bluuebunny/crossref_metadata_2025_split huggingface dataset:
Analysis on dynamic change of vegetation coverage in coastal wetland of Yellow River delta
Authors: Jin Kangkang , Fan Jinshan , Zhao Xuan , Zhang Peng 
Published: March 2020

Abstract
How to efficiently use multi-source remote sensing images to extract the coastal wetland vegetation landscape information of the Yellow River Delta, and provide scientific basis for wetland protection, utilization and ecological restoration, is of great significance. In this paper, the vegetation coverage of Landsat TM/OLI remote sensing images from 1984 to 2018 is dynamically monitored, and the remote sensing images are analyzed using NDVI and pixel dichotomous models. The conclusions are as follows: From 1984 to 2018, the coverage of vegetation in the northern part of the Yellow River Delta is relatively low, and the coverage of vegetation in the south due to agricultural development is high; Over the past 30 years, the vegetation coverage area of the Yellow River Delta has shown an overall upward trend, and the area of low vegetation coverage areas has declined significantly, decreasing by 19.64% from 1984 to 2018. For the study of the Yellow River Delta coastal wetland, the methods used include the NDVI and pixel dichotomy model, and the results obtained are consistent with the facts, which can help the local ecological protection or soil and water conservation.
Effect of Acid Rain Pollution on Durability of Reinforced Concrete Structures
Authors: Yong Ding 
Published: March 2020

Abstract
In order to solve the problem of insufficient accuracy and effectiveness of the current analysis model of the durability of reinforced concrete, the corrosion process of concrete by acid rain and the corrosion process of steel bars by acid rain are analyzed; based on the acid rain corrosion process, the structure of reinforced concrete composite beams under acid rain erosion Carbonization depth of medium concrete; Corrosion depth of reinforced concrete composite beam structure was obtained by carbonization depth; Durability index was calculated by carbonization depth and corrosion depth. It is suitable for analysis of the influence of acid rain pollution on the durability of reinforced concrete composite beam structures.
Marine Pollution of Ship Domestic Waste and Countermeasures
Authors: Zhang Rongjun 
Published: March 2020

Abstract
Ocean is the natural environment for human survival and development. The exploitation and utilization of marine resources is one of the main methods to solve the pressures of the world's population, resources and environment. Moreover, the development of marine resources put forwards an important problem for mankind to prevent marine pollution, the various domestic waste produced by various ships in the ocean is one of the important sources of marine pollution. Therefore, preventing marine pollution caused by ship domestic waste, studying and formulating reasonable antipollution countermeasures, which has great practical significance for maintaining the sustainable development of the marine environment. For this reason, this paper analyzes the marine pollution caused by marine domestic waste, and proposes a waste recovery ship based on trimaran technology for recycling ship domestic waste.
Application of FCTEM60-1 Instrument in Invert Rebar Testing for Highway Tunnel
Authors: Liu Qiuzhuo , Wang Yao 
Published: March 2020

Abstract
The invert of a highway tunnel is the foundation for the entire tunnel structure. Its quality has a direct influence on the stability of tunnel structure. However, in practice the tunnel invert has various defects for a variety of reasons. FCTEM60-1 instrument is able to rapidly cut off the current using constant voltage clamping technique, thus significantly reducing the shallow dead-zone effect of transient electromagnetic (TEM). In this study the instrument is applied to testing invert rebar execution in a highway tunnel. The study result shows FCTEM60-1 instrument successfully detected the invert rebar, demonstrating its feasibility and reference value to tunnel quality test.
Numerical Modeling of the Strata Deformation During Tunnel Excavation Based on Discrete Element Method
Authors: Cao Peng , Wu Mengjun , Fang Lin , Chen Shouchao 
Published: March 2020

