Temperature Control Measures and Feedback Analysis in Rapid Construction of Guandi RCC Dam

2012 ◽  
Vol 594-597 ◽  
pp. 1979-1982
Author(s):  
Wei Zhou ◽  
Xiang Yang Jing ◽  
Xing Hong Liu
Keyword(s):  
Temperature Control ◽  
Control Method ◽  
Dynamic Control ◽  
Cooling Water ◽  
Control Measures ◽  
Obvious Effect ◽  
Feedback Analysis ◽  
Cooling Water Temperature ◽  
Rcc Dam ◽  
Rapid Construction

Due to the shortcomings of conventional methods, the temperature control in rapid construction of Guandi dam is less effective. Then improved measures are designed and implemented based on the dynamic control method of pipe cooling, which depends on the real-time adjustment of five factors affecting pipe cooling (beginning time of cooling, lasting time of cooling, water temperature, rate of flow and direction of flow). The monitoring and feedback calculation are conducted. It is found that the newly-designed measures have obvious effect, and that there are no harmful cracks in the whole construction of Guandi dam. The conclusion is that it can effectively solve the problem of temperature control and crack prevention of high RCC dam via these measures, and provide some guide and reference to other similar projects.

Theory of Temperature Dynamic Control in Arch Dams and its Application

2012 ◽  
Vol 594-597 ◽  
pp. 738-741 ◽  
Author(s):  
Yin Duan ◽  
Xing Hong Liu ◽  
Xiao Lin Chang
Keyword(s):  
Real Time ◽  
Temperature Control ◽  
Control Method ◽  
Dynamic Control ◽  
Arch Dam ◽  
Real Time Control ◽  
New Techniques ◽  
Time Dynamic ◽  
Arch Dams ◽  
Time Control

Main factors of the temperature control and crack prevention in arch dams are summarized. The Space-time Dynamic Control method in pipe cooling process and the Temperature Real-time Control and Decision Database System are introduced to help for temperature real-time control and rapid analysis. Successful application of these new techniques in the construction of Dagangshan arch dam indicates that the proposed method are of significant effectiveness on the temperature control and crack prevention, and have good application prospect in practical project.

Temperature Control of RCC Dam in Yongding Project

2012 ◽  
Vol 238 ◽  
pp. 272-277
Author(s):  
Xiang Dong Xu ◽  
Jin Chao Yue
Keyword(s):  
Temperature Control ◽  
Cooling Water ◽  
Practical Method ◽  
Gravity Dam ◽  
Counter Measures ◽  
Water Pipes ◽  
Rcc Dam ◽  
Key Points ◽  
Concrete Temperature ◽  
Key Factor

Yongding RCC gravity dam with large project scale is in the construction all over the year, and the big temperature stress is a key factor for construction quality and progress. The temperature of the RCC dam in typical season with and without control conditions was analyzed by FEM, the temperature situation in typical season of RCC dam was controlled by the embedded cooling water pipes by practical method. Key points in concrete temperature control during high temperature season are found out, the counter measures and issues to be noticed are put forward.

A Correlation Analysis of Cooling-Induced Temperature Changes

2008 ◽  
Vol 131 (1) ◽  
Author(s):  
Tiebao Yang ◽  
Henry Hu ◽  
Xiang Chen ◽  
Yeou-li Chu ◽  
Patrick Cheng
Keyword(s):  
Water Temperature ◽  
Temperature Control ◽  
Linear Time ◽  
Cooling Water ◽  
Casting Process ◽  
Temperature Control System ◽  
Outlet Temperature ◽  
Local Surface ◽  
Cooling Water Temperature ◽  
Die Temperature

Proper temperature control is essential for producing superior quality components and yielding high production rates in high temperature manufacturing processes. Due to the closure of machine tools such as casting dies during production, it is usually very difficult to monitor their local surface temperatures without destructively inserting thermal sensors into them. However, the measurement of cooling water temperature at the coolant outlet is relatively unproblematic. This work demonstrates that there is a correlation between these two temperatures. As an example, the effect of the local surface temperature of a casting die on the cooling water outlet temperature is analyzed from a laboratory die casting process simulator. Based on the system identification theory, a control-oriented linear time-invariant model has been developed, which correlates the local die temperature to the cooling water outlet temperature. The model enables the prediction of the local die temperature with the measurements of the cooling water temperature. Thus, it provides an alternative approach other than the destructive sensing method to acquire the local die temperatures, and the model could be applied to design a real-time temperature control system for die cooling process.

