bluuebunny/crossref_metadata_2025 huggingface dataset:
Research Advances in Concrete Filled Steel Tube Connection Device
Authors: Ren Hong Wei , Tian Jie Fang , Li Qiu Ming
Published: March 2015

Concrete filled steel tubular structure is a new type of composite structure, widely used in monolayer or multilayer industrial workshop structure column, frame column, all kinds of equipment support and super high-rise building and bridge structure, connection pipe attracted more research on its theory and experiment at home and abroad on the concrete force has carried on the preliminary summary, analysis of the advantages and disadvantages of concrete filled steel tube of various existing connection mode, and illustrates the current situation of domestic and international research on concrete filled steel tube are connected, and finally puts forward some problems in the study.
Research on Value-Engineering-Based Construction Costs of Energy-Saving Buildings
Authors: Wu Rui , Du Huan , Wu Qi
Published: March 2015

With the energy crisis being ever increasingly serious, energy-saving buildings have become a breakthrough for the development of the construction industry. Firstly, this article analyzes the current status of building energy saving in mainland China, and elaborates the necessity of building energy saving in the viewpoint of the entire lifecycle cost by using the value engineering principle. Secondly, this article analyzes the incremental cost of energy-saving buildings and describes the components of the incremental cost. Thirdly, this article analyzes in detail the impact of the incremental cost in the construction phase of buildings by illustrating examples. Finally, this article lists measures and suggestions for cost management to achieve the optimal economic benefits for the entire lifecycle with a minimum incremental cost in the construction phase, resulting in smooth development of energy saving buildings.
The Heating Energy Consumption Analysis and Energy Saving Transformation for the New Rural Apartment
Authors: Liu Xiao Rui , Xu Shu Hui , Guo Yang , Hao Qing Ru
Published: March 2015

The main purpose of this test is to analysis heating energy consumption in new rural apartments in north china. At the first, we analysis the present situation of energy consumption and feature for new apartment in north china, then we proposed the measures to improve the performance of energy saving thermal insulation in new apartment in the area of north china, we conducted comparative analysis for energy consumption in new apartment before and after energy saving.
Construction of Plant Communities for Ecological River Training and their Impacts on Biological Diversity
Authors: Wang Lei , Ye Sui Gao , Ye Jian Hua , Lu Fang Chun
Published: March 2015

River play a very important role in regional landscape structure as an ecological element and corridor, and vegetation is very important for the healthy eco-system of a river. The advances of the research and application of near nature river training and vegetation measures were reviewed. The concept, content and function of ecological river training and near natural river training were discussed.. According to the principle of landscape biology, the positive influence of river vegetation on biodiversity was analyzed through edge effects, corridor effects and interference effects. On the basis of in-site experiments of more then ten sample rivers for years, it was concluded that to meet the needs of biodiversity conservation and maintain river ecosystem healthy and steady, in the design and construction of a river, the ecological function should take into due account, proper habitat conditions for plants and plant communities should be created through suitable plan layout, cross section, slope structure and construction material.
Pollution Load Estimation of Weihe River Watershed above Linjiacun Section Based on Characteristic Section Load Method
Authors: Zhu Lei , Song Jin Xi , Zheng Chang Qin
Published: March 2015

Weihe River Watershed above Linjiacun Section is taken as the research objective in this paper and NH3-N is chosen as the water quality parameter. According to the discharge characteristics of point source pollutions and non-point source pollutions, a new method to estimate pollution loads-characteristic section load method is suggested and point source pollution and non-point source pollution loads of Weihe River Watershed above Linjiacun Section are calculated in the rainy, normal and dry season in the year 2007. The results show that the monthly point source pollution loads of Weihe River Watershed above Linjiacun Section are discharged stably, the monthly non-point source pollution loads of Weihe River Watershed above Linjiacun Section change greatly, the non-point source pollution load proportions of total pollution load of NH3-N are gradually decreased in the rainy, normal and wet periods.
Profit and Loss Analysis on Ecosystem Services Value Based on Land Use Change along Expressway
Authors: Tang Xiu Mei , Ren Yan Min , Liu Yu , Pan Yu Chun
Published: March 2015

Taking the area within 10 km along Beijing section of Jingcheng expressway as study area, this paper calculates the area changes and conversions of landuse types based on the land use map derived from TM images of 1995, 2004 and 2009, and analyze the variation of ecosystem services value of landuse types. The following results are gotten:(1) the construction of the expressway hadadramatic influence to the land use types along and the agricultural structure change obviously; (2) The total value is 20.77×108Yuan in 1995, and increased to 20.96×108 Yuan in 2004, then decreased to20.78×108 Yuan in 2009; (3)The reduction of cultivated land and the increase of construction land were the most important reason for the loss of the ecosystem services value, but because of the increase of garden plot, the total ecosystem services value was stable and increased a littlefrom 1995 to 2009.
Research on Dynamic Responses of a Transmission Tower under Monsoon Wind
Authors: Xie Wen Ping , Chen Bo , Li Peng Yun , Gong Xiao Fen
Published: March 2015