Abstract
The construction of transportation infrastructure is transferring from ground to underground, which could evacuate the urban traffic and is also the future trend of the expansion of our cities. The cobble stratum brings about many technical problems in the underground engineering. Based on the calibration test and macroscopic mechanical characteristic curve, the microscopic calculation parameters of particle flow code simulation used for cobble strata in Urumchi were determined. According to establishing the numerical model of pebble tunnels using double-side-drift method, both the ground deformation and force chain evolution were analyzed for the tunnels using subsurface excavation method. This manuscript presented the differentiation of influence on ground deformation in cobble stratum under different excavation stages, the influence extent was ranked as follows, upper bench > double-side-drift > lower bench; the result of numerical simulation test was compared with the field monitoring data, proving that it is reasonable to adopt the particle flow code to simulate the excavation of pebble tunnels, and the research result could be provided for reference for the similar engineering.
Reinforcement Analysis of Bifurcated Highway Tunnels with Large Section of Different Surrounding Rock Grades in Tiger Leaping Gorge
Authors: Zhou Dong , Ding Wenqi , Xie Dongwu , Chen Shuwang 
Published: March 2020

Abstract
In order to analyse the reinforcement effect of tunnels with different surrounding rock grades in Tiger Leaping Gorge, a three-dimensional tunnel model was established. The effects of surrounding rock parameters and bolt supporting on the displacement and tension strain disturbance zone of surrounding rock were explored. The numerical results of tension strain and displacement show that the improvement of surrounding rock stability is limited by reinforcement measures, and the change of tension strain disturbance zone is also small when the rock is intact. However, when the surrounding rock is relatively fragmented, the range of tension-strain disturbance zone and displacement of the cave are very large. After strengthening, the range of tension-strain disturbance zone is reduced by 61.5%. Comparing the displacement of vault and arch waist, it can be seen that the displacement of cave in grade V surrounding rock is larger, the vertical displacement of vault is 3.5 times higher than that of grade IV surrounding rock, and the horizontal displacement of large section in arch waist is 58.63 mm, and it has great influence on the stability of tunnel. The displacement value of vault and arch waist reinforced in grade V rock is similar to that of tunnel without reinforcement in grade IV rock.
Seismic and sealant behaviour of segmental joint gaskets in shallow immersed tunnel
Authors: Wu Weifeng , Ding Wenqi , Ge Shiping , Lu Xingbang , Zhao Tianchi 
Published: March 2020

Abstract
Joint gaskets of the immersed tunnel are critical for the seismic safety of the immersed tunnel. In this study, a rigorous numerical model of rubber gaskets is conducted and validated against experimental results. Then, the model is used to estimate the mechanical and water tightness behaviour of three types of gaskets. Finally, a coupled nonlinear soil-structure interaction beam-mass-spring model is developed. The joints are simulated with the nonlinear hyperelastic elements following obtained load-deformation of three gaskets. The hydrostatic installation is modeled properly, then the seismic excitation is fired on bedrock. Finally, the results are discussed in the aspects of joint deformation and water tightness during the seismic loading.
Study on Section Selection of Super Large Oil Storage Tunnel Based on Strength Reduction Method
Authors: Xiang Liang , Wang Fei , Kong Chao , Zou Zaiyan , Zhang Huijian 
Published: March 2020

Abstract
To study the section selection of super large oil storage tunnel could help make full use of underground space and arrange tunnels reasonably. The stability of tunnel with three different section (horseshoe section, circular section, elliptic arch section) was studied using the strength reduction method by finite difference element software. The FoS evolution with depth was discussed and the limiting failure state of tunnel were observed with the depth. The results indicated that the stability of different section are basically the same, because of the surrounding rock conditions are good. Cost and space utilization can be the main factors in the section selection.
Study on deformation law of double-line shield tunnel obliquely crossing underneath existing municipal tunnel
Authors: Qi Xingxin , Qiu Wenge , Gao Ganggang , Zhou Zhenghao , Deng Zhiheng , Zhao Hailin , Wan Shifu , Huang Qiming 
Published: March 2020

