bluuebunny/crossref_metadata_2025 huggingface dataset:
On the super edge local antimagic total labeling of related ladder graph
Authors: Kurniawati E Y , Agustin I H , Dafik  , Marsidi
Published: March 2020

A graph G is an ordered pair of sets G = (V, E), where V is a set of vertices and E is a set of edges. The concept of labeling graphs has recently gained a lot of papularity in the area of graph theory. Antimagic labeling is the interest topic to studied. The study of antimagic labeling motivated by Hartsfield and Ringel. Arumugam et.al developed the concept of antimagic labeling that is local antimagic coloring. Thus, we study the concept of local antimagic namely edge local antimagic total labeling. By an edge local antimagic total labeling, a bijection f : V(G) ∪ E(G) → {1, 2, 3, …, |V(G)| + |E(G)|} satisfying that for any two adjacent edges e
1 and e
2, wt
(e
1) ≠ wt
(e
2), where for e = ab ∈ G, wt
(e) = f(a) + f(b) + f(ab). Thus, any edge local antimagic total labeling induces a proper edge coloring of G if each edge e is assigned the color wt
(e). It is considered to be a super edge local antimagic total coloring, if the smallest labels appear in the vertices. The chromatic number of super edge local antimagic total, denoted by γleat
(G), is the minimum number of colors taken over all colorings induced by super edge local antimagic total labelings of G. In this paper we study edge local antimagic total labeling and determined the chromatic number of graphs as follow grid graph, prism graph and mobious ladder graph.
On rainbow antimagic coloring of some graphs
Authors: Sulistiyono B , Slamin  , Dafik  , Agustin I H , Alfarisi R
Published: March 2020

Let G(V, E) be a connected and simple graphs with vertex set V and edge set E. Define a coloring c : E(G) → {1, 2, 3, …, k}, k ∈ N as the edges of G, where adjacent edges may be colored the same. If there are no two edges of path P are colored the same then a path P is a rainbow path. The graph G is rainbow connected if every two vertices in G has a rainbow path. A graph G is called antimagic if the vertex sum (i.e., sum of the labels assigned to edges incident to a vertex) has a different color. Since the vertex sum induce a coloring of their edges and there always exists a rainbow path between every pair of two vertices, we have a rainbow antimagic coloring. The rainbow antimagic connection number, denoted by rcA
(G) is the smallest number of colors that are needed in order to make G rainbow connected under the assignment of vertex sum for every edge. We have found the exact value of the rainbow antimagic connection number of ladder graph, triangular ladder, and diamond.
Design of assessment based on guided discovery to improve the quality of teachers’ professionalism of mathematics
Authors: Hidajat F A , Hidajat B I
Published: March 2020

This research aims to improve the quality of teachers’ professionalism in designing assessments based on guided discovery. Guided discovery is a good learning method in encouraging students to discover mathematical concepts themselves. However, the problem that occurs is teachers tend to apply traditional methods, do not recognize guided discovery methods and do not know how to design assessments based on guided discovery. Therefore, this research fills the gap of the problem by compiling a design of assessment based on the guided discovery. The research subjects were mathematics teachers and students in Probolinggo. The method in this research was conducted in 6 stages, namely: initial investigation, design, construction, validation, evaluation and revision, and implementation stages. Data analysis consisted of data reducting, displaying data, making a conclusion. The results of this research are five aspects of assessment, namely aspects reflecting previously idea; experiments openly; experiments independently; find solutions convergently; implement discovery into the problem-solving process. The percentage of validity from experts on the five aspects of this assessment system was 81.25% with criteria of “valid” whereas; the percentage of validity from practitioners is 90.62% with criteria of “valid”. The researcher recommends that improving the quality of teachers’ professionalism should be focused on the design of assessment based on guided discovery.
The development of think together about science in society (TToSS) learning model to increase critical thinking skill in science lesson
Authors: Yuwentin O , Mahardika I K , Nuriman  , Sudiatmika A A I A R , Sugiartana I W
Published: March 2020

This article discusses of how TToSS learning model is used to increase the critical thinking skill in science. The critical thinking is an skill to think rationally in assesing something in which before deciding or doing something. Critical thinking is a thinking skill that can be trained, so that this skill can be learn and developed. The development model used in this research is the 4-D development model. The question used in the experiment is development question that refers to train the critical thinking of students that is suitable with their age development. The first sintax model of TToSS is Think Alone; a stage of giving the illustration of the problem to stimulate the critical thinking skill of the students. The second stage is Think Together; the student with his/her group discusses about the problem given. The third stage is Share and Discuss, in this stage the students do the presentation of the result of the group discussion with entire groups in the classroom. The fourth stage is Evaluating; in this last stage the teacher evaluates all the activities during the lesson and corrects all misconception that might occur on the presentation and discussion.
Analysis of students critical thinking skills in junior high school on natural sciences based on the difference of learning styles
Authors: Aini M , Suratno  , Asyiah I N
Published: March 2020

