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Showing papers in "Journal of Xi'an University of Architecture &technology in 2005"


Journal Article
TL;DR: In this article, the authors proposed a model of cost estimation of construction engineering based on the BP Neural Network. But the model is not suitable for the case of large-scale construction projects.
Abstract: Cost estimation of construction projects is a very important task for management of construction projects. According to the basic principles of the neural network and the characteristics of project cost estimation, with the breakdown of project cost and factors having effect on them,and the functions of structures and their characteristics reviewed in detail,seven major factors are identified as neural network input variables. On the basis of the theoretical analysis, the paper brings up the model of cost estimation of construction engineering based on the BP Neural Network. Eighteen actual construction projects are used as training samples and two projects are used as test samples. Test results show that the precision meets the estimation requirements well. Therefore, this method shows the promising perspective in cost estimation of construction project.

8 citations


Journal Article
TL;DR: In analyzing many kinds of risk elements that appear in the process of real estate invest ment, the index system and the index weight of the assessment are determined by applying analytic hierarchy process method.
Abstract: In analyzing many kinds of risk elements that appear in the process of real estate invest ment, the index system and the index weight of the assessment are determined by applying analytic hierarchy process method. The fuzzy comprehensive evaluation system for risk of real estate investment has been established by means of fuzzy mathematics. A lot of fuzzy problems in appraisal of the risk of real estate investment is solved by applying mathematic method.

5 citations


Journal Article
TL;DR: A new method on the basis of relation database — artificial neural network method, which reinforces the current data mining methods, and deals with qualitative variables and complex mobile data sciontifically.
Abstract: After analysing the current data mining methods, this paper introduces a new method on the basis of relation database — artificial neural network method It highlights automatically a great deal of knowledge among database by learning from data sample It also comes up with the learning model and algorithm of Artificial neural network method The method reinforces the current data mining methods, and deals with qualitative variables and complex mobile data sciontifically

4 citations


Journal Article
TL;DR: The method of two levels fuzzy comprehensive evaluation is put forward, which adapts to the highway tunnel operation management system and the result shows that the method has better adaptability and can objectively reflect the status of highway Tunnel operation management.
Abstract: Based on an analysis of the highway tunnel operation management,the paper has adopted 23 factors,which influence on highway tunnel operation management,as the evaluation index from three aspects,i.e.the equipment status,management system and operation effect.It has set up the evaluation index system of highway tunnel operation management.The level model,the index weight and the fuzzy comprehensive evaluation model of highway tunnel operation management are confirmed by adopting the level analysis method and fuzzy mathematics theory.The method of two levels fuzzy comprehensive evaluation is put forward,which adapts to the highway tunnel operation management system.The instance of Huanghe Mountain tunnel operation management is calculated and analyzed with this method,and the result shows that the method has better adaptability and can objectively reflect the status of highway tunnel operation management.

4 citations


Journal Article
TL;DR: In this article, the effects appraisal of project management is examined by means of back-propagation(BP) network from Artificial Neural Network, and the effects model for project management, considering comprehensively the four control indexes about project time limit, quality, cost, and safety.
Abstract: Individual linear analysis is applied mainly to traditional effects appraisal of project management.Though it is easy to use,it can;t reflect complicated relations between evaluation indexes without linear connections.Then the effects appraisal of project management is examined by means of back-propagation(BP) network from Artificial Neural Network,and the effects appraisal model for project management,considering comprehensively the four control indexes about project time limit,quality,cost,and safety.The evaluation result is proved to be comprehensive and complies with practical conditions by example,so the BP network well contributes the improvconent of the project management level.

4 citations


Journal Article
TL;DR: In this article, the authors presented a research on the aseismic performance and design theory of multi-ribbed slab wall, which is the main bearing member of a new structure.
Abstract: On the basis of previous study, this paper presents a research on the aseismic performance and design theory of multi-ribbed slab wall ,which is the main bearing member of a new structure. It introduces the main failure modes of the wall, suggests the three-staged mechanical mode, gives the restoring force mode, discusses the aseismic design method, and brings forward the relevant constructional requirement. Theoretic analysis and experiment show that the main failure modes of the wall can be classified into the shearing failure mode and bending failure mode, with the former being a reasonable failure mode. Infilled bricks, ribs and frame in the wall can exert their effects at different stages of the experiment. Therefore, the multi-ribbed wall has multi-line to actagainst earthquake, and represent favorable aseismic performance. The aseismic design method of the wall highlights the idea of aseismic control, and the construction measure assures the whole performance of the structure.

