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January 30,2013
Volume 6,Issue 2
Pages -
Subject Area:Hydraulic Material,Hydraulics,Flood Control Project,Environmental Water Conservancy,Engineering Structures,Civil Construction Structure,Foundation Engineering

Title: Application of PVC-U pipes in the safe drinking water project for peasants in Shunyi district, Beijing

Authors: ZHANG Junwei
PP: 198-202
Abstract: In this paper, took the application of unplasticized polyvingl chloride (PVC-U) pipe in the safe drinking water project for peasants in Shunyi district as an instance, the strengths and limitations of steel tube, ductile cost-iron pipe, polypropylene (PP), polyethylene (PE) pipe, pipe and PVC-U pipe were evaluated and analyzed. In contrast, PVC-U pipe has more technological advances and economic rationality. Construction methods of PVC-U pipes were introduced in detail for providing useful experiences and lessons in the safe drinking water project for peasants.
Keywords: municipal engineering; unplasticized polyvingl chloride pipe; safe drinking water; application

Title: A way for extending the life of pipe well

Authors: LIU Zhichao, KANG Li, LIU Lanfang
PP: 194-197
Abstract: Based on actual investigation and through careful analysis on the damage causes of pipe wells, it was found that the main reason for destroy of pipe well was pipe rupture by external force due to the low intensity of submersible pumps Duan filter pipe. In thie paper, the method of strengthening the filter pipe wall partially was proposed: using armored concrete windowing filter tube to replace the nothing grit concrete filter tube in submersible pump Duan. The practice proved that this method can extending tube well life, which produces significant social and economic benefits.
Keywords: other subjects of water conservancy project; tube well; submersible pump Duan; armoured concrete windowing filter tube; nothing grit concrete filter

Title: Research on method of water demand simulation in middle and lower reach of Hanjiang river

Authors: GU Wenquan, SHAO Dongguo
PP: 189-193
Abstract: Long series simulation of water demand is the basis of water resources planning and management. During the process of water demand simulation, the correlation coefficient of water demand is a difficult point simulation. In this paper, the data transfer methods of Thomas-Fiering and Box-Cox are introduced for simulating the water demand in middle and lower reach of Hangjiang river for 500 years. This model is proved to be precise by comparing the statistical parameters such as mean, standard deviation, and correlationship coefficient with those of real situations, which might provide new method for water demand forecasting.
Keywords: water management; water demand simulation; Thomas-Fiering; data transfer; middle and lower reach of Hangjiang river

Title: Model test research of hydraulic characteristics of spillway tunnel in middle chamber downstream with sudden lateral enlargement and vertical drop aerator

Authors: WANG Chao, MA Xudong, DAI Guangqing, YANG Qing
PP: 183-188
Abstract: The hydraulic characteristics, cavities length and pressure characteristics of spillway tunnel in middle chamber downstream with sudden lateral enlargement and vertical drop aerator were studied through physical model test method. The experiment results showed that the water wing phenomenon of spillway tunnel caused by vertical drop and sudden lateral enlargement aerator could not be avoided. However, it could be reduced by optimizing the aerator type to avoid the spillway tunnel top wall being erosion. Moreover, the aerator could lengthen lateral cavity length and link the lateral cavity with the bottom cavity to prevent cavitation damage. With the upstream water level heightening and the width of lateral expansion increasing, the maximum pressure of floor and sidewall would decrease. Besides, there was no negative pressure zone existing along the spillway tunnel.
Keywords: hydraulics and river dynamics; sudden lateral enlargement and vertical drop; water wing; cavity; pressure

Title: Convergence of drainage and drainage standards in riverside urbanized area

Authors: DING Huakai, ZHOU Conghui, LIU Jun
PP: 178-182
Abstract: In terms of drainage features in riverside urban areas, analysis the difference and correlation between the various sampling methods, the convergence method of drainage and drainage standards was proposed. Taking Nanjing, a typical city in the riverside area as an example for calculation, using the calculation results of other 4 cities in riverside area for revision, the convergence method of draw pipe network drainage design standards and urban storm design standard was obtained.
Keywords: flood control works; riverside urbanized area; drainage; drainage standards; convergence

Title: Research and application of water regime information and flood forecasting system in Danjiangkou reservoir