Natural Science is a learning related to everything around us. One of the subject matter in natural science is the motion system that often occurs in daily life. However, some of the students have misconceptions about the motion system. It required the critical thinking skills of the students in understanding the concept to resolve a problem in society. Critical thinking skills is one of the skills that must be possessed by students because of the demands in the 2013 curriculum. Critical thinking skills can be influenced by several factors, one of them is students’ learning style. This study aimed to analyze the critical thinking skills of junior high school on natural sciences based on the differences in learning styles. This study took sample of students in the first, second and third grade of junior high school. In this research, the researcher uses descriptive method. To analyze the data, the researcher used mix methods (qualitative and quantitative). The technique of collecting data uses observation and tests. Observation is used to find out the types of the students’ learning styles, while tests to measure student’s critical thinking skills. The results showed that there were verbal-linguistic learning style (73.0%), logic-mathematic (67.6%), kinesthetic (60.0%), visual-spatial (60.2%), music (62.0%), and interpersonal (61.1%). So, the verbal-linguistic learning style was better than critical thinking skills.
The profile of students’ mathematical representation in constructing line equation concept
Authors: Mulyono O C F , Sunardi  , Slamin
Published: March 2020

Mathematical representation is the way from students to express their ideas in understanding and solving mathematical problems in the form of images, words, and symbols. This research aimed to know the profile of students’ mathematical representation in constructing the straight-line equation concept. This research used a qualitative approach with descriptive research type. The subjects were 36 junior high school students at Jember. Data were obtained from the test, observation, and interview. Data triangulation was done by comparing data from the analysis of the answer sheet with interview data. The results showed in the activity of defining the concept of slope and straight-line equation, students made a visual representation during the process of finding slope and made verbal representation when defining straight-line equation. In the activity of determining a straight line equation, students made a symbolic representation and carrying out visual representation with among of them doing unique guesses in making an overview of the requested line position. In solving problems related to the concept of the straight line equation, some students chose visual representation to solve the two different problems. Some of the other students chose symbolic representation with some inaccuracy, and errors in the algebraic concept. While students who have been identified in the previous process have low ability tend to choose to use verbal methods and made guesses about the number of patterns.
Anxiety: how was the process of the undergraduate students who were in visualization level in constructing the definition?
Authors: Purnomo R C , Sunardi  , Yuliati N , Yudianto E , Mahfut M , Sa’dijah C
Published: March 2020

Definition is important mathematical construction which had been recorded as a challenging topic for teacher and students. This research showed the illustration of anxiety that happened to undergraduate students of Mathematics education who were in visualization level of thinking in constructing quadrilateral definition and definition form that had been successfully recorded. The analysis was done to determine the anxiety’s indicator that appeared and indicators of quadrilateral’s definition. Triangulation method was done to compare subjects’ worksheet, observation, and interview. The results showed that anxiety appeared when subjects started to construct the definition of quadrilateral so that the definition that had been defined was not efficient.
The analysis of students metacognitive in science with different learning environments on junior high school
Authors: Musyafaah N N , Suratno  , Nuriman
Published: March 2020

The essential nature of science includes the process of observing, discussing, analyzing and representing. Science must be supported by metacognitive abilities that refer to prediction, planning, monitroring, and evaluation skills and can make students become independent learners. This research was to analyze the metacognitive of students in science with different learning environments. This research place was in Junior High School, Boarding school and Islamic Junior High School in Bondowoso. This research has qualitative descriptive study with mix method (qualitative and quantitative). Qualitative data were descriptive based on the results of observations with teachers and students. Quantitative data were from the MAI test (Metacognitive Awarness Inventory). MAI test has two indicators, namely knowledge about conditions includes declarative knowledge, procedural knowledge, and conditional knowledge, and regulations of cognition including planning, information management strategies, and monitoring comprehension. The results of this research showed a difference in metacognitive 20% in the Junior High School and Islamic Junior High School in science.
Analyzing types of interaction in nuclear magnetic spectroscopy online discussion forums that affects student learning outcomes
Authors: Terra I W A , Wonorahardjo S , Suharti S
Published: March 2020

Many research shows that interaction can increase concept understanding. Course interaction can be categorized in student-student interaction and student-lecturer interaction. Strong interaction can increasing students high order thinking skill. Learning design begins to pay attention to that interaction effect. Interaction can be done online and lead to cognitive understanding. This qualitative descriptive research aims to describe the cognitive process in an online discussion, specifically in analytical chemistry course. They learn about nuclear magnetic spectroscopy that most used in both qualitative and quantitative analytical chemistry. The subjects are seven groups consists of three chemistry students in their third year. They have three worksheets to discuss in three weeks about basic principal, instrument, spectrum, and experimental design in Nuclear Magnetic Resonance spectroscopy. Data sources are their online discussion transcript obtained from their elearning discussion forum. They also have pretest and posttest to analyze N-gain score. Their discussions are analyzed using coding categories to count the number of meaningful interaction. The trend of n-gain score and number of meaningful interaction are analyzed. Type of interaction that showed is ARA, ARC, ARI, DRA, DRI, and DRC. Results show that gain score correlates with number of meaningful interactions.
HOTS student worksheet to identification of scientific creativity skill, critical thinking skill and creative thinking skill in physics learning
Authors: Astutik S , Mahardika I K , Indrawati  , Sudarti  , Supeno
Published: March 2020