4 citations


Journal Article
TL;DR: In this paper, an experimental study was carried out on the kinetic process of oil pollutants released from sediments of WangYao reservoir-an important municipal source water of Yan'an, which showed that the releasing intensity mainly depends on the oil diffusion rate and also on the intensity from pore water into overlap water.
Abstract: Under static conditions,an experimental study was carried out on the kinetic process of oil pollutants released from sediments of WangYao reservoir-an important municipal source water of Yan'an.The results show that the releasing intensity mainly depends on the oil diffusion rate and also on the intensity from pore water into overlap water. In the case of high intensity of sediments contaminated by oil(the load of contaminated sediments is 59.752g/kg),the releasing equilibrium would last more than 3 months and the oil content in the overlap water could reach 29mg/L.On the basis of this, a kinetic model was developed.It was shown that the simulation result by the kinetic model can well fit the measured data.

4 citations


Journal Article
TL;DR: In this paper, the authors apply the Delph's method to the study of human settlements in the small watershed of the gully area on the loess plateau, and propose a planning concept of human settlement, land use and industrial layout from the perspectives of ecology, intensify and profession.
Abstract: The authors attempt to apply ecological planning method to the study of human settlements in the small watershed of the gully area on the loess plateau. By sieving out major restriction factors that affect human settlement with Delph's method,the authors start with the area background and some of their investigation data and give a step and carto-superositional analysis of the ecological sensibility and an evaluation of the ecological suitability. On the basis of the quantitative analysis, an ecological security pattern of “ecology first” is set up with the yardstick of a small watershed, and a division of land used is proposed for the watershed development.The planning concept of human settlement, land use and industrial layout from the perspectives of ecology,intensify and profession are presented.

3 citations


Journal Article
TL;DR: Based on the statistic analyses with the test data of R.C. corroded members, the flexural and compressive axial loads are put to experiments under repeated horizontal loading as discussed by the authors.
Abstract: As R.C. members with flexure and compression is very important in R.C. structures, the research on the effects which reinforcement corrosion has on restoring characteristic in R.C. with flexure and compression is also very important in the researches on seismic performance of existing R.C. structures. Based on the statistic analyses with the test data of R.C. corroded members, the flexural and compressive axial loads are put to experiments under repeated horizontal loading. The parameter of the three-line restoring model was given, and the relationship between the parameter of the three-line restoring model and the bars' corroded quantum was presented. As a result of this, the basic theory of repairs of seismic damage of existing R.C. structures, and the evaluating of existing members under earthquake was acquired.

3 citations


Journal Article
TL;DR: In this article, a nonlinear model was developed to reflect the relationship of decentralized water use and reclaimed water supply and demand, and the model was applied for predicting and analyzing the future fresh water use to the example of the resident district, reused water demand and supply and the sige of water treatment projects.
Abstract: With the application of system dynamics, a dynamic, nonlinear model was developed in this paper in order to reflect the relationships of decentralized water use and reclaimed water supply and demand. Through a system analysis, the model was applied for predicting and analyzing the future fresh water use to the example of the resident district, reused water demand and supply and the sige of water treatment projects. It illustrated that wastewater decentralized reuse can decrease fresh water consumption, ensure rational reuse water treatment size. The paper also predicts systematic relevant influencing factors including water pricing and consumers' acceptable degree of reuse water.

3 citations


Journal Article
TL;DR: According to the theory of entropy weight and fuzzy mathematics, we can take advantage of the comparison of the three structure systems respectively, the technical-economical, social and environmental profit of the light structure is expounded as mentioned in this paper, furthermore the basis for further widespread development of the new building structure is provided.
Abstract: Brick-concrete mixture structure or frame-structure, limitations are used for mutti-floor. The dense-rib light structure is a new structure system. According to the theory of entropy weight and fuzzy mathematics, we can take advantage of the comparison of the three structure systems respectively, the technical-economical, social and environmental profit of the light structure is expounded. furthermore the basis for further widespread development of the new building structure is provided.

