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ISSN 1674-2850
CN 11-9150/N5
 
Current Issue
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January 30,2014
Volume 7,Issue 2
Pages -
Subject Area:Hydraulic Structures,Architectural History,Foundation Engineering,Concrete and Reinforced Concrete Structures,Civil Engineering Design,Civil Construction Structure
 
Title: Effect of boundary condition of underground hydropower plant on structural vibration
Authors: MAO Liudan, WANG Haijun
PP: 197-202
Abstract: In this paper, taking one plant underground hydropower station as a case, the different boundary conditions were analyzed. The emphasis of the boundary conditions was how the structure connects with the rock mass. Using ANSYS software, different models were calculated and analyzed. According to the results of resonance check and dynamic response, various schemes were appraised. This study is helpful to how to select the rational boundary of the structure.
Keywords: special hydraulic structure; hydropower station; boundary condition; resonance check; dynamic response
 
Title: Research on temperature control and crack prevention of concrete floor for large pump station during the construction
Authors: ZHANG Hongye1, CHEN Wei
PP: 191-196
Abstract: After the concrete floor of large pump station is poured, it produces a large amount of cement heat of hydration at early age and it is easy to produce temperature cracks. Main influencing factors, such as placing temperature of concrete, the heat of hydration of cement, surrounding temperature, diurnal amplitude, the intermission of pouring and so on are considered in the present paper to establish a fine finite element mesh which contains concrete floor, elbow-shaped inlet conduit, the pump layer, outlet conduit of pump station. Many simulation conditions are computed in and the tensile stress state of concrete floor is compared. In addition, this paper focuses on the change of temperature stress of the concrete structure and the stress around the pipe cooling wall. This paper proposes a reasonable and economical arrangement of temperature control and crack prevention in the process of design and construction.
Keywords: hydraulic structure; pipe cooling; temperature stress; simulation analysis; temperature control and crack prevention
 
Title: Upper bound method for aseismatic ultimate capacity analysis of rock-fill dams using finite elements
Authors: CHI Shichun, YANG Xinguang
PP: 186-190
Abstract: The Mohr-Coulomb criterion is taken as a linearized yield surface in limit analysis using finite elements, but it can’t be used directly in earth-rock material possess nonlinear strength properties by upper bound method. In this paper, a static form, which is corresponding dual second-order cone programming (SOCP) problem of the upper bound limit analysis, is formulated. By solving the dual problem, the distribution of stress of slopes can be obtained. Then, the equivalent shear strength parameters of materials with nonlinear criterion can be determined by means of iterative solutions. So the method is applied to rock-fill dams with nonlinear criterion, and the aseismatic ultimate capacity of dam can be determined.
Keywords: hydraulic structure; earth rock dam; limit analysis; upper bound theorem; nonlinear failure criterion
 
Title: Analysis on the plan layout mode of the palace in Shangjing city of Bohai state
Authors: Liu Daping, Sun Zhimi
PP: 180-185
Abstract: Shangjing city is one of the capitals of Bohai state(AD 698-926). The shapes of the city and building represented the highest level of Bohai state. Based on the archaeological data of Shangjing city, the palace complex sites are taken as examples, and this paper studies the plan layouts of the palace complex and reveals the characteristics of the Bohai palace.
Keywords: architectural history; Shangjing city; palace complex; plan layout mode
 
Title: Brief analysis on British landscape character assessment system and its reference and inspiration to China
Authors: ZHU Jie, ZHANG Bin
PP: 173-179
Abstract: This paper analyzes the British landscape character assessment (LCA) system from three different periods evolving process, in real detail at the features, principles, characterization, making judgements and every steps of process. At the same time, this paper points out the imperfect of China LCA. This article aims to analyze the basic concept, assessment ideas, assessment approach of LCA, in order to provide primary references and inspiration for theoretical and practical study of LCA in relevant areas of China. In addition, the author proposes some advices from a commonly shared conceptual framework of assessment method, flexibility methodology, following value-free concept, etc.
Keywords: method and theory of urban planning; landscape character; assessment system; reference and inspiration
 
Title: Urban land use planning strategies in hilly areas based on conservation of watershed
Authors: GAO Qing, WANG Wei, WEI Chunyu, JIAO Sheng
PP: 165-172
Abstract: Current watershed management approach fails to prevent watershed ecosystem from the destruction caused by landscape fragmentation. Aiming at how to avoid the occurring of these impacts, this work proposes an urban land use planning technique framework in hilly areas based on geographic information system (GIS) and applies it to the Binjiang area of Wangcheng district in Changsha city as a research case. The study results include potential wetland ecological corridor and the drainage texture of watershed where these wetlands locate. On a basis of integrating these analysis results, the land use planning strategies that favors to the ecological conservation of watershed are further put forward.
Keywords: method and theory of urban planning; landscape fragmentation; impervious surface; landscape pattern; drainage texture; geographic information system
 
