bluuebunny/crossref_metadata_2025_split huggingface dataset:
The contribution of wildland fire emissions to deposition in the U S: implications for tree growth and survival in the Northwest
Authors: Koplitz Shannon N , Nolte Christopher G , Sabo Robert D , Clark Christopher M , Horn Kevin J , Thomas R Quinn , Newcomer-Johnson Tamara A 
Published: February 2021

Abstract
Ecosystems require access to key nutrients like nitrogen (N) and sulfur (S) to sustain growth and healthy function. However, excessive deposition can also damage ecosystems through nutrient imbalances, leading to changes in productivity and shifts in ecosystem structure. While wildland fires are a known source of atmospheric N and S, little has been done to examine the implications of wildland fire deposition for vulnerable ecosystems. We combine wildland fire emission estimates, atmospheric chemistry modeling, and forest inventory data to (a) quantify the contribution of wildland fire emissions to N and S deposition across the U S, and (b) assess the subsequent impacts on tree growth and survival rates in areas where impacts are likely meaningful based on the relative contribution of fire to total deposition. We estimate that wildland fires contributed 0.2 kg N ha−1 yr−1 and 0.04 kg S ha−1 yr−1 on average across the U S during 2008–2012, with maxima up to 1.4 kg N ha−1 yr−1 and 0.6 kg S ha−1 yr−1 in the Northwest representing over ∼30% of total deposition in some areas. Based on these fluxes, exceedances of S critical loads as a result of wildland fires are minimal, but exceedances for N may affect the survival and growth rates of 16 tree species across 4.2 million hectares, with the most concentrated impacts occurring in Oregon, northern California, and Idaho. Understanding the broader environmental impacts of wildland fires in the U S will inform future decision making related to both fire management and ecosystem services conservation.
Nitrogen -addition accelerates phosphorus cycling and changes phosphorus use strategy in a subtropical Moso bamboo forest
Authors: Li Quan , Lv Jianhua , Peng Changhui , Xiang Wenhua , Xiao Wenfa , Song Xinzhang 
Published: February 2021

Abstract
Ecosystem-level effects of increasing atmospheric nitrogen (N) deposition on the phosphorus (P) cycle and P use strategy are poorly understood. Here, we conducted a seven year N-addition experiment to comprehensively evaluate the effects of N deposition on P limitation, cycling, and use strategy in a subtropical Moso bamboo forest. N addition significantly increased foliar litterfall by 4.7%–21.7% and subsequent P return to the soil by 49.0%–70.1%. It also increased soil acidity, acid phosphatase activity, and soil microbial biomass P, which substantially contributed to a significantly increased soil P availability and largely alleviated the P limitation. This resulted in a significant decrease in the foliar P-resorption efficiency and the abundance and colonization of arbuscular mycorrhizal fungi. Our results indicate that N deposition can reduce plant internal cycling while enhancing ecosystem-scale cycling of P in Moso bamboo forests. This suggests a shift in P use from a ‘conservative consumption’ strategy to a ‘resource spending’ strategy. Our findings shed new light on N deposition effects on P cycle processes and P use strategy at the ecosystem scale under increasing atmospheric N deposition.
Static analysis of PC slab stiffened beam suspension bridge under temperature
Authors: Yang Minghu , chen Lu , Liu Yuancai 
Published: February 2021

Abstract
In view of the influence of temperature on the construction of PC slab stiffened beam suspension bridge, combined with the Moon Bay Bridge, the finite element software Midas Civil is used to conduct a static analysis of the Moon Bay Bridge under temperature. The calculation results can be similar to the bridge construction Provide reference, there is a certain reference significance.
Coupling of SWMM With 2D Hydrodynamic Model for Simulation of Sponge City Construction Scheme
Authors: Fan Yuyan , Wang Chengwen , Yu Haijun , Pan Junhao , Ouyang Zilu 
Published: February 2021