In the learning context of 21st century, teachers encounter many challenges in optimizing the process and the outcome of learning. Students who have higher order thinking skills will be able to think of scientific creativity, critical thinking and creative thinking. In this study, identification is done by measuring the ability of scientific creativity, critical thinking and creative thinking skills by HOTS student worksheet. The result showed that student’s scientific creativity with 6 indicators need to be develop esspecialy for physics problem solving and technical production. For critical thinking skills students obtain moderate results but have shown good results in answering physics problem. For creative thinking skills students get good results on the indicator fluency, flexibility and elaboration but for the originality still needs to be developed. Therefore, it is very important to develop a proper physics intructional design that can develop scientific creativity, crtical thinking and creative thinking skills.
Lipids source and degradation as revealed by molecular biomarkers in soils after acid-pretreatment: A case of a plantain soil under long-term cultivation
Authors: Li Yan , Liang Ni
Published: March 2020

The extractable lipids are important components in soil organic matter (SOM) which were used to trace the sources and degradation of SOM. The protection of lipids by soil mineral have been suggested through organic solvents. But, the extraction efficiency of some lipid compounds was low. This study applied a mild acid treatment to firstly remove most of the reactive mineral particles, and without altering SOM chemical structures in 10% HF/1M HCl (1:4 w: v). Based on the obtained lipid biomarker information, we observed that the lipid extraction efficiency significantly increased by organic solvents on after removal of active minerals. The acid treatment increased the scientific to quantitative the amount of lipids. The minerals showed significant differences in the selective protection to different components of lipids. In this study, the amount range of protected n-alkanoic acids is 73~85%, n-alkanol 41~62% and n-alkanes 26~46%. After the vegetation was replaced, the increased alkenoate and alkane in soil input by the plant tissues of plantain directly, and the alkanols probably input by the hydrolysis of wax esters. Under the interference of man-made tillage activities, the C content in 0-20 cm decreased, suggesting that cultivated activities may enhance SOM degradation and accelerate SOM turnover. Understanding SOM behaviour in this area will provide important information for soil management and to evaluate carbon cycling in human-affected ecological systems.
Catalytic performance of nickel catalyst dispersed in emulsion for the co-liquefaction of lignite and heavy residue
Authors: Yang Tengfei , Yan Ruming , Liu Congcong , Deng Wenan , Jiang Yao , Hu Tong , Li Chuan , Niu Qingshan
Published: March 2020

A kind of nanoemulsion nickel catalyst was prepared for the application of coliquefaction of lignite and heavy residue. The particle size and microstructures of dispersed phases in emulsion and the sulfurized product were characterized by dynamic light scattering and transmission electron microscope. Catalytic performances of prepared catalysts at different dosage were investigated and the microscopic features of solid residues with catalyst or not were compared. Experimental results showed the optimization mixing speed for emulsion nickel catalyst preparation was 2000 r/min, with an average diameter of 180 nm, and the active phases of prepared catalyst after sulfurization was Ni3S2. The emulsion nickel catalyst displayed a favorable catalytic activity, with a coal conversion efficiency of 93.7 % and an oil yield of 72.33 wt%. The fragmented shapes and lowed diameters of solid residue with prepared catalyst relative to no catalyst further displayed its significant roles in the inhibition of condensation reaction and coke formation.
Research on the path of low-carbon city system construction mode based on energy consumption per unit output value method
Authors: Bi Xiaoqing , Wang Dandan
Published: March 2020

In recent years, low-carbon research has become a research hotspot in urban system construction. Cities consume a large amount of carbon-based energy and are an important research object in low-carbon research. This paper first quantitatively analyzes the correlation between the three major industrial structures and the industrial energy consumption structure. At the same time, it studies the substitution of multiple energy sources, and obtains the mechanism of action of the low-carbon city system. Through the collection and analysis of data, the necessity of improving energy efficiency for the development of low-carbon cities has been proven. On the basis of this data analysis, this paper uses the method of energy consumption per unit output value to build a scenario analysis model of urban carbon emissions, puts forward four models of low-carbon urban system construction in terms of material flow, and gives the path planning and selection of low-carbon urban system construction.
Research and countermeasures of the influence of air pollution on human body
Authors: Yang Kai
Published: March 2020

