Safety Assessment Of Hydraulic Structure Engineering Based On FLAC ^3D During Construction And Operation By

The safety of hydraulic structures has become a major event related to people's livelihood in hydraulic project. The stress and deformation of these structures are complex under various loading and restraint. Safety evaluation on hydraulic structural engineering has some practical significance during design, construction and operation.This article summarizes the safety assessment and technical status of hydraulic structures at home and abroad. It takes shiplock lock chamber and sluice of Dayuandu Hydroproject and surge shaft of Gangqu River Hydropower Station as the object of study. The author selects three-dimensional finite difference calculation software FLAC3D to analysis stress deformation of the hydraulic structure to evaluate project safety. The author selects constitutive model of Mohr - Coulomb model and D-P model, using ANSYS→FLAC3D technology to build three-dimensional model. In this paper, the two examples come from some results of the project"River Navigation Project post-evaluation methods and Empirical Study"and"Safety Evaluation on the surge tank and the slope behind the plant of Gang Qu River powerstation in Shangri-La".Major work and conclusions are as follows:(1) Through summarized the cases of Water accident at home and abroad, cause of the crash of Water, the development status and trends of Water Safety Evaluation of domestic and foreign.(2)The author introduced the concept of safety evaluation of Water Resources and Hydropower Engineering, described in detail the various methods and theory of safety evaluation in hydraulic structure engineering; Briefly introduced three-dimensional calculation software FLAC3D which based on the finite difference method and constitutive model.(3)Calculated lock chamber and the high and low sluice of Dayuandu Hydroproject.The results showed that the entire lock chamber has not been due to the fluctuation of water level greater impact, lock chamber is in a stable and secure state. The displacement magnitude of the main part of high, low sluice is very small, less than 2mm, sluice structure is relatively stable and safe.(4)The author simulated the excavation and support measures on surge shaft of Gang Qu River Hydropower Station. The results showed that maximum settlement deformation appeared in the top of surge shaft. The value of the maximum settlement deformation will not exceed 10mm during construction and operation. Lining will not produce subsidence damage under the role of gravity and water pressure. Shaft of the settlement will not lead to diversion tunnel deformation of safety problems. The result is valid with existing support measures on surge shaft. Bolt axial force are small, it can meet the design requirements on its strength.(5) Calculation by FLAC3D; the author put the lock chamber and the high and low sluice analysis results compared with monitoring information or on-site construction; the author put the excavation and support measures of the surge shaft analysis results compared with monitoring information or on-site construction.The results show that the use of FLAC3D for hydraulic structures safety assessment is feasible.