and the Drucker Prager model (DP) are used. Considering that the soil does not bear tension, the tensile part of DP is cut off. Then the constitutive integration could be reduced to mix complementarity problem, which is solved by the Gauss Seidel projection contraction method (GSPC). The discretization sequence is altered to resolve the transfer issue of degrees of freedom when dealing with dynamic discontinuities evolving. Different with the traditional discretization approach, the discretization of temporal variable is set prior to that of spatial variable so that all the degrees of freedom are valid only in a current step without the necessity to be transferred to the next time step. In this way, the shear band tip could stop anywhere naturally, without being improperly forced to stay on the element edge. For simplicity, the shear band is treated as a strong discontinuity with zero width. The interface contact is described by the NMM contact approach where open-close iteration is involved. Finally, a soil dam is studied to check the capability of the proposed method to capture the dynamic evolution of shear band.
Risk Factor Recognition of Shield Tunnel Crossing Underneath the Existing Subway Tunnel
Authors: Wu Shangkun , Shi Jinjiang , Wu Jin , Li Lu , Jin Hui 
Published: March 2021

Abstract
Studying and controlling the risk factors of shield tunnel crossing underneath the adjacent existing subway tunnel will be of great significance for guaranteeing the safety of tunnel structure. Under the background of subway undercrossing engineering in Shenzhen, 3D finite element models under different working conditions were established using the theory of orthogonal experimental design. The disturbing impacts generated by newly built tunnel shield crossing beneath the existing tunnel to the existing tunnel were explored in consideration of different factors. Based on the impact degrees of different experimental indexes, the priority and weight of each index were determined via the analyses of range and variance in the orthogonal experiment. The results show that the clear distance and spatial angle between new and old tunnels, and soil chamber pressure exert highly significant impacts on the settlement of the existing tunnel structure; the maximum tensile stress of the existing tunnel structure is significantly impacted by the clear distance, spacing, thickness of overburden layer, and angle; the settlement value of the existing tunnel is extremely sensitive to the soil chamber pressure, with the impact weight reaching 24.9%, and the maximum tensile stress of the existing tunnel is sensitive to the change in the thickness of overburden layer: With the increase in the thickness of overburden layer, the maximum tensile stress presents a significant trend of progressive increase, and the impact weight reaches 19.25%. The study results will be of reference significance to the safety construction of shield tunnel crossing beneath the adjacent existing subway tunnel.
Study on the Layout of the Section from Yangtse River to Hongze Lake of the Second Phase Project of the East Route of South-to-North Water Diversion Project
Authors: Cheng Jianhua , Yang Wanhong , Yang Chenxia , Wang Kai , Qiang Chao , Ding Yanxia , Gao Zhifa 
Published: March 2021

Abstract
In the section from the Yangtze River to Hongze Lake of the east route of the South-to-North Water Diversion Project, the river system, irrigation and drainage system are complex, and the responsibility and power limits of the industry management and control are not clear. As a result, the layout of the water conveyance project in this section is difficult, and there is a large space for the optimization of the water conveyance scheme. In order to better realize the water conveyance task of this section (current water conveyance scale is 500∼450m3/s, and newly added water conveyance scale is 370m3/s), optimize investment, save land, form convenient management and control, and ensure ecological safety, in this research, the layout of the water conveyance project in this section is studied, and the Liaojiagou whole lake water conveyance scheme, the Mangdao River whole lake water conveyance scheme, the semi-special channel water conveyance scheme, the special channel water conveyance scheme, and the Sanyang River-Tonghe River water conveyance scheme are proposed. Five schemes are compared from the elements of environment, shipping, construction, management and economy, and the optimal scheme is determined to be the West Liaojiagou whole lake water conveyance scheme.
Calculation method of natural characteristics of beam element considering initial state
Authors: Cui Jiawei , Che Ailan 
Published: March 2021

Abstract
Natural frequencies and modal shape play an important role in the analysis of the dynamic characteristics of long-span bridges including wind resistance and seismic. The initial static load, which caused by overloading, etc., has a certain impact on the natural characteristics. Therefore, the initial effect of static load on the inherent characteristics of the beam is studied. The vibration control equation of beam with initial state is obtained by using the energy conservation equation and Hamilton principle. Under different boundary conditions, the analytical solution of the natural frequency considering the initial state, and the influence law of the initial static load and the height-span ratio on the natural characteristics are obtained. The results show that the increase in the deflection of the beam caused by the static load will increase the stiffness of the beam, and further lead to the change of the natural characteristics of the beam. Therefore, in the analysis of the natural characteristics of the bridge, the influence of the initial state caused by static load should be fully considered.
The use of non-ionic surfactants with different Hydrophilic-Lipophilic Balance (HLB) and their effect on flow properties in palm oil biodiesel
Authors: Azaria A P , Bethari S A , Nasikin M 
Published: March 2021