In recent years, with the development of the economy, environmental problems have become more and more serious. Air pollution not only affects the climate and the living environment, but also has an unimaginable impact on the human body. The adverse effects of air pollution are not limited to physiological health damage, but also involve negative effects in many aspects such as cognitive function, mood and behavior; air pollution can cause damage to the nervous system, brain function and cognitive function, and the damage is concentrated in children, Susceptible people such as the elderly and chronically ill patients. Air pollution can reduce subjective well-being, leading to anxiety, depression, and even increased risk of suicide. The physiological mechanisms by which different sources of pollution affect cognitive and mental health are different. In order for human beings to survive for a long time, research and countermeasures against the causes of air pollution are essential. This paper analyzes the causes of a series of effects of air pollution on humans and proposes corresponding countermeasures.
Hydrothermal Oxidation of Polyethylene (PE) Plastic to Short-chain Fatty Acids (C1 - C5)
Authors: Zhou Wanning , Zhong Heng , Jin Fangming
Published: March 2020

In most of the past studies on disposal of waste plastic, due to the irreversible hazards for human environmental health (incineration), and the strict requirements of reaction conditions (pyrolysis, gasification), the cost of disposal and research also increases. In this study, we converted waste polyethylene (PE) plastic into high value-added organic products by high-temperature water (HTW) to obtain C1 to C5 short-chain fatty carboxylic acids (formic acid, acetic acid, propionic acid, butyric acid and valeric acid). In addition, the reaction parameters (temperature, time, oxidant amount, pH) were investigated under hydrothermal conditions, and the yield for PE to short-chain fatty acids (C1 -C5) was optimized to 20%. Then the concentration of TOC and IC in the solution was used to measure the conversion and degradation of PE. In addition, the oil phase and solid residue after the reaction were also discussed in this research.
Study on the variation characteristics of annual rainfall and runoff in Oujiang River Basin of Zhejiang Province
Authors: Hu Haiying , Lin Junsheng , Huang Huamao
Published: March 2020

In this paper, Mann-Kendall method and wavelet analysis method are used to analyze the annual rainfall and runoff data in Oujiang River Basin of Zhejiang Province, and the following conclusions are obtained: in the past 50 years, the annual average rainfall series increase and the annual runoff series decrease in Oujiang River Basin. The reason for this is that in 1960s, many hydraulic structures were built near Xuren station, such as river dams, which led to the rapid decline of runoff in the flood season. The results of Morlet wavelet analysis show that there is significant multi-time scale variation characteristic in the annual average rainfall and runoff series. The periodicity of the annual rainfall series exhibits three types of variation trends for different time-scales, i.e. 22-to 30-year scale, 10-to 22-year scale, and 3-to 10-year scale. While the periodicity of the annual runoff time series exhibits three types of variation trends for different time-scales, i.e. 15-to 25-year scale, 8-to 15-year scale, and 3-to 8-year scale.
Study on the Uncertainty of the Calibration Device of PM2.5 Mass Concentration Monitor
Authors: Zou Junchen , Fan Wei , Shi Enjie , Lu Xindong , Zhou Xingang , Li Guoqiang , Fan Zhenxing , Liu Huiyuan , Xu Xueqiong , Liu Xiuxiu , Wang Lin , Liu Wensi , Zhang Ye
Published: March 2020

The fine particles (PM2.5) has become a major air pollution problem in China, and PM2.5 mass concentration monitor was used to measure the concentration of PM2.5, and whether it is accurate or not determines the quality of the atmosphere. In this study, the uncertainty of the calibration device of PM2.5 mass concentration monitor was estimated. By analyzing the source of the uncertainty of calibration device, the analytical method of the uncertainty was determined. It was proved that when the aerosol concentration were 50μg/m3, 200μg/m3 and 500μg/m3, the expanded uncertainty of the calibration device were 0.90%, 0.90% and 10.02% respectively, and it showed that the major influence factor of the uncertainty of the calibration device was the mass concentration indication error.
Heat transfer characteristics of activated coke in the moving bed for sulphur resource recovery
Authors: Wu Gongpeng , Tang Rongsheng , Wang Yiyu , He Yan
Published: March 2020

A counter-flow moving bed and tube heat exchanger was designed and built for the heat transfer process of activated coke desorption, the heat transfer law between particles and tube wall surface in the moving bed was studied. The results show that with the increase of hot air inlet temperature and moving velocity of activated coke particles, the heat transfer coefficient inside the tube largely increases and then remains a small change. As the air velocity increases, the heat transfer coefficient inside the tube also shows increasing trend. In addition, with the increase of air temperature and particles moving velocity, total heat transfer coefficient of the moving bed and heat transfer coefficient outside tube increase first and then decrease. Finally, based on experimental data, the correlation coefficient of heat transfer coefficient outside the tube is obtained.
The Effect of Air pollution on the Hospitalization for AECOPD
Authors: Chen Cai , Li Xiyuan , Meng Xiangwei , Ma Zhixiang , Li Wei , Ma Dedong
Published: March 2020