Abstract
This paper mainly relies on the project of Hangzhou Metro Line 5 obliquely crossing underneath Zijingang Road Tunnel. The paper analyzes the influence of the shield position on the vertical displacement and torsion of the existing tunnel. Grouting pressure and stratum reinforcement conditions are also considered. And find the law of the influence of various construction technical parameters on deformation under different excavation stages. Then give corresponding advice for the project and provide guidance and reference for similar projects in the future.
Three-dimension numerical analysis of large-span bridges’ pile foundation adjacent to an existing tunnel
Authors: Sun Keguo , Xiao Zhifei , Liu Xu , Hong Yiqin , Hou Zonghao 
Published: March 2020

Abstract
In the process of urban transportation construction, it is inevitable that the new bridges will be adjacent to the existing tunnels. According to the spatial relationship between the new bridge and the existing tunnel, a three-dimension finite differential model of the pile-tunnel interaction is established by a numerical simulation method. The influence of the upper load of the new bridge on the adjacent tunnel is simulated, with the results of the numerical simulation method and the Boussinesq method are compared. It is found that the results of numerical simulation are verified by the Boussinesq method, with the deviation less than 10%. Moreover, the horizontal deformation of the tunnel is central-symmetrically distributed, and the symmetrical point of the horizontal deformation and the position of maximum vertical deformation are both near the midpoint of the two cushion caps. Besides, the deformation of the tunnel is mainly vertical. Last but not least, the influence of the construction and operation of the pile foundation of the bridge on the rails in the existing tunnel meets the control criteria. Therefore, the methods of analysis and parameters in this paper can provide a reference for similar projects.
Study on the Characteristics of Flow Field and Gas Migration in Gas Tunnels
Authors: Cao Zhengmao , Liu Xiao 
Published: March 2020

Abstract
In order to improve the ventilation efficiency and gas dilution effect in the gas tunnel, the main source and formation mechanism of the gas in the tunnel were analyzed, and the hydrodynamic calculation model is established for the gas tunnel ventilation with the auxiliary vertical shaft. The k-ε two-equation turbulence model was used to simulate the ventilation effect under different wind velocity, the flow field distribution characteristics and gas migration regularity under the auxiliary ventilation conditions were obtained. The results indicate that the internal space of the tunnel can be divided into different zones in the longitudinal direction according to the distribution characteristics of the flow field in the tunnel. The distribution of gas concentration in the tunnel is closely related to the flow field characteristics of each zone. The ventilation of the gas tunnel must meet both the requirements of the gas concentration dilution and the cross section wind velocity. When the cross section wind velocity is greater than 0.5m/s, the airflow reaches full turbulence state in tunnel. There is obvious effect on eliminating accumulation of gas at the top of the tunnel by the cross section wind velocity controlling. Under the condition of cross-section wind velocity is 0.5∼1.0m/s, the methane zone is prone to accumulate at the top of the tunnel, which can be diluted when the cross-section wind velocity is greater than 1.0m/s.
Monitoring Study on Dust Diffusion in High Altitude Tunnel under Drilling and Muck Removal Conditions
Authors: Nima Zhuoma , Hu Xuebing , Chen Jianzhong , Yuan Ye 
Published: March 2020

Abstract
In the high altitude area, the air density and the air pressure are low. In this paper, combined with a high altitude tunnel engineering in Tibet, the dust concentration during the drilling and muck removal was monitored, and tunnel dust diffusion situation was analyzed. The result shows that the dust concentration on the middle line of tunnel is higher than the dust concentration at the tunnel side. The dust concentration near the tunnel face is the highest. In the longitudinal direction, the change rule of the total dust and respirable dust concentration, are totally the same. With the increase of distance from tunnel face, dust concentration declines rapidly, then gradually become stable. The dust diffusion rule in the process of muck removal is basically similar to that of drilling process, but the dust concentration is larger, and the concentration of respirable dust accounts for a higher proportion than that in the drilling operation.
Study on influence partition of tunneling adjacent to multi-storey building in upper-soft and lower-hard stratum
Authors: Rui Zhu , Yujie Yang , xiaoyu Niu , Huijian Zhang , Hongbo Guo , Wenge Qiu 
Published: March 2020