A New Method for Improving the Stress Status of the Dam

2013 ◽  
Vol 444-445 ◽  
pp. 849-853
Author(s):  
Jian Hua Cui ◽  
Yong Feng Qi ◽  
Jie Su
Keyword(s):  
Temperature Control ◽  
Cooling Water ◽  
Control Measures ◽  
Sensitivity Analyses ◽  
Mass Concrete ◽  
Water Cooling ◽  
Concrete Gravity Dam ◽  
3D Fem ◽  
Construction Period ◽  
Operation Period

Under the action of annual change and sudden drop of air temperature, thermal induced cracking will occur in concrete dam during the operation period. For exploring the temperature control measures for crack prevention, taking a concrete gravity dam section as the research object, sensitivity analyses to the factors which affecting the water-cooling effect are conducted with 3D FEM, some significant suggestions for the water cooling are presented. The results show that, the stresses of the dam surface will decrease to a certain extent after water cooling in the operation period using the cooling water pipe which embedded during construction period, and the cracking risk of the dam will reduce. The study provides a new train of thought for the temperature control and crack prevention of the mass concrete during the operation period.

Temperature Cracks Controlling Technology for the Mass Concrete in Solid Sections of Lower Pylon Column

2013 ◽  
Vol 467 ◽  
pp. 262-269
Author(s):  
Fu Liang Gao ◽  
Yan Wei Fang
Keyword(s):  
Temperature Control ◽  
Thermal Stresses ◽  
Cooling Water ◽  
Control Measures ◽  
Mass Concrete ◽  
Removal Time ◽  
Control Scheme ◽  
Section Size ◽  
Circulating Cooling Water ◽  
Binder Ratio

According to the case that mass concrete in solid sections of lower pylon column of Jiashao Bridge was easy to crack in construction because of the bigger section size, larger content of cementitious material and lower water binder ratio, the temperature and thermal stresses distribution of mass concrete was simulated and temperature control scheme was adjusted constantly based on the results of field temperature monitoring. Through taking some temperature control measures such as applying circulating cooling water and prolonging the time appropriately, thermal insulation and moisture retention curing, extending the form removal time and controlling the quality of concrete, harmful cracks did not appear in solid sections of lower pylon column of Jiashao Bridge and anticipated temperature control requirements were achieved.

Study on Temperature Control Method of Yeywa Hydropower Station RCC Dam Construction

2012 ◽  
Vol 170-173 ◽  
pp. 2110-2114
Author(s):  
Yuan Chun Xia ◽  
Dong Fei Lin
Keyword(s):  
Temperature Control ◽  
Temperature Rise ◽  
Control Method ◽  
Technical Problem ◽  
Raw Material ◽  
Hydropower Station ◽  
Dam Construction ◽  
Construction Period ◽  
Rcc Dam ◽  
Batch Plant

Yeywa hydropower station RCC dam is located in the torrid zone of Asian, During the construction period, it meet Technical problem of temperature control in hot season. We can utilize the peculiarity of RCC that has a slow temperature rise due to hydration heat and a low early strength, according to analyse the blending and concreting procedure of RCC, adopt comprehensive and effective temperature control method, such as confirm concrete mix, control the temperature of raw material and RCC out of the batch plant, prevent temperature rise during transporting and concreting, setting joint to avoid structural crack and temperature crack. From Yeywa hydropower station RCC dam construction finished to now, no dangerous crack is detected, It accumulate experiences for RCC dam construction in high temperature place.

Study on Crack Prevention for Concrete Rapid Construction

2011 ◽  
Vol 291-294 ◽  
pp. 1149-1153 ◽  
Author(s):  
Min Zhi Liu ◽  
Sheng Qiang ◽  
Bing Lei Wang ◽  
Zhan Qiang Zhen ◽  
Xiang Rong Wang
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Temperature Control ◽  
Control Measures ◽  
3D Finite Element ◽  
Time Space ◽  
Rapid Construction ◽  
Thin Walled ◽  
3D Finite Element Method ◽  
Element Method

Pier concrete is vulnerable to cracking when using concrete rapid construction after long off period. In order to solve this problem, crack mechanism and effects of several temperature control measures of thin-walled structure concrete is analyzed. Through analyzing the temperature and stress time-space variation using 3D finite element method, it can be found that stress is more sensitive to controlling concrete placing temperature than other measures. It also shows that under the condition of taking other proper temperature control measures, low placing temperature can not be spared.

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