bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of Random Variations of Partially Saturated Soils Properties on Site Amplification of Seismic Ground Motions
Authors: Xie Jiang , LI Dan 
Published: March 2020

Abstract
Based on the principle of random vibration and the Tajimi-Kanai spectrum model, a seismic model with a given magnitude and epicenter distance is used to simulate the seismic motion. For the random variation of soil properties such as shear modulus, mass density, damping ratio and saturation of partially saturated soils, it is assumed that the input seismic wave is SH wave. The random dynamic response analysis of the site is conducted by using the linear wave propagation method and the Rosenblueth method, and the digital features of the amplified power spectral density function, the acceleration power spectrum density, the mean value and the standard deviation are obtained respectively. In a numerical example, a clay ground is considered. For the random variation of soil properties and the different of incident angles, the digital features of the amplified power spectral density function, the acceleration power spectral density, the mean value and the standard deviation are analyzed. The results show that the random variation of quasi saturated soils properties and the different of incident angles have great influence on the site amplification effect.
Stability Evaluation of Concrete Structure Considering the Local Damage Using Nondestructive Detection and Numerical Analysis
Authors: Tan Xuyan , Chen Weizhong , Yang Jianping , Wang Luyu 
Published: March 2020

Abstract
Shield tunneling is one of the most important technologies for building of underground engineering. Many grouting holes were prefabricated for the requirement of backfill grouting, which is easy to induce local damages and potential disasters, such as leakage and cracking. Accordingly, an integrated workflow for damage detection and stability evaluation was performed based on nondestructive testing (NDT) and numerical simulation. As a case study, this method was applied to an underwater shield tunnel. Firstly, Ground Penetrating Radar (GPR) was used to detect the conditions in grouting holes. Then, the infrared camera was used to determine the damaged positions induced by grouting holes. According to NDT results, the numerical models were developed to analyze the mechanical behaviors of structure. It indicated the geophysical inversion results are consistent with field conditions. The influence area increases with a significant value of water pressure, and stress magnitude would increase to 45KPa if the increment of water pressure reaches to 10KPa. As a promising application, structure stability was evaluated in the light of analytical results.
The Study of Slope Protection with Gravel-Polymer Composite Porous Material
Authors: Xu Yi , Wang Jun , Wang Maomei , Zhao Gang , Xu Tianhang 
Published: March 2020

Abstract
In this study, strength reduction method, steady state analysis and transient analysis are used to simulate and compare the stability and permeability characteristic of bank slope in three different states: natural, slope protection with concrete and slope protection with gravel-polymer composite material. The result show that the slope with protective surface is more prone to shallow shear failure than the bank slope in natural state and their stability is reduced. For the bank slope of slope protection with gravel-polymer composite material, the appropriate thickness of the surface layer should be selected to give full play to the bending performance. In terms of permeability characteristics, slope protection with gravel-polymer composite material has good permeability and it is more difficult to destroy by percolation when the water level drops rapidly.
Effect of Quality and Replacement Rate on the Double Recycled Aggregate Concrete
Authors: Guo Yuanxin , Li Qiuyi , Yue Gongbing , Zheng Shidong , Wang Liang 
Published: March 2020

Abstract
Recycled aggregate can be used as a substitute for natural aggregate to produce good regenerated concrete, so the text use recycled coarse aggregate and recycled fine aggregate to substitute for natural aggregate with different replacement rates preparing double recycled aggregate concrete, and researching the effect of the quality and replacement rate of recycled aggregate on the mechanical properties of recycled aggregate systematically. The results show that the compressive strength of double recycled aggregate concrete is increased gradually with the improvement of the quality of recycled aggregate, and the effect from weak to strong is class I, class II and class III. On the other hand, the compressive strength of double recycled aggregate concrete is decreased gradually with the increase of the replacement rate of recycled aggregate, and the maximum reduction is up to 57.2%. Therefore, the simultaneous use of recycled coarse aggregate and recycled fine aggregate have an effect of “double weakening” on the compressive strength of recycled concrete, and it can be applied to the concrete products of low strength grade.
Study on Drying Shrinkage Deformation of Metro Lining Concrete
Authors: Gao Song , Wang Shouhui , Li Qiuyi , Yin Xianfeng , Zhou Guiyin , Guo Yuanxin 
Published: March 2020

