Applied Mechanics and Materials Vols. 170-173

Abstract: Risk analysis for large and medium-sized pumping stations was conducted by using the theory of fault tree. Model was established for fault tree analysis on running risk of pumping stations. Structural importance of minimal cut sets was analyzed and compared on the magnitude based on the probability description of fault tree given. Then the major influencing factors were identified and risk rating of pumping stations was discussed. In addition, appropriate countermeasures were provided for management. And application example was given.

Abstract: A mathematic model of the optimal posture of airliner landing onto water is built in contacting water stage. By using solid-fluid coupling, momentum conservation, motion equation and pressure drags, the difference equation is constructed to find the influences of the contact water surface angle. The numeric results shows that the peak pressure keeps long time if impact angle small..

Abstract: By using solid-fluid coupling, momentum conservation, motion equation and pressure drag, a difference algorithm is employed to find the posture of airliner landing onto water in bowing stage for the different angle. The results show that the final velocity is positive correlated with impact angle when the angle is less than 80; the final velocity is negative correlated with impact angle when the angle is more than 80, waves make the immersed part decrease, which leads to a buoyancy reduction and acceleration increment.

Abstract: There are corresponding stability criterions for limit equilibrium method, which is simple to implement and has been used for long-term. But this method is only considered the equilibrium of system without considering deformation, compatibility conditions and material constitutive. To improve the method, which is used to analysis the stability of Lanna dam, was proposed to optimize the boundary conditions, consider the discontinuity between the media in junction and add additional stress to consider the effects of buoyancy and seepage. After completion, tests showed that this approach could overcome limit equilibrium method’s shortcoming and describe the discontinuous characteristics of media naturally, such as dislocation, opening, slip and so on. And the result is reliable.

Abstract: This paper puts the theory of Multi-Agent into control automation, setting up a Automatic Control System of Water Conservancy Project Model based on Multi-Agent, applying Multi-Agent theory to Automatic Control System of Water Conservancy Project Model Test, and coordinating and solving a great deal of problems that exists in Automatic Control System at present through the communication among a lot of Agents, which will offer very important basis and advanced scientific means for Water Conservancy Project Model Test implementing intellectual control of real meaning.

Abstract: Based on field compaction test of Nuozhadu I district rockfill engineering, numerical simulation was conducted to study the rolling compaction (RC) process using Particle Flow Code (PFC). Effects of different particle content to the quality of dam filling were discussed based on both numerical and filed test results. Numerical results also revealed the particle movement of the rockfill, the density of the formation mechanism and compaction characteristics during the RC process. Field test and simulated results both indicated that the RC process can be divided into three stages of vibration compaction, void filling and the unloading rebound phase

Abstract: According to lacking a statistical method of resource and quantity under a unified standard in hydraulic and hydropower engineering construction, the budget quota method based on P3e/c was proposed. The hierarchy structure of data-frame of P3e/c and the data structure of budget quota were analyzed. The budget quota system based on P3e/c was developed by utilizing JAVA programming language. A certain hydraulic and hydropower engineering in southwest of China was taken as an example. The results indicate that the veracity, universality and efficiency of construction scheduling have been improved significantly by integrating budget quota and P3e/c. Moreover, it provides the basic data for construction scheduling statistic and analysis. The proposed method provides decision making basis for designers and managers.

Abstract: A new type of ecological fishway was developed in this paper, including a new protection technique of the natural fishery resources, biodiversity and sustainable development. The ecological fishway belongs to the Denil type, installed with arc-type baffles. Arc-type baffles separate the fishway channels into several cascades partly like ship locks. Orifices around the V-shape notch provides additional passageways of water flow. Respectively outflowing from orifices and the notch, the interaction of water currents can help to dissipate energy, decrease water velocity and weaken the turbulence. Hence fish need less energy to overcome water resistance and improve passing efficiency. Water flow can automatically take away the sediments accumulated in the fishway through both bottom corners of the baffle, keeping a clear environment for fish. The flow conditions of the proposed type were investigated and the results have preliminarily verified the improved hydraulic characteristics.

Abstract: Monitoring data of the arch crown dam section of the Geheyan concrete gravity arch dam were qualitatively and quantitatively analyzed. The analysis results show that the measured data and year changes of the dam horizontal displacement are small, the influence of the water level and temperature on the arch crown dam section is normal, the influence of the aging on the dam horizontal displacement is little, and the aging component has become stable. Therefore, it can be shown that the arch crown dam section of the Geheyan concrete gravity dam is in elastic state, and the horizontal displacement is accord with general deformation law of concrete arch dams.

Abstract: The upstream cofferdam of the Pinecone Hydropower Station was an upstream earth-rock cofferdam built on the deep overburden layer of upstream foundation pit, which has many characteristics such as big reservoir capacity in front of the cofferdam, deep foundation pit behind the cofferdam and long anti-seepage time. In order to provide reference and a basis for seepage control construction, the sensitivity analysis on permeability coefficients of the seepage control system was made to analyze the seepage characteristics of upstream cofferdam at design water level and to discuss the permissible value range of permeability coefficients. The calculation results show that correct and reasonable seepage control measures are able to realize an effective control of the seepage field. Besides, the engineering design parameters are obtained when the optimization analysis on permeability coefficients meets the seepage control requirements, and thus provide the basis for engineering optimization design.