More evidences showed that there was a relationship between air pollution and hospitalization of acute exacerbation of chronic obstructive pulmonary disease. This paper aimed to investigate the effect of air pollution (fine particulate matter, inhalable particle, sulfur dioxide, nitrogen dioxide and ozone) on the hospitalization for acute exacerbation of chronic obstructive pulmonary disease. Thus, generalized additive model was built to evaluate the impact of air pollution on people’s respiratory system. After controlling for temperature and relative humidity, the increase in average daily concentrations of PM2.5, PM10 and O3 would aggravate the risk of admission of patients with acute exacerbation of chronic obstructive pulmonary disease, and the results were statistically significant.
Effect of Wet Scrubbing Oxidation Denitration Technology Combined with Ultraviolet Online Irradiation on the Efficiency of Desulfurization and Denitrification of Ship Exhaust Gas
Authors: Chen Peng
Published: March 2020

In order to alleviate the air pollution caused by nitrogen and sulfur oxides discharged from ships, the efficient method of deoxidization and desulfurization of marine diesel engine exhaust gas has been explored. In this study, at present, the mainstream technology of ship exhaust gas removal at home and abroad, wet scrubbing oxidation denitration technology is taken as the research object. Ultraviolet (UV) online irradiation is introduced into the process of wet scrubbing oxidation denitration of NaClO2 solution. The effects of different parameters, such as the concentration of NaClO2, the temperature of washing solution, the concentration of O2 and SO2, on the removal of No are studied. The reaction mechanism is further analyzed. The results show that photochemical reaction will take place between UV online irradiation and NaClO2 solution, resulting in a large number of active radicals with strong oxidation, which can obviously enhance the effect of No removal by wet scrubbing of NaClO2 solution. It can be seen that the wet scrubbing oxidation denitration technology combined with UV online irradiation can greatly improve the efficiency of desulfurization and denitrification of ship's exhaust gas. It is an efficient method of deoxidization and desulfurization of ship's diesel engine exhaust gas, which is of great help to alleviate exhaust gas pollution.
Study on the Scattering Properties of Cylinders in Suspensions Containing Sediment Particles
Authors: Yin Linli , Han Qingbang
Published: March 2020

A method is presented that combining the Mcclements suspension model with the cylindrical model to solve the complexity of calculating the scattered acoustic pressure around the cylinder, when suspended particles are contained in the water. The scattered acoustic pressure of an infinitely long cylinder in water is derived based on the boundary conditions. Then, the wave number of the particle-containing suspension is calculated by the Mcclements suspension model, which is combined with the scattered acoustic pressure of an infinitely long rigid cylinder in water. The scattered acoustic pressure of an infinitely long rigid cylinder in suspension is obtained. The results show that the content of sediment particles has a greater impact on the distribution of scattered acoustic pressure. The scattered acoustic pressure is more directional with the increase of the content of sand particles, laying a foundation for further research on other target objects in suspension.
Treatment process of rural domestic sewage based on small purification tank technology
Authors: Bi Xiaoqing , Guo Lijuan
Published: March 2020

With the continuous development of our country's economy, the living standard in rural areas has been greatly improved, rural water consumption has also increased significantly, especially in recent years, the popularity of rural tap water, improve the rural water availability, rural sewage has also increased significantly. As China's rural sewage treatment technology and facilities are generally backward, some rural areas even have no sewage treatment facilities, a large number of living directly into the surface or rivers. According to the characteristics and analysis of the discharge of rural domestic sewage, this paper puts forward the method of purifying rural domestic sewage with the technology of tank.
Research on Low Altitude Illumination Configuration Technology of Highway Tunnel
Authors: Bei Dengrong , Liu Peng , Ma Fei , Xia Yangyuyu
Published: March 2020

In view of the problem of light efficiency utilization in low altitude illumination in tunnels, it is proposed in this paper to improve the lighting benefits by optimizing the light configuration. Combinational analysis of such parameters as light height, elevation angle and spacing in low altitude illumination is performed in this research by Dialux optical simulation software. The average road surface luminance, overall uniformity of road surface luminance and longitudinal uniformity of road surface luminance are taken as key evaluation indicators. The study shows that the optimal height, elevation angle and spacing of low altitude illumination are 3 meters, 40° and 1 meter respectively. The overall uniformity of road surface luminance of low altitude illumination can reach 0.97, the longitudinal uniformity of road surface luminance can reach up to 1.0. The luminous flux per meter is equal in the longitudinal direction of the tunnel. The average road surface luminance is affected by the light arrangement spacing to a very small extent, and the longitudinal uniformity of road surface luminance is affected by the height and elevation angle of the light very slightly.
Review on Tunnel Concrete Invert NDT Methods
Authors: Qiuzhuo Liu , Yunteng Zhou
Published: March 2020