The research on dynamic responses of a transmission tower under monsoon wind is actively carried out in this study. A real transmission tower-line system constructed in the southern coastal areas of China is taken as an example to investigate the structural performance subjected to monsoon wind. The finite element model of the transmission tower-line system is established with the aiding of commercial package. The equation of motion of the transmission tower-line system under monsoon wind is established. The dynamic wind loading are applied on the tower-line system to examine the structural responses.
Research on Improved Method of Wind Turbine Airfoil S834 Based on Noise and Aerodynamic Performance
Authors: Chen Ya Qiong , Fang Yue Fa
Published: March 2015

In this paper, aerodynamic performance and noise of the wind turbine airfoil are the optimization design goal and based on this, the optimization design method with multi-operating points and multi-objective of the airfoils is built. The Bezier curve is used in parametric modeling of the contour of the airfoil and the general equation for control points is deduced form the discrete points coordinates of the airfoil. The weigh distribution schemes for multi-objective and multi-operating points are integrated designed by treating the NREL S834 airfoil as the initial airfoils. The results show that the lift-to-drag ratio of the optimized airfoils has a improvement around the designed operating angle and the overall noise has a reduction compared with the initial airfoils, which means that the optimized airfoils get a better aerodynamic and acoustic performance.
Seismic Behavior of Coupled Eco-Composite Wall
Authors: Hou Li Na , Wen Bao Jun
Published: March 2015

Coupled eco-composite wall is one of the most commonly used lateral-load resisting member in eco-composite wall structure. The test of a coupled eco-composite wall under low-frequency cyclic loading is carried out to study the seismic behavior of the coupled eco-composite wall. At the same time, the main influencing factors of shear capacity for the wall are analyzed by numerical simulation. Experimental results and numerical analysis show that: the coupled eco-composite wall has better seismic performance in contrast with the standard wall, and such factors as shear-span ratio, ribbed steel bar, block strength, section height and reinforced area of end column and concrete strength of end frame column are the main influencing factors of shear capacity 。
Static Analysis of Mega Steel Frame-Cable System Bracing Structure
Authors: Yang Si Qi , Cai Jun Hua , Chen Jia , Tang Bai Jian
Published: March 2015

In order to study the static performance of a new type e vertical prestressed steel structure called mega steel frame-cable bracing structure, structure deformation, internal force of beam and column and the remaining pretension of cable under pretension, vertical load and horizontal load alone as well as pretension with vertical load, wind load combination condition were analyzed in this paper. Research shows that prestressed cable can effectively improve mechanical and deformation performance of mega beam under vertical load, improve the system stiffness and make the overall stiffness more uniform.
Study on Buckling of Two Kinds of Thin-Walled Steel Members with Imperfection
Authors: Niu Peng , Wang Hai Tao , Jin Chun Fu , Guo Ying
Published: March 2015

Based on Ježek method of computing the elastic-plastic buckling of the members under the axial compressive load and the bending moment, considering the initial imperfection, the analytical expressions of calculating the ultimate load of buckling about the neutral axis with the maximum moment of inertia for an H-shaped member and a square steel tube member are derived. Using the elastic-plastic finite element method and the theory of nonlinear buckling, the impact by initial geometric imperfections on the H-shaped steel member and the square steel tube member under the axial compressive load and the bending moment are analyzed and the numerical solutions of ultimate bearing capacity are obtained. By compared with the values of the finite element method (FEM), it shows that the analytical method in this paper is valid. The results of the example show that the presence of initial imperfections reduces the ultimate bearing capacity of the two kinds of steel members to a great extent. It is also found that the influence of the initial geometric imperfection on the ultimate bearing capacity of members is smaller when the bending moment increases.
The Force Characteristics of Three-Hinged Arch with Non-Uniform Loads and its Reasonable Arch Axis Calculation
Authors: Wu Yong Ping , Yan Rui , Xie Pan Shi
Published: March 2015

In order to solve the stability and reasonable design technology of arched tunnel in tunnel engineering.Based on the general characteristics of the arch tunnel,build a three-hinged arch structure model with non-uniform loads.Through mechanical analysis,obtained the calculation formula of supporting and internal forces of flat and inclined arch with non-uniform loads,and as a basis to calculate their reasonable arch axis equation by MATLAB software.By describing a instance of tunnel engineering,proved the usefulness and accuracy of this method.It provides a reliable calculation method for stability control and design of arched tunnel in tunnel engineering.
Analysis on Local Stresses in Anchorage Zone of a PC-Box Girder
Authors: Li Rong Da , Yu Hong Run
Published: March 2015

The stress distributions of the related anchorage zones are complicated under the large tonnage anchorage device. The safety and the crack resistance of the anchorage zone which exists due to the usage of are the critical part of the structural design. Do research on the general distribution regularity of stress of anchor-region by using ANSYS and gives the reason of the cracks occurred on web-plate.
Land Uplift in CO2 Geological Storage Projects
Authors: Yu Zi Wang , Zhang Yan Jun , Gao Ping
Published: March 2015

