bluuebunny/crossref_metadata_2025 huggingface dataset:
Settlement and damage analysis of working shaft for underground high-voltage electricity cables
Authors: Wang Yanfeng , Guo Jingen , Tang Yongfeng , Liu Tingjin , Yang Yubing
Published: September 2019

Working shafts or manholes, usually made of concrete or reinforced concrete, are essential parts of the underground electrical power transmission system. However, the working shaft frequently encountered differential settlement, tilt and other damage like cracking when construction activity was carried out near the high-voltage electricity cables. This paper reported a severe damaged working shaft in South China including its settlement and cracks. Numerical simulation was also performed to reveal the evolution of structural damage with an increased differential settlement. The results show a good agreement with field observation in respect to the initiation of concrete tension damage. It is proposed that if a differential settlement higher than 5mm is observed, preventative measures are needed and the risk is conditional acceptable.
Parametrical intelligent design of steel bridges based on APDL language
Authors: Tan Jinhua , Zhang Han , Jin Jingwen
Published: September 2019

Bridge is a hub project of traffic engineering, and it also reflects the comprehensive national strength of a country and a region, such as economic strength, science and technology, productivity development and so on. Parametric intelligent design is an inevitable trend of bridge engineering’s development under the existing knowledge system. A parametric static and dynamic analysis software has been developed for two types of typical steel bridges -- steel tube arch bridges and steel truss bridges based on APDL language. It can do the intelligence design work automatically for those bridges, which including the preprocessing work and the postprocessing work, such as the input of material data, section data, structure size, loads and constraints, and the output of force results, stress results, capturing images, and writing the design report file. Even the designer who is not professional can do the preliminary design work of a same type bridge quickly and easy with this software.
Study on Natural Ventilation in Gridiron of High-pile Wharf to Enhance The Durability Performance
Authors: Zhang Qin , Zhou Yubao , Zhang Yibin
Published: September 2019

The salt which origins from offshore zone is easy to gather in the semi-closed space formed by beams and slabs of pile-supported wharf called gridiron space, and that could induce the premature failure of durability of the wharf’s substructure. Previous work commonly focused on material-level measures which will lead to increased costs such as anti-corrosion concrete and anti-corrosion coatings to eliminate the adverse effects of that gathering of salt fog. In fact, the salt fog could be extracted from the gridiron by natural ventilation in some cases, so it is necessary to examine the flow characteristics in the gridiron space. In this work, the numerical simulation has been conducted with natural ventilation and auxiliary ventilation group. Critical value of the blocking ratio (defined as height ratio of edge stringer to air inlet) that makes the airflow inside the gridiron reach the strongest turbulence is found in natural ventilation group. In addition, the effect of different auxiliary ventilation schemes is compared in auxiliary ventilation group. Some recommendations for designing were proposed to enhancing pile-supported wharf’s durability.
Research on the traffic organization optimization countermeasures in highway service area under the abnormal condition
Authors: Wang Jiaxian , Zhao Baocai , Jia Wenli , Yang Yunxing
Published: September 2019

In order to effectively improve the utilization rate and service turnover rate of highway service area, and make the traffic flow more smoothly, this paper studies the transportation organizations under special circumstances, such as extreme weather, natural disasters, holiday peak trips and other special situations. Traffic organization optimization countermeasures are proposed from three aspects: controlling the total amount of traffic, optimizing the internal organization and improving the departure rate. The result can provide reference for the construction and optimization of service area in the future.
Torsional vibration solution of tapered pile considering stress diffusion effect of pile end soil
Authors: Guan Wenjie , Wu Wenbing , Jiang Guosheng , Leo Chin Jian , Liu Hao
Published: September 2019

Based on the torsional plane strain model and tapered fictitious soil pile model, the torsional vibration characteristics of tapered pile considering stress diffusion effect of pile end soil is investigated theoretically. Considering the coupling conditions of pile-soil system, the torsional impedance at the tapered pile head is obtained by means of Laplace transform and impedance transfer method. A parametric study is performed, the rationality of the tapered fictitious soil model is verified and the influence of the cone angle of tapered fictitious soil pile on the torsional vibration characteristics of tapered pile embedded in layered soil is studied. The results show that: the cone angle of tapered fictitious soil pile has obvious effect on the torsional vibration characteristics of tapered pile with the shorter length.
Vehicle load updating of roadway bridges based on Bayesian method and Monte Carlo simulation
Authors: Li Zhan , Jiang Wei , He Jiaqi , Yang Yang , Narilige
Published: September 2019

