bluuebunny/crossref_metadata_2025_split huggingface dataset:
Numerical analysis of reasonable distance between tunnel faces for twin tunnel
Authors: Li Changgui , Zhao Junbo , Hu Juan , Ju Xiuying , Tian Xiaoxu 
Published: February 2021

Abstract
Based on the MIDAS-GTS numerical analysis platform, the construction characteristics of the left and right holes of the newly-built twin tunnel with a large section and a small distance were systematically analyzed, and the evolution laws of the displacement changes of the tunnel and the mid-rock pillar under the left and right full-section tunnel method were studied. The results show that: (1) with the increase of the lag distance, the surface settlement decreases gradually. When the lag distance is greater than 2.0D, increasing the lag distance has little effect on the maximum settlement value. (2) The maximum value of the surface settlement trough occurs between the left and right tunnels, which is the superposition area affected by the two tunnels. (3) The increase of lag distance has little effect on the final horizontal displacement of arch waist and mid-rock pillar. Considering that the influence range of face excavation on the surrounding rock of the tunnel is within 15m, the lag distance should not be too large and should not be less than 15m. (4) With the decrease of the lag distance, the superposition effect of the twin tunnel becomes more and more obvious. With the increase of lag distance, this phenomenon begins to weaken obviously, and obvious separation phenomenon appears.
Particle flow analysis of basalt fiber gabion slope under conditions of rapid drawdown of water level
Authors: Fan ZHU , Zhenxue ZHU , Chao SU , Jianjian DAI , Heng ZHANG , Yujun MA 
Published: February 2021

Abstract
As a new green material, basalt fiber has the advantages of high strength and corrosion resistance, and is an ideal material for ecological protection technology. The rapid change of the hydraulic gradient within the slope caused by the sudden drop of river water level is an important factor inducing bank slope instability. Studying the stability of gabion slope protection under this condition is the key to evaluating the effect of gabion support. Taking a basalt fiber gabion slope protection project as an example, this paper carried out the stability study of the gabion slope protection under the condition of sudden drop in water level and compared it with the original slope. The stability was analyzed from the perspectives of deformation and stress, and revealed The deformation mechanism and the beneficial effects of the gabion structure during the instability failure process of the original slope. The results show that under the condition of a sudden drop in river water level, the use of gabion support from the left side of the slope to the slope surface can improve the stability of the slope, and there will be no continuous sliding surface in the slope, and the failure of gabion appears as partial dislocation and separation phenomenon. The research results provide important reference value for river gabion slope protection design and stability evaluation.
Simulation analysis of mechanical properties of shear connectors of steel-concrete composite beams
Authors: Fan Xin , Wu Jiong 
Published: February 2021

Abstract
In order to further study the mechanical properties and development distribution of shear connectors of steel-composite beam under the influence of concrete shrinkage and creep. In this paper, on the basis of the existing experimental research, ABAQUS software is used to establish the steel-composite beam model. The structural forms of the model include simply supported beam and continuous beam, and the shear connectors of steel-composite beam include three types: stud connectors, PBL connectors and composite connectors. The time development and spatial distribution of vertical displacement, connector shear force and slip at interface of each composite beam with concrete creep are calculated by finite element software, and some calculated results are in good agreement with the existing test results. By comprehensively comparing the calculation results of the key sections of each composite beam at some time points, the mechanical properties and their respective applications of the shear connectors of the steel-composite beam are analyzed and summarized, and the research results can guide the design and engineering application of the shear connectors of the steel-composite beam.
Comparative study on compressive and uplift load tests of PHC pipe pile
Authors: Ding Jihui , Zhang Cong , Gan Yu , Zhang Jinlei 
Published: February 2021

Abstract
There are 5∼8 m thick non self weight collapsible loess in the project site of a power plant. In order to study the bearing relationship between compressive and uplift piles in loess site, static load tests were carried out on PHC pipe piles with diameter of 400 mm and 500 mm and pile length of 12 m. Under the same pile top load, the displacement of uplift pile top is greater than that of compression pile top. Based on the measured load displacement curve, the uplift bearing capacity of PHC pipe pile with pile diameter of 500 mm is 32.5% higher than that of pile diameter of 400 mm. When the pile diameter is 400 mm and 500 mm respectively, the ultimate bearing capacity of PHC uplift pile is 26.24% and 27.70% of compression pile respectively. GM (1,1) model of grey system can fit and predict the load displacement curve of PHC pipe pile under compression and pull-out. Compared with the measured results,the relative error of GM (1,1) model of grey system is larger in the previous stages of load, and decreases gradually with the increase of load.
Layered soil exploration based on the time domain spectral induced polarization method
Authors: Li Xin , Chao Manni , Ju Lei , Wang Junlong , Zhang Kai , Wang Jiancheng 
Published: February 2021