Technology of CO2 Geologic Storage (CGS) especially its possible developments is helpful for improvements in reducing greenhouse gases and alleviating the greenhouse effect, which are necessary at global scale due to rising demand for fossil energy. The theory of deformation due to liquid injection was learned. A test on laboratory scale which injects water into compacted sand covered by low permeability clay showed the land uplift phenomenon. Some further discussions of the land uplift with different injection quantity was studied.
Application of Damp Newton Algorithm on FEPG Platform
Authors: Hou Shi Wei , Zhang Yi Fang , Qu Jin Hong , Du Xiu Li
Published: March 2015

Damp Newton algorithm based on FEPG system is developed for calculating strain softening problem. The algorithm can solve displacement and yield surface equation simultaneously. Soften modulus is introduced into D-P yield function. The example result shows that, the algorithm with damp factor can be used to solve softening problems. The plastic theory described by finite element weak form has no requirement of continuity, so appropriate outcome can be obtained by first-order element. Descent segment of stress-strain curve and cloud picture of finite shear band are presented.
Damage Mechanism Research of Yushu Airport Road Landslide No.3 Base on Elastoplastic Damage Constitutive Model
Authors: Wu Hong Gang , Yang Tao , Chen Xiao Yun , Ma Hui Min , Zhang Hong Li , Zhang Jun De
Published: March 2015

Due to the earthquake of Yushu in April 14, 2010, Airport Road landslide No.3 deformed cracking, resulting in lower stability of slope, triggering landslides and other diseases. Selecting the section 2-2 (mileage K823 + 809) of Airport Road landslide No.3 as the calculation section, we use the ABAQUS finite element program to establish landslide numerical mode. The slip mass of landslide was simulated by the elastic-plastic damage constitutive model, and the bedrock was analyzed as Mohr - Coulomb constitutive model. Landslide No3 is analyzed for example, and showed that earthquake triggering mechanism elastplastic damage constitutive model can describe the landslide very well.
Grouting Improvement in a Mined-Out Area under Tangshan-Tianjin Expressway, China
Authors: Gao Ling , Mu Huan Sheng
Published: March 2015

Expressway construction in mined-out area is faced with some challenges, such as differential settlement and excessive deformation. This paper presents a case study of grouting improvement in a mined-out area under Tangshan-Tianjin expressway, China. The geological conditions in the mined-out area and the mechanisms of surface subsidence are described. A detailed grouting treatment scheme is planned and carried out to reinforce the rock masses. Technical requirements for grouting are described to ensure the reinforcement effect. Verification of the reinforcement effect is carried out using several techniques such as packer test and core drilling method. The results show that the proposed grouting scheme achieves desired effects.
Research on Security Risk Assessment System of Soil Slope Based on AHP
Authors: Zhan Wei , Lin Hao , Li Zhi Lei
Published: March 2015

Based on the investigation of soil slope in Zhejiang province, the main influence factors of soil slope stability were analyzed and the risk assessment indexes of soil slop were selected. Then the risk assessment model of soil slope was established by the method of analytic hierarchy process according to the importance of each index. The security risk assessment system of soil slope was obtained finally. The research result has important reference for the soil slope management.
Slope Stability Analysis by Peridynamic Theory
Authors: Lai Xin , Liu Li Sheng , Liu Qi Wen , Cao Dong Feng , Wang Zhen , Zhai Peng Cheng
Published: March 2015

Peridynamic simulations have been carried out to perform the slope stability analysis. A slope is first modelled with discretized particles in 2D. Then the non-ordinary state-based Peridynamic model is utilized. In order to obtain a more realistic behavior of the soil, Drucker-Prager constitutive model is used to describe the mechanic properties of soil. Results show great agreements with the FEM results, while provides the dynamic slide progress in the post-failure process.
Stability Analysis of Dam Slope by Double Safety Factors of Dynamic Local Strength Reduction Method
Authors: Meng Yuan
Published: March 2015

When calculating the dam slope failure process, traditional strength reduction method doesn't consider the difference of decay rate between cohesion and internal friction angle and discount the strength parameters for all elements. This paper uses two different reduction factors for material strength parameters, slope cohesion and internal friction angle. Based on the yield approach index criterion, we change the reduction region in time and put forward a double safety factor of dynamic local strength reduction method for engineering analysis of dam slope stability.
Stability Analysis of Unsaturated Expansive Soil Slope Covered by Geo-Membrane
Authors: Zhang Hong Yu , Chen Jiang Hu , Wu Wen Qing , Wu Jun Hua
Published: March 2015

In view of the holes appearing in different area of geo-membrane when the geo-membrane technology is applied to the unsaturated expansive soil slope, the VADOSE/W is used to analyze the wetting-drying cycles caused by rainfall and evaporation on slopes covered by geo-membrane. The influence on the pore-water pressure and volume water content were discussed just caused by the holes. The results show that the hole is nearer to the toe of slope, its impact on the whole seepage field is greater. In addition, the hole appears on the top of slope that the wetting-drying cycle effect is remarkable. It is ensured that the integrity of the geo-membrane which in the lower slope and take some drainage measures in the construction process.
Study on the Vertical Acceleration Effect on Slope Stability
Authors: Wu Hong Gang , Yang Tao , Xue Zhi Wen , Ma Hui Min , Zhang Hong Li , Zhang Jun De
Published: March 2015