Journal Article
TL;DR: In this article, the pollutional characteristics of ship domestic sewage are studied with the examination aboard ship and actuality at home and abroad through the production of domestic sewage aboard ships, arrangement of wastewater system, and determination of hydraulic characteristic and pollution load.
Abstract: Through the production of domestic sewage aboard ships,arrangement of wastewater system,and the determination of hydraulic characteristic and pollution load,the pollutional characteristics of ship domestic sewage are studied with the examination aboard ship and actuality at home and abroad.According to the study,the domestic sewage volumes and quality vary greatly with the types of ships,sanitary conditions and wastewater systems.Types,research actuality and influencing factors of ship domestic sewage treatment plant are analysed.The research direction,emphases and difficulties are indicated.MBR is thought to be a hopeful technology in treaing domestic sewage aboard ships.

Journal Article
TL;DR: Particle Image Velocimetry (PIV) measurements were carried out on a 2D flow field around the greenhouse in the atmospheric boundary layer wind tunnel as mentioned in this paper, where the rules and status of mean-time or instantaneous flow field were observed in steady flow.
Abstract: Particle Image Velocimetry (PIV) Measurements were carried out on a 2-D flow field around the greenhouse in the atmospheric boundary layer wind tunnel The rules and status of mean-time or Instantaneous flow field were observed in steady flow The streamlines were smooth at the foreside with a curved line and the free shear layer separation was generated at the backward edge of the greenhouse to form a turbulent recirculating region where there is not only an anticlockwise eddy near the back border but also 1~3 clockwise eddy synchronously The intense interaction between vortexes may reduce the recirculating region to about 77H

Journal Article
TL;DR: In this paper, a new type of calcium aluminate cement containing MA spinel was produced by sintering the raw materials of dolomite and alumina mixture, and the effects of raw materials and sinter-ing temperature and additives on the properties of cements were investigated.
Abstract: A new type of calcium aluminate cement containing MA spinel was produced by sintering the raw materials of dolomite and alumina mixture.The effects of raw materials and sintering temperature and additives on the properties of cements was were investigated.X-ray diffraction(XRD) results indicate that the final products consisted of CA,CA_(2)and MA.The microstructure of product was analyzed by means of scanning electron microscope(SEM)and energy dispersive spectrometry(EDS).The experiments results showed that the cement had the satisfied cold bonding strength and sintering properties when the light-burned dolomite and alumina were employed and fired at 1600℃.The new type cements has relatively uniform microstructure The early stage strength of the refractory castables bodies was greatly improved by adding 2wt.% of CaCl_(2) as a strength modifier.

Journal Article
TL;DR: In this article, a genetic algorithm is introduced for searching the critical slip of soil-nail bracing and the corresponding minimum factor of safety in the unsaturated soil and the optimal course is automatically implemented with MATLAB.
Abstract: The unsaturated soil water movement formula is adopted for calculating the transient water content within the slope. With equilibrium method the dynamic stability of soil-nail bracing of unsaturated soil slope is analyzed, considering the connection between the shear strength of unsaturated soil and water content. Genetic algorithm is introduced for searching the critical slip of soil-nail bracing and the corresponding minimum factor of safety in the unsaturated soil. The optimal course is automatically implemented with MATLAB.

Journal Article
TL;DR: The scheme utilized the superiority of embedded Transmission Control Protocol/Internet Protocol(TCP/IP protocol) for connolting internet, and better solved the connecting probrerm of the limited resource voltametric system with the internet.
Abstract: Steady and reliable remote meter for reading electricity is the required urgently for solving problems of power division and power managern.At present,remote meter reading of electricity mainly is realized by manpower or power line carrier or special communicating net.These schemes can't satisfy modern managing requirement for various reasons.In this paper,a remote meter reading system of electricity based on S7600A is suggested.The scheme utilized the superiority of embedded Transmission Control Protocol/Internet Protocol(TCP/IP protocol) for connolting internet,It better solved the connecting probrerm of.the limited resource voltametric system with the internet.The related network construction and the key technigue were inguired into.And,the detailed design idea was given,too.