Tunnel concrete invert is very important to the stability of the entire tunnel structure. However, invert’s quality is usually insufficient due to various reasons. Traditional approaches to detecting tunnel concrete invert focus on inefficient coring. The results of detection often cannot reflect all realities of the invert and concrete fill layer. These approaches are short of meeting current detection requirements for concrete invert. In order to increase the effectiveness and accuracy of invert test this paper summarizes technical features of GPR method and Rayleigh wave method according to concrete structure NDT and tunnel invert test technologies at home and abroad. The results show: the GPR method is simple and efficient and capable of qualitative test of tunnel invert, though with a trade-off between detection depth and accuracy; the Rayleigh wave method provides high accuracy and the qualitative test ability for tunnel invert thickness and unconsolidated fill, though inefficient due to a lack of pertinent equipment.
Experimental Investigate on Pulling out of Anchor Based on Fiber Bragg Grating Monitoring
Authors: Duan Jun , Mou Chunhai , Wang Zhongwei
Published: March 2020

The stability of the anchor plays an important role in slope engineering, mining engineering and construction engineering. Based on the Fiber Bragg Grating (FBG) sensor detection technology, this paper carries out the pulling out the test of the anchor with different tensile strengths. The results show that the center wavelength of the FBG has a good mathematical relationship with its axial strain, and the wavelength change data can be processed into the strain result of the FBG sensor to characterize the strain deformation and stability of the anchor further. What’s more, the measured data from the FBG sensor agrees with the load of the test, and the accuracy of the FBG sensor monitoring data on the anchor is varified.
Study on Slope Stability of Baoshi Expressway Based on the Analytic Hierarchy Process
Authors: Yang Zhihua , Wang Zhongwei
Published: March 2020

Combining with the actual situation of section K13+165 in Baoshi Expressway, the hierarchical structure model of the slope stability is established based on the analytic hierarchy process (AHP) in operational research. Fourteen factors, which affected the slope stability, are analysed, quantitatively calculated and ranked. The consistency test was carried out. On this basis, the influence weights of each factor are sorted, and the main influencing factors of the slope stability are found out. The research can provide a basis for the maintenance and treatment of Baoshi expressway.
Design and Calculation Method for Composite Foundation Using Large-diameter Rigid Piles in Pebble Bearing Soil
Authors: Zhang Wenhan , Li Feng , Cheng Lijuan , Xu Jianxiao
Published: March 2020

In the composite foundation using rigid piles, large pile-soil stress ratio often results in insufficient exploitation of bearing capacity of soil among piles. The rigid piles bear most of the vertical loads which makes the stress mechanism similar to that of pile foundation and fails to save cost. Based on the test and study of pile shaft resistance and tip resistance in the composite foundation using large-diameter rigid piles in pebble bearing soil and the stress monitoring of pile top and soil among piles, the pattern of variation in pile-soil stress ratio of composite foundation using large-diameter rigid piles was achieved. Furthermore, according to field test, use of cushion would lower the stress in rigid piles and exert bearing capacity of soil among piles which leaded to higher bearing capacity of composite foundation and smaller differential settlement. In contrast to “Technical Code for Ground Treatment of Buildings” (JGJ79-2012), a new design and calculation method for composite foundation using large-diameter rigid piles in pebble bearing soil was proposed based on the results from field test, numerical simulation and theoretical analysis. This improved and practical method has fully considered the potential bearing capacity of soil among piles and has been verified through practical engineering cases.
Development of an automatic monitoring system for ground settlement induced by shield tunnelling
Authors: Wan Shifu , Huang Qiming , Zhao Hailin , Qi Xingxin , Liu Yi , Qiu Wenge
Published: March 2020

During the construction of the modern subway, it is often the case that subway tunnel construction is close to existing buildings, causing the deformation of existing buildings. In order to minimize the impact of new line construction, real-time monitoring and feedback warning of building deformations are required. This paper is based on the current mature automated monitoring data acquisition system. A comprehensive monitoring management system is developed, which includes engineering information management, monitoring equipment management, monitoring data reception, monitoring data analysis and processing, early warning information release as well as monitoring report automatic output. The developed automatic monitoring system was applied to the monitoring of the construction of Chengdu Metro Line 5, completed the automatic monitoring and real-time data processing and early warning of the underpass process. The operation safety of the existing lines was guaranteed. In the future, this system will also be extended to other tunnel monitoring, gradually forming a comprehensive tunnel construction monitoring and management system.
Quantitative analysis and calculation of traffic social cost during the construction of open-cut subway station
Authors: Liao Jixuan , Guo Chun , Xu Yumin , Zhang Jiapeng , Yang Kun
Published: March 2020

With the rapid development of rail transit, traffic problems caused by open-cut metro construction have become increasingly prominent. In order to quantify the negative impact of subway station construction, taking a metro stations under construction in Chengdu as example, collected relevant data such as traffic flow, congestion time, speed during congestion and noise decibel value at metro construction intersection by field test. Through quantitative calculation, the negative effects of open-cut construction are monetized from four aspects: extra fuel cost, time delay cost, environmental pollution cost and fatigue cost. It is found that the social cost is as high as 20 million yuan per year. Based on the calculation results and the actual traffic situation in Chengdu, the corresponding measures to reduce social costs are put forward.
Optimization of Gas Drilling in Pre - pumping Coal Seam of Gas Tunnel
Authors: Wang Yuqi
Published: March 2020

