Research On Key Technology Of Internal Deformation Monitoring In Large Rock-fill Dam

The Rock-fill dam has the advantages of easy construction,making full use of construction rockfill materials for local use,good adaptability to dam foundation,good seismic performance and so on.With the development of social economy and the acceleration of hydropower technology,a number of rockfill dams（large-scale rockfill dams）with a height of more than 300m are being built in the southwest of China.The safety of high dams and large reservoirs directly affects the personal and property safety of the people in the downstream.Therefore,the deformation monitoring of high dams and large reservoirs is very important.However,the development of large rockfill dam monitoring technology is slow,especially the backward internal deformation monitoring technology of rockfill dam.The traditional internal deformation monitoring technology has been unable to meet the demand of large rockfill dam deformation,and it is difficult to adapt to the 300m level large rockfill dam for the traditional monitoring instrucment.This paper takes the internal deformation monitoring of large rockfill dam as the research core,solves the engineering problems faced by traditional monitoring through interdisciplinary,improves the internal deformation monitoring technology level of large-scale rockfill dam,and applies the new technology and method in this paper in the actual project.The main research work is as follows:1.A deformation measurement system based on pipeline robot is proposed.In view of the shortcomings of traditional monitoring methods for the internal deformation of large rockfill dam,such as fixed-point,long measurement period,pipe blockage and short service life.This paper puts forward a new idea of embedding flexible pipes in the rockfill body in advance,and then cooperating with robot measurement system to monitor the internal deformation,and obtains the three-dimensional curve of the internal deformation of the dam body,which solves the shortcomings of traditional monitoring methods.The measurement principle,measurement system,horizontal and vertical displacement calculation method of pipeline robot are introduced in detail.The experimental results show that the relative measurement accuracy is 10^-5of the pipe length.The results show that the difference between the pipeline robot and the traditional monitoring method is within 1.8mm,which further proves the feasibility of the new method in the deformation monitoring of large rockfill dam.2.A core wall deformation monitoring method based on array robot is proposed.The pipeline robot is used to monitor the deformation of rockfill body of rockfill dam,and the pipeline is buried horizontally.In order to solve the problem that it is inconvenient to bury the core wall vertically,this paper proposes a core wall deformation monitoring method based on array robot.The measurement principle,measurement system and calculation method of accumulated displacement of the array robot are introduced in detail.The theoretical accuracy is estimated.Combined with the experimental data,the new method can improve the observation accuracy by 54%compared with the traditional monitoring method.Combined with the actual measurement results of the core wall of Lianghekou,the settlement change of the core wall of the rockfill dam is analyzed,and the deformation law of the uneven settlement of the high core wall of the large rockfill dam along the dam axis is revealed.3.The deformation monitoring data analysis model of large rockfill dam is proposed.Based on the data collected by the pipeline robot and the array robot,the deformation monitoring data analysis model of the large rockfill dam is proposed based on machine learning.Compared with the traditional multiple linear regression,the model has the characteristics of stable modeling,reliable results and strong generalization ability.The modeling principle,abnormal value judgment,multicollinearity diagnosis and data prediction of the model are introduced in detail.The data analysis model of the construction period and the impoundment period is established based on the experimental data.The experimental results show that the main influencing factors of the dam displacement during the construction period are the dam filling elevation and the construction time,and the main influencing factors of the dam displacement during the impoundment period are the upstream reservoir water level and the impoundment water time.It has been applied in Lianghekou and Nuozhadu projects to reveal the deformation law of large-scale rockfill dam during construction and impoundment,and to construct the deformation monitoring model technology system of large-scale rockfill dam.