Abstract
In metro engineering, due to the large amount of lining concrete pouring, it is easy to produce large shrinkage deformation in the maintenance stage, which leads to cracks in lining concrete and seriously affects the operation and safety of metro. Therefore, this paper adopts the test scheme of large dosage of mineral admixtures to compare and analyze the influence of the amount of cementing material, the dosage of mineral admixtures and the binder/water ratio on the dry shrinkage performance of metro lining concrete. The results show that the shrinkage ratio of lining concrete increases with the increase of cementitious material content or binder/water ratio, but decreases with the increase of the dosage of mineral admixtures. When the cement variety is P.I 42.5 and the dosage of mineral admixture is 40%, or the cement variety is P.I 52.5 and the dosage of mineral admixture is 50%, the shrinkage deformation of lining concrete is small, which can meet the needs of subway construction and will have a broad application prospect in practical engineering.
The Threshold Value of Effective Replacement Ratio of Fly Ash Mortar Based on Amount of Calcium Hydroxide
Authors: Liu Guibin , Guo Yuanxin , Li Qiuyi , Wang Liang 
Published: March 2020

Abstract
The effective mineral admixture in mortar can consume the calcium hydroxide produced by hydration reaction because of pozzolanic effect. For high volume mineral admixture mortar, when the replacement ratio exceeds a certain ‘threshold’ value, the supply of Ca(OH)2 amount is insufficient, the superfluous and ineffective mineral admixture will no longer react in mortar but as fine aggregate. This study presents an experiment study on the threshold value of effective replacement ratio of fly ash mortar by the comprehensive analysis of Ca(OH)2 amount and consumption curves. Under the conditions of different curing temperature, the effective replacement ratios of fly ash mortar have been determined ultimately. The results showed that Ca(OH)2 amount and consumption in mortar both decreased with replacement ratio. For fly ash mortar, at 20°C curing temperature, when the replacement ratio was less than 40%, the Ca(OH)2 amount decreased obviously with replacement ratio. However, when replacement ratio was more than 40%, Ca(OH)2 amount at 91d changed slightly with replacement ratio, the Ca(OH)2 amount was consumed to a limit value at this time. Under the condition of 30°C curing temperature, when the replacement ratio exceeded 30%, the change of Ca(OH)2 amount with replacement ratio was close to a straight line, the superfluous fly ash no longer consumed Ca(OH)2 basically. Moreover, the consumption of Ca(OH)2 was not much difference to the Ca(OH)2 amount at the same replacement ratio under the condition of 20°C curing temperature. This result has a great significance on effective utilization of mineral admixtures in engineering application.
Research on Dynamic Perception Algorithm for High Speed Maglev Track Irregularity
Authors: Ding Sansan , Jiang Fujie , Sun Xiangdong , Huang Jingyu , Li Dongshuai , Li Huibai 
Published: March 2020

Abstract
The high-speed maglev track irregularity is an important factor affecting the safety and stability of high-speed maglev trains. Based on the basic principle of high-speed maglev vehicle orbit, the deep neural network is used to establish the relationship between the vibration acceleration of the vehicle body and the track irregularity, so as to realize the real vehicle detection of the track irregularity. The results show that the relative error of the prediction of the track irregularity by the deep neural network is 6.04%, which basically meets the actual measurement requirements in the project. At the same time, it is demonstrated that the model with 8 input nodes has higher prediction accuracy and the high-speed maglev track is not smooth. Measurement provides theoretical support.
Studies on Vibration Response of the Continuous Girder Highway Bridge under Horizontal Multi-Vehicle Loads
Authors: Chen S S , Luo H , Song Y 
Published: March 2020