In order to optimize the gas drilling in pre-pumping coal seam and strengthen the gas emission effect, This paper uses Chenggui high-speed railway Baiyanglin tunnel as the research object. The FLUENT numerical simulation software is used to simulate the change of coal seam gas pressure during the process of gas emission and the influencing factors of the effect of gas emission. According to the numerical simulation results, the parameters including hole spacing, hole depth and aperture are optimized. The results show that the recommended diameter of the pre-emission gas is 75 ∼ 100mm, the drilling depth is 1.5 ∼ 2.5m, and the hole spacing is 2m.
Numerical simulation study on the width of coal pillar in dynamic pressure roadway
Authors: Ren Peiliang , Li Zongze , Guo Xiangyin
Published: March 2020

The deep coal mine roadway is easy to deform and destroy under the high ground stress. At the same time, it is disturbed by the mining stress of the adjacent working face. At present, the scope and size of the influence of stope mining are mainly studied at home and abroad. However, there is not enough understanding of the propagation law of the working face support pressure and the surrounding rock control of the deep well dynamic pressure roadway, and there is no in-depth study of the influence of the pillar width on the stability of the roadway. Therefore, this paper comprehensively uses the methods of field investigation and FLAC3D numerical simulation to study the deformation and stress distribution of surrounding rock under the influence of mining. By using FLAC3D numerical simulation software, this paper studies the distribution of surrounding rock stress and the law of surrounding rock deformation under different pillar width in the mining process of adjacent working faces. Studying conclude that when the pillar width is 80m, the roadway is less affected by mining.
Deformation Control Standard of Utility Tunnel Based on Crack Control Standard
Authors: Cai Yanbiao , Du Zipeng , Zhang Gen , Feng Jiajia
Published: March 2020

The construction of underground utility tunnel is being carried out on a large scale in China, however there is no corresponding control standard for the structural deformation of utility tunnel, so it is very necessary to establish the deformation standard of utility tunnel. In this paper, the maximum longitudinal bending moment of utility tunnel and the maximum stress of reinforcement controlled by cracks were used to establish the longitudinal deformation standard of utility tunnel structure. In addition, numerical simulation was used to analyze the deformation characteristics of underground composite utility tunnel under different section sizes and soils. And simulation results indicate that the crack reached its maximum of 0.2mm when maximum deformation curvature of utility tunnel was 2.12025*10−5.
Research on Fault Diagnosis Method of Tunnel Inspection Robot Based on T−S Fuzzy FTA
Authors: Li Wen-feng , Ding Hao , Li Ke , Liu Qiu-zhuo , Jiang Xing-hong
Published: March 2020

Aiming at the intelligent fault diagnosis of tunnel inspection robot, the T-S fuzzy fault tree method was proposed to build the intelligent diagnosis system. Taking positioning system of the robot as an example, the T-S fuzzy FTA model of the system was established. And the T-S importance of each component and fault checking sequence were calculated using the T-S fuzzy gate rule. The example analysis results show that, the method improves the accuracy and practicability of fault diagnosis of the robot system.
Study on Prediction of Gas Burst Hazard Before Advancing a Tunnel Through Coal Seam
Authors: Hu Xuebing , Cheng Liang
Published: March 2020

This paper discusses how to predict burst hazard when advancing a tunnel through a gassy coal seam in order to prevent gas burst disaster during tunnel excavation. It covers prediction of burst hazard for Huayan Tunnel of Chengdu-Chongqing Expressway in the city of Chongqing before its left tube is advanced through a gassy coal seam at ZK3+200. The prediction result is reliable and has ensured the safety and stability of the Huayan Tunnel while it is advanced through the gassy coal seam.
Safety Analysis of the Secondary Lining Structure of Existing Tunnel with Cracks
Authors: Cai Shuang , Ding Hao
Published: March 2020

Because cracking of the secondary lining is one of the most common diseases in road tunnel, it is of great practical significance and theoretical value to analysis and research on the safety of lining structure of existing tunnel with cracks. Based on crack models of fracture mechanics, the calculation method of safety evaluation for the secondary lining structure of existing tunnel with cracks was discussed through numerical analysis. The bearing capacity of non - destructive lining and cracked lining was analyzed and compared by model tests. Results showed: (1) the finite element method of fracture mechanics could be used to evaluate the safety of the secondary lining structure of existing tunnel with cracks. (2) The size order of the required load when the cracks occurred in the different parts; The arch foot is smaller than the vault; the vault is smaller than the haunch; the haunch is smaller than the invert. (3) When the crack was located at the crown and arch foot, it had the most significant influence on the safety of lining structure. (4) The bearing capacity of the lining structure declined because of cracks, and it decreased by 37.5% when there was longitudinal crack at the bottom of the inverted arch of tunnel.
Study on the Influence of Micro Parameters of Numeric Model Using Particle Flow Code on Macroscopic Mechanical Properties in Cobble Stratum
Authors: Fang Lin , Hu Peng , Wu Mengjun , Cao Peng , Chen Shouchao
Published: March 2020

