Zhou C.,Shanghai JiaoTong University |
Zhou C.,China Shanghai Architectural Design and Research Institute Co. |
Kou X.-J.,Shanghai JiaoTong University
Harbin Gongye Daxue Xuebao/Journal of Harbin Institute of Technology | Year: 2011
In order to study the partial safety coefficient concerned the effect of human error in construction. The contaminated distribution model was employed to obtain the realistic mean value and standard variance of variable X of structural parameters which coexisted with random error and human error. The reasonable partial safety coefficient can be calculated based on the realistic value of structural parameters concerned the effects of random error and gross error. The results show that the current studies of partial safety factors do not consider human error in construction for structural reliability. It is not comply with the real situation. Partial safety factors must be evaluated precisely for the given target β to ensure the certain level of structural reliability due to uncertain factors.
Cheng B.,Shanghai JiaoTong University |
Qian Q.,China Shanghai Architectural Design and Research Institute Co. |
Zhao X.-L.,Monash University
Thin-Walled Structures | Year: 2015
This paper presents a numerical study on stress concentration square bird-beak square hollow section (SHS) welded joints. Both conventional and square bird-beak SHS joints considered have T-shapes and are simply supported at their chord ends. Refined finite element models are developed to obtain the strain/stress concentration factors (SNCFs/SCFs) of square bird-beak joints with various dimensions. The FE models are validated by comparing with the experimental data. The SNCF differences among considered hot spots are analyzed for the identification of critical locations. The influences of three major non-dimensional parameters, i.e., brace/chord width ratio β, chord wall slenderness ratio 2γ, and brace/chord wall thickness ratio τ, on the stress concentration factors (SCFs) of square bird-beak T-joints are revealed on the basis of numerous parametric studies. Comparisons of joint types are finally made. The results indicate that, in case of identical non-dimensional parameters, square bird-beak SHS T-joints provide SCFs smaller than conventional SHS T-joints in most occasions, especially when β is small; and SCFs of square bird-beak T-joints are expected to be lower than CHS T-joints with small β and large 2γ and τ. © 2015 Elsevier Ltd. All rights reserved.
Zheng H.,Hohai University |
Zheng H.,China Shanghai Architectural Design and Research Institute Co. |
Liu H.-L.,Hohai University |
Lei Y.-H.,Tianjin Huazheng Geotechnical Co. |
Ren L.-W.,Hohai University
Yantu Lixue/Rock and Soil Mechanics | Year: 2011
JG(jet grouting) soil-cement-pile strengthened pile, simply called JPP pile, is a new sort of composite pile used in soft foundation. It may improve the vertical bearing capacity effectively; and it has been practically used in a considerable scale. In order to study the behaviors under lateral load, large-scale model test is carried out, using large test room made by Hohai University. It is shown that the JPP pile could improve horizontal bearing capacity by about 15% compared with bored concrete pile; and the biggest bending moment of JPP pile is located in the place 2 m below the pile tip; and lateral earth pressure is concentrated in the top 2 m soil. Meanwhile, with a cap added, JPP pile has a much higher horizontal bearing capacity. According to the formula for bored concrete pile based on m method, which standard remmends, horizontal bearing capacity of JPP pile has been calculated; and calculation results basically coincide with the experimental results. The results may be useful for the practical engineering and analysis of JPP pile in the similar soil layer.
Wang Y.,Harbin Institute of Technology |
Chen J.,Harbin Institute of Technology |
Zong B.,China Shanghai Architectural Design and Research Institute Co. |
Geng Y.,Harbin Institute of Technology
Jianzhu Jiegou Xuebao/Journal of Building Structures | Year: 2011
This paper presented experimental study on 12 recycled aggregate concrete filled steel tubular (RACFST) stubs and 12 reinforced recycled aggregate concrete (RRAC) stubs with spiral reinforcement under axial compressive loading. To highlight the beneficial effects of the confinement effects on the mechanical behavior of RACFST specimens, the weight of the steel used in RACFST specimens and their companion RRAC specimens are the same. Influences of the parameters including concrete strength and recycled coarse aggregate (RCA) replacement rates on the ultimate response of axially loaded RACFST stubs and RRAC stubs were discussed. It can be seen that RACFST stubs exhibit better static behavior under axial pressure compared with RRAC stubs. The RACFST stubs fail in shear modes due to the confinement effect coefficient is relative small (ξ<1.0). The effects of RCA replacement rates on ultimate bearing capacity of RACFST specimens are smaller than those on RRAC specimens. The influences of the concrete strength on the axial behavior of the RACFST stubs and RRAC stubs are similar to the corresponding concrete filled steel tubular (CFST) stubs and reinforced concrete (RC) stubs, respectively.
Niu C.K.,Harbin Institute of Technology |
Tan Y.F.,Harbin Institute of Technology |
Feng L.Y.,China Shanghai Architectural Design and Research Institute Co.
Advanced Materials Research | Year: 2014
One of the major technical challenges in storing CO2 by multi-well gas injection is the stability of CO2 in the aquifer. In this paper, according to an underground aquifer property in north China, a numerical model of multi-well gas injection for storing CO2 is developed to understand this mechanism, based on nonlinear seepage theory of CO2 in aquifer. The impact of working parameters during gas injection period (arrangement form of well group, the schemes of injection rate of multi-well and well spacing) on the stability of CO2 in the aquifer is analyzed. It is proved that the average reservoir pressure could be reduced using the triangular layout. Appropriately increasing the injection rate of the center well and reducing well spacing could increase the gas storage capacity of reservoir. Based on the results, the optimal gas injection schemes and the optimal well spacing of multi-well gas injection for CO2 geological storage are obtained. These results provide technical guides for CO2 sequestration using multi-well gas injection to aquifer reservoir in real projects. © (2014) Trans Tech Publications, Switzerland.