Title: Effect of air movement in free-running buildings on the thermal comfort in hot summer and cold winter area
Authors: LIU Hong, YANG Jie, TAN Qing
PP: 157-164
Abstract: Objective: To verify the high limit operative temperature of thermal environment in free-running buildings which the temperature in hot summer and cold winter area can reach to 30℃. Methods: In this paper, the field surveys were conducted during the summer from July to September in 2011, in the classroom of Chongqing university which have no air-conditioning. During the survey , we collected effective questionnaire 1 007 copies, the air temperature range covering from 24℃ to 38℃. Results: We found that in free-running buildings, the thermal sensation of people seriously influenced the airflow sensing. We also found that people under different operating temperature would choose different adjustment measures to correspond the environment. Conclusion: Main results indicated that people in civil buildings can satisfy through the natural ventilation when the operative temperature was less than 28℃. During 28℃ to 30℃, it needed to open mechanical equipment to adjust the indoor environment. When the operative temperature is above 30℃, opening the air-conditioning can regulate the indoor environment. Therefore, the high limit operative temperature of thermal environment in free-running buildings is 30℃.
Keywords: ventilation and air conditioning engineering; thermal comfort; air movement; acceptability limits; thermal sensation
 
Title: Effect of additives on the strength of high-salt soil improved by cement
Authors: XING Haofeng, LI Haoming
PP: 152-156
Abstract: Based on the research results of effect of single ion on the salt-rich soft soil improved by cement, the combined effect of additives on the characters of the salt-rich soft soil with Mg2+, Cl-, SO2-4 improved by cement was researched through the orthogonal tests of multiple ions, and the feasibility of curing agent and additive to improving the strength of the salt-rich soft soil improved by cement was explored as well. The research results have the good references for exploring the feasible technology of improving the characteristics of the salt-rich soft soil improved by cement.
Keywords: foundation engineering; soft soil; cement; additives; unconfined compressive strength
 
Title: Study on strata deformation induced by backfill grouting of shield in construction period
Authors: ZHONG Xiaochun, WANG Hai, WANG Huijie, ZHAO He, JIA Caihong
PP: 145-151
Abstract: Based on the test of shield grouting material and its mechanical characteristics, the thesis puts forward variable rigid body model to simulate the process of grouting consolidation and compares it with other grouting models. Combining with the shield tunnelling project from Fumin station to Jintian station in Shenzhen city, the thesis analyzes the strata deformation induced by backfill grouting and the sensitivity of strata deformation induced by the thickness of backfill grouting. The results shows that the calculation conforms to the observed site, indicating the proposed model in this paper can simulate construction period of backfill grouting well.
Keywords: underground engineering; shield tunnel; strata deformation; backfill grouting; variable rigid body model
 
Title: Rotational behavior of bolted glulam beam-to-column connections with different lamina alignments
Authors: SONG Xiaobin, WANG Mingqian, GU Xianglin, ZHANG Yunfan
PP: 136-144
Abstract: This paper presented a recent experimental research on the rotational behavior of bolted beam-to-column connections with steel plates under monotonic and cyclic loading. Generally flatwise laminated glulam members (horizontal alignment of laminas) were applied in this kind of connections, and brittle splitting failures often happened in these connections. Using edgewise laminated glulam members (vertical alignment of laminas), the development of splitting failure could be limited by glue lines, and these innovative connections exhibited higher stiffness and moment bending capacity because of high strength of glue. The experimental results showed that under monotonic and cyclic loading, the ductility ratio of edgewise laminated specimens were extraordinarily high compared with that of flatwise laminated specimens. For monotonic loading, the ultimate moment capacity, the rotation angle for the ultimate moment capacity and the rotation angle for the failure moment were increased by 27%, 62% and 68% respectively. For cyclic loading, the energy dissipation ratio of edgewise laminated specimen was higher (up to 20%) than that of flatwise laminated specimen. Therefore, the edgewise laminated glulam connections gained their own value in practical timber frame structures.
Keywords: timber structure; alignment of laminas; beam-to-column connection with steel plate; monotonic loading; reversed cyclic loading; ductility
 
