Applications Research On Umpty Uncertainty Problems Analysis In Construction Diversion System

The paper aims to study the construction diversion scheme selection process, a significant impact on the key factors, and these factors often contain uncertainties, such as the impact on the reliability of the diversion structures safe.The uncertainty analysis of Construction Diversion does not arrive at its end. Based on the academic progress of uncertainty in the field of water conservancy and hydropower engineering and construction diversion, this thesis will be focused on the study of several key problems presented from retaining the uncertainty of the type, discharge type different types of buildings, expanding the range of analysis and research. Mainly related to the construction of diversion structures reliability analysis, the Overflow Earth-rock cofferdam parameters back analysis model established initially.Combined currently under construction in Guangdong Province, the largest water conservancy-Lechangxia Diversion Dam construction project example, the diversion tunnel discharge risk-free rate calculation model performance function is established, using the MC algorithm, in the VB language environment programmed to calculate the actual results. Compared to engineering observations, the actual results is in line with the actual project. By contrasted with the B.C.Yen classical probability formula calculation, The Calculated risk rate gets approximate agreement. Risk of diversion tunnel for the discharge of this research results, for the same type, in particular with the other basin diversion project programming, providing a frame of reference. Risk of diversion tunnel for the discharge of this research results can provide a frame of reference for the same type, in particular with the other basin diversion project programming.On the type of construction diversion of water retaining structures-cofferdam reliability of slope stability problems is to be discussed. Combined hydraulic structures soil slope reliability studies generally, through an integrated variable N, L, T as the core, with other exporting these three random variables, including soil parameters c,φ value, slope rate m, and sliding the arc center coordinates, radius, etc. the analytical expression is constituted and reliability analysis of slope limit state performance function is established. Being Used MC algorithms, in IDEL program language environment, the weir slope reliability of the Xiluodu Hydropower Project on the downstream cofferdam in the steady flow period is calculated. Thus the degree of sensitivity relationship between the reliablity and the size of the coefficient of variation is analyzed with the changes of the random variable.Worthy of note is that the two engineering examples of uncertainty calculation results are compared with the original design results of the design institute based on deterministic theory and the conclusion is consistent. Thus, as a research question two angles, certainty and uncertainty theory are similar, furtherly they can mutually support and complement.The research is rare over the back analysis of the overflow earth-rock cofferdam structure parameters. The thesis tries to do a preliminary exploration in this area.In such circumstance of the unknown distribution function about the observational data, using the maximum entropy method to strike a prior distribution and the likelihood function, the Bayesian theory and maximum entropy methods can be combined,thus the most effective use of observational data and the most objective probability density function (PDF)can be obtained. Through trial calculation, the impact velocity head hvR is got, the head hvR and the one under the older model tests can obtained mutual corroboration in a certain sense.Based on furtherly depth combing the Bayesian theory and maximum entropy method, Bayesian maximum entropy back analysis model of uncertainty parameter (BME) is established.Once the BME model entering engineering entity to use, combining with the necessary observational data, The model can be extended to apply to overflow earth-rock cofferdam structure parameter back analysis. More objective and rational analysis and judgment can be made. It can provide a useful theoretical basis for the revision of grades and standards about the overflow earth-rock Cofferdam.