For the life-cycle design of bridges, it is of significance to establish and update the probabilistic model. However, for the current situation of practical engineering, popularizing data acquisition equipments to collect long-term data could not meet the facts. The Monte Carlo simulation is utilized to simulate the prior samples and expand the sample size. The Bayesian method is adopted to update the sectional distribution. A mathematical example based on self programming is given to illustrate the method. The results show that: the cooperation of the Bayesian method and Monte Carlo simulation could update the short-term vehicle load model. The method is of good reliability and serviceability which could be references for further studies.
The static analysis of arch dam-foundation system by using scaled boundary finite element method
Authors: Xue Binghan , Fang Hongyuan , Wang Fuming , Hu Zhiqiang , Lei Jianwei
Published: September 2019

The scaled boundary finite element (SBFEM) as a semi-analytical numerical method has been used in many fields. SBFEM has the following advantages: reducing the spatial dimension by one, rigorously modelling the unbounded domain and involving no fundamental solution. The computational model based on SBFEM will be conducive to the reliability and efficiency of safety evaluation of arch dam. However, owing to the requirement of scaling inherently, the SBFEM cannot be immediately applied in the analysis of arch dam which belongs to irregular shell structure. This limitation can be overcome by employing the sub-structure method to subdivide the arch dam into several sub-structures which satisfy the scaling requirement. An example of static analysis of the arch dam-foundation system is presented to verify the effectiveness of the SBFEM sub-structure method. The result is helpful to establish the calculating model of arch dam-reservoir-foundation system based on scaled boundary finite element method.
Influence of Rock Quality and Excavation Mode on Horizontal Displacement of Crushing-zone Tunnel
Authors: Xu Binbin
Published: September 2019

In order to simulate the tunnel excavation of super-long broken rock zone, finite element analyses using Plaxis3D are carried out along with the construction, in which the influence of grade of surrounding rock, are excavation method on the deformation of tunnel are specially considered. Before numerical calculation, the parameters are reasonably simplified. The calculation results show that the CD method can efficiently reduce the deformation of rock in the broken zone to keep the stability. In the practical construction, it is recommended that the CD method is preferred when entering the broken zone.
Discussion of Proper Ribs in Hollow Torsion Test using Numerical Method
Authors: Xu Binbin
Published: September 2019

In the numerical simulation hollow torsion test, the number of rigid ribs applied on the top surface of the specimen is the key to guarantee the success of the calculation. If the number of rigid ribs is too large, the stiffness difference between the pedestal and the specimen would be too big to get a reliable result. While if the number of ribs is too little, the torque cannot be transferred to the specimen faithfully. A numerical calculation is carried out to determine the suitable number of rigid ribs from the aspects of shear strain, ap-parent mechanical behavior and torque rate and the results show that 6 ribs are suitable for the numerical hollow torsion test.
Characteristics and mechanism of loess landslide induced by drill vibration
Authors: Si-yi Jiang , Hai-liang Li , Fu Wu , Chun-ling Li
Published: September 2019

In order to reveal the disaster mechanism of loess landslide induced by rig vibration, based on the analysis of typical cases of loess landslide, the disaster process of loess landslide triggered by rig vibration was analyzed through field investigation, physical model test and stress path test. The results showed that the instability mechanism of vibration-type loess landslide was a dynamic process under the action of vibration load. This process can be summarized as follows: stable loess slope – vibration load of drilling rig – adjustment of slope stress – shear failure occurs under continuous load – slope body begins to slide after sliding surface gradually forms – landslide forms
Study on Vibration Characteristics of Piers and Foundation Sites in Seasonal Frozen Soil Areas under Train Load
Authors: Zheng Haizhong , Yan Wujian , Wang Ping , Li Fuxiu
Published: September 2019

In order to study the vibration characteristics of railway piers and different foundation sites in seasonal frozen soil region under train load, the piers and foundation sites of Tieling-Siping of Harbin-Dalian high-speed railway were tested on site, and the vibration attenuation characteristics of different sites and different seasons were analysed using numerical simulation method. The results show that the vibrations in the Y and Z directions are amplified on the side of piled soil-filling in both freezing and non-freezing seasons, when the distance R from the bottom of pier is less than 0.8m. But the vibration is amplified only in Z direction on the side of non-piled soil-filling. In the freezing season or in the non-freezing season, when R is between 1 and 2m, the vibration attenuation speed on the side of piled soil-filling is obviously lower than that on the side of non-piled soil-filling. When R is larger than 3m, the vibration attenuation of three directions is not affected by the piled soil-filling or not. Whether on the side of piled soil-filling or non-piled soil-filling, the vibration attenuation speed in freezing season is lower than that in non-freezing season.
Treatment of Errors in Dam Safety Monitoring Data
Authors: Zhang Xuan , Li Junjie
Published: September 2019