Abstract
Based on several examples relating to tunneling near the multi-storey building in Qingdao Jiaozhou bay tunnel connecting engineering, the study on influence partition of tunneling adjacent to multi-storey building has been conducted by the finite element strength reduction method. The safety factor of 2.0 was defined as the boundary of the strong to weak influence zone, and the peak safety factor was considered as the boundary of weak to none influence zone. Based on the distribution of safety factors in three cases with relative scale of 2, 1, 1/2, and considering the convenience use on site, a influence partition map of tunneling to the existing multi-storey building in upper-soft and lower-hard stratum has been proposed.
The numerical analysis of the cross passage of large diameter shield tunnel beneath the river
Authors: Chen Biguang 
Published: March 2020

Abstract
The construction of the cross passages of twin shield tunnel is confronted with high uncertainty and huge risk. Ground freezing method is widely used for passages excavation in sandy ground condition when the tunnel is under the water. Earlier studies usually concerned the effectiveness of the freezing program, such as the space between the the freezing pipes or the temperature variation in the frozen soil. In this paper, the structure force of the cross passage of a large diameter shield tunnel beneath the river is discussed. A 3-dimensional numerical method is described to calculate the stress of the frozen soil and the internal force of the cross passage lining. The critical situations in construction and operation phases and the key mechanical parts are recognized. The safety of the design scheme is checked.
Study on Traffic Organization around Pivotal Tunnel Entrance/Exit
Authors: Jiang Xinghong , Li Ke , Cui Xiangyang 
Published: March 2020

Abstract
With increasing pressure on above ground space and surface traffic, more and more cities choose to construct underground transportation junction to speed up traffic and improve travel efficiency. This paper covers survey and VISSIM simulation of vehicles at the entrance and exit of an in-progress tunnel at Zengjiayan, Chongqing. The results show: during construction of the pivotal tunnel, the entry of trucks to the construction area near the “left-in left-out” entrance and exit will significantly affect traffic on the artery where the tunnel is located; the flow line scheme under which trucks change lanes in advance at the entrance to the construction area is optimal. In addition to optimization of entrance and exit points, traffic organization around the tunnel during construction should be optimized to mitigate traffic pressure on the artery where the tunnel is located.
ShenZhong Passage (Island-Tunnel) Project – Refined Exploration Technology and Management
Authors: Liu Jian , Xia Fengyong 
Published: March 2020

Abstract
For Shen-zhong Link project with two islands and a tunnel, the survey process is in full compliance with international standards. The large-scale survey equipment with international advanced level (offshore power head drilling platform, support drilling platform) is used to carry out survey operations and tests in accordance with international standards, so as to minimize the disturbance to the undisturbed samples. Various in-situ test and indoor test methods are used to carry out all-round and multiple means for rock and soil layers. The results of the investigation are better than that of the conventional investigation and have been verified in the implementation of the island and tunnel project. Experience of this survey is helpful to promote the fine geological survey in China.
Summary of the Development of New Technologies for Submarine Immersed Tunnel Foundation Reinforcement and Settlement Control
Authors: Fu Bai-yong , Chen Wei-le , Xu Guo-ping , Song Shen-you , Xia Feng-yong 
Published: March 2020

