ZhongRu Wu

Deep Stability Evaluation of High-Gravity Dam under Combining Action of Powerhouse and Dam

AbstractThe rock foundation of a gravity dam is usually cut into slide blocks by the structural surfaces. Its stability is controlled by the characteristics and the combining action of these structural surfaces. The failure of a gravity dam can be caused by the destruction or large deformation of local rocks under the condition of certain loads. The coupling of continuous-discontinuous deformation is a typical characteristic of the process. As a new design idea, the powerhouse and dam are combined into an integer with one structural pattern to improve the antisliding stability of the gravity dam. The external loads are undertaken together by the powerhouse and dam. The loads acting on the dam can be transferred partly to the powerhouse, and the powerhouse weight and tail water pressure can increase the dam’s stability. The optimal design of a gravity dam section can be implemented, decreasing the project quantity, and reducing construction costs. This design idea has been adopted by the Yangtze Three Gorg...

Nonparametric Change Point Diagnosis Method of Concrete Dam Crack Behavior Abnormality

The study on diagnosis method of concrete crack behavior abnormality has always been a hot spot and difficulty in the safety monitoring field of hydraulic structure. Based on the performance of concrete dam crack behavior abnormality in parametric statistical model and nonparametric statistical model, the internal relation between concrete dam crack behavior abnormality and statistical change point theory is deeply analyzed from the model structure instability of parametric statistical model and change of sequence distribution law of nonparametric statistical model. On this basis, through the reduction of change point problem, the establishment of basic nonparametric change point model, and asymptotic analysis on test method of basic change point problem, the nonparametric change point diagnosis method of concrete dam crack behavior abnormality is created in consideration of the situation that in practice concrete dam crack behavior may have more abnormality points. And the nonparametric change point diagnosis method of concrete dam crack behavior abnormality is used in the actual project, demonstrating the effectiveness and scientific reasonableness of the method established. Meanwhile, the nonparametric change point diagnosis method of concrete dam crack behavior abnormality has a complete theoretical basis and strong practicality with a broad application prospect in actual project.

Analysis of crack stability in concrete dams with chaos optimized neural network

Because calculation of stress intensity factors using the finite element method of the linear elastic fracture mechanics cannot satisfy the need for the real-time monitoring and the real-time analysis of cracks in concrete dams, a four-layer neural network for calculating stress intensity factors is proposed. The neural network is improved by chaos optimization algorithm. An example is given to validate the improvement. The example shows that the optimized neural network can yield-good results.

A DECISION SUPPORT SYSTEM FOR MONITORING DAM BEHAVIOR

The development of decision support system for monitor ing dam behavior is an important approach to implement the real -time analysis and reasonable diagnosis for dam safety based on prototype observations, thereby realize the effective control of dam life process, viz. construction, operation, aging and end of its useful life. With systems engineering, mathematical and mechanical methods, a decision support system for monitoring dam behavior is developed. It is used to resolve problems over factual data and employ heuristic techniques with the accumulated knowl edge. This system was composed of integration control module, intelligent inference engine, support base cluster, information management and input/output modules. Metadata base based on object oriented data model is used to implement the integration of dam safety data from different information sources. The multilevel link style was used to manage model base. Intelligent inference engine is the central processing unit. It can be used to monitor the operation characteristics and diagnose the unexpected behav ior. It includes monitoring models, inference model and evaluation model for dam behavior. The proposed system has been used to monitor dam safety successfully. The applications show that the system structure is feasible, the adopted key technologies are e ffective, and the results are reasonable.