Research On The Whole Process Control And Evaluation Method Of Curtain Grouting Quality Driven By Digital Twin

As a construction method widely used in hydraulic engineering construction,grouting has become an important means to solve common problems in hydraulic structures such as dam body and dam foundation leakage,tunnel structure cracking and deformation,rock and soil landslides and collapses,etc.It is very important to ensure the long-term safe and stable operation of water conservancy projects.However,the curtain grouting project has the characteristics of concealment,dynamic variability,complexity,and uncertainty.It is difficult to directly observe the diffusion of grout in the grouted area,and the grouting effect and its quality cannot be judged intuitively.As th e construction of water conservancy and hydropower projects in my country gradually expands to areas with complex and changeable engineering geological conditions,the problems of hydrogeological conditions faced by water conservancy projects in the future will become increasingly prominent,and the difficulty of curtain grouting design and construction will gradually increase.an d evaluation pose new challenges.At present,the control and evaluation of the whole process of grouting quality are faced with key problems such as single simulation model medium,the low prediction accuracy of grouting effect,and difficulty in the comprehensive evaluation of grouting quality.Th erefore,based on system engineering theory,CFD numerical simulation,artificial intelligence algorithm,and fuzzy mathematics method as the main theoretical basis,this paper proposes the whole process control theory and evaluation method of curtain grouting quality driven by digital twin and uses the Huanggou pumped storage power station in Heilongjiang.The curtain grouting of the main dam is carried out on an engineering basis to carry out applied research.The main research contents and results are as follows:(1)In view of the deficiencies in the current grouting quality whole process control and evaluation method,the whole grouting process is divided into three parts:"before-during-after"and combined with the digital twin technology and the characteristics of the grouting project.The whole process control and evaluation method of grouting quality is driven by digital twin.The method includes three aspects,namely,pre-control and evaluation theory of grouting quality based on CFD numerical simulation,in-process control and evaluation method of grouting quality based on artificial intelligence algorithm,and post-event evaluation method of grouting quality based on fuzzy mathematics theory.(2)In view of the fact that the current numerical simulation technology of grouting engineering mostly adopts porous media or one-and two-dimensional crack simplification methods,which cannot truly reflect the grout diffusion law in the grouting area,based on the geometric parameters of the cracks in the real crack sketch data Statistical analysis,established a three-dimensional "crack-pore" dual-media grouting diffusion model,and then respectively established the control equations for the grout diffusion movement of crack channels and pore channels,and proposed a rock mass dual-media grouting simulation theory and method based on CFD simulation analysis.By solving the grout diffusion of cement grout in the single grouting hole model,the influence of different grouting or geological parameters on the grout diffusion is studied,and the grout diffusion filling law in cracks and pores is obtained.At the same time,a"crack-pore" dual-media multi-grouting hole model is established,which realizes the fine simulation of multi-grouting holes in the porous sequence during the grouting process,and intuitively and effectively reflects the dual diffusion of cement grout in random fracture networks and porous media.It provides reliable theoretical and technical support for the prior control and evaluation of grouting quality in hydraulic projects.(3)In view of the current situation of insufficient prediction accuracy and lack of autocorrelation analysis in grouting events,according to the characteristics of grouting engineering data,the Transformer model is refined,and a lightweight Transformer grouting prediction model is proposed.Predict and analyze the output parameters real time,and control and evaluate the grouting quality in the process.Using the real grouting data of Huanggou Pumped Storage Power Station,the prediction models of grouting amount and grouting effect were constructed respectively.Through the comparative analysis with other methods,the high precision and superiority of the lightweight Transformer grouting prediction model were verified.Using this method,the real-time unit grouting volume can be predicted and checked at the grouting construction site,and the grouting effect at any position can also be judged,the number of inspection holes and the damage to the rock mass after grouting can be reduced,and the grouting quality can be controlled in the process.(4)In view of the uncertainty and ambiguity problems such as the lack of an evaluation index system,fuzzy index classification standards,and unclear boundaries of index categories in the comprehensive quality evaluation of grouting projects,firstly consider the groutability before grouting,design rationality,and grouting quality.Based on factors in the whole process of grouting,such as construction standardization and post-grouting quality inspection,a comprehensive evaluation index system for grouting quality was established,which includes 3 first-level indicators and 12 second-level indicators.Then,a comprehensive evaluation method of grouting quality based on FRES-VFS is proposed,and the complex coupling mechanism among various indexes in grouting engineering is analyzed by using FRES theory,and the influence weights of 3 first-level indexes and 12 second-level indexes are calculated.Finally,the membership relationship between the evaluation index and the grade will be determined according to the standard interval and the relative membership degree.Complete post-event control and evaluation of grouting quality.