Abstract
Soil stratification is the basic problem of soil development and utilization in the farmland, which can be used as a reference for later development and planting. Traditional soil stratification method is inefficient and needs to introduce new methods and techniques. In this paper, time domain spectral induced polarization method was introduced to carry out electric sounding exploration for the certain soil, and the observed data were processed and interpreted by using half-life time and deviation degree. The results show that the application of time domain spectral induced polarization method in soil stratification is feasible, and the half-life time and deviation degree are effective as interpretation parameters. The measured results and conclusions of this work can provide a basis for related research and the reference for relevant work.
Study on effect of mechanical sand on mechanical properties and fractal characteristics of mortar pore structure
Authors: Chen Can , Yang Haicheng , Yu Fang 
Published: February 2021

Abstract
The influence of stone powder content, fly ash and other factors on mechanical properties, pore structure and fractal dimension of machine-made sand mortar were studied, and the relationship between fractal dimension and mechanical properties of mortar was explored. The research shows that with the increase of the content of stone powder, the mechanical properties of mortar and the fractal dimension of pore structure of different sizes increase; the porosity and average pore size of the mortar decrease, and the ternary of cement-fly ash-stone powder The micro-particle system can effectively optimize the pore structure distribution of the mortar; the fractal dimension of the mortar using ordinary river sand is significantly smaller than that of machine-made sand under the same conditions; with the increase of the fractal dimension of the pore structure, the compressive strength and flexural strength of the mortar continue to increase Large, the fractal dimension and the macroscopic mechanical properties of the mortar show a good correlation.
Study on the Reinforcement Mechanism of the Deep Replacement Caverns for the Giant Slope Block Combined by Structural Planes
Authors: Lai Daoping , Xu Jianrong , Wu Guanye , Chen Yuan 
Published: February 2021

Abstract
The left bank of the cushion pond of Baihetan hydropower station is a slant and dip slope. The gently inclined intra-layer fault zones, the steep-dip faults and the unloading fissures cutting the slope to form several potentially unstable blocks. The computational results show that the stabilities of the blocks are controlled by inclined intra-layer fault zones. A method of treatment applying deep replacement caverns and load-reduction excavation was proposed to reinforce the unstable blocks. In order to study the reinforcement mechanism of the deep replacement caverns for the giant slope blocks controlled by inclined intra-layer fault zones, the 3D simulation analysis of the slope treatment construction was carried out by use of FLAC3D software, and a 3D geo-mechanical model was developed to carry out experimental research. The results of the calculation and experiment show that the deep concrete replacement caverns effectively control the shear and sliding deformation of the bottom slide surface and improve the stability of the blocks combined by structural surfaces. In the process of slope strength reduction and overloading, the slope deformation and cracking are gradually extended from the surface to the inner part, and shear stresses of the front deep replacement cavern are the largest of all the caverns. Therefore, it is more beneficial to control the deformation of the slope and improve the stability of the giant blocks by increasing the size of the front deep replacement cavern. The research results have important guiding significance for the reinforcement treatment of the giant blocks in the left bank of Baihetan cushion pond and similar projects.
Analysis on the Mechanical Characteristics of Onshore Wind Power Generation Foundation Structure
Authors: Zhou Heng , Li Xiaomin , Liu Jing , Di Shengjie 
Published: February 2021

Abstract
Based on the 3D finite element method, considering the plastic damage model of concrete, the uncoordinated deformation relationship between steel foundation ring and concrete, and the coordinated displacement relationship between steel bars and concrete, this paper conducts a simulation analysis on onshore wind power generation foundation, and studies the stress characteristics of the foundation under ultimate load condition. The results show that the lower part of the steel foundation embedded plate is a weak part, which not only needs to pay attention to the tensile failure, but also needs to prevent the compression failure. Perforated steel bars arranged on the top of steel plates have a obvious stress effect, which obviously strengthens the connection between steel plates and concrete. With the weakening of the connection between steel foundation and concrete, the top displacement and relative displacement of the contact surface between steel plate and concrete gradually increase. With the increase of friction coefficient between steel foundation and concrete, the stress of perforated steel bars and the displacement of foundation ring top surface also decrease. The research results of this paper can provide an important reference for the design and reinforcement of infrastructure.
Automatic detection method of bridge cracks based on residual network
Authors: Yan Wang , Junjie Ying , Junteng Mao , Yong Chen , Kai Wu 
Published: February 2021