It is found from the earthquake statistics in recent decades that the vertical seismic oscillation of near field was strong. And even the recorded peak value of vertical seismic oscillation was far more than the peak value of horizontal seismic oscillation in some sites. In order to study the characteristics of vertical and horizontal seismic oscillation acceleration acted on the slope. Calculate the slope earthquake dynamic response characteristics under the horizontal and vertical seismic acceleration by the FLAC3D numerical analysis method. Compared the acceleration, velocity and the displacement amplification coefficient under two kinds of excitation. Analyzed the influence on seismic stability by the acceleration of different direction.
The Experimental Study of Filling Mortar and Stones Construction Technology
Authors: Jiang Gui Hui , Li Yu Qing
Published: March 2015

Filling mortar construction techniques of stone masonry is a innovation and improvement on construction technology. It uses the pressure of water slurry washed sand, relying on the impact and gravity filling the small gap of the mortar and stones. which a has good surface to form the stone body. Test by adjusting the amount of mixing on cement mortar and water, the ratio of water-cement and sand-lime on mortar study compared the performance impact on the mortar, initially identified the ratio on technical requirements of construction which mixing the mortar. On the basis of this test proposed the method using mortar, designed to verifies on using the mortar to fill the small gap, and to determine the optimal mixing on mortar for this new construction technology foundation.
Type of Slope Failure Identified from Pore Water Pressure and Moisture Content Measurements
Authors: Hakro Muhammad Rehan , Harahap Indra Sati Hamonangan
Published: March 2015

Rainfall-induced landslides occur in many parts of the world and causing a lot of the damages. For effective prediction of rainfall-induced landslides the comprehensive understanding of the failure process is necessary. Under different soil and hydrological conditions experiments were conducted to investigate and clarify the mechanism of slope failure. The failure in model slope was induced by sprinkling the rainfall on slope composed of sandy soil in small flume. Series of tests were conducted in small scale flume to better understand the failure process in sandy slopes. The moisture content was measured with advanced Imko TDR (Time Domain Reflectrometry) moisture sensors in addition to measurements of pore pressure with piezometers. The moisture content increase rapidly to reach the maximum possible water content in case of higher intensity of rainfall, and higher intensity of the rainfall causes higher erosion as compared to smaller intensity of the rainfall. The controlling factor for rainfall-induced flowslides was density of the slope, rather than intensity of the rainfall and during the flowslide the sudden increase in pore pressure was observed. Higher pore pressure was observed at the toe of the slope as compared to upper part of the slope.
Effects of Water Cement Ratio on Workability and the Uniaxial Compressive Strength of Zhong Guan Iron Ore’s Filling Body
Authors: Zhang Yi , Liu Bin , Li Zhen Fang , Liu Bo , Zhang Yan Qiu , Chen Bin
Published: March 2015

To design a reasonable packing material, solve the problem of solid pollution brought by the iron ore mining, alleviate a lot of backfilling affect national economic development and the current situation of environmental governance. Backfilling materials in this paper, we study the different water-cement ratio pack slump and uniaxial compressive strength and discusses the workability of water-cement ratio on filling body and the influence of uniaxial compressive strength. The experimental results show that with the increase of water cement ratio, the filling body's workability is better and uniaxial compressive strength is lower. When water cement ratio is 0.4, workability and strength of filling body is the best. The experiment provide reliable data for engineering application practice, at the same time to provide reference for other related experiment.
Application of Analytic Hierarchy Process in Bridge Safety Comprehensive Evaluation
Authors: Wang Jun Li
Published: March 2015

In order to appraise the safety and reliability of bridges effectively, the comprehensive evaluation model based on analytic hierarchy process was established. The weight of evaluation index was calculated by using the model, and each evaluation index was given score by experts according to actual circumstances, and, on this basis, safety level of the bridge was obtained. And, afterwards, the model was applied to an engineering example for Huangjiaba Bridge. The results show that the evaluation level of bridge safety is third-level, with serious problems existing in this practical example, and the corresponding measures are proposed, which can provide scientific reference for bridge safety management.
Estimation and Optimization of Cable Force in Completion State of Cable-Stayed Bridge
Authors: Wu Xun , Li Bao Lei
Published: March 2015

The reasonable cable force is the key factor for the safe use of cable-stayed bridge. This paper adopts the method of continuous beam on rigid supports, zero displacement method and the internal force balanced method for cable force estimation of completion stage. The estimation value of cable force is determined by comprehensive considering various methods. With the estimate value as the initial cable force of feasible domain method, conducting the cable force optimization. Comparing the optimization with estimation value and conducting analysis calculation to ensure the rational completion status. Referring a cable-stayed bridge’s example, and conducting the estimation and optimization of cable force, the calculated results meet the requirements. The results show that the method is effective and practical.
Mechanical Analysis and Economic Research of RPC Beam Bridge
Authors: Peng Xin , Yang Jian , Wang Jin Sheng
Published: March 2015

