Temperature Rebound Influenced by Environment Temperature Analysis of the Irrigated Area of a High Arch Concrete Dam under Constrcution

2014 ◽  
Vol 580-583 ◽  
pp. 2045-2049 ◽  
Author(s):  
Xun Hui Chen ◽  
Yao Ying Huang ◽  
Bai Lin Xu ◽  
Dan Dan Liu ◽  
Xiao Bin Wei
Keyword(s):  
Thermal Conductivity ◽  
Arch Dam ◽  
High Arch Dam ◽  
Concrete Dam ◽  
Construction Period ◽  
Average Temperature ◽  
Environment Temperature ◽  
Dam Site ◽  
Heat Preservation ◽  
Annual Average Temperature

For a temperature rebound in the irrigated high arch dam during the construction period, using finite element method to research the influence of environment temperature to temperature rebound of the irrigated high concrete arch dam. Assuming that the initial temperature of the dam concrete is the joint grouting temperature. This paper presents a simulation of the temperature rebound of the high arch dam which is caused by the monthly average environment temperature, and performs sensitivity analysis to research the influence of thermal conductivity and surface heat preservation on the temperature rebound. According to the analysis,when the high arch dam sealing temperature is lower than the dam site annual average temperature, the dam site temperature inevitably would flow backward,slowly,to the irrigation area.The larger the thermal conductivity is,the quicker the temperature rebound speed will be. And benzene board insulation can reduce concrete temperature rebound rate, if the heat preservation benzene board is thicker,the temperature rebound rate is smaller.

Analysis on the Causes of Crack Formation and New Methods of Temperature Control during Construction of Super-High Arch Dam

2011 ◽  
Vol 243-249 ◽  
pp. 4453-4457 ◽  
Author(s):  
You Zhi Liu ◽  
Guo Xin Zhang ◽  
Yi Liu
Keyword(s):  
Temperature Control ◽  
Arch Dam ◽  
Cooling Mode ◽  
High Arch Dam ◽  
Height Control ◽  
New Methods ◽  
Under Construction ◽  
Heat Preservation ◽  
Selection Of ◽  
Temperature Crack

In this paper, the mechanism of typical temperature crack is systemically analyzed and the main cause for crack is discussed. Some efficient methods such as surface heat preservation, low temperature placing, interior heat gradient control, cooling height control, selection of water cooling mode have been discussed in depth. In additional, temperature monitoring, feed-back simulation instantaneous and crack risk early-warning are also considered as indispensable component for the temperature control and crack prevention work. At last, a series of temperature control and crack prevention new methods for super-high arch dam are suggested to ensure the safety of the dam under construction.

Key Technical Issues and Optimization Analysis on Temperature Control and Crack Prevention Measures for Xiluodu Super-High Arch Dam during the Construction Period

2014 ◽  
Vol 584-586 ◽  
pp. 2043-2051
Author(s):  
You Zhi Liu ◽  
Guo Xin Zhang ◽  
Ping Yang ◽  
Shao Wu Zhou
Keyword(s):  
Simulation Analysis ◽  
Arch Dam ◽  
Control Measures ◽  
Effective Control ◽  
Engineering Practice ◽  
Prevention Measures ◽  
High Arch Dam ◽  
Safety Control ◽  
Construction Period ◽  
Transverse Joint

By utilizing the transverse joint opening and closing iteration technique and the finite element method based on the discontinuous deformation theory for manifolds, and with the help of measured data in situ of temperature, stress and displacement and so on during the construction period, the dynamic tracing feedback simulation/analysis was carried out to the temperature field and the stress field. On this basis, a series of effective safety control measures and methods were systematically put forward, which are beneficial to safety construction in the high temperature season and winter, improvement of the safety coefficient for restrained zones, lowering the cracking risk of low gradation concrete in portholes, ensuring the transverse joints aperture and groutability as well as effective control of the cantilever height and so on; and good effects have been obtained in the engineering practice and the important guarantee may be provided for the overall safety of Xiluodu Super-high arch dam.