Abstract
Sponge city is a new urban stormwater management concept proposed by China to solve the urban water environment and security problems. The stormwater management model (SWMM) is one of the most commonly used urban stormwater and sponge city simulation models. SWMM is coupled with a two-dimensional hydrodynamic model based on the finite volume method to establish a coupled 1D and 2D hydrodynamic model in this research. The coupled model can simulate the drainage pipe network, sponge measures and flood inundation at the same time. A predictor-corrector method with good stability was used in the coupled model to ensure the non-negativity of the water volume of the 2D model cell. The sponge city construction scheme for a community in Beijing was simulated and analyzed using several design rainstorm processes with different return periods based on the proposed model. It is proved that the coupling model can be applied to sponge city construction problems and sponge measures can reduce the flood inundation and the load of drainage network system by simulating the drainage conditions and ground waterlogging before and after the reconstruction of the drainage community.
Borehole shear test and its application to saturated silty clay
Authors: Zhu Jianmin , Yu Yongtang , Huang Xiaowei , Zeng TAO , Zheng Jianguo 
Published: February 2021

Abstract
An improved borehole shear test (BST) instrument was utilized to obtain the shear strength index of the soil layer in-situ. The results show that the shear strength index of the saturated silty clay measured by the improved borehole shear apparatus has a good linear correlation with the normal pressure, and the correlation coefficient can be greater than 0.98. The testing results were also compared with those obtained by the direct shear test (DST) in the laboratory. It was found that when the soil layer has a depth of less than 8.75m, the difference in the internal friction angle by the BST and DST is small. The former is 8%–33% larger than the latter. The deviation in the cohesion is obvious, which ranges from 20% to 61%. For the soil layer deeper than 8.75m, the situation is different. The difference in the cohesion measured by the two methods is small, which ranges from 8% to 9%, while the difference in the internal friction angle is distinct, and reaches 62%–85%.
Hydraulic Coupling Numerical Simulation of Heterogeneous Rocks with Rrandom Defects
Authors: Yang Yachao , Cui Yongqiang , Song Daifu , Lu Keyu 
Published: February 2021

Abstract
As the research base damage and water inrush problem, this article obtains from the body micro units, on the basis of seepage of rock mass and rock mechanics theory, considering the heterogeneity of rock, and established the heterogeneity of rock containing random defects of mesoscopic scale on the seepage flow in heterogeneous model by means of FLAC3D simulation software built-in fish language from the model unit randomly in the unit ID number, total group as defects in the model group, while the rest of the unit as a complete set, the different group gives different mechanics parameter values, implement different defect degrees of homogenization model established The results show that the overall bearing capacity of rocks with high defect degree decreases obviously, and the failure of rocks precedes that of intact rocks.
Soil Hydrothermal balance in farmland system and its response to human activities
Authors: Dong Xin , Zhang Hengjia 
Published: February 2021

Abstract
The problem of soil hydrothermal balance in farmland system is an important issue to study the formation and change mechanism of farmland climate and microclimate. As an important part of terrestrial ecosystem, the farmland ecosystem has dynamic changes in soil moisture and heat. Due to its particularity, the farmland ecosystem is also a land type directly affected by human activities. This paper systematically summarized the importance of soil hydrothermal interactions in farmland systems, the law of water and heat balance in farmland system and the recent research on the coupling model of hydrothermal balance in farmland system at home and abroad. In addition, this paper also elaborated the research progress of the response of farmland water and heat balance to farmland irrigation, film mulching and other human activities, so as to provide a theoretical basis for the effective use of farmland water resources and the cultivation of high-quality crops in the future.
Study on Tensile Properties and Failure Modes of BFRC
Authors: He Jingjing , Shi Junping , Zhang Yong , Lu Haodan , Wang Haiting , Fan Lihao 
Published: February 2021