Huang L.,Hunan University |
He D.,Hunan University |
Wu Z.,Hunan University |
Wu Z.,China Shanghai Architectural Design and Research Institute Co.
Tumu Gongcheng Xuebao/China Civil Engineering Journal | Year: 2014
Sufficient redundancy may provide shear wall with multiple seismic fortification lines, and enhance its ability to resist seismic actions. To investigate the seismic performance of redundant shear wall, two under-reinforced specimens with joint are designed in this work, one is combined with single-layer reinforced RC wall, and the other is combined with reinforced concrete masonry wall. The failure pattern and failure mechanism, hysteretic property, attenuation process, stiffness degradation and energy dissipation are analyzed through low-cycle loading test. Test results show that there is an obvious hierarchical characteristic in the failure process for both specimens, and the residual structure can still bear additional loads after weak portion of wall fails, reflecting their good redundancy performances. The seismic performance of the specimen combined with single-layer reinforced RC wall may outperform the specimen combined with reinforced concrete masonry wall, due to its better energy dissipation and post bearing capacity.
Huang L.,Hunan University |
Wu Z.,Hunan University |
Wu Z.,China Shanghai Architectural Design and Research Institute Co. |
Fan Z.,Hunan University |
And 4 more authors.
Tumu Gongcheng Xuebao/China Civil Engineering Journal | Year: 2012
The failure mode of common shear wall due to earthquake is onefold, and there is no obvious hierarchy in the failure process. A combined redundant shear wall composed of wall-frame and dumbbell-shaped shear wall or shear walls with concealed bracings is proposed. The bearing capacity, stiffness, ductility, hysteresis property, attenuation process and failure mode at each stage are especially analyzed through a low-frequency cyclic loading test of 2 floors 1/2 scale shear wall models of each type the story drift angle at different failure stage is regarded as a preliminary performance quantitative indicator. Test results show that the combined redundant shear wall has a good seismic performance, and there is an obvious hierarchical characteristics in the failure process. When one part in the wall fails, the other can still bear additional locals. It should be noticed that this type of wall hasn't been studied previously, and the present study is a tentative work for the combined redundant RC shear-wall.
Cui L.,China Shanghai Architectural Design and Research Institute Co. |
Jiang H.,Tongji University |
Lv S.,China Shanghai Architectural Design and Research Institute Co.
Jianzhu Jiegou Xuebao/Journal of Building Structures | Year: 2013
Numerical models of two steel-concrete composite shear walls, one with steel truss and the other with steel plate were verified firstly. Then the two shear walls with the same steel ratio were analyzed under cyclic load. The load carrying capacity, stiffness, degradation of strength and stiffness, ductility, energy dissipation characteristics and hysteresis characteristics of the two walls were compared. The seismic performance of structures with two steel-concrete composite shear walls were compared. The result proves that, at component level, with the increase of the aspect ratio, the bearing capacity, ductility and energy-dissipating capacity of steel plate RC shear wall gradually become stronger than RC shear wall with steel truss in the case of same steel ratio. At the structure level, when the aspect ratio is big, the seismic performance of structure with steel plate reinforced concrete shear wall is better than the structure with steel truss RC shear wall.
Fan R.,Tongji University |
Chen X.,China Shanghai Architectural Design and Research Institute Co. |
Ma H.,Tongji University |
Long W.,Tongji University
Taiyangneng Xuebao/Acta Energiae Solaris Sinica | Year: 2013
A coupled heat conduction and heat advection numerical model for ground heat exchanger(GHE) simulation was used to analyze the heat transfer characteristics of GHE under the special wetland circumstance. Then we can see the impacts of some factors such as water table, groundwater flow rate and water content etc. Furthermore, through multiple regression analysis for the large quantity simulation results, it is clear to see the relationship and the influence sequence of various factors on heat transfer quantity per meter borehole and water temperature from GHE. Those are beneficial to theoretical research and practice both.
Luan W.,China Electric Power Research Institute |
Wang B.,China Shanghai Architectural Design and Research Institute Co. |
Zhou N.,Henan Electric Power Research Institute |
Guo Z.,Henan Electric Power Research Institute
Dianwang Jishu/Power System Technology | Year: 2015
For a long time, due to various reasons, power utilities don't have full or accurate mastering of information of LV distribution network. This is one of the cases for distribution network parameters. Accurate circuit parameters of LV distribution network are basis of power flow calculation, loss analysis and energy theft detection. Electrical parameters are important, but research on them is far from sufficient mainly because of absence of measured data in LV distribution network. Implementation of advanced metering infrastructure (AMI) provides new ways for solving this problem. This paper researches approaches on accurate electrical circuit parameter calculation in LV distribution network using smart meter measurements, so as to obtain accurate model of LV distribution network. Provided distribution network topology is known, the method leverages a series of smart meter measurements at end nodes of distribution network, mainly voltage, active power and reactive power at customer sides. It calculates voltage of the most upstream node or source node in radial network with bottom up approach and builds an optimization model to minimize source node voltage variance derived from different meter node measurements, or the differences between estimated source node voltage from different smart meter measurements and actual voltage measurement in source node over a period of time. Then the best estimates for branch impedances are obtained. Validity of the proposed method is verified with a practical distribution network with 17 metering nodes and 21 branches. ©, 2015, Power System Technology Press. All right reserved.