Abstract
Based on the immersed tunnel foundation improvement modeling and analysis of data through investigations and researches on immersed tunnel diseases at home and abroad, this paper proposes that the adverse loads and poor geology are main causes inducing settlement and diseases. On top of the review on technical innovations in typical immersed tunnel foundation improvement abroad, the innovation and advancement of immersed tunnel foundation improvement of Hong Kong-Zhuhai-Macao Bridge Project is introduced with emphasis and these technical innovations mainly comprise the technology of double-layer bed with both rigidity and flexibility, the technology of SCP(Sand Compaction Piles) plus surcharge loading in ground improvement, the settlement computation method based on CPTU of rebounding and recompression and determination of settlement control criteria and others new development. Furthermore, through analysis the corresponding foundation improvement countermeasures are provided in this paper to meet such construction challenges faced in the immersed tunnel foundation improvement of Shenzhong Link and those challenges are super-wide width varied immersed tunnel element, soft soil ground of sand pit, weathered rock softening in water, sandy soil liquefaction, intense siltation. Finally, as the State key study and development program, it is pointed out that the technical study on diseases inducing mechanism and corresponding pro-active prevention and control of submarine immersed tunnel founded on poor ground conditions shall be carried out based on the full consideration of interactive actions between the structure and its foundation and the technical route and main study contents are further proposed for reference of relevant technical professionals.
Analysis on Application Effect of Prestressed Anchor Cable in Large Span Tunnel
Authors: Li Ke , Jiang Xinghong 
Published: March 2020

Abstract
Safety is the top priority during the construction process, the construction risk increases sharply with the increase of section size. Bifurcated tunnel structure is adopted in the entrance portal section of Bibanpo tunnel. The span of transition section reaches 25.79m (type A) and 22.11mm (type B), To ensure safety, a new support method of pre-stressed anchor was used. during the construction, we monitored the structure stress of primary support, and the tension stress of pre-stressed anchor cable, and we get that: the pre-stressed anchor cable on hence can support quickly, prevent plastic zone from deepening, decrease the load of primary support structure, especially the load of shaped steel. Through engineering practice, it can be concluded that pre-stressed anchor is an effective active support method. The successful application experience in Bibanpo tunnel is of great significance for similar projects.
Study on Deformation of Shallow Buried Underground Pipe Gallery
Authors: Xie Junfei , Huang Nenghao , Feng Jiajia , Zhang Gen 
Published: March 2020

Abstract
The underground pipe gallery is a symbol of modernization and intensification of urban construction. Domestic research on the deformation of underground pipe gallery started late and has not yet formed a unified standard. Based on the deformation requirements and deformation control standard of the internal pipeline of the pipe gallery, the longitudinal deformation control standard of the integrated pipe gallery is preliminarily established. The main conclusions are as follows: Based on the deformation requirements of the underground pipe gallery, the equation for calculating the allowable value of the longitudinal radius of curvature of the pipe gallery is proposed. Comparing the safety standards of various types of inlet pipelines, the longitudinal deformation allowable value of the pipe gallery is given. At the same time, the influence of surface load on the deformation of pipeline gallery is analyzed by theoretical analysis and model test, and the theoretical and experimental results are compared. The results indicate that theoretical calculation features accuracy and practicality.
Research on Assessment of Highway Tunnel Operating Safety
Authors: Chen Siyang , Xia Yangyuyu , Ma Fei , Liao Haomiao 
Published: March 2020

Abstract
The operating safety of highway tunnels is governed by a complex system of people-vehicle-tunnel-environment and influenced by many factors. Its assessment is complex and unique to the specific tunnel. In this paper we discuss the assessment of the operating safety of highway tunnels from three aspects of rating, risk evaluation and resiliency, and propose the concept of operating safety resiliency of highway tunnels. We also summarize prior research in these aspects and analyze advantages and disadvantages of each assessment method.
Web Crawler Based Study on Traffic Accident Data Acquisition for Operating Tunnels
Authors: Liao Zhipeng , Ding Hao , Xia Yangyuyu , Ma Fei 
Published: March 2020

Abstract
With constant development of tunnels, traffic accidents in the tunnels continue to rise. To control and manage tunnels and reduce traffic accidents. Based on Web crawler technology, this paper, based on Web crawler technology, covers research on traffic accident information characteristics for operating tunnels and Web crawler mechanism to establish a PySpider-based Web platform for real-time acquisition of traffic accident data for operating tunnels. This platform can fetch valid traffic accident data URL for operating tunnels from designated websites and to extract, analyze and store traffic accident feature data, thereby managing and controlling traffic risks existing in an operating tunnel, reducing traffic accidents and safeguarding people’s properties.