FEM Simulation of Temperature and Thermal Stress of Xiaowan Arch Dam

2012 ◽  
Vol 212-213 ◽  
pp. 887-890 ◽  
Author(s):  
Xing Ping Yang ◽  
Xiao Lin Chang ◽  
Xing Hong Liu
Keyword(s):  
Thermal Stress ◽  
Fem Simulation ◽  
Arch Dam ◽  
Three Dimension ◽  
Construction Process ◽  
Thermal And Mechanical Properties ◽  
High Arch Dam ◽  
Reservoir Impounding ◽  
General Law ◽  
Environment Temperature

Taking all the effects into account of thermal and mechanical properties, construction process, environment temperature, arch-closure and reservoir impounding orders, three dimension (3D) finite element methods(FEM) was adopted to simulate the whole construction process for temperature changing and thermal stress distribution of the dam. Typically, the results of the highest 22nd monolith were analyzed, from which the general law for both temperature field and thermal stress was acquired. And the results are valuable for temperature control of Xiaowan high arch dam.

scholarly journals Design of Thermal Insulation Materials with Different Geometries of Channels

Polymers ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 2217
Author(s):  
Daniela Șova ◽  
Mariana Domnica Stanciu ◽  
Sergiu Valeriu Georgescu
Keyword(s):  
Thermal Conductivity ◽  
Porous Structure ◽  
Base Material ◽  
Cost Effective ◽  
Heat Radiation ◽  
Average Temperature ◽  
Temperature Regimes ◽  
The Face ◽  
Inclined Channels ◽  
Air Channels

Investigating the large number of various materials now available, some materials scientists promoted a method of combining existing materials with geometric features. By studying natural materials, the performance of simple constituent materials is improved by manipulating their internal geometry; as such, any base material can be used by performing millimeter-scale air channels. The porous structure obtained utilizes the low thermal conductivity of the gas in the pores. At the same time, heat radiation and gas convection is hindered by the solid structure. The solution that was proposed in this research for obtaining a material with porous structure consisted in perforating extruded polystyrene (XPS) panels, as base material. Perforation was performed horizontally and at an angle of 45 degrees related to the face panel. The method is simple and cost-effective. Perforated and simple XPS panels were subjected to three different temperature regimes in order to measure the thermal conductivity. There was an increase in thermal conductivity with the increase in average temperature in all studied cases. The presence of air channels reduced the thermal conductivity of the perforated panels. The reduction was more significant at the panels with inclined channels. The differences between the thermal conductivity of simple XPS and perforated XPS panels are small, but the latter can be improved by increasing the number of channels and the air channels’ diameter. Additionally, the higher the thermal conductivity of the base material, the more significant is the presence of the channels, reducing the effective thermal conductivity. A base material with low emissivity may also reduce the thermal conductivity.

scholarly journals Research on concrete temperature control measures in deep hole area of super high arch dam

2021 ◽  
Vol 826 (1) ◽  
pp. 012035
Author(s):  
Yuchen Fu ◽  
Yaosheng Tan ◽  
Chunfeng Liu ◽  
Lei Pei ◽  
Yajun Wang ◽  
...  
Keyword(s):  
Temperature Control ◽  
Arch Dam ◽  
Control Measures ◽  
Deep Hole ◽  
High Arch Dam ◽  
Hole Area ◽  
Concrete Temperature

scholarly journals Analysis of the influence of asymmetric geological conditions on stability of high arch dam

2021 ◽  
Vol 28 (1) ◽  
pp. 426-436
Author(s):  
Zelin Ding ◽  
Xuanyi Zhu ◽  
Hongyang Zhang ◽  
Hanlin Ban ◽  
Yuan Chen
Keyword(s):  
Safety Factor ◽  
Negative Impact ◽  
Decisive Role ◽  
Arch Dam ◽  
Test Method ◽  
Stable Operation ◽  
High Arch Dam ◽  
Reinforcement Scheme ◽  
Structural Plane ◽  
Geological Conditions

Abstract Geological conditions play a decisive role in the stability of arch dam engineering, and the asymmetric geological conditions of the abutment have a very negative impact on the safety of the arch dam. This article takes Lizhou arch dam as the research object, and determines that the arch dam is preliminarily affected by the geological asymmetric characteristics. Through the geomechanical model test method, the overload failure test of the Lizhou arch dam was carried out, and the resistance body, the instability deformation of the structural plane of the two dam abutments, and the influence of each structural plane on the dam body are obtained, and the safety factor is determined. According to the test results under the condition of asymmetric foundation of arch dam, for the structural plane which affects the geological asymmetry of the arch dam, the corresponding reinforcement measures are carried out. The feasibility of the reinforcement scheme is verified by the finite element method, and the safety factor after reinforcement is obtained. According to the results, it is suggested that some engineering measures can be taken to reduce the geological asymmetry between the two banks and ensure the safe and stable operation of the arch dam in the future.

Effect of the impounding process on the overall stability of a high arch dam: a case study of the Xiluodu dam, China

2015 ◽  
Vol 8 (11) ◽  
pp. 9023-9041 ◽  
Author(s):  
Danni Luo ◽  
Peng Lin ◽  
Qingbin Li ◽  
Dong Zheng ◽  
Hongyuan Liu
Keyword(s):  
Arch Dam ◽  
High Arch Dam ◽  
Overall Stability
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