Title: Mechanical behaviour of the full-scale bonded prestressed concrete beams and slabs under high temperature
Authors: ZHENG Wenzhong, YAN Kai, OUYANG Zhiwei, WANG Ying
PP: 125-135
Abstract: Fire resistance of the full-scale bonded prestressed concrete beams and slabs can not be reflected by experiment results of small-scale specimens exposed to fire. Based on fiber element model, stress iteration method is adopted to solve thermal-mechanical coupled constitutive equations, and the mechanical behaviors of the full-scale bonded prestressed concrete beams and slabs under high temperature are studied. The result shows that composite reinforcement index, prestress degree and effective prestress have little effect on the ratio of limit moment under high temperature and normal temperature for bonded prestressed concrete of the beams and slabs, while the concrete cover of prestressed reinforcement has significant effect on the ratio. When the ratios of height to width are similar, and the concrete covers of reinforcement in the first row are the same, the biggest descent rate of flexural bearing capacity of beams under 3 h fire duration, which the height are 700 mm, is almost 80% attenuation, compairing with 20% for beams which the height are 4 500 mm. Fire resistance of large scale beams is better than small scale beams. The calculation formula on the ratio of bonded prestressed concrete slabs is established introducing the effect of concrete cover of prestressed reinforcement. The calculation formula on the ratio of bonded prestressed concrete beams is also established considering the distances between the bottom of beams and the force points of prestressed reinforcement and reinforcement. The calculation method on fire resistance of the full-scale bonded prestressed concrete beams and slabs is put forward.
Keywords: concrete and reinforced concrete structure; fire resistance; fiber element model; bonded prestressed concrete; beams and slabs
 
Title: Parametric analysis of transverse effect of bottom continuity tendons
Authors: WU Xun, XIANG Xiaoyang
PP: 120-124
Abstract: In this paper, the mechanism of producing transverse effect from bottom continuity tendon was investigated. At the same time, this paper selected installation with or without diaphragm plate, the thickness of bottom slab, the longitudinal line shape of bottom slab as structure parameters and conducted paramatric analysis. By analyzing a main span of 170 m continuous beam bridge, the result showed that installing with diaphragm plate, increasing the thickness of bottom slab and improving the longitudinal line shape of bottom slab could ameliorate the transverse stress in bottom slab, however, the effect of improving the longitudinal line shape was most obvious.
Keywords: civil engineering design; road engineering; transverse effect; parametric analysis
 
Title: Construction technology and economic analysis of steel bar truss deck
Authors: SHANG Xia, LI Leilei
PP: 110-119
Abstract: In this paper, the advantages and disadvantages of the floor system, with widely used in the high-rise building, were discussed based on the Xiamen Shimao Haixia building. Then the construction technology of the steel bar truss used in this high-rise building was discussed. And the technical difficulties of the steel bar truss were analysised in detail. The solution of these technical difficulties was put forward. The economic of the steel bar truss-concrete composite slab, cold-formed steel-concrete composite slab and reinforced concrete slab were discussed based on the construction technology. Then the comprehensive cost of construction and cost of construction were obtained, and the basis of the selection of the slab system and the cost control were also gotten. Through the analysis of the construction technology and economic of the steel bar truss, the references were provided for the same structure high-rise building.
Keywords: civil engineering structure; steel bar truss deck; floor; construction; economic analysis
 
Title: Research status of chemical adhesive steel bar
Authors: XU Xingwei, GONG Yongzhi
PP: 101-109
Abstract: This paper summarizes the development on the study of chemical adhesive steel bar at home and abroad, and especially states the product characteristics of anchoring adhesive, the failure mode of adhesive steel bar, the influential factors of anchorage behavior under one-way stress conditions, group bar effect, the mechanical properties of adhesive steel bar under complicated environment stress conditions and the research overview on different performances of bond-slip. According to the current research situation, this paper summarizes the shortcomings of current study on adhesive steel bar, and proposes some recommendations.
Keywords: civil engineering structure; adhesive steel bar; review; anchorage behavior; complex environment; bond-slip
 
Title: Research status and development trend of the stability of landfill pile
Authors: HUANG Faxing, ZHAO Ying
PP: 94-100
Abstract: The unstability of landfill pile has become a new problem in the research field of environmental geotechnical engineering. According to the mechanism of landfill deformation, the study on the characteristics of deformation parameters and the analysis of pile body stability, the research status and development trend of the stability of landfill at home and abroad were analyzed. The analgsis shows that the focus of many scholars in a considerable period of time will be the following: revealing the deformation mechanism and deformation characteristic of landfill under complex environment from multifield coupling angle, determining the linear and nonlinear of the parameters in constitutive model which contain stress, strain, seepage and degradation, establishing the coupling model that are more closer to the actual situation through the multi-disciplinary theory. This may provide theoretical basis for enhancing the control level of the unstability of landfills.
Keywords: municipal engineering; landfill; review; unstability; status; trend