Abstract
At present, the level of bridge crack detection is not high. In order to solve the problems of weak robustness of traditional image processing methods and time-consuming and laborious manual detection, a pixel level detection algorithm of bridge cracks based on adding residual block is proposed, which provides more intuitive and accurate detection results for bridge health assessment. Firstly, the concrete beam slab crack data set with a certain amount of data is built to train and test the model. After comparing and analyzing the four learning rates, 2×10−4 is chosen as the initial learning rate. Finally, in the aspect of fracture segmentation, the model proposed in this paper has good performance and good crack identification effect. It can accurately and efficiently locate, classify and identify fractures, which has certain practical application value.
Carbonation and Mechanical property of the Concrete Core Samples from a concrete dam after long-term operation
Authors: Zhiguo NIU , Yuan LI , Ri YOU 
Published: February 2021

Abstract
To investigate the ageing characteristics of dam concrete, concrete core samples were obtained from an existing dam. The compressive strength and carbonation depth were determined. The relationship between compressive strength, carbonation depth and operation time were analyzed. The results show that the compressive strength of dam concrete increases with operational time, the increasing rate of compressive strength was gradually decreased, and the compressive strength gradually increases with depth carbonation growth. There was a certain correlation between compressive strength, operational time and depth carbonation. The research results will provide a reference for the safety evaluation of hydraulic concrete structures in service.
Study on Mechanical Characteristics of Support Structure in Tunnel Entance Section under Mechanized Construction
Authors: Guo Hongyan , Tang Dengzhi , Yao Chengrui , Zhang Xiaolong 
Published: February 2021

Abstract
In view of the mechanical characteristics of the support structure under the mechanized construction conditions of the shallow buried section of the tunnel entrance, numerical simulation methods are used to compare and analyze the different cycle footage and the different tunnel face depth before and after the tunnel face reinforcement been carried out when the shallow buried section of the tunnel entrance is constructed by the micro-step method. The results of the study show that the primary support and pipe shed force increases with the increase in the depth of the tunnel face (buried depth), and decreases with the increase of the cyclic footage; When the fiberglass bolt is used to reinforce the face, the axial tensile stress of the fiberglass bolt can reach 18kN; Without reinforcement of the tunnel face, the primary support of the arch at the entrance of the tunnel is vulnerable to cause tensile damage; After the tunnel face is reinforced, the tensile stress of the primary support is significantly reduced.
Study on The Evaluation of Surrounding Rock Stability and Limit Displacement of High-Pressure Stratum Tunnel
Authors: Zhang Xiaolong , Guo Hongyan , Ye Lianchao , Tang Dengzhi 
Published: February 2021

Abstract
Aiming at the problem of the value of the stability and limit displacement of the surrounding rock of highway tunnel with high pressure, the method of numerical limit analysis is adopted, and one of the working conditions is analyzed in detail. Firstly, this paper adopts the formation structure method to calculate and establish a plane model for calculation and analysis with the help of FLAC3D software, so as to study the influence of reduction coefficient on surrounding rock deformation and its law. Secondly, by holding other variables unchanged, two different working conditions with and without high water pressure are compared and analyzed, and it is obtained that the ultimate safety factor of the integrity instability of surrounding rock of the formation tunnel with high water pressure is 1.30, and that of the integrity instability of surrounding rock of the formation tunnel without high water pressure is 1.80. Finally, the results are compared and analyzed and it is found that the stability of tunnel surrounding rocks with high pressure is lower than that without high pressure, and the limit displacement is greater than that without high pressure.
Study on the length of cable-free zone of wide cantilever cable stayed bridge with low pylon
Authors: Li Shuqin , Fan Keyu , Gan Tianyu 
Published: February 2021

Abstract
Low pylon cable-stayed bridge is a new type of composite bridge between girder bridge and traditional cable-stayed bridge. Because of its good mechanical properties, economic benefits and beautiful shape, low pylon cable-stayed bridge is widely used in highway and urban landscape bridges. In this paper, a wide and low pylon cable-stayed bridge under construction is taken as the research background, and the numerical simulation model is established by using the finite element analysis software MIDAS CIVIL. The influence of the length of the cable-free zone is studied. By changing the length of cable-free zone at the tower root and the length of cable-free zone in the middle of span, the influence of the length of non-cable zone on the deformation, bending moment, internal force and cable force of low pylon cable-stayed bridge at the completion stage is studied. The reasonable value range of non-cable zone length is obtained. The research results will provide theoretical guidance for the design and construction of similar projects.
Research on construction quality control of prefabricated concrete bridge based on BIM technology
Authors: Chao Song , Haoli Zhang , Guogang Ying , Shuangshuang Wang , Yidong Xu 
Published: February 2021