RPC(Reactive Powder Concrete) is a kind of high performance concrete which has many excellent mechanical properties, e.g. ultra-high-strength, high tenacity and good durability, and it has been applied in engineering practice. However, at present the economic research about RPC bridge is few at home and abroad, which has hindered the development of RPC bridge to some extent. By means of the mechanical analysis and economic research about NC(normal concrete ) beam bridge of pre-stressed steel strand (the span is 40m), RPC beam bridge of pre-stressed steel strand and RPC beam bridge of pre-stressed CFRP(Carbon Fiber Reinforced Polymer) tendon after the sectional optimization has been done, this paper reach the conclusion that the RPC beam bridge can greatly reduce the sectional size of beam bridge and reduce the weight by 23.7% , besides, the total cost of RPC beam bridge of pre-stressed steel strand is almost same with the total cost of NC beam bridge during the entire service period of bridge. Therefore, considering the long-term perspective, the integrated economy of RPC beam bridge of pre-stressed steel strand is good.
The Key Measures on Safety and Linear Control in Catwalk Erection
Authors: Liu Min , Xia Guo Bang , Liu Lai Jun , Chen Yong Rui , Zhang Xiao Yu
Published: March 2015

Multiple factors affect internal force and linear of catwalk, meanwhile, there are many safety and quality risks caused by these factors during its erection. So the control of the catwalks during its erection is very important. Based on the Puli grand bridge, the key control technology of catwalks erection is studied in this paper . The unstressed length of track cable in catwalks and the ultimate unbalance horizontal force on top of bridge tower during erection are calculated, which are part of precondition for safety control. The effects of temperature and tower deviation, which are main factors influenced the linear of catwalk track rop, are analyzed in this paper. Then the safety and linear control measures are put forward. The construction result shows that the safety control methods and linear adjustment measures are effective.
Solid Finite Element Analysis on close Frame of Airport Project
Authors: Teng Qi Jie
Published: March 2015

The close-frame is the main structure type of underground passage in airport project. Its characteristics are long route, multi-zone crossing, heavy load capacity. The suitable calculation method is a key issue to simulate the force of structure. Single-span close frame bearing Class A380F aircraft load is discussed in detail about stress and moment by solid finite element analysis. Therefore, it has important engineering significance in guiding structural design.
An Improved Stochastic Finite-Fault Method Based on Energy
Authors: Zhong Ju Fang , Liang Jun Wei , Fan Zhi Peng , Zhan Luo Long
Published: March 2015

Owing to the simulated ground motion energy distribution by stochastic finite-fault method is not reasonable, near-field bedrock strong ground motion acceleration time histories are used to study. Fourier transform is adapted to analysis the variation of the energy accumulation curve with frequency. The results show that the record energy accumulation curve is a steep rise curve, 80% of total energy of the vertical ground motion is concentrated on the 2.5-15Hz, while the horizontal is mainly concentrated on the 2-11Hz. An improved stochastic finite-fault method is proposed by multiplying an amplification factor in some frequency. The results show that multiplying an amplification factor, the simulated acceleration energy accumulation curve matches to the record acceleration energy accumulation curve, and the peak of simulated acceleration response spectrum tends to the record acceleration value.
Analysis of Pipe Settlement Based on Numerical Simulation
Authors: Guo Jian , Xia Peng , Shen Shuang Shuang
Published: March 2015

Settlement of comprehensive pipe is inevitable disturbed by construction and surrounding environment, in order to better understand the settlement rule of comprehensive pipe. Based on a large amount of monitoring data collected from integrated trench, a simulation model is proposed to analyzed comprehensive pipe settlement by using ABAQUS, the case results show that the simulation model performance can analysis the synthesis trench settlement. It has high prediction accuracy and fit for the settlement of integral comprehensive pipe.
Engineering Characteristics of Talus and its Influence Imposed on Tunneling
Authors: Jiang Xiang Yang , Xu Yong Ping
Published: March 2015

The special geological conditions of talus are often encountered in southwest China, it brings a lot of difficulties to tunnel construction. The formation mechanism and developmental properties of talus are analyzed in this paper. Based on field investigation on talus diseases, the hazard to tunnel engineering induced by talus and its corresponding measures are also analyzed. The results can be used for the safe and fast construction of tunnels which go through talus deposit.
Numerical Analysis and Spot-Survey Study of Horizontal Artificial Ground Freezing in Tunnel Connecting Passage Construction
Authors: Yue Feng Tian , Lv Shan Guo , Shi Rong Jian , Zhang Yong , Lu Lu
Published: March 2015

In this paper, a comprehensive method combined spot-survey and numerical simulation tests has been used to make an approach to systematically study of the technology of level artificial ground freezing in tunnel connecting passage construction. By simulating the freezing process of artificially frozen soils of Dalian Road tunnel connecting passage with finite element analysis method, the varying laws of temperature fields, displacement fields and stress fields had been worked out. According to the results of actual field survey, the changing laws of frost heave pressure and tunnel deformation with freezing temperature, elapsed freezing time during the artificial ground freezing period are obtained. The laws from finite element analysis are consistent with that from field survey, which has proved that finite element analysis is correct. The conclusions of the research prove the advantages of horizontal artificial ground freezing in such similar construction and set up a successful model for related freezing projects in the future, which, will guide the coming practice and safeguard the success.
Numerical Analysis of Tunnel Running through Bridge Pile Foundation
Authors: Li Jin Kui , Tang De Jin
Published: March 2015

