岩爆预测的概率模型

基于岩石单轴抗压破坏特征和强度概率分布规律，首次引入岩爆烈度是岩石概率破坏表现的观点，建立岩爆烈度与岩石单轴压缩强度概率密度函数的对应关系，进而确定不同应力强度比条件下各级岩爆烈度发生概率的计算式。该预测模型能够反映洞室岩爆发生的基本规律，并可以预测不同应力条件下的各级岩爆的发生概率。工程实例分析表明该预测模型是有效的。     

蒙特卡罗数值模拟技术在桥梁状态评估中的应用

介绍了蒙特卡罗数值模拟的基本原理及方法。以润扬大桥状态评估系统为例 ,对大桥在正常运营和损伤状态下的结构可靠度进行分析 ,对超过限值的结果进行预警 ,其分析结果形象直观 ,提高了评估的效率 ,使维护决策的制定更加客观准确。     

赣江大桥基于应力谱的疲劳寿命可靠度分析

结合对南昌赣江大桥南桥第 1 0孔桁梁桥的疲劳寿命评估 ,介绍了采用蒙特卡罗法模拟疲劳荷载的情况 ,随后对比了实测数据与模拟数据 ,确定模拟数据可以用于实际疲劳寿命评估。利用模拟数据分析了赣江大桥的疲劳损伤的概率分布情况 ,确定了在给定概率下的赣江大桥的疲劳寿命     

数据规划处理在人工神经网络中的应用

神经网络所用的样本数据以及这些数据的规划处理对网络性能和实际运用有着至关重要的影响!本文首先对神经网络在结构可靠性领域中应用的重要意义进行了探讨,然后在已有的数据处理方法的基础上提出了简便的数据规划处理算法,最后,用结构可靠度的实例验证了该算法的正确性!     

摇珠法在工程招投标过程中的报价分析

按照综合评估法中摇珠法的运作原则对投标竞争环境进行了分析,利用概率统计的方法研究并得出了各个不同级别的投标单位的最佳投标报价策略,以期为相关单位的竞标提供一些参考。     

The choice of optimal checking strategies for error control in structural engineering

Probabilistic models are given for estimatingthe error content in a structure afte.r thre" application of a checking strategy with given efficiency. The use of these models to optimize the level of effort expended on error control is illustrated. The analysis is carried out using-a Bayesian-decisiorv-theory approach,-and an overall model for structural decision-making is described. The applicability of the approach is illustrated by an example which considers the overall checking efficiency in the building process, combined with some failure statistics and failure cost estimates. The application of the approach to specific structural members is also discussed in the paper.     

PARAMETER ESTIMATION FOR 2-PARAMETER LOG-LOGISTIC DISTRIBUTION (LLD2) BY MAXIMUM ENTROPY

The principle of maximum entropy (POME) was employed to derive a new method of parameter estimation for the 2-parameter log-logistic distribution (LLD2). Monte Carlo simulated data were used to evaluate this method and compare it with the methods of moments (MOM), probability weighted moments (PWM), and maximum likelihood estimation (MLE). Simulation results showed that POME's performance was superior in predicting quantiles of large recurrence intervals when population coefficient of variation was greater than or equal to 1.0. In all other cases, POME's performance was comparable to other methods. In terms of parameter bias and root mean square error, POME was comparable to MLE and superior to both MOM and PWM.     

同塔多回输电线路杆塔可靠指标及失效概率分析

输电线路杆塔结构可靠指标及失效概率的分析研究,目前已经广泛应用于实际工程当中,本文着重研究了500kV同塔四回输电线路杆塔的可靠指标及失效概率。对于风荷载占控制因素的杆塔结构,本文研究了可靠指标计算参数组合对于杆塔失效概率的影响,同时计算了500kV同塔四回典型杆塔的可靠指标及失效概率,提出基于输电杆塔可靠度理论的杆塔风险规避的建议。     

Measures of uncertainty

In spite of the fact the engineers are familiar with the idea that physical systems can be modelled in various ways, it is often stated that probability theory is the only way of modelling uncertainties and degrees of belief about those uncertainties. The thesis advanced here is that within certain bounds (which are specified) there are many ways of representing uncertainty. In particular the ideas of probability and fuzzy sets are shown to be entirely compatible. A voting model is used to illustrate the argument before the basis of the formal treatment is outlined. Finally a set of conjectures are advanced about the types of problem that might best be tackled by probabilistic and fuzzy inference.     

Modelling of probability of failure of concrete columns

This paper predicts the probability of failure or short and long columns of square reinforced concrete for deterministic and probabilistic loads. The effect of various parameters; width, length of column, effective length coefficient, percentage of steel, axial load, grade of concrete and random numbers; on the probability of failure of the column is studied. The material, geometric parameters and the load are treated as probabilistic. The results for short columns show that the rate of decrease of probability of failure is a maximum with increase in width, while it increased to a maximum with increase in loads, whereas for long columns the length of column had the predominant effect.