Font Size: a A A

The Reliability Theory And Application On Slope Stability Of Earth And Rock-Filled Dams And Liquefaction Of Dams Foundation

Posted on:2005-05-02Degree:DoctorType:Dissertation
Country:ChinaCandidate:J P ZhouFull Text:PDF
GTID:1102360152465807Subject:Geotechnical engineering
Abstract/Summary:PDF Full Text Request
The paper is based on researching reliability theory both the stability of earth and rock-filled dam and the liquefaction of sand foundation. The paper is finished combining with research projects and building projects, including reliability stability of Yele Earth and Rock-filled Dam, improvement research of sand foundation of Yongle Hydroelectric Power Station and stability investigation of Shimenkan slope on the National Road 213 in flood area in Zipingpu Reservoir. The reliability research of tall earth and rock-filled dam is tough task, because the analysis needs statistical data from many kinds of soil of the dam foundation and natural building materials. Especially when the dam encounter earthquake, the reliability analysis is more difficult. The liquefaction judge of sand foundation of dams is difficult problem. The reliability analysis of the problem is more difficult when the dam encounter earthquake plus seepage. The paper aims at building a series of model of reliability analysis, solving the computing of reliability both the stability of slope and the liquefaction of sand foundation. The following aspects of research work are done, and the research achievements are gained.Data of both the physical feature and the strength in soil and rock mass, which are used as foundation of the dam and natural building materials of dam, is random variable. The paper taken YeLe earth and rock-filled dam as an example, and the probability distribution models of the data is checked, and the statistical character of the data is analyzed.The paper have introduced three methods of reliability analysis: 1) Using First Order Second Moment (JC method) recommended by JCSS organization and national codes computes both failure probability and reliability index for independent variable; 2) Using Monte-Carlo random simulation calculates both failure probability and reliability index for independent variable; 3) Using Jacobi transfer method changes dependent variable into independent variable.Three scale type of soil strength tests; small, middle and big size is extensively existed in engineering practice. The data from different project have indicated the statistical scale effect of soil strength. In order to solve the dimension size effect inxperiment, the facsimile theory is adopted in determination the rock parameters. It is also used in discussing the size effect relationship of small, medium and large size samples. The results of research express that the strength of medium and large size samples have more suitable representative. The calculation results of an example explain how the size effect to influence the slope stability.The limit function of Bishop's Simplified method is deduced. The paper has taken stability analyses of practice engineering as an example. The example is Yele Earth and Rock-filled Dam. The coefficient of variation of soil strength is less, when the data from in-site tests with big size is reasonably divided into statistical groups. The model of probability distribution was checked. Jacobi transfer method is used to change dependant variable into independent. The results computed by the engineering example show that the deterministic stability method is consistent with reliability stability method. The seepage must be calculated in both the deterministic stability method and reliability stability method. The critical circles, factor of safety equate to 1.00, is more than one, but index of reliability ( ) in the critical circles is not equal.The liquefaction evaluating process of sand foundation for earthquake includes preliminary judge and precis judge. The methods of liquefaction evaluation are systematically summarized. The paper has taken Yongle Hydroelectric Power Station as an example, the results of liquefaction analysis aid to improve foundation of the powerhouse. Liquefaction couple from the seepage liquefaction of groundwater in the foundation pit and the liquefaction for jetting grounded pile with high-pressure gasified water was discovered during foundation pit excavated. The mechanism of liq...
Keywords/Search Tags:earth rock-filled dam, reliability, scaling effect, stability of slope, liquefaction of sand foundation, failure probability
PDF Full Text Request
Related items