Based on the background of Dalian subway running through bridge pile foundation, a 3d numerical model is built by the finite element software MIDAS/GTS in order to research the laws of the internal force and the displacement of the pile and soil during the Construction process. The outcome reflects that the sedimentation value of the top of the pile is bigger than others. Because the bigger thrust about the shield machine, the horizontal displacement of the pile is increasing at first and decreasing at last from a positive into a negative. Because of the loss of the soil, the soil beside the pile collapses and causes strong friction force. The surface sedimentation value which is near the central line of the tunnel is bigger than other place. This paper is of good reference roles in the similar underground engineering in Dalian.
Surface Settlements Caused by Three-Bench Seven-Step-Excavation of Large Span Twin Tunnels
Authors: Yan Li , Yang Jun Sheng , Nan Kang
Published: March 2015

As a new method, the three-bench seven-step-excavation method is more and more adopted by the construction of large span tunnel in weak rock mass. At the portal of Yunyangshan tunnel, there is a long section of the mild clay stratum. Considered that the whole excavated cross section area is very large, the three-bench seven-step-excavation method was adopted. In order to investigate the surface settlements caused by the construction of twin tunnels, three typical cross-section were selected. At each section, the ground surface settlements were monitored. It is shown that the depth of tunnel and the construction time of twin tunnels have influence on the surface settlement curves, and the three-bench seven-step-excavation is effective in the mild clay stratum.
In chains, yet prophetic! An African liberationist reading of the portrait of Paul in Acts 27
Authors: Mtshiselwa Ndikho
Published: March 2015

New Testament scholars have argued that Luke-Acts presents an apologetic historiography and political propaganda which portrayed Roman officials as saviours of the world. The problem with the discourse on the apologetic historiography and political propaganda in Luke-Acts is that the presence of various forms of oppression behind and in the text becomes hidden. Thus, it is pertinent to highlight the reality of oppression as well as the prophetic voice that responded to them, as illustrated by the text of Acts 27. In this article, Lucky Dube’s Mickey Mouse freedom song is employed as a hermeneutical tool to unlock the meaning of Acts 27, and to argue that whereas Acts 27 contains an apologetic narrative, Paul’s prophetic voice is equally evident in the chapter. From an African liberationist perspective, lessons are therefore drawn from Acts 27 regarding the liberationist prophetic voice of Paul. In the end, this article sees Paul’s prophetic voice as an embodiment of both resilience and resistance in the face of imperialism and chains (oppression).
Seasonal changes in the tropospheric carbon monoxide profile over the remote Southern Hemisphere evaluated using multi-model simulations and aircraft observations
Authors: Fisher J. A. , Wilson S. R. , Zeng G. , Williams J. E. , Emmons L. K. , Langenfelds R. L. , Krummel P. B. , Steele L. P.
Published: March 2015

Abstract. The combination of low anthropogenic emissions and large biogenic sources that characterizes the Southern Hemisphere (SH) leads to significant differences in atmospheric composition relative to the better studied Northern Hemisphere. This unique balance of sources poses significant challenges for global models. Carbon monoxide (CO) in particular is difficult to simulate in the SH due to the increased importance of secondary chemical production associated with the much more limited primary emissions. Here, we use aircraft observations from the 1991–2000 Cape Grim Overflight Program (CGOP) and the 2009–2011 HIAPER (High-performance Instrumented Airborne Platform for Environmental Research) Pole-to-Pole Observations (HIPPO), together with model output from the SH Model Intercomparison Project, to elucidate the drivers of CO vertical structure in the remote SH. Observed CO vertical profiles from Cape Grim are remarkably consistent with those observed over the southern mid-latitudes Pacific 10–20 years later, despite major differences in time periods, flight locations, and sampling strategies between the two data sets. These similarities suggest the processes driving observed vertical gradients are coherent across much of the remote SH and have not changed significantly over the past 2 decades. Model ability to simulate CO profiles reflects the interplay between biogenic emission sources, the chemical mechanisms that drive CO production from these sources, and the transport that redistributes this CO throughout the SH. The four chemistry-climate and chemical transport models included in the intercomparison show large variability in their abilities to reproduce the observed CO profiles. In particular, two of the four models significantly underestimate vertical gradients in austral summer and autumn, which we find are driven by long-range transport of CO produced from oxidation of biogenic compounds. Comparisons between the models show that more complex chemical mechanisms do not necessarily provide more accurate simulation of CO vertical gradients due to the convolved impacts of emissions, chemistry, and transport. Our results imply a large sensitivity of the remote SH troposphere to biogenic emissions and chemistry, both of which remain key uncertainties in global modeling. We suggest that the CO vertical gradient can be used as a metric for future model evaluation as it provides a sensitive test of the processes that define the chemical state of the background atmosphere.
Mesoscale modeling study of the interactions between aerosols and PBL meteorology during a haze episode in Jing–Jin–Ji (China) and its nearby surrounding region – Part 1: Aerosol distributions and meteorological features
Authors: Wang H. , Xue M. , Zhang X. Y. , Liu H. L. , Zhou C. H. , Tan S. C. , Che H. Z. , Chen B. , Li T.
Published: March 2015