The error processing of dam safety monitoring data is the basic work of the whole data analysis, and it is the guarantee for objectively evaluating the safety of dams. This paper summarizes the sources of error, analysis methods and research status of dam monitoring data, lists several commonly used error processing methods and the latest research progress, and compares 3σ criterion, Grubbs criterion and mathematical model method, and finally analyzes through engineering examples.
Probabilistic Assessment on Stability of Slopes Reinforced with Piles Considering Spatial Variability of Soil Properties
Authors: Chen Fuyong , Cheng Longfei , Zhou Tingqiang , Chen Xiang , Zhang Wengang
Published: September 2019

The spatial variability is an inherent property of soil materials, which heavily affected the failure probability of slope. In the present study, deterministic analysis with factor of safety and reliability analysis in uniform soil grounds and spatial variable soil conditions are successively carried out to investigate the effect of uncertainties and the spatial variability of soil on the stability of slope reinforced with piles using random limit equilibrium method (RLEM). The optimal location and length of pile are also analysed based on the calculation results of RLEM, which is inconsistent with the results of traditional deterministic method. The obtained results demonstrate the significant effect of the spatial variability on the failure probability of slope reinforced with pile.
Seismic behavior of perforated brick walls with HPFL strips composite ring beam and constructional column
Authors: Min Lei , Shou-ping Shang
Published: September 2019

The existing perforated brick masonry structures are usually lack of ring beam and constructional column. Aiming at this problem, a new method of HPFL strips composite ring beam and constructional column is proposed. Six perforated brick walls with HPFL strips composite ring beam and constructional column and two comparative walls are tested under low cycle reversed loading. The failure mode, ultimate strength, energy dissipation capacity, and ductility of the strengthened walls and the comparative walls are compared. A calculation method is proposed for predicting the seismic shear capacity of perforated brick walls with HPFL strips composite ring beam and constructional column. The results show that using this method, the cracking load, ultimate load, energy dissipation capacity and deformation capacity are improved greatly. The calculated results are in good agreement with the measured results. The calculated method can provide the reference for seismic strengthening design of the perforated brick masonry.
Vertical Seismic Response Analysis of Large Span Isolated Structures under Multi-Dimensional and Multi-Support Excitations
Authors: Gu Zhen-yuan , Sun Zhen , Xu Yi-kang , Wang Yi
Published: September 2019

The multi-point random ground motion is artificially synthesized based on the triangular series method. Then the variation law and damping effect of vertical seismic response of large span isolated structures with different spans are studied respectively, under the action of both frequent earthquake and rare earthquake. The results show that in some areas of large span isolated structures, the vertical seismic responses are larger than those of non-isolated structures, under the multi-dimensional multi-point seismic input. The damping effects of large span isolated structures under rare earthquake are better than those under frequent earthquake. The area that is near the supports is prone to a large increase in response after isolation, so there should be strengthened during the engineering design.
Identification and Analysis of Main Harmful Factors in Tailings pond
Authors: Li Quanming , Liu Yinkun , Zhang hong
Published: September 2019

Combined with the particle size classification of the tailings pond, according to the corresponding laws and regulations of the safe production process, the tailings pond is identified and analyzed from four aspects: human, material, environment and management. From the source, the possible harmful factors in the tailings pond are pointed out, which will provide reference for the safe and effective operation of the tailings pond in the future.
Study on evaluation of emergency plan for production accident
Authors: Zhou Ying , Li Feng , Liu Xixiao , Jiang Wen
Published: September 2019

The emergency plan assessment plays an important role in strengthening production safety accident prevention and improving the ability to respond to emergencies. This paper analyzes the causes of production accidents and the problems existing in the treatment, and combines the existing evaluation system to establish a more practical evaluation index system. Taking project A’s emergency plan as the evaluation object, the project is evaluated by rough set and gray comprehensive evaluation model. The project evaluation grade of A is optimal, and the feasibility of the program implementation needs to be further improved. This paper can evaluate the whole and part of the project more scientifically and accurately, by the establishment of the evaluation index system and method, and it has strong practicability.
Comparative Study on Calculation Methods for Stability Evaluation Based on BIM Models of Soil Landslides
Authors: Wei Cheng , Wang Jinbao , Cheng Feng
Published: September 2019