Abstract
The use of surfactants has been known to reduce the interfacial tension between the two fluids. Surfactants have Hydrophilic-Lipophilic Balance (HLB) values that vary depending on their function. Previously, the addition of the Sorbitan Monooleate (SMO) had succeeded in reducing the Cloud Point (CP) by 4.2°C and the Cold Filter Plugging Point (CFPP) by 2°C. In this research, two different types of nonionic surfactants were tried, named the Sorbitan Monolaurate (SML) and the Sorbitan Trioleate (STO), which have HLB values of 8.6 and 1.8, respectively. This research aims to prove whether these surfactants can improve the flow properties of palm oil biodiesel by reducing the interfacial tension. Each surfactant was varied in palm oil biodiesel with a content of 1 and 2% at room temperature (±27°C) for a month with every week observation. Then, it was tested using the flow properties parameters, which are the CP, Pour Point (PP), and CFPP. The FTIR analysis is also carried out to determine the interactions between MG and these surfactants. The addition of 1% SML caused escalation in the CP, PP, and CFPP by 3.2, 3.5, and 6°C, respectively. Meanwhile, the addition of 2% STO caused a reduction in the CP and PP by 0.5 and 1°C, respectively but the CFPP tended to be constant.
The study of palm kernel shell updraft gasification for supplying heat to an asphalt mixing plant
Authors: Pranolo S H , Waluyo J , Setiawan A , Hidayat H , Hati W P 
Published: March 2021

Abstract
Air-gasification converts biomass using air into combustible gaseous components which also known as producer gas. The combustion of those gases provides energy for any purposes. In an asphalt mixing plant, this technology is implemented using palm kernel shell as feedstock to generate heat for aggregate heating as a part of hot-mixed asphalt production. Both Cold Gas Efficiency (CGE) and Carbon Conversion Efficiency (CCE) are the common performance indicators of such process. This study examines a performance of an updraft fixed-bed gasifier to convert the shell into producer gas in supplying heat for increasing aggregate temperature from ambient to about 145 – 165°C at capacity of 800 kg/min. The feedstock flowrate was set at 990 kg/hour and equivalence ratios were varied at 0.04, 0.05 and 0.08. Because the gasification reactions were in equilibrium, the producer gas composition for calculating the CGE was predicted using thermodynamic model with minimizing Gibbs free energy. The feedstock and solid residue of the process were analysed to determine the carbon content for calculating the CCE. It is indicated that the performance of the gasification operation for supplying heat in an asphalt mixing plant is limited by operating conditions.
Height and width effect on brick masonry wall to defection through finite element analysis
Authors: Zega B C , Prayuda H , Rusdin D F 
Published: March 2021

Abstract
The wall is an important structure to protect the inside of a house or building. The wall also functions to carry and forward loads from the roof. Wall collapse can be a structural failure that can make people die. Therefore, it is necessary to do an analysis in the form of modelling to the wall that will be built to review the damage that can be occur. There are 3 types of the wall, which is 3 meters, 3.5 meters and 4 meters of width wall with variation of height and load direction. The walls are modelled using software STERA FEM. This research was conducted to see the pattern of wall damage and to determine the high effect on wall stiffness. The result from this research shows that the pattern of damage to the wall, press on the bottom right and drag on the bottom left to the load direction X, then press on the upper right and left angles to the load direction Y. The walls were tested using variations in height and width produce the same pattern of damage. However, the deflection value for each wall is different.
Compressive stress-strain behavior of concrete with artificial lightweight aggregates and steel-fibers
Authors: Wulandari M 
Published: March 2021

Abstract
Artificial lightweight aggregate used in the concrete mix is able to reduce the volume of concrete so that when applied to structural concrete it will reduce the weight of the structure. To be used in the structural concrete mix, the compressive strength produced must be able to meet the minimum requirements of structural concrete compressive strength. The addition of steel fibers to concrete with artificial lightweight aggregate can provide a good behavior change to its mechanical properties. This research was conducted experimentally which investigated compressive stress-strain behavior, the main ingredients used to make artificial lightweight aggregate were Styrofoam and acetone with the composition of 0%-100% of coarse aggregate and to increase the compressive strength of steel fibers by 0%-1.5% from the specimen volume. The specimen used was a 100×200 mm cylinder tested using a Universal Testing Machine, the output obtained was the value of stress and strain. The test results show that the stress-strain of the concrete increases with increasing steel fiber composition. Strain value increased by 23% from normal concrete strain. The compressive strength produced from concrete with a mixture of lightweight artificial aggregates and steel-fibers is able to reach the minimum concrete compressive strength requirements.