Journal Article
TL;DR: In this paper, the interactive loadbearing properties between the multi-ribbed compound wall-slab and the frame, and also between in-filled blocks and surrounding frame grids are simulated by using six different Finite Element analysis models.
Abstract: The interactive load-bearing properties between the multi-ribbed compound wall-slab and the frame,and also between in-filled blocks and surrounding frame grids are simulated by using six different Finite Element analysis models.The rigid frame-plane compound substructure(RFCS) analytical model is proposed by comparing the computing result of these models with the test results.The method for revising the analytical model by amending elastic modules of in-filled block is introduced,as a result of the computing and mathematical statistics of different elastic modules value used.The result of comparison between theoretical and experiment results express that the revised RFCS analytical model is convenient and reliable for computing,and is an ideal model for the analysis of elastic load-bearing properties of multi-ribbed compound wall-slab structure.

Journal Article
TL;DR: In this paper, a calculation formula of investing recoupment period n and economizing funds P for thermal insulated of external wall, and deduces the economic thickness of thermal insulated layer of compound wall.
Abstract: In accordance with the special weather in hot summer and cold winter zone ,by means of dynamic investment recovery period and introducing the year heating and air condition recovery coefficient ,this paper puts forward a calculation formula of investing recoupment period n and economizing funds P for thermal insulated of external wall , and deduces the economic thickness of thermal insulated layer of compound wall.On the basis of the cost efficiency e(inv)formula, through simplifying and calculating, a conclusion is drawn that saving expenditure increase with the rise of cost efficiency e(inv) in the investment of unit energy sources, and the economical efficiency and the rationality of the investment are analyzed by the case.

Journal Article
TL;DR: In this article, a finite element model of corroded reinforced concrete members is built by selecting proper material stress-strain relationship and bond-slip model between corroded steel bar and concrete.
Abstract: By selecting proper material stress-strain relationship and bond-slip model between corroded steel bar and concrete,finite element model of corroded reinforced concrete members is built.Taking corrosion rate of steel bar and axial compression ratio as variables,numerical value analysis is made on corroded reinforced concrete compressive and flexural members,which aims to provide basis for non-linear analysis of existing corrosion-damaged structures.Results of analysis indicate that both corrosion rate and axial compression ratio affect the performance of corrosion-damaged members.and with the increased corrosion rate of steel bar,bending capacity and deformation capacity of members decrease.The degrading of bond quickens the deterioration of member's behaviors,and members with low axial compression ratio are more sensitive to the degrading of bond.And in terms of corrosion rate,deterioration of member's behaviors lags behind the degrading of bond;and the deterioration extent of behaviors is also related with axial compression ratio.The extent of member with low axial compression ratio is high,and for member's with high axial compression ratio,its deformation capacity decreases a little,while the decrease of bearing capacity is larger than deformation capacity.

Journal Article
TL;DR: In this article, a diseussion on the use of modern strengthening technology such as mordern steel-embeded strengthening technology, CFRP strengthening technology and conservation of cracks is presented.
Abstract: This paper presents a diseussion on the use of modern strengthening technology such as mordern steel-embeded strengthening technology,CFRP strengthening technology,restoring technology and conservation of cracks.etc.in ancient culture relics protection and repairs,based on the engineering example of Wuyang gateway of Han dynasty,and great achievement has been made in conserving and restoring the Han dynasty gateway with safety as well as in renewing its great history image.This is rarely seen overseas and is a new idea for the conservation and restoration of the ancient relics with valued experience in our country.

Journal Article
TL;DR: In this article, a more realistic and secure escaping method-Domino-Rope, which is a more effective approach to people trapped in a fire, is proposed, which can be used in high-rise buildings.
Abstract: With the fast development of the urban construction,high density population,expensive land,more and more high-rise buildings and even skyscrapers stand out in cities.They are mostly up-to-dated,macro-scale operated and multi-functioned.Due to its high-rise floor,complicated function and various facilities, 3-dimensional burning,thick smog and toxic gas pose great threat to people's lives in case of fire.Therefore,evacuation and rescued word may be held up.It may cause a fatally economic loss and heavy casualties as well.Although there are many breaking-loose methods available for people in these buildings,they still face desperate situations and danger.This paper is to offer a more realistic and secure escaping method-Domino-Rope,which is a more effective approach to people trapped in a fire.