Abstract
In order to study the vibration response of continuous girder bridges under horizontal multi-vehicle loads, we used ANSYS to build the three-dimensional solid finite element model of continuous girder highway bridge, simulated three-axis self-dumping truck by three-dimensional models, and considered the impact of road roughness to establish the multiple vehicle-bridge coupled vibration equation. We studied the vibration response of bridges under the horizontal two-vehicle, longitudinal two-vehicle and single-vehicle conditions by running MATLAB program. The result shows that the impact coefficients of the bridge under horizontal two-vehicle condition are close to that of single-vehicle condition, and the impact coefficients of the bridge under longitudinal two-vehicle condition fluctuate around that under single-vehicle condition. The vibration response of the bridge under multi-row vehicle loads is related to various factors such as vehicle velocity, bridge span, vehicle spacing, and the quality level of the bridge surface.
Construction Quality Evaluation Framework of CRTS I Double-Block Ballastless Track Applied in Chinese High-Speed Railway: Based on AHP and Fuzzy Extension Element-Matter Model
Authors: Chen Huihua , Li Na , Li Hujun , Mei Min , Tang Rujia 
Published: March 2020

Abstract
The construction quality of CRTS-I double block ballastless track (CRTS-I-DBBT) is the basis of ensuring the comfort, safety and durability of high-speed railway, which helps to promote sustainable development of high-speed railway. This research constructs a quality evaluation framework for CRTS-I-DBBT construction. AHP and Fuzzy Extension Element-matter model were integrated to evaluate the construction quality of CRTS-I-DBBT. Besides, empirical research was carried out to test the applicability of the proposed evaluation system. Besides, the evaluation system will have a wide range of applicability and it will help facilitate the maturation of high-speed railway ballastless track construction quality management.
Intelligent Integral Improvement Technology of Double Block Sleeper Production Line of Zheng-wan High-Speed Railway
Authors: Wang Minghui , Wang Jian , Zhang Qiao 
Published: March 2020

Abstract
Double block sleeper is an important part of high-speed railway. Relying on the sk-2 double-block sleeper production line of Chongqing section in Zhengwan high-speed railway, a set of intelligent integrated lifting sleeper production technology system is designed and put into use. The system provides a safe operation platform for the operators to ensure the production schedule, reduce labor intensity, save costs, improve economic benefits, and has great promotion value.
Stability Analysis of Hollow Thin-Walled High Pier Curved Bridge Without Diaphragms
Authors: Xiang Musheng , Wang Ge , Peng Longfan 
Published: March 2020

Abstract
As the height of bridge increases, more and more high piers are designed with diaphragms to ensure their stability. However, the insertion of the diaphragms will have a significant impact on the speed and efficiency of the pier construction. For the stability problem of hollow thin-walled high piers, the numerical simulation of the model with or without diaphragms is carried out to compare and analyze the force mode, ultimate bearing coefficient and deformation characteristics of high pier of curved bridge from the perspectives of full bridge buckling analysis, high pier integral stability and high pier local stability in this paper. Studies have shown that the effect of installing concrete diaphragms on the stability of such single hollow thin-walled high piers is not obvious. If the wall thickness of the high pier meets the requirements for strength and stiffness and the theoretically calculated maximum allowable width-to-thickness ratio, the long-span continuous rigid frame curved bridge high piers may not be provided with diaphragms.
Numerical Analysis of Wind Loads on Bridges in Sandy Environment
Authors: Jia Ying , Zhan Mei , Zhang Yahui 
Published: March 2020

Abstract
Based on the Euler two-phase model, sand is regarded as a flowing fluid. In the numerical analysis, the sand is simulated as two-phase flow. Wind load variation on the windward side of the bridge under the wind-blown environment is analyzed numerically. Wind load variation on the bridge is studied when the flow velocity, particle size, and sediment concentration are different. This paper’s wind load numerical analysis is compared with the wind load calculated in the Code for Wind Resistance Design of Highway Bridges. Results show that the effect of sand load under wind and sand environment cannot be ignored.
Research on the Application of Full Space Support Construction Technology in Frame Bridge Construction
Authors: Chen Tao 
Published: March 2020

