Research On The Influence Of Poured Roller Compacted Concrete On The Safety Of Gravity Dam

The roller compacted concrete dam is one of the dam types that combine the construction advantages of normal concrete dams and roller compacted earth-rock dams.The dam type does not have the strict limitations of traditional concrete column pouring in terms of pouring speed.It has simplified construction technology,fast construction speed,and savings Because of its advantages such as low cement consumption and low engineering cost,it is widely used.However,the construction process of RCC gravity dams is not continuous.For example,changes in the external environment such as the way of overwintering in high-cold and high-altitude areas have caused the safety phenomenon that the poured RCC threatens the overall dam.The research on the impact of roller compacted concrete on the safety of gravity dam formation has important guiding significance for the construction of roller compacted concrete dams.This paper takes a roller compacted concrete gravity dam as an example.The quality of the roller compacted concrete is affected to a certain extent due to changes in the way of overwintering during the construction of the dam.It is not known whether the subsequent concrete can be poured smoothly and safely.In view of this situation,this article firstly uses on-site testing to evaluate the durability of the poured RCC;secondly,based on the finite element numerical simulation technology,the impact of the poured RCC on the safety of the gravity dam is studied;finally,The influence of cracks on the safety of RCC gravity dam formation is discussed.The main research results are as follows:(1)Through the analysis of the test results of the impermeability,homogeneity and compactness,compressive strength,and interlayer bonding quality of the poured concrete,complete the evaluation of the durability of the poured concrete,and calculate the finite element based on the field test data The model parameters in the process are revised to ensure the reasonableness and accuracy of the calculation results.The test results show that the homogeneity,compactness,impermeability and interlayer bonding quality of the randomly tested parts of the casted roller compacted concrete are good,the compressive strength and impermeability properties all meet the design requirements,and the durability of the casted concrete buildings is basically Meet the specification requirements.(2)According to the specific dimensions of typical RCC gravity dam sections and on-site inspection results,a three-dimensional RCC gravity dam finite element model is established,and the subsequent concrete pouring process,the completion period and the impact of later water storage are considered,and the poured part is calculated and analyzed The displacement and stress of the concrete change with the pouring process;and according to the normal storage level,design water level,and check water level,the stress state of the poured part of the concrete is calculated and analyzed,and the concrete and foundation and new The safety factor of anti-sliding stability between the poured parts of the concrete.Numerical simulation results show that with subsequent concrete pouring layer by layer and reservoir storage to each characteristic water level,the displacement and stress of the poured concrete meet the specification requirements,and the safety factor of anti-sliding stability between the foundation surface and each roller compacted layer Both are greater than the specifications and meet the safety requirements.(3)Combining the appearance quality and crack depth detection data,simulate the cracks in the poured roller compacted concrete,and explore the rules of the subsequent concrete pouring process,the completion period and the later impounding period on the safety of the dam when the cracks exist.The calculation results show that with the subsequent concrete pouring and the storage of the reservoir to each characteristic water level,the crack width has not changed significantly,which does not affect the subsequent dam safety.Based on the above results,it can be seen that the quality of the poured concrete of the RCC gravity dam meets the specification requirements,and the pouring can be continued.