Void Area Identification Of The Sluice With Soft Foundation

Affected by the water flow, sluice foundation has some diseases in the operation process, such as differential settlement?hollowed sediment. When since sluice is built on the soft soil or sand foundation, sluice foundation will be voided easier. Because the void located in the water under the floor is difficult to find in safety inspection, security risks can not easily be found. Therefore, it's very important to detect the sluice foundation void area for the protection of the safe operation of hydraulic structures. Specific contents are as followed:(1) According to engineering data, this paper uses ANSYS software to establish sluice model using shell element. The sluice foundation void area is described by parameters. According to the vibration characteristics that effected by the different void area, vibration pattern classification method is proposed. After modal pattern classification, the new response surfaces equations are established. Compared the result of the response surface with the finite model's result, this paper adjusts the cavity parameters to make the comparison result as close as possible. These cavity parameters can describe the sluice foundation void area well. It is verified that this algorithm can identify the sluice foundation void area.(2) In order to be more accord with actual engineering, this paper establishes the solid element sluice model. And the dynamic characteristics of this model are more realistic. Based on the modal analysis by ANSYS software, the response surfaces between natural frequency?vibration mode and the cavity parameters are established. The modal information is used to construct objective function. Then the genetic algorithm is studied to identify the solid element sluice foundation void area.(3) For the purpose of improving the robustness of the recognition algorithm, the statistical moment method is introduced. The time history analysis of the sluice model is made by ANSYS software, and the displacement information is extracted. Then the fourth order displacement statistical moments is calculated. Further, the function between the characteristic parameters and the cavity parameters is established. Compared the result of the function with the finite model's result, the target function is constructed. Finally, the identification study of sluice foundation void area is done by solving optimization problems.Numerical simulation analysis shows that, the method to identify the sluice foundation void area based on modal information can indicate the sluice foundation void area well. With the improvement of the noise level, the recognition result will become worse. Because of better robustness, the sluice foundation void area recognition method is proposed based on displacement statistical moments. The results show that the algorithm can identify the solid element sluice foundation void area when the noise level is relatively high.