Abstract
The cast-in-situ construction of full space support is a traditional beam bridge construction method. Because of its advantages of simple structure, convenient disassembly, assembly, and transportation, etc., the construction technology of full space support is applied more and more widely. The control of support erection in the construction process plays a key role in the formation of the bridge. Based on the practical experience, this paper makes a detailed study on the construction technology of cast-in-situ bowl-buckle full space support.
Feasibility Study on Application of Full Depth Asphalt Pavement in National Trunk Road
Authors: Yan Xiangpeng , An Ping , Wu Wenjuan , Wang Lin , Wei Jincheng 
Published: March 2020

Abstract
Axial load spectrum survey was carried out on site, and the analysis and calculation of the structure design of full depth asphalt pavement was carried out according to the actual traffic volume. The permanent deformation of the asphalt mixture layer, fatigue cracking of the asphalt mixture, inspection and analysis of design indicators were verified. The test road was paved, and the feasibility of the application of the full depth asphalt pavement in the national and provincial roads was verified through the comparison between the actual measured deflection and the theoretical calculated deflection. The results show that the traffic load level of ordinary national and provincial roads reached the heavy traffic level. The service life of full depth pavement structure calculated can reach more than 40 years. And the designed service life of permanent deformation can reach more than 15 years. The actual measured deflection of the test road satisfies the calculated deflection values of both the subgrade top surface and road surface. The full depth asphalt pavement structure is applicable to national and provincial trunk lines under heavy traffic load conditions.
Study on Dust Movement in Long Tunnel during Blasting Period
Authors: Wang Qingbiao , Ren Guohui , Shi Zhenyue 
Published: March 2020

Abstract
In order to solve problems raised tunnel ventilation and dust removal, grew up in this paper, the tunnel blasting dust migration rule, through theoretical analysis, experiment on site and numerical simulation of the synthetic study method, study of phase grew up in the tunnel blasting dust migration rule, the conclusion is as follows: (1) Based on fluid mechanics, mechanics of elasticity theory, and combining the fick’s second law, in the initial conditions and boundary conditions, that along the longitudinal tunnel dust unsteady diffusion distribution; (2) The experiment found that the dust concentration decreased gradually with the increase of ventilation time, and the dust accumulated with the increase of distance from the palm surface. The dust in the same section was mainly distributed in the arch waist and below, with obvious stratification. (3) By comparing the numerical simulation with the field monitoring data in FLUENT, the accuracy of the numerical simulation results was verified, which provided theoretical guidance for tunnel construction and dust removal design.
Numerical Experiment for Support Effect of Umbrella Arch in Tunnel
Authors: Wang Yuwen , Hu Zhao , Xie Yongli , Wang Chao , Hua Kaicheng , Lai Jinxing , Lai Hongpeng 
Published: March 2020

Abstract
Umbrella arch is often used as pre-support for shallow tunnel and poor surrounding rock. To evaluate the support effect quantitatively, 12 cases by numerical analysis were used to study the effect of cover depth and condition of surrounding rock on the support effect of umbrella arch. Load percentage of umbrella arch was proposed to evaluate the effectiveness of umbrella arch. The umbrella arch could not work when the percentage was less than 50%. When the surrounding rock was poor and the shallower the cover depth, the better the support effect.
Research on Surface Settlement of Subway Station Construction Using Pile-Beam-Arch Approach
Authors: Xu Yushan , Tang Bo , Duan Yanwei 
Published: March 2020

Abstract
The pile-beam-arch (PBA) approach is illustrated as a creative construction method in shallow-buried tunneling excavation of subway construction. Attentions have been paid to this method due to its unique advantages of construction technology. Subway station construction by using PBA approach will make disturbance to the ground surface. Research on surface deformation caused by PBA approach is of great significance to the surrounding environment and its structure. The example of subway construction in Beijing is presented as the research background, a three-dimensional model is established by using the Midas-GTS finite element numerical simulation software to simulate the practical excavation support conditions, and to analyze the surface settlement, the initial support structure settlement and crustal stress caused by PBA construction method.
Research on Assembly Waterproofing Technology of Prefabricated Utility Tunnel
Authors: Li Liangcheng , Lu Tian , Jia Rubin , Li Yuanyuan , Zhou Wenyan , Khater Ahmed , Luo Dong 
Published: March 2020