Abstract
The effects of basalt fiber volume fraction and fiber length on the tensile properties of concrete are studied by experiments. The mechanism of fiber improving the tensile failure mode of concrete is analyzed. The results show that the tensile properties of BFRC are significantly improved compared with the matrix concrete. The initial crack strength and yield strength increase significantly with the increase of fiber volume fraction, while the initial crack strain and yield strain increase significantly with the increase of fiber length. The roughness coefficient of BFRC fracture surface can be used as the index of fiber improving concrete tensile properties.
Study on suitability of basalt artificial aggregate in Cambodia
Authors: Ge Longjin , Du Bin , Jin Hongjie , Han Xinjie 
Published: February 2021

Abstract
Aggregate property directly affects concrete property. When natural aggregate sources are lacking, artificial aggregates should be considered. The strata in Cambodia are dominated by sedimentary rocks with weaker lithology, which are not suitable for artificial aggregate. The quality of gneiss and limestone is good, but the distribution area is small, so it is not suitable for mass mining. Basalt is widely distributed, and the rock strength is generally high. There are problems such as scattered distribution, poor uniformity, and large property changes. Suitability of basalt artificial aggregate is studied in combination with specific projects. Research works are from outside to inside, from shallower to deeper. Through general survey and primary selection of quarry, surveying and sampling, rock mineral identification and chemical composition analysis, rock physical mechanics test, alkali activity test and aggregate processing property and other analysis tests, its quality indicators and reserves are found out. Studies have shown that quality and reserves of aggregates in the survey yard can meet the needs of the project, mining and transportation are convenient, making it an ideal choice for concrete artificial aggregates. Research methods and results can be used as the reference for similar projects.
Constitutive relation of stiffened square CFST Columns
Authors: Xinzhi ZHENG , Shuang ZHENG , Yuanhong ZHANG 
Published: February 2021

Abstract
Using the constitutive model of a square CFST column with binding bars, the constrained mechanism of the stiffened square CFST columns is analyzed in great detail. The equivalent constitutive model under uniaxial compression is established for square CFST columns. The model is then used to describe the stress-strain curve process for concrete and to calculate the bearing capacity. Models of ten concrete-filled square steel tubular columns under axial compression specimens are created with constitutive relation. The results are compared with the axial compression test of an ordinary square CFST specimen column and stiffened square CFST specimens. Our results show that the bearing capacity and stress-strain curves under axial compression are consistent with the actual test measurements. Analysis can be applied to the square stiffened CFST columns, the square CFST columns with binding bars, and the ordinary square CFST columns.
Study on highway dynamic load vibration propagation characteristics in surrounding soil and influence control distance
Authors: Zhang Yuqi , Guo Xiaohong , Wang Ning , Qiao Maowei 
Published: February 2021

Abstract
The dynamic monitoring for the scene of the engineering vehicle dynamic load of the vibration was performed. By developing a subroutine of ABAQUS DLOAD to simulate the process of vehicle traffic, the characteristics of vehicle vibration transmission in soil was analyzed. Based on three different indicators: displacement, acceleration and vibration level, the influence of different speeds and different weights of the vehicle vibration on the surrounding soil and reasonable control distance was analyzed. This paper provides reference and guidance to avoid the influence of traffic dynamic load when designing and constructing.
Simulation and crack analysis of the whole process of a Roller Compacted Concrete dam during construction and operation
Authors: Ding Jianxin , Yang Qingzhou 
Published: February 2021

Abstract
The structural safety calibration is an essential problem of Roller Compacted Concrete (RCC) dams. Due to the simulation complexity of RCC dams and shortcomings of conventional methods, usually, the actual mechanics state cannot be obtained easily by the numerical methods. In this paper, a RCC gravity arch dam in Laos is taken for an example, the simulation program has been developed, and three-dimensional simulation analysis of the temperature field and stress-strain field of the whole process of RCC dam during construction and operation is carried out. The composite contact crack element is proposed to simulate the complicated mechanical behaviors of various kinds of joints and cracks. The research results show that the simulation results of the temperature field, the stress-strain field and cracking are close to the monitoring data, the space-time evolution of the temperature field and the stress-strain field of the RCC dam are obtained. The whole working state of the RCC dam is evaluated, and the causes of the dam cracks are revealed. The research results are adopted by the design institute, which is of great importance to ensure the engineering safety of design, construction, impoundment and operation.
Research on the Efficiency Path of Civil Construction Management Engineering Based on BIM Technology
Authors: Duan Rongrong 
Published: February 2021