The purpose of landslide prevention and control is to keep the stability within a safe range. This paper proposes a new direction of landslide information prevention and control with BIM technology for soil landslide, which is a typical type of landslide. The BIM model was established by referring to the engineering geological parameters of typical soil landslides, and then several commonly used landslide stability calculations were compared and studied by using the model research method. On the basis of BIM model of typical soil landslide, the results of calculating related engineering geological problems by different stability calculation methods were verified, and the characteristics of different stability calculation methods were revealed. When several common methods were used to calculate the stability of typical soil landslides. How to select the appropriate methods for calculations is an inevitable problem whenever the stability evaluation of landslide prevention and control is carried out, so it is of important engineering value and significance for this research.
Study on the Influence of Soil Parameters Change on the Stability of Foundation Pit
Authors: Wang Yongwei
Published: September 2019

Combining with engineering examples, the influence of grouting on the stability of foundation pit is analyzed by comparing the parameters before and after grouting. The numerical analysis software FLAC is used to simulate the original foundation pit without grouting. The relationship between the maximum horizontal displacement and cohesion, friction angle and elastic modulus is explored. The fitting formulas of the influence of elastic modulus, friction angle and cohesion on displacement are put forward. Enclosure design provides basic data.
Study on the Influence of Dry-wet Cycle on the Pore Size of Dam Soil
Authors: Ye Wei , Ma Fuheng
Published: September 2019

In view of the influence of dry-wet cycle on soil structure, the suction variation of different parts of the model dam slope was obtained, and the soil-water characteristic curve was drawn accordingly. According to the soil-water characteristic curve, the pore size of soil was analyzed. Based on the assumption that the pore size of soil was a sphere, the change of pore radius in the process of drought was analyzed, and the change of pore volume in the whole process of drought was studied. The results showed that the pore volume of soil without cracks would increase in the process of drought, and the greater the influence of dry-wet cycle condition was, the more obvious the change was. The increase of pore volume would reduce the compactness of soil and threaten the safety of filling engineering.
Performance of tuned tandem mass dampers based on shape memory alloy
Authors: Chang Ke , Li Chunxiang
Published: September 2019

Tuned tandem mass dampers based on shape memory alloy (SMA-TTMD) are proposed in this paper. The SMA-TTMD is formed by replacing the connection damping between two mass blocks in the TTMD with a shape memory alloy spring. Firstly, the stochastic equivalent linearization of non-linear SMA is presented. It is attached to a single-degree-of-freedom structure excited by stationary filtered white noise to study the performance of SMA-TTMD. Based on the minimum displacement variance of the main structure, the structure random vibration method is used to study the optimal control performance. The effectiveness and stroke of the SMA-TTMD under the changes of mass ratios are studied, and the optimal parameters of the system are proposed. The results are compared with those of TTMD. The numerical analysis shows that the control performance of SMA-TTMD is better than that of TTMD. The results demonstrate that the stroke of SMA-TTMD is obviously superior to that of TTMD.
Study on the creep behavior of Tianjin marine soft clays and its improved Mesri model
Authors: Li Gang , Yan Zhen , Zhang Jinli , Liu Jia , Liu Rui
Published: September 2019

Marine soft clays are widely distributed in coastal areas. Owing to their strong creep properties, soft clay foundations undergo significant post-construction settlement, thereby affecting the life cycle of buildings. In this study, the creep behavior of Tianjin marine soft clays was investigated by consolidated-undrained triaxial creep tests. Based on the creep test results and the Mesri creep model and by treating the final clay deformation under each increment of load as the initial strain, an improved Mesri creep model that describes both the stress-strain and strain-time relationships using hyperbolic functions was established. The creep curves under various levels of cell pressure and deviatoric stress showed notable decay and stable creep characteristics but contained no accelerated creep stage. The stress-strain isochronous curves exhibited notably nonlinear characteristics. Relative to the results calculated by the Singh-Mitchell and Mesri models, the results calculated by the improved Mesri model were in better agreement with the test results, which suggests that the established model is suitable for describing the creep behavior of Tianjin marine soft clays and can provide a reference for predicting the long-term settlement of foundations.
Analysis on the Variation Rule of Aperture of the Normal Circulation Bored Pile
Authors: Wu Yan , Wang Yibo , Liu Lan , Gao Wenlong
Published: September 2019

The hole formation is the most important link in the construction of bored piles. The quality of the hole formation plays a decisive role in the bearing capacity of cast-in-place piles. Combined with the field measurement data of hole formation in Changzhou Science And Technology Financial Center, combined with the time factor and the buried depth factor, the pore diameter change was analyzed. At the same time, the monitoring data was compared and analyzed by means of numerical simulation. The results show that the stress releases and the pore diameter decreases with the change of depth. With the increase of time, the pore size decreases. Due to the influence of soil structure, the pore diameter shrinkage of silty sand layer is up to 12.5%, while the silty clay layer is generally relatively small, with the maximum value not exceeding 6.25%.
Experimental study on elastic modulus of concrete mortar under high temperature
Authors: Wei Jiang , Derui Huang , Kuizhou Liu , Yujie Shen , Yang LI
Published: September 2019