The widely distributed cobble in the subsurface brings about lots of technical problems to underground projects. Based on the physical and mechanical characteristics of the pebble layer, PFC particle flow software was used to establish a triaxial numerical test model. Considering multifarious situations, triaxial numerical tests were carried out with different mesoscopic parameters, and the influence of mesoscopic parameters of different types of sand pebbles on macroscopic mechanical properties was analyzed. Studying the influence of both contact stiffness and friction coefficient on the macroscopic response of pebble, the conclusions could provide references for the numerical simulation of cobble tunnel excavation.
Simulation study on rock slope reinforced by anti-slide pile: a case study
Authors: Liu ZhongShuai , Xu Feng , Fu Yu , Kang Hong
Published: March 2020

For the collapse of bedding rock slope in Yuqian Expressway, by using simulation software FLAC-3D this paper established simulation models bedding rock slope before and after reinforced by combined supporting, i.e., “slide-resistant pile+ diagonal bracing wall+ anchor cable”, and collected parameters such as deformation and shear stress through three monitory points established. As simulation results compared with field monitoring data, bedding rock slope before reinforced was unstable, belonging pull-type failure model, and this failure model was sudden; the displacement contour map after the slope was reinforced by combined supporting showed that there existed one bigger shear zone in the rock interface, and the shear zone was disappeared after this slope was reinforced, then maximum deformation was decreased; the displacement vector map of slope showed that this slope slipped along the rock interface before it was reinforced, but the whole slope slid along one arc after it was reinforced; shear stress concentration phenomenon in the rock interface was disappeared obviously after this slope was reinforced. As monitoring deformation compared with simulation deformation, slope deformation was less; and the slope was stable; the reinforcement measure of combined supporting has the better retaining effects.
Study on calculation method of new corrugated steel reinforcement structure of highway tunnel
Authors: Yu Chengshuo , Ding Wenqi , Wu Tianxiang , Zhang Qingzhao
Published: March 2020

Corrugated steel, a new structure, shows great advantages in many fields, however, it is rarely used in the reinforcement of highway tunnels. Besides, corresponding design method and mechanical properties are still not clear yet. In this study, a full-scale test is carried out to explore the calculation method of corrugated steel as a new reinforcement structure. Combining with numerical simulation and theoretical calculation, the load-deflection law of corrugated steel is revealed, which has a two-stage stiffness characteristic (anti-backlash stage and elastic stage). Equivalent stiffness coefficient is proposed to establish a simplified calculation method of the equivalent stiffness of corrugated steel. And RDP (Ratio of Depth to Pitch) is the main factor affecting the equivalent stiffness coefficient.
Analysis and Evaluation of the Countermeasures for the Protection Measures of Subway Near-line Pipeline
Authors: Xu Weiping , Zhao Chuxuan , Hou Zonghao , Yuan Ziyi , Xiao Zhifei , Sun Keguo
Published: March 2020

With the rapid development of urban rail transit, engineering cases such as subway proximity pipelines are not uncommon, and it is increasingly important to take corresponding measures to protect existing pipelines. In this paper, the numerical simulation method is used to study the effect of protective measures on an underground pipeline. It is found that: (1) The maximum tensile and compressive stresses of the underground pipelines when they are not applied as protective structures are 0.719 MPa and 1.319 MPa, respectively. The maximum tensile and compressive stresses are located at the top and both sides of the pipeline; (2) the pipeline is not protected. The maximum vertical displacement of the structure is below the frame bridge, which is 2.42mm, which is less than the displacement control amount of 10mm. (3) The simultaneous protection structure and the sand pebble replacement layer have the largest reduction of stress and deformation, among which the stress The effect of controlling the replacement layer is better than that of the protective structure, and the control effect for the deformation is similar. The research results can provide theoretical support for the selection of underground pipeline protection measures, with technical guidance and reference.
Parameter optimization of corrugated steel initial support structure of mountain tunnel based on sensitivity analysis
Authors: Li Guofeng , Yu Chengshuo , Wang Xiaoming , Ding Wenqi , Zhang Qingzhao
Published: March 2020

New corrugated steel initial support in mountain tunnels, as a kind of assembly structure, can achieve purposes of rapid construction, green environmental protection. However, optimization design of corrugated steel initial support in mountain tunnels is seldom researched. In this paper, Qipanshan Tunnel in Yunnan Province is taken as engineering background. Numerical simulation calculation is carried out by ABAQUS. Combined with sensitivity analysis of tunnel convergence, internal force of corrugated steel and second liner, the design parameters of wave thickness, wave height and wave pitch of initial support of corrugated steel are optimized. Research shows that sensitivity analysis method can be applied well in the optimization of tunnel innitial support parameters. Effectively improving internal force of corrugated steel and secondary lining can be achieved by adjusting thickness of corrugated steel. Optimization effect of parameters of corrugated steel is more obvious in the RDP range of 0.333 ∼ 0.375.