Journal Article
TL;DR: The grey system theory can be applied to analyse and predict concrete cracks based on the cause of concrete cracks and Visual Basic 6.0 can be used to program and software be designed.
Abstract: The problems caused by concrete cracks are so complicated and universal that three comprehensive influence of the design, material and construction should be taken into account from the view of system. The grey system theory can be applied to analyse and predict concrete cracks based on the cause of concrete cracks. Visual Basic 6.0 can be used to program and software be designed.

Journal Article
TL;DR: In this article, the scheme of specialist used for comprehensive control system against reactive voltage of substation is adopted, with the operation manner diserimina fion and the specialiged experience as.
Abstract: The schemes of specialist used for comprehensive control system against reactive voltage of substation is adopted,with the operation manner diseriminafion and the specialiged experience as.On the basis of the principle of the diagram of nine district of manner,controls over the position of switch of sub-terminals of main transformer and the manner of the switch of compensating capacitors are realiged.By minimum number of operating strokes it urges the position of the sub-terminals of the main transformer and the feature of the switch of compensating capacitors entering into the 9th district.As a result.the oscillation and the frequent operation of changing position of the sub-terminals of the main transformer and of the switching on and off of capacitor for compensating reactive power resulting from the fluctuation of the system and the instantaneous variation of loading are avoided.The stability in operation of the comprehensive control system against reactive voltage of the substation IS ensured.

Journal Article
TL;DR: Wang et al. as discussed by the authors proposed a regulatory system of the scenic spots regulatory detailed planning, which consists of seven aspects: land-use regulatory,environmental capacity regulatory,construction regulatory, landscape regulatory,behavior activity regulatory, protection tourism regulatory.
Abstract: Blankness in resenrch,blindness in practice and potentiality for development are the three prominent features characteristic of the detailed planning of the scenic spots regulatory.In this period,the research of regulatory system is the first and foremost work that requires immediate studies.Focusing on the noticeable questions of China's scenic area,and on the basis of reasonable application of the method for the city's regulatory detailed planning,the regulatory system of the scenic spots regulatory detailed planning was proposed.It consists of seven aspects: land-use regulatory,environmental capacity regulatory,construction regulatory,landscape regulatory,behavior activity regulatory,protection tourism regulatory.Each of these has been deeply discussed and the connotation and the selection method are presented as a result.

Journal Article
TL;DR: In this paper, the authors examined the impact of simulated acid rain on asphalt mixtures with four different grades by using periodical immersion method and found that acid rain with different pH values all have erosive effect on the four different asphalt mixture.
Abstract: Influences of simulated acid rain on asphalt mixtures with four different grades are examined by using periodical immersion method The pH values of the three kind of simulated acid rain liquid are 10,30,56 and the four different grades of asphalt mixtures are AC-16、SMA-16、Superpave-16和SMA-16 The phenomenon of the tests are described and analyzed in this paper Test results show that acid rain with different pH values all have erosive effect on the four different asphalt mixtures The erosive effect firstly caused loss of some asphalt composition At the same time, loss of some asphalt composition bring about exposure of aggregate to the simulated acid rain and this in turn give the acid rain chances of eroding the aggregate The loss of asphalt and aggregate are the fundamental reason of mass and strength reduction of the asphalt mixtures Therefore, the harm to the asphalt mixtures brought by acid rain is mainly due to the chemical erosion and this may be one reason for early moisture damage of asphalt pavement

Journal Article
TL;DR: In this article, the aluminum alloy LF2(3mm thick) was successfully friction-stir welded and the maximum tensile strength, achieved at a welding speed 60mm/min and a tool rotation speed of that of 1200r/min(pressure 400N), was 245Mpa, which was 92% of the strength of the base metal.
Abstract: The aluminum alloy LF2(3mm thick)was successfully friction-stir welded.Optical microscopic(OM) observation revealed that the elongated pancake microstructure of the base material(BM) was transformed into a dynamically recrystallized microstructure with considerably small grain size in the weld nugget.Tensile tests showed that the HAZ is the weakest region of the weld.The maximum tensile strength,obtained at a welding speed 60mm/min and a tool rotation speed of that of 1200r/min(pressure 400N),was 245Mpa,which was 92% of the strength of the base metal,with the extension rate exceeding 80% that of the base metal.