Abstract
My country’s economic pillar industry is the civil construction industry. With the rapid development of our country, modern buildings have greatly increased the difficulty of construction project management due to complex construction techniques and long construction periods. Therefore, we must improve the traditional. In this way, the management model can better improve engineering efficiency. This article is based on the BIM technology of the civil construction management engineering efficiency path to study, the experiment uses the analytic hierarchy process to determine the weights, in order to evaluate the BIM technology of construction engineering safety management. Three local survey units were selected for the experiment, and the survey form was distributed to each unit according to the experimental procedures and requirements. When handing over the BIM model, it could give the acceptance conclusion of the model. Experimental data shows that the incidence of accidents at the entrance of the cave and the border is the highest, which is the most difficult point in construction safety management. Effective measures should be taken to reduce the occurrence of accidents. The experimental results show that the following problems in BIM application have led to a reduction in the efficiency of civil construction management engineering: 85% of BIM standards are unfamiliar, 79% of BIM technology costs are overused, BIM technology is poorly applied 82%, and BIM-related software is not applied. Mature accounted for 78%, and BIM related management methods accounted for 80%. The use of BIM technology can provide an effective way to improve the efficiency of construction project management. This article conducts in-depth research on BIM technology, hoping to make a meager effort in related fields.
Influence of Molding Methods on the Polymer Pervious Concrete
Authors: Li Wenqiang , Chen Fan , Ai Zubin , Zhang Chao , Wang Chao , Li Yue , Zhang Yankun 
Published: February 2021

Abstract
The influence of vibration molding method and manual poking molding method on strength and water permeability of polymer pervious cement concrete with water cement ratio of 0.27, 0.30 and 0.33 is studied. It is found that the compressive strength of vibration molding increases with the increasing of vibration time and the water permeability coefficient decreases. The strength of concrete with vibration molding is higher than that of manual poking molding, and the water permeability coefficient is lower. However, the water permeability coefficient with both molding methods is more than 0.5mm/s.
Analysis of the influence of lately excavated tunnel blasting on the vibration of early excavated tunnel in small-space tunnel
Authors: Luan Guitao , Wang Zhirui , Song Zhanping , Yu Haibao 
Published: February 2021

Abstract
In order to study the impact of the blasting construction of lately excavated tunnel of the large-section tunnel with small spacing on the early excavated tunnel, the propagation law of vibration velocity of initial support of early excavated tunnel under blasting load is analyzed by combining field test and numerical simulation based on the Mongol Road Tunnel of the Zamalong-Daotanghe Highway Reconstruction and Expansion Project in Qinghai Province; The results show that the radial vibration velocity in the initial support of early excavated tunnel is obviously greater than the vertical vibration velocity and tangential vibration velocity in the blasting construction of lately excavated tunnel with large section and small spacing. The radial vibration velocity of the blasting side of the tunnel is obviously greater than that of the back side, and the maximum is found at the arch waist of the blasting side. The peak value of the radial vibration velocity of the initial support of early excavated tunnel is the maximum at the same section position as the blasting excavation face, and gradually decreases with the increase of the blasting center distance. Compared with the vibration velocity of the initial support before and after the excavation face, the peak attenuation rate of the vibration velocity in front of the blasting excavation face is slightly less than that behind the excavation face.
Study on the effect of resistivity and meso-structure evaluation of alkali solution strengthening loess: A case study
Authors: Hu Wenle , Liu Hua , Wang Tiehang 
Published: February 2021