In order to study the change of elastic modulus of mortar concrete under high temperature, the mortar cube was tested at high temperature.The results show that the elastic modulus of the mortar cube is not linear with the change of temperature. The elastic modulus of the mortar decreases with the increase of temperature. When the temperature rises to 150 °C, the mortar elastic mold will have a The situation of slowing down and then falling again.
Mechanical properties of ultra-low temperature mortar stone
Authors: Kui-zhou Liu , De-rui Huang , Wei Jiang , Yu-jie Shen , Yang Li
Published: September 2019

In order to study the mechanical properties of concrete materials in the normal operation phase of LNG tanks, the longitudinal strain of the loading direction and the transverse strain of the vertical loading at the corresponding temperature were measured by using the resistance strain gauge test technique. The elasticity of the mortar block and stone in the ultra-low temperature environment was studied. Modulus, Poisson’s ratio and shear modulus are respectively related to temperature. The results show that the Poisson’s ratio of stone and mortar is not obvious with temperature, which can be considered as a fixed value; the elastic modulus and shear modulus of mortar block increase linearly with the decrease of temperature, and the elastic modulus and shear modulus of stone The temperature decrease is a quadratic function relationship of decreasing first and then increasing. The elastic modulus and shear modulus of the stone are all the smallest at around -60 °C. It is concluded that the concrete material has better mechanical properties than the normal temperature environment in the ultra-low temperature environment, and can be used to further improve the design and construction of the LNG tank.
Study on the Effects of Joint Inclination and Size Effect on the Failure Process of Rock-like Materials
Authors: tao Dong , ping Cao , Zhizhen Liu , fei Wang
Published: September 2019

To explore the effects of joint inclination angle and the size on the mechanical properties and failure process of rock-like specimens, a series of uniaxial compression tests were carried out on rock-like specimens.The specimens are consist of two sizes and contain three parallel joints with various inclination angles. During testing, the variation characteristics of apparent strain field of specimens is recorded by digital image correlation (DIC) system. Testing results reveal the uniaxial compression strength of the specimen decreases gradually with the joint inclination increases from 0° to 60°, while increasing gradually with the joint inclination increases from 60° to 90°. In addition, the peak compression strength of the large-size specimens is obviously lower than that of the small-size specimen when the joint inclination angle is 0°~30°. By contrast, the peak compression strength of the large-size specimens is the same as that of the small-size specimen when the angle is 30°~60°, approximately. But, the peak compression strength of large-size specimen is obviously higher than that of small-size specimen when the joint inclination angle is between 60° and 90°. Finally, five different types of cracks are observed in this work, i.e., tensile crack,airfoil tension crack,pull-shear mixing crack,secondary crack and far field tensile crack.
Experimental Study on Thermal Conductivity of Sand Solidified by Microbially Induced Calcium Carbonate Precipitation
Authors: Ding Jinhua , Wang Zhaoyu , Zhang Nan , Jiang Pengming , Peng Mingxing , Jin Yong , Li Qi
Published: September 2019

Soil thermal conductivity is relatively low in low saturation ranges in arid regions, resulting in low heat transfer efficiency of ground source heat pump (GSHP) systems. In this study, thermal conductivity of sand solidified by microbially induced calcium carbonate precipitation (MICP) was measured at different saturation levels. The test results reveal that the thermal conductivity of MICP treated sand increases with the increase in saturation degree (Sr), and the increasing rate gradually decreases. Use of the MICP technique not only increases the thermal conductivity of sands, but also reduces the influence of saturation degree on sand thermal conductivity when Sr is less than 0.22. This study provides a new research direction for the MICP technique and a technical reference for GSHP applications.
Experimental Study on The Effect of Cement-Lime Double Admixture on Dewatering and Strength of Sludge
Authors: Peng Cheng , Tian Zongkun , Tan Yuqing , Long Hui
Published: September 2019