Journal Article
TL;DR: In this article, the concepts, categories and harmful character of environmental hormones were highlighted, and the present situation of environmental hormone contamination in water environment of our country mainly introduced, the trend and the urgent problem for the research of the treatment techniques for environmental hormones contamination in our country's water environment are also presented.
Abstract: As the third generation environmental pollutant, environmental hormones have become a serious problem that influences human surviral and development. On basis of reference papers concerned, the concepts, categories and harmful character of environmental hormones were highlighted, and the present situation of environmental hormones contamination in water environment of our country mainly introduced. The trend and the urgent problem for the research of the treatment techniques of environmental hormones contamination in our country's water environment are also presented.

Journal Article
TL;DR: In this paper, the results showed that at pH 5, the best removal of HA corresponds to nearly zero zeta potential so that adsorption and charge-neutralization is the main mechanism of coagulation.
Abstract: Jar tests were conducted for the coagulation of humic acids(HA) as representational natural organic matters and kaoline as representational inorganic suspended particles.The results showed that the optimum pH value of HA is 5~6,while the optimum pH value of kaoline is 7~8.At pH 5,the best removal of HA corresponds to nearly zero zeta potential so that adsorption and charge-neutralization is the main mechanism of coagulation,while at pH 7 the best removal of kaoline is the result of sweep flocculation of aluminum hydroxide.By means of a photometric dispersion analyzer(PDA),online monitoring of the Al-humic coagulation process was realized.It is revealed that the coagulation process of HA experiences four stages of stabilization,destabilization,restabilization and sweep coagulation,while the one of kaoline only two stages of destabilization and sweep coagulation.It was also found that in the Al-humic floc growth process,the fractal dimension decreased gradually with the increase of floc size and finally to an equilibrium value.On the contrary,in the Al-kaoline floc growth process, the mean diameter and fractal dimension increase with the agitation time,and finally reach a steady state.

Journal Article
TL;DR: In this paper, the difference of thrust force between flat surface and inclined surface at the initial drilling stages was investigated by using NC Grinding Center and three-dimensional dynamometer, and an analytical model is proposed based on the experiment results.
Abstract: The There is a growing necessity for small holes to be finely drilled directlly on an inclined surface in precision manufactural industry.Drilling on inclined surface givesrise to such problems as the decrease of hole accuracy and damage of tool,comparing with the case of drilling on flat surface.In this study,the difference of thrust force between flat surface and inclined surface at the initial drilling stages was investigated by using NC Grinding Center and three-dimensional dynamometer.An analytical model is proposed based on the experiment results.From the model,the effects of the dip angle and feed rate on thrust force are estimated.The model shows reasonable result in the phenomena caused at the initial stage of drilling on the inclined surface.

Journal Article
TL;DR: In this paper, the authors measured the temperature contraction coefficient of porous concrete, analyzed the test result, and drew the coefficient change law in different temperature intervals from −25 ℃ to 25℃.
Abstract: Porous concrete will shrink,so it is necessary to deal with its shrinkage character firstly when studying the problems of joint location and reflection crack of porous concrete base.By aopting the sensor method,the authors measured the temperature contraction coefficient of porous concrete,analyzed the test result,and drew the coefficient change law in different temperature intervals from-25 ℃ to 25 ℃.The temperature contraction coefficient in the whole interval is from 3 to 10 μm/(m·℃),less than that of common semi-rigid base materials.To different gradation,the temperature contraction coefficient in the whole temperature interval can take the average value,namely 6.5 μm/(m·℃).Besides,by dry shrinkage test,the authors also got the dry shrinkage coefficient.Compared with some semi-rigid base materials,the dry shrinkage of porous concrete is much less,so the anti-crack performance of porous concrete is better.