【作者】 张琴；

【导师】 申向东；

【作者基本信息】 内蒙古农业大学 ， 农业水土工程， 2002， 硕士

【摘要】 传统的结构设计和强度校核是基于确定性分析，也即结构计算时假定结构的几何尺寸、材料的物理性能以及所受的载荷都是确定值。而实际上这些因素都带有随机性，工程结构可靠度理论即为考虑各参数的非确定性或随机性，从概率的角度出发进行结构设计与强度校核，并计算结构的可靠指标与可靠度的一种方法。本文以随机块体理论为基础，建立了拱坝坝肩三维可靠度分析的计算模型，推导了分析其可靠度的基本公式。对于一已建成的拱坝，利用这一计算模型，采用改进一次二阶矩法，编制电算程序，计算该拱坝坝肩岩体的可靠指标。对于所取的拱坝实例，以扬压力折减系数，校核洪水位，摩擦系数、，凝聚力、为随机变量，在已知其均值并设定变异系数的前提下，利用电算程序计算其坝肩岩体的可靠指标。计算所得各高程的可靠指标与原设计取得了较为一致的结论，这一结果也验证了本方法的可行性和实用性。作为对比，本文还在改变各随机变量变异系数的前提下，计算了坝肩岩体各高程的可靠指标。从而得到以下结论：在坝肩岩体可靠性计算中，各随机变量的变异性对坝肩岩体的整体可靠性有显著影响，且不同的随机变量，当其变异系数有所增大时，对可靠指标的影响程度是不一样的。更多还原

【Abstract】 The traditional construction of structure and verification of intensity is based on fixed value analysis, in another words, the geometrical size, physical performance and the load of structure are all fixed values. In fact, the factors are all have randomicity. The reliability theory of engineering structure is a method in which design of structure, verification of intensity and calculation of reliability index are all carried though with probability way. In the paper, based on random block theory, a mathematical model is developed for reliability analysis of 3-dimensional abutment stability against sliding. Calculative formulas of reliability analysis are given. Give an example, for a built arch dam, the paper worked out calculational programme based on the calculational model and calculate the reliability index of abutment with simple and double quadrature method. According to the instance of the arch dam built, take the discount quotiety , the verification flood water level , the frictional quotiety and , the agglomerate force and as stochastic variable quotiety, calculate the reliability index of the abutment with the calculational programme after the average value and variable quotiety is known. The results are coincident with the primary design, and the results are also verified the feasibility and practicability of the method.By contrast, the paper calculated the reliability index of the abutment after changing variable quotiety of the stochastic variable. Thereby drew a conclusion that variability of stochastic variable has remarkable effect on the reliability. And the different stochastic variable has different effect on the reliability while the variable quotiety increasing.The obtained results shown that the calculating method presented in the paper can be widely used in reliability analysis of abutment stability against sliding.更多还原