Abstract
For evaluating the structure and strength of loess effectively, a series of laboratory tests were performed to investigate and compare the pore meso-structural characteristics, the shear strength and the resistivity of natural loess and loess treated with alkali solutions under 4 different concentrations. Scanning electron microscope(SEM) method, direct shear tests, electrical resistivity tests, and X-ray diffraction analysis were used to detect the changing process in strength parameters, micro-structure, and mineral composition. The evolution result of shear strength index and stress-strain characteristics of loess were analyzed. Combined the SEM micro-structure analysis and X-ray diffraction technology, the microscopic mechanism of alkali solutions and loess interaction was revealed. The results of tests show that the curves of shear stress- displacement featured as strain-hardening, and the increasing of shear strength indexes with the increasing of alkali solutions concentration. Then the relationship between the shear strength index and resistivity was established. The SEM images of LTA specimens were used to quantify the structural parameters by Image Processing Techniques. The changes of multiple structural indicators of LTA such as directionality, abundance, circularity, fractal dimension, and the orientation probability entropy were revealed. The potential mechanism of LTA was revealed by the XRD and EDS tests from the perspectives of mineral composition and chemical element composition. The results of this study show that alkali-loess interaction was the main influence factor for the changes in the shear strength and meso-structure s. The results provide a valuable implication for the construction in the loess deposits.
Study on Signal Processing of IES of Tunnel Lining Based on Wavelet Analysis
Authors: Li Ruijun , Shi Yaqing 
Published: February 2021

Abstract
As we all know, high-speed rail is a very important business card in China, and the rapid development of high-speed rail is inseparable from the rapid development of tunnel construction, so tunnel construction has become very important. The quality of the tunnel lining directly affects the construction quality of the entire tunnel construction. This paper first introduces the use of IES, one of the most advanced testing methods for non-destructive testing, to achieve non-destructive testing the quality of tunnel lining. The signal is more or less affected by the surrounding environment and human factors, so In this paper, wavelet analysis is used to eliminate the signal noise in order to extract characteristic signals that better reflect the defects of tunnel lining and realize the intelligent diagnosis of the defects of tunnel lining.
Eccentric compressive behaviour of double steel-concrete shear wall constrained with ribs and bars
Authors: Xinzhi ZHENG , Shuang ZHENG , Songbiao LI 
Published: February 2021

Abstract
By adding ribs and bars to form the double steel-concrete shear wall constrained with ribs and bars, the steel plate of the whole steel-concrete shear wall can be strengthened of the constraint. The research on Eccentric compressive behavior of double steel-concrete shear wall constrained with rib and bar is less, this paper analyzes double steel plate concrete shear wall by using larger length-width rectangular CFST column research methods. Based on the constitutive relation of the rectangular CFST column with ribs and bars, the relative parameters are changed, and a program is written to compare and analyze eccentric compressive behavior of double steel-concrete shear wall constrained with ribs and bars compared with that double steel plate concrete shear wall only constrained with bars.
Study on the influence of surrounding rock parameters on the stability of tunnel face
Authors: Wei Xiaohang , Sun Ze , Wang Zheng , Zhuang Dequan , Ba Wenwen 
Published: February 2021

Abstract
The surrounding rock is the construction environment and main load source of the tunnel, and its physical parameters have an important influence on the stability of the tunnel face. Based on orthogonal test method, with the Georgia E60 highway 3.0.04 - TA tunnel under construction as the engineering background, numerical test method is used to compare and analyze the influence of different surrounding rock parameters ( elastic modulus E, cohesion C, internal friction Angle φ) on the stability of tunnel face. The multiple linear regression fitting equations of three factors and extrusion deformation are given and verified. The results showed that the elastic modulus and cohesion of surrounding rocks had a significant influence on extrusion deformation of the tunnel face, while the internal friction Angle had no significant influence. The extrusion deformation of the tunnel face is negatively correlated with the elastic modulus, cohesion and internal friction Angle of surrounding rocks. The fitting equation can provide a means for predicting the stability of surrounding rock and guide the construction of the tunnel.