Cement and lime are mixed into the sludge in different ratios to analyze the effect of curing agent on sludge dewatering and the dehydration rate, improve the strength of sludge, and promote the application of sludge in water conservancy and geotechnical engineering. The solidified sludge was subjected to test of moisture content and direct shear test to study the dewatering effect and strength characteristics of the improved soil. It was found that the precipitation and dehydration rate of solidified sludge were related to the ratio of curing agent incorporation. The higher the incorporation ratio is, the more obvious the dehydration effect is, and the maximum reduction value of dehydration is 13%. The sample’s dehydration rate is from the large to the small, and the average precipitation rate of 0-12h is 2-6 times than that of 12-72h. With the increase of the dosage of curing agent, the cohesion of solidified soil increases obviously, and its range of variation is between 32 and 77kPa. The internal friction angle of the sample increases with the increase of cement content, but fluctuates slightly under the action of lime. After comprehensive consideration of dehydration effect, shearing strength parameters and economic benefits, the optimal ratio of cement and lime to modified sludge soil can be controlled at 10% and 10%, respectively.
Experimental study of five element creep model for high salt saturated fine sand soil
Authors: Zhang Guoqi , Wu Yaping , Cheng Gaojun
Published: September 2019

A series of creep tests on high salt saturated fine sand under different stress and salt content were carried out by uniaxial compression test. Based on the classical K-H body model of three elements and the Bu body model of four elements on the linear viscoelastic plasticity theory, a creep model of five elements under the consideration of the comprehensive effect of salt water soil is proposed combined with the experimental analysis results under different stresses and salt content. The analysis results show that the creep model of the five element can fit well the creep law of high salinity fine sand under different stress and salt content, and the validity of the model is proved by comparing the three models and comparing the experimental data with the fitting results.
Study on optimum design and repair of fair-faced recycled concrete
Authors: Fang Xiaojun , Fang Guangxiu , Liang Xiaoxu , Hu Pengjie , Jin Xianze
Published: September 2019

Guided by strategies for renewable resources and sustainable development, in the mix ratio design of the fair-faced recycled concrete, use broken waste concrete test blocks, and replace natural coarse aggregate by 40 % equal amount. The optimum dosage of water reducer and foaming agent was 1.33 % and 1.5 % respectively, and the optimal match ratio was put forward. At the same time, the improved vibration technology is proposed to treat the quality of surface air bubbles and holes in fair-faced recycled concrete. Finally, using the scale model of bridge structure and the reserved Honeycomb and hemp surface, the repairing technology of fair-faced recycled concrete is studied, which is an effective treatment of construction quality disease, providing reference for the design and repair of fair-faced recycled concrete.
Study on conductive mechanism of graphene conductive and anticorrosive coatings on steel bar surface in concrete
Authors: Zhang Xingduo , Sun Hongyao , Qian Benlei , Sun Gaoxia
Published: September 2019

When conductive and anticorrosive coatings are applied on the surface of reinforcing bars, electrochemical protection measures can be taken when the construction need secondary maintenance. Because graphene is a sp2 hybrid honeycomb structure, higher conductivity can be obtained by adding a small amount of graphene in the coating. In this paper, graphene-based conductive anticorrosive coatings were prepared with mixed conductive fillers (acetylene carbon black, conductive carbon black, graphite, graphene and zinc powder). The conductive mechanism was determined by studying the effects of conductive properties on the change of the content of different conductive fillers and analyzing the microstructural characteristics of conductive coatings with XRD, SEM, TEM and Raman spectroscopy tests. The results show that the conductivity of mixed fillers with different shapes in coatings is better than that of single filler in coatings when the filler content is the same. Because of the flexible structure and thin layer of graphene, the isolated fillers and conductive paths in different areas of the coatings can be connected with it and the conductive efficiency can be improved. The conductive paths are formed by the contact among conductive fillers in the coatings. Finally, the conductive mechanism model of graphene conductive and anticorrosive coatings was established.
Numerical simulation for the matching effect of rock parameters on explosives and rocks
Authors: Li Tingting , Niu Xuefeng , Fei Aiping , Zhu Chunyu , Wang Mingchang
Published: September 2019

China’s mine blasting technology is gradually mature, but there are deficiencies in low blasting efficiency. The reasonable matching of explosives and rocks can effectively improve the blasting efficiency and is of great significance for mine blasting. Based on ANSYA/LS-DYNA, the matching effects of rock physical density, elastic modulus, Poisson’s ratio, compressive strength and shear modulus in double-hole blasting were studied and verified by simulation. By comparing the length of time that the shock wave caused the rock to be crushed, the experiment shows that the longer the blasting time, the better the matching effect. Numerical simulations show that the five physical factors affecting the matching effect of explosives and rocks are: compressive strength, Poisson’s ratio, density, shear modulus, and elastic modulus. It has been verified that the experimental results can provide reference for the development of blasting technology.
Fences Application of the CATIA Program in Architecture and Construction
Authors: Tubielewicz-Michalczuk Malwina
Published: September 2019

