西藏江雄水库左坝肩山体稳定可靠性分析

通过运用概率评价中的Rosenblueth方法和定值法中的简布法相结合，对西藏江雄水库左坝肩山体蓄水前后的稳定性进行评价，得出失稳的可能性比较大，山体的加固处理是非常必要的结论。实践表明，该方法对西藏异常多变的高原气候下的边坡稳定性评价有重要的意义。     

Probability distribution characteristics and estimation method of prestress of concrete structures based on Gaussian mixture model

为解决预应力混凝土框架结构预应力筋数量众多、有效应力不确定性强且分布不均匀、抽样检测评估无法准确表征结构有效应力整体特征等结构评价难题，引入高斯混合模型研究结构有效应力概率分布特征，并据此提出了一种概率估计方法。该方法通过MonteCarlo模拟建立预应力筋集有效应力的高斯混合模型；通过中心化、去除离散点等方式修正模型以增强其高斯特性；基于模型高斯显著性检验准则确定正态分布近似估计范围，并以此为总体样本进行抽样检测，进而估计预应力筋集实时有效应力的概率分布；以某无黏结预应力混凝土框架结构为工程实例验证了该方法有效性。研究结果表明：既有结构预应力筋集有效应力概率分布由多个均值与方差相近的子分布组成，可采用近似正态的高斯混合模型统一表征；由设计差异导致的有效应力分布不均匀性可采用中心化的数学方法进行消除，进而提升模型近似估计的准确性；既有结构施工阶段以张拉工艺为主的建造误差上限可通过模型计算结合实测值统计分析综合推定。     

Estimation of torsional-flutter probability in flexible bridges considering randomness in flutter derivatives

Torsional-flutter instability is an aeroelastic phenomenon of interest to the bridge engineer, corresponding to a torsionally unstable vibration regime of the deck driven by wind excitation and appearing beyond a certain critical wind velocity. In this study a method for the derivation of the flutter probability for long-span bridges with bluff decks is proposed.In the first part of this study the deterministic problem is addressed. In contrast with the classical solution method in the frequency domain based on a numerical procedure for assessing the critical wind velocity, a single-mode “closed-form” algorithm for the derivation of the critical velocity was investigated. A polynomial representation of the aeroelastic-loading coefficients (flutter derivatives), necessary for torsional-flutter analysis, was utilized.In the second part an algorithm for estimating the torsional-flutter probability was developed, considering randomness in bridge properties, and flutter derivatives in particular due to their preeminent role in torsional-flutter velocity estimation.Experimental errors in the extraction of flutter derivatives from wind tunnel tests were analyzed. The “closed-form” algorithm, developed in the first part, allowed for a direct numerical solution of the flutter probability in a simple way.The torsional-flutter probability for three simulated bridge models with rectangular closed-box and truss-type girder deck was numerically determined. A set of experimental data, available from the literature, was employed. The simulations enabled the validation of the proposed algorithm.     

桩基超声检测分析的逆概率法

本文论述了应用概率论的逆概率法分离超声波测桩曲线中缺陷信息与干扰的原理和计算方法，并通过实例将邀