Authors: YANG Chunlan, GAO Bo, HE Yousheng
PP: 170-177
Abstract: This paper introduced two typical flood prediction cases since the hydrological information and flood forecasting system was applied in Danjiangkou water conservancy project. Through the analysis on applicability of the model problem, optimization problem, parameter selection problem, timely human experience factors and comparison of prediction results and measured flood runoff process, this paper summarized the operation strategies, forecast precision and application effect of this system in flood forecast of Danjiangkou water conservancy project. Combined with other existing flood forecasting methods in Danjiangkou water conservancy, the correct and appropriate application of the water regime information and flood forecasting system can greatly improve the accuracy of flood forecasting and reduce uncertainty of data from artificial processing, which can be used as a reliable reference tool for flood forecasting of reservoir.
Keywords: flood control works; reservoir flood forecasting and dispatching; national hydrological information and flood forecasting system; prediction model; scheme optimization; experience factor

Title: Research on sensor position optimization based on lower order modal

Authors: LIU Fushun, WANG Weiying, LU Hongchao
PP: 161-169
Abstract: Concerning structural modal order, this paper proposed a sensor optimization method for offshore platforms based on the effective independence method, which can take into account different optimization purpose of lower order mode/modes. The validity of the proposed method is verified using a five-DOF mass-stiffness numerical model. Furthermore, this method is proved to be correct, and then a numerical model of JZ20-2MUQ platform is employed and a large-scale and complex three-dimensional structure is investigated. Numerical results indicate that the sensor positions of sensor optimization based on lower order modal parameters can define the optimal the number and positions of sensor according to different modal Identification target, which has certain engineering application prospects.
Keywords: ocean engineering; sensor; position optimization; lower order mode; offshore platform

Title: Water environmental variation tendency and countermeasure in Cangzhou city in recent decades

Authors: HA Jianqiang, ZHANG Dongjiang, WU Xu
PP: 153-160
Abstract: Through analysis on the river course closure, runoff volume, water burying depth change under the deep and shallow layer ground and water pollution in Cangzhou city during recent decades, we discussed the impact factors of water environment from natural and human influences and summarized water environmental variation tendency of Cangzhou city. Then, we proposed the ideas of regional water management including developing the research of flood converting into resources and wetland recovery in detention basin, etc. Furthormore, we gave the suggestion of adjusting the aim and pattern of water environment repair, to promote the improvement of water environment as soon as possible.
Keywords: environmental hydranlic engineering; river course closure; review; water environment; surface subsidence; flood converting into resources

Title: Numerical simulation study on influence of nearby buildings to deep excavation

Authors: ZHANG Hongye, LI Hongjing
PP: 147-152
Abstract: Taking deep foundation pit enginering in Huai’an as background, the process of deep excavation engineering was simulated using 3D analysis model based on finite element method ABAQUS. The influences of nearby building parameters such as building location, and building loads on foundation pit deformation in the process of foundation pit excavation were studied, and the deformational laws of the soil around foundation pit were obtained. According to the analysis, we obtained the following results: with the farther distance of buildings from foundation pit, the influence on foundation pit deformation reduced, and the influence of nearby building in axis location on excavation is smaller than the building deviating from the axis location. In addition, with bigger building load, the bigger influence occurred to excavation. The conclusions have guiding significances for the design and construction of excavation.
Keywords: engineering structure; foundation pit enginering; foundation pit excavation; numerical simulation; finite element method

Title: Calculation model and analysis of thin-walled cold-formed steel framed structure with double bracing

Authors: LI Leilei, CHEN Shiming
PP: 135-146
Abstract: Based on one thin-walled cold-formed steel structure with double slant bracing, the characteristics of node of the double slant bracing was analyzed, and simplified node calculation model was proposed. Regarding different ways of connection of beams, columns and slant bracings, four finite element analysis models were constructed using finite element analysis method and SAP2000 software. Through analyzing the whole structure of the model, the displacement and internal force of the structure under the load of wind and earthquake was obtained, and comparisons were made among the four models. The results showed that double slant bracing significantly increased the anti-lateral displacement stiffness, improved the anti-lateral displacement and earthquake resistant ability of the structure. Changing the ways of connection among beam, column and slant bracings did not improve the anti-lateral displacement stiffness and other ability.
Keywords: engineering structure; double slant bracing; thin-walled cold-formed steel; frame structure; finite element analysis; component connection

Title: Research on water intake technology of water source heat pump system in lakes and reservoirs of Chongqing