Abstract. The urbanized region ofJing(Beijing)-Jin(Tianjin)-Ji (alias of Hebei province) and its nearby surrounding region (3JNS) is becoming China's most polluted area by haze, exceeding even the Yangtze and Pearl river deltas. Aside from pollutant emission, the meteorology of the planetary boundary layer (PBL) is the most important factor affecting haze pollution. Focusing on July 2008, the aerosol optical properties and PBL meteorology features closely related to haze formation were simulated in the 3JNS region using an online atmospheric chemical transport model. The relationship between regional PBL meteorology, PM2.5, and haze is discussed. Model results accurately simulated the aerosol optical depth (AOD), single scattering albedo (SSA) and asymmetry parameter (ASY), validated by comparison with observations from the MODerate Resolution Imaging Spectroradiometer (MODIS), the China Aerosol Remote Sensing NETwork (CARSNET) and the Aerosol Robotic NETwork (AERONET). Modeled PBL wind speeds showed reasonable agreement with those from the National Centers for Environmental Prediction (NCEP) Reanalysis 2. A monthly mean AOD value as high as 1.2 was found from both model and observations, with a daily mean larger than 2.0 during haze episodes in the 3JNS region. Modeled and observed SSA values of 0.90–0.96 and ASY values of 0.72–0.74 demonstrated the high scattering characteristic of summer aerosols in this region. PBL wind speeds from modeled and NCEP data both showed a reversing trend of PM2.5 variation, illustrating the importance of the "PBL window shadow" in haze formation. Turbulence diffusion and PBL height had opposite phases to surface PM2.5, indicating that lower PBL height and weaker PBL turbulence diffusion are essential to haze formation. It is noted that homogeneous air pressure does not occur at the surface, but at an 850–950 hPa height during the haze episode. The momentum transmitting downward of the cold air from above the PBL to the low PBL and surface lead to an increase in surface wind speeds and haze dispersal.
Mesoscale modelling study of the interactions between aerosols and PBL meteorology during a haze episode in China Jing–Jin–Ji and its near surrounding region – Part 2: Aerosols' radiative feedback effects
Authors: Wang H. , Shi G. Y. , Zhang X. Y. , Gong S. L. , Tan S. C. , Chen B. , Che H. Z. , Li T.
Published: March 2015

Abstract. Two model experiments, namely a control (CTL) experiment without aerosol–radiation feedbacks and a experiment with online aerosol–radiation (RAD) interactions, were designed to study the radiative feedback on regional radiation budgets, planetary boundary layer (PBL) meteorology and haze formation due to aerosols during haze episodes over Jing–Jin–Ji, China, and its near surroundings (3JNS region of China: Beijing, Tianjin, Hebei, East Shanxi, West Shandong and North Henan) with a two-way atmospheric chemical transport model. The impact of aerosols on solar radiation reaching Earth's surface, outgoing long-wave emission at the top of the atmosphere, air temperature, PBL turbulence diffusion, PBL height, wind speeds, air pressure pattern and PM2.5 has been studied focusing on a haze episode during the period from 7 to 11 July 2008. The results show that the mean solar radiation flux that reaches the ground decreases by about 15% in 3JNS and 20 to 25%in the region with the highest aerosol optical depth during the haze episode. The fact that aerosol cools the PBL atmosphere but warms the atmosphere above it leads to a more stable atmospheric stratification over the region, which causes a decrease in turbulence diffusion of about 52% and a decrease in the PBL height of about 33%. This consequently forms a positive feedback on the particle concentration within the PBL and the surface as well as the haze formation. Additionally, aerosol direct radiative forcing (DRF) increases PBL wind speed by about 9% and weakens the subtropical high by about 14 hPa, which aids the collapse of haze pollution and results in a negative feedback to the haze episode. The synthetic impacts from the two opposite feedbacks result in about a 14% increase in surface PM2.5. However, the persistence time of both high PM2.5 and haze pollution is not affected by the aerosol DRF. On the contrary over offshore China, aerosols heat the PBL atmosphere and cause unstable atmospheric stratification, but the impact and its feedback on the planetary boundary layer height, turbulence diffusion and wind is weak, with the exception of the evident impacts on the subtropical high.
The impact of parameterising light penetration into snow on the photochemical production of NOx and OH radicals in snow
Authors: Chan H. G. , King M. D. , Frey M. M.
Published: March 2015