Abstract
Prefabricated utility tunnel is the key development direction of urban infrastructure in the future because of its greater advantages of quality, construction period, cost and other aspects, compared with cast-in-place method. For prefabricated utility tunnel, both of joint type and waterproofing construction could directly affect its function and normal operation. This paper introduces main types of prefabricated utility tunnels, and compares the performance of frequently-used waterproof materials. Meanwhile, the existing waterproof projects in prefabricated utility tunnel are summarized and analyzed, and the development trend of assembly waterproofing technology in the future is prospected based on the above research.
Study on the Layering Length in a Railway Tunnel with Semi-transverse Extraction Ventilation
Authors: Tu Jiachao , Bi Haiquan , Wang Honglin 
Published: March 2020

Abstract
In this study, the long-distance subway tunnel in Qingdao of China adopted semi-transverse extraction ventilation is taken as the research object. STAR-CCM+ software is used to simulate the smoke movement status and study the influence of different exhaust volumetric flow and heat release rates on the smoke layering length in tunnel with the semi-transverse extraction ventilation. Results show that the layering length has a linear decreasing relation with the natural logarithm of the exhaust volumetric flow under different heat release rates. There is opposite relation between the layering length and the natural logarithm of the heat release rate. Based on dimensional analysis and numerical simulations, the prediction model of the layering length and the critical exhaust volumetric flow in tunnel with semi-transverse extraction ventilation is proposed.
Numerical Simulation Analysis on the Supporting Effect of Different Pre-reinforcement Methods in Portal Section of the Shallow Buried Soft Rock Tunnel
Authors: Shi Shaohua 
Published: March 2020

Abstract
The surrounding rock of shallow buried soft rock tunnel has already been weathered severely, which has a large number of fracture zone, so construction of these tunnel projects is difficult and risk. The tunnel is vulnerable to deformation and collapse during the construction especially in the portal section, so certain advanced support must be used to ensure the tunnel excavation smoothly. Base on the Xikema no.1 tunnel engineering, the numerical simulation using finite difference software (the FLAC3D) was conducted in this paper to model different excavation with pipe-roof and double-row small duct advanced support in the portal section. Some meanful conclusions are drawn by comparative analyzing the support effects of pipe-roof and double-row small duct through stress, displacement, plastic zone of surrounding rock, and inner force of primary support, such as follows: (1) Pipe-roof or double-row small duct advanced support and surrounding rock can form into a complex well, which play a role of load-bearing arch. The complex effectively reduce the disturbance of upper rock, and commendably control the relaxation of surrounding rock in the vault, but for arch feet and arch bottom the control effect is not ideal. (2) Pipe-roof or double-row small duct advanced support make primary support and surrounding rock of tunnel face only beared the deformation pressure caused by the deformation of complex, effectively improve the safety of primary support and tunnel face. The research result will be useful for the design and construction of the pre-reinforcement measure to the project associated.
Numerical Analysis And Research of Entrance Slope of Shallow Buried Karst Tunnel
Authors: Zhong Tao , Ma Qun 
Published: March 2020

Abstract
Based on practical engineering condition of Highway karst tunnel, ANSYS was used to numerical simulate the slope of the tunnel in the entrance, and the result was used to compare with monitoring measurement result. The numerical simulation results showed that the bottom karst cave has a big influence on arc bottom of the tunnel after the excavation. The most influenced part is vault, with 2 times tunnel diameter influence area to the tunnel. At the first 35 m of excavation, there is a relatively greater influence to slope, and measures should be taken; after 35 m of excavation, there is little influence to slope. The result can be a reference to the design, construction and research of the tunnel.