Nowadays, modern computer programmes are widely used in the design process. Information technology provides designers with the tools for extending and facilitating creative practices. Computer programmes offer a modern approach to the architectural design process, help maintain control over it and ensure the accuracy of documents. The use and application of CATIA, increasingly chosen as support for design activities, has been discussed in the paper. Both key features to create the surface geometry of the model and the analyses of extremely complex shapes have also been demonstrated.
Analysis of the Creativity Development and Assessment of Architectural Design Education: A Case Study of Basic Design Studio
Authors: Sat Gungor Beyza , Yorgancioglu Derya
Published: September 2019

Basic design education retains its seminal role in most of the architectural curricula today. Having the primary goal of getting acquainted students with knowledge and skills of design basics, basic design education supports the development of creative ways of thinking combined with hands-on learning experiences. The assignments address the articulation of the basic design in 2D and 3D elements such as lines, planes, volumes, structures and forms, while students are encouraged to experiment the potentials of different materials and techniques. Course included 9 different 2D and 3D exercises that focus on design principles and elements together by adding different design problems in process. For instance, structural problems as self-standing or modular 3D units’ penetrations and strengthens for complex design problems are added for further assignments in the schedule. In this process ‘creativity development’ is assessed and evaluated by considering the whole course schedule at the example of individual student assignments. The objective of this paper is to make an analysis of creativity development with regard to the assessment and evaluation procedures, taking the process and products of a basic design studio as a case study. The methodological framework of this paper is based on the examination of two sets of data; (1) ‘quantitative data’ that includes the grades of assignments that are designed as part of ARCH 101 Design course of architecture program at Özyeğin University Faculty of Architecture and Design in “ARCH 101 in Fall term of 2017-2018 academic program; (2) ‘qualitative data’ that includes the studio observations and reflective interpretations of instructors regarding the creativity development process for individually student assignments. Grades give the idea of which student exercise has been understood well and reached its learning objectives by considering the whole class. Majority tendency of the grades help assessment of the schedule from the aspect of creativity development. The evaluation of creativity includes manifold aspects of assessment. Teachers’ style, schedule of the course, personal factors such as students’ personal backgrounds, former education, and the styles of thinking and learning, being individual or collective are all effective on creativity.
Radiosity Model and Compensation Theorem
Authors: Ficker Tomas
Published: September 2019

In the preceding conference contribution called “Radiative Heat Transfer in Buildings”, a general model for radiative heat transfer in inner spaces of buildings has been developed. The model is capable of determining radiosities, heat fluxes and heat flows with each surface of the interior. In closed spaces like interiors, the radiative energy should be conserved so that the total heat flow should be zero. This property may be formulated as the compensation theorem and should be mirrored in each reasonable model. Thus, it is desirable to verify whether our developed model satisfies such a property. The mathematical proof has been presented which has confirmed that the developed model obeys the compensation theorem. As a numerical illustration, radiative heat flows in a simple room have been computed and their total sum has been quantified and shown that this summation leads to zero value. The numerical illustrations start with formulating matrix of view factors that describe the ‘mutual visibility’ of interior surfaces and in this way they assist to redistribute radiative heat among the interior surfaces. As soon as the matrix of view factors is established, the system of algebraic equations is formed. These equations serve for computing surface radiosities. The radiosities enable estimating heat fluxes and heat flows occurring in the interior. Some of the heat flows are positive and some are negative. The positive value of heat flow means that the corresponding surface emits energy into the interior whereas the negative value indicates that the corresponding surface absorbs energy from the interior. By summing the positive and negative values of heat flows, the total heat flow can be obtained whose value is zero in agreement with the compensation theorem.
Urban Insertion Projects for the University of Louisiana at Lafayette
Authors: Sammons Thomas C.
Published: September 2019

The Community Design Work Shop (CDW) is an Institute within the School of Architecture and Design at the University of Louisiana at Lafayette. The CDW has been involved with the community urban design projects in architecture and planning for over twenty years. During this time, the CDW has been involved with the small town projects that promoted the revival of their downtown areas and neighborhoods along with the large infrastructure designs for interstate highways and major arterials for Municipalities and the State of Louisiana Department of Transportation and Development. The CDW was engaged in restoration projects for small towns following Hurricanes Katrina and Rita devastation in 2005. Additionally, the CDW has completed multiple projects for the University of Louisiana at Lafayette where the CDW team proposed the design, developed the construction documents and was involved with supervising the building construction. The purpose of the CDW is to function as an outreach Institute to the community for urban design and provide the graduate architecture students an opportunity to gain practical experience with real world design problems. The paper will focus on the process of engaging the university’s administration and students in charrettes and public meetings. Working as a team, the CDW produces the design, develops the construction documents and consults with local architects and engineers. The paper discussion will highlight three of the CDW’s projects: The University Bike Path – which links the University Research Park to the main campus completed in 2014; the redesign of the main campus Quadrangle completed in 2017; and the University International/Cultural Space, currently in progress. These three projects demonstrate how the public can be engaged in a design process; how the student learning benefits of all the students, the public, the development of the design show the construction process to completion.
Modelling of the Impact of the Retention Reservoir on the Flood Protection of the City – A Case Study for the City of Kalisz (Central Poland)
Authors: Laks Ireneusz , Walczak Zbigniew
Published: September 2019