Abstract
In recent years, China has made great efforts to promote prefabricated concrete bridge technology. However, due to the construction quality problems, the application of prefabricated concrete bridge technology is limited. BIM technology can be applied to the whole life cycle of a construction project, which is a new way to solve the problem. This paper uses questionnaires to investigate the quality problems of prefabricated concrete structures, the necessity of BIM application at various stages and the application effects are analyzed. The results show that the application of BIM Technology in each stage of the project can improve some quality problems.
Research on neural network in consolidation effect of soft foundation
Authors: Wang Guang lu 
Published: February 2021

Abstract
The method and application situation of neural network is universal application. Datum of project and monitoring from a project of soft foundation by vacuum preloading was filtrated and summarized. After analysis and comparison, establishment of optimization neural network model was used to evaluate the consolidation effect. By the sensitivity of impact factors, it was analyzed that the main parameter of soft foundation consolidation process.
Uniaxial Tensile Test and Numerical Simulation of Hybrid Fiber Reinforced Concrete
Authors: Yu Jing , Zhang Hui , Qi Yanglong 
Published: February 2021

Abstract
According to the reinforcement principle of hybrid fiber, steel fiber and PVA fiber were used to prepare hybrid fiber reinforced concrete (HyFRC) with compression strength of 120 MPa (SPHFC120). The tensile properties of SPHFC120 were studied by uniaxial tensile test, and the uniaxial tensile constitutive equation was established according to the stress-strain curve. An efficient and applicable three-dimensional mesoscale model to simulate HyFRC was developed. It consists of two components involving concrete matrix and fibers, and the bond between concrete matrix and fibers was considered indirectly by defining the fiber constitutive model. The model was validated with uniaxial tensile test. Then parametric studies were conducted to investigate the effect of fibers content on the tensile performance of HyFRC. The results show that PVA fibers obviously improve the tensile strength, peak tensile strain and tensile toughness of steel fiber reinforced concrete.
Research on Basic Mechanical Properties of Large Scale Thermal Steel Slag Cement Concrete
Authors: Yang Xingsheng , Huo Zhiqiang , Zhang Zheng , Yang Zhengxun 
Published: February 2021

Abstract
The basic mechanical properties of steel slag concrete with waste thermal steel slag instead of the coarse and fine aggregates in concrete are studied and compared with the mechanical properties of ordinary concrete. The test results show that the addition of steel slag as coarse aggregate will enhance the compressive strength and flexural strength of concrete, and it will improve with the increase in the steel slag content. When steel slag is used as fine aggregate, the compressive strength of the steel slag concrete subjected to first increases and then decreases with increase in the steel slag sand content. To obtain better performance for the steel slag concrete, the suggested optimum content of steel slag sand as fine aggregate is 50%. Within. The addition of steel slag as fine aggregate can improve the flexural strength of concrete, and the flexural strength increases with the increase of the addition of steel slag sand. The steel slag concrete with the highest strength can be obtained when 100% of steel slag replaces the concrete aggregate, and the steel slag has good basic mechanical properties for the application of road engineering.
A Comprehensive Evaluation Method of Safety Behavior of Concrete Face Rockfill Dam Based on Regression Relationship Method and Fuzzy Recognition Model
Authors: Wen Lifeng , Yang Ying , Li Yanlong 
Published: February 2021

Abstract
The concrete face rockfill dam (CFRD) generally encounters structural health problems during long-term operation. Therefore, it is necessary to study the safety evaluation of CFRDs. This paper proposes a comprehensive evaluation method for the safety behavior of CFRDs on the basis of regression relationship method and fuzzy recognition model. The method of sub-index safety evaluation is established by using regression relationship method. The multiplication scale method was adopted to determine the sub-indexes weight. In combineing of sub-index safety evaluation value and sub-indexes comprehensive weight, the fuzzy recognition model is used to determine the comprehensive evaluation grade of dam safety. Safety evaluation of several CFRDs were evaluated by the method proposed in this paper and exisiting safety evaluated method to verify reasonable and rationality of the method.
Rheology Test and Finite Element Analysis: A Case Study of a Rockfill Dam in China
Authors: Deng Chengfa , Xu Chang , Li Xuemei , Zheng Minsheng 
Published: February 2021

Abstract
Rheology often occurs in the dam rockfill deformation. In this paper, we carried out a large-scale triaxial rheological test for the tuff rockfill materials of a concrete faced rockfill dam in China, and then obtained the parameters of the seven parameter rheology model. Finally, we analyzed the dam rheology using the three-dimensional finite element model. The results show that the dam settlement, horizontal displacement, face deflection and the displacement of the joints around the face slab are all obviously increased when considering the rheological behavior of the rockfill. We find that the calculated settlement of the dam body is in good agreement with the filed measured value when the dam is completed, and the maximum settlement during the impoundment period is within the normal range.