Authors: FAN Gongduan
PP: 124-134
Abstract: In order to develop intake technology of water source heat pump (WSHP) in lake and reservoirs system, temporal and spatial distribution characteristics of water temperature and quality and water features were carried out in Caiyun lake in Chongqing. The results showed that the average water temperature of Caiyun lake in Chongqing was 26-30℃ in summer, 11-15℃ in winter, indicating that Caiyun lake was a suitable hot and cold source of WSHP. The water tempature had obvious vertical stratification in summer, but not obvious in winter. As the hot-cold source of WSHP, the quality of the lake meets the basic requirements of water source heat pump structure. pH, turbidity and chlorophyll a had obvious vertical stratification characteristics while hardness and salinity did not have. According to temporal and spatial distribution characteristics of water temperature and quality, water intake should be located in the middle or lower of the lake. Intake ways of infiltration diversion, pump, floating ship and siphon were suitable for lakes and reservoirs of Chongqing. This study provided the basic data and scientific basis for design of lake and reservoir water in Chongqing, also promoted technical support for the efficient application and spread of water source heat pump system of lakes and reservoirs.
Keywords: municipal engineering; water source heat pump of lakes and reservoirs; temporal and spatial distribution; water intake structure; water-intake technology

Title: Study on wind load type coefficient of air-cooled support structure

Authors: BAI Guoliang, LIU Feifei
PP: 116-123
Abstract: In this paper, through 1∶150 rigid model wind tunnel test and numerical simulation, the wind load type coefficient of A type structure, wind-break wall and pipe column in single-span air-cooled support structure was studied. The effects of fans, surrounding structure and wind direction angle on wind load type coefficient of the structure were analyzed, and the most unfavourable conditions were determined. Through comparison of the test results with the numerical simulation results, it was found that they agreed well with each other. Finally, the recommended values of wind load type coefficient of single-span air-cooled support structure was given, which provided a new basis for the structural design.
Keywords: civil engineering structure; air-cooled support structure; wind load; rigid model wind tunnel test; numerical simulation; type coefficient

Title: Review and experimental measurement of silica gel’s adsorption isotherm

Authors: ZHENG Yuwei, LIU Xiaohua, TU Rang
PP: 110-115
Abstract: The given adsorption isotherm of silica gel is important for simulating the process of dehumidifying and regenerating of the equipment and optimizing the design and control. This paper reviews and compares the various adsorption isotherms in of different silica gels (including RD silica gel, ID silica gel and silica gel with Al3+) literature. which differ in curve shape and the corresponding to temperature, and among them the moisture absorption ability of silica gel with Al3+ is the best. Then the adsorption isotherm at 20℃/40℃ of a king of silica gel is measured. Compared with those from literature, the adsorption isotherm shape factor of this silica gel particle is 0.6.
Keywords: ventilation and air-condition engineering; silica gel; adsorption isotherm; experiments

Title: A new method of measuring the horizontal displacement of foundation pit

Authors: HU Yuanyuan, SHI Ruixu
PP: 104-109
Abstract: Horizontal displacement surveying is an important part for the construction monitoring of foundation pit. There are many kinds of methods to measure horizontal displacement, which are suitable in different conditions. Considering the advantages and disadvantages for both axis method and small: angle measurement method, this paper puts forward a new method for monitoring horizontal displacement, which is named normal line method. This method does not need distance measurement and complicated calculation, and the baseline can be easily arranged, which is suitable for irregularly shaped foundation pit, especially circle pit.
Keywords: geotechnical engineering; foundation pit; horizontal displacement monitoring; normal line method

Title: Consolidation theory of development unsaturated soft soil under cyclic loadings

Authors: GENG Xueyu, ZHAO Jian
PP: 97-103
Abstract: This paper retrospects the historical development of the theory of soil consolidation process and reviews unsaturated soil consolidation theory research under cyclic loadings at home and abroad from theory research and experimental model. In addition, this paper summarized the research methods and the latest research results of unsaturated soil consolidation theory under cyclic loadings and discussed the importance of unsaturated soil consolidation theory research under cyclic loadings. In terms of the subgrade and pavement disease control problems associated with unsaturated soft base for domestic road and rail construction, this paper proposed the future development direction.
Keywords: geotechnical engineering; consolidation theory; review; unsaturated soil; cyclic loading

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