Floods are natural phenomena related to the circulation of water in nature and they cannot be avoided. Despite the methods of predicting floods, technological development and civilization progress, the flood risk has been still increasing. The relevant hydrotechnical advancement, rational spatial development and optimal water management have a significant impact on reducing the consequences of flooding. Particularly retention reservoirs are decisive to rising flood safety and living conditions of urban residents who are at risk of flooding. The construction of a retention reservoir is a serious engineering, economic and eco-scale challenge. It must be preceded by numerous studies and analyses necessary to carry out the entire construction process and subsequent operation in an optimal way. At present, a number of engineering and environmental analyses are supported by the use of forecasting and computational tools based on the mathematical description of a given physical phenomenon. With their use, it is possible to determine, at the design level, the impact of a technical facility on various elements of the natural or the human environment. The paper presents the impact analyses of a planned retention reservoir located on the Prosna river in the flood protection system in Kalisz (Poland). The flood protection system is insufficient in Kalisz and its weakness was demonstrated, among others, by flood in May, 2010. Analyses were based on data received from the unsteady flow numerical modelling system and optimisation methods to support the management process of retention reservoir resources for extreme periods. The formulated task of dynamic optimisation due to its non-linearity was simplified to a static task by discretisation of an independent variable.
Performance of Electrochromic Glazing: State of the Art Review
Authors: Anissa Tabet Aoul Kheira , Efurosibina Attoye Daniel , Al Ghatrif Lama
Published: September 2019

Globally, buildings are responsible for about 45% of energy consumption, 40% of atmospheric emission, 30% of water usage and 30% of waste generation, yielding negative environmental impacts which drove intensive research to achieve a sustainable built environment. Architects are primarily responsible and bear a major stake in the design of the built environment; being professionally mandated to achieve environmentally friendly, functional, structurally stable, and aesthetically pleasing designs. Adopting innovative solutions, which do not compromise these conventional, building requirements, is therefore crucial to promoting sustainability in the built environment. This investigation reviews electrochromic (EC) glazing as a sustainable design option for buildings: its types and properties are presented along with an added focus on design, energy and cost analysis aspects. The findings indicate that EC glazing can reduce electricity demand by 7-8% for moderate window size and 14-16% for large windows. Based on building type, 6 to 11% and 8 to 15% savings are possible for commercial building and residential buildings, respectively. Based on their performance and market success, alternative strategies, such as hybrid EC windows with PV cells, are presented. Further research areas are then deduced based on this review, which may provide design, energy and cost saving benefits.
Managing Delays in Construction Projects Aiming at Cost Overrun Minimization
Authors: Anysz Hubert
Published: September 2019

The effects of the delay in construction contract execution are always negative for every party being involved. Cancelling the delays of the time schedule means the use of more production means that it was planned. It creates an additional cost. If the delays of the schedule are not cancelled, the contractor suffers from the cost increase. The penalties arisen from not keeping the milestones or the completion date are expected too. There is a trade-off: cancelling delays spending additional money now (during the contract execution) or executing a delayed contract till its end awaiting for its final settlement (showing the cost increase) and possible penalties. There is no one, correct answer how to manage a delayed construction project. There is a natural unwillingness to spend money over the budget. Nevertheless, the delayed completion date can cause much higher contractor’s expenses, than cancelling delays during the contract execution. The decisions made by the project manager depend on various factors discussed in the paper. A delay concerning the single task increases the cost of its execution at a different level. The same, the level of influence of delaying a single task, influences the completion date with varied strength. These influences depend on the location of the task in a net model – the base of a schedule. The tasks located on the critical path – defined in the Critical Path Method – should be of the special care. However, delays on not critical tasks can also break the budget and the planned completion date. The nature of delay is important as well. Lowered productivity of a workers’ brigade can make the execution of the task longer, the same as forced breaks in their efficient work. The reaction of a site manager to such causes of delay should be different, as the origin of the delays is different. The impact of the delay noticed on the single task is discussed in the paper and possible reaction (varied on the type of a delay and a task location too) are proposed. The proposed solutions aim at cost minimizing considering the total expenses spent by a contractor and possible penalties in case of the delayed completion date of a construction contract.