Abstract. Snow photochemical processes drive production of chemical trace gases, including nitrogen oxides (NO and NO2), and HOx radicals in snowpacks which are then released to the lower atmosphere. Coupled atmosphere–snow modelling on global scales requires simple parameterisations of actinic flux in snow to reduce computational cost. The disagreement between a physical radiative transfer method and a method based upon the e-folding depth of light-in snow is evaluated. In particular for the photolysis of the nitrate anion (NO3-), the nitrite anion (NO2-) and hydrogen peroxide (H2O2) within snow and photolysis of gas-phase nitrogen dioxide (NO2) within the snowpack interstitial air are considered. The emission flux from the snowpack is estimated as the depth-integrated photolysis rate, v, calculated (a) explicitly with a physical radiative transfer model (TUV), vTUV and (b) with a simple parameterisation based on e-folding depth, vze. The evaluation is based upon the deviation of the ratio of depth-integrated photolysis rate determined by the two methods,vTUV/vze, from unity. The disagreement in depth-integrated photolysis rate between the RT model and e-folding depth parameterisation depends primarily on the photolysis action spectrum of chemical species, solar zenith angle and optical properties of the snowpack, (scattering cross-section and a weak dependence on light absorbing impurity (black carbon) and density). For photolysis of NO2, the NO2- anion, the NO3- anion and H2O2 the ratio vTUV/vze varies within the range of 0.82–1.35, 0.88–1.28 and 0.92–1.27 respectively. The e-folding depth parameterisation underestimates for small solar zenith angles and overestimates at solar zenith angles around 60°. A simple algorithm has been developed to improve the parameterisation which reduced the ratio vTUV/vze to 0.97–1.02, 0.99–1.02 and 0.99–1.03 for photolysis of NO2, the NO2- anion, the NO3- anion and H2O2 respectively. The e-folding depth parameterisation may give acceptable results for the photolysis of the NO3- anion and H2O2 in cold polar snow with large solar zenith angles, but can be improved by a correction based on solar zenith angle.
In-situ, satellite measurement and model evidence for a~dominant regional contribution to fine particulate matter levels in the Paris Megacity
Authors: Beekmann M. , Prévôt A. S. H. , Drewnick F. , Sciare J. , Pandis S. N. , Denier van der Gon H. A. C. , Crippa M. , Freutel F. , Poulain L. , Ghersi V. , Rodriguez E. , Beirle S. , Zotter P. , von der Weiden-Reinmüller S.-L. , Bressi M. , Fountoukis C. , Petetin H. , Szidat S. , Schneider J. , Rosso A. , El Haddad I. , Megaritis A. , Zhang Q. J. , Michoud V. , Slowik J. G. , Moukhtar S. , Kolmonen P. , Stohl A. , Eckhardt S. , Borbon A. , Gros V. , Marchand N. , Jaffrezo J. L. , Schwarzenboeck A. , Colomb A. , Wiedensohler A. , Borrmann S. , Lawrence M. , Baklanov A. , Baltensperger U.
Published: March 2015

Abstract. A detailed characterization of air quality in Paris (France), a megacity of more than 10 million inhabitants, during two one month intensive campaigns and from additional one year observations, revealed that about 70% of the fine particulate matter (PM) at urban background is transported on average into the megacity from upwind regions. This dominant influence of regional sources was confirmed by in-situ measurements during short intensive and longer term campaigns, aerosol optical depth (AOD) measurements from ENVISAT, and modeling results from PMCAMx and CHIMERE. While advection of sulfate is well documented for other megacities, there was surprisingly high contribution from long-range transport for both nitrate and organic aerosol. The origin of organic PM was investigated by a comprehensive analysis of aerosol mass spectrometer (AMS), radiocarbon and tracer measurements during two intensive campaigns. Primary fossil fuel combustion emissions contributed less than 20% in winter and 40% in summer to carbonaceous fine PM, unexpectedly little for a megacity. Cooking activities and, during winter, residential wood burning are the major primary organic PM sources. This analysis suggests that the major part of secondary organic aerosol is of modern origin, i.e. from biogenic precursors and from wood burning. Black carbon concentrations are on the lower end of values encountered in megacities worldwide, but still represent an issue for air quality. These comparatively low air pollution levels are due to a combination of low emissions per inhabitant, flat terrain, and a meteorology that is in general not conducive to local pollution build-up. This revised picture of a megacity only controlling part of its own average and peak PM levels has important implications for air pollution regulation policies.
Family and Work–Life Balance Mechanisms
Authors: Poggesi Sara , Mari Michela , De Vita Luisa
Published: March 2015

Since 2000, research on female entrepreneurship has evolved substantially; however, some areas of research remain underinvestigated. In particular, to grasp the facets of this growing phenomenon, analysis of the characteristics of female firms in countries that are different from the USA and UK and the consideration of the embeddedness of entrepreneurship in family contexts are strongly needed. Thus, these two areas represent research gaps that this paper aims to address by analysing the influence that the family and work–life balance mechanisms have on the performance of 200 Italian female service firms. Contrary to the authors' hypotheses, the results show that family does not influence these firms' performance, and data from work–life balance mechanisms confirm these results.
The Belgian Law on Mediation, in light of the UNCITRAL Model Law on International Commercial Conciliation and of the UNCITRAL Project on Enforceability of Settlement Agreements
Authors: Knieper Judith , Montineri Corinne
Published: March 2015

The Belgian Law on Mediation, in light of the UNCITRAL Model Law on International Commercial Conciliation and of the UNCITRAL Project on Enforceability of Settlement Agreements

This contribution sets out the work done so far by UNCITRAL in the field of conciliation/mediation, but also examines whether the Belgian Mediation Act is compatible with the UNCITRAL Model Law on International Commercial Conciliation of 2002. Finally, it gives an introduction to the proposal made by the U.S. delegation to the UNCITRAL Commission to elaborate an international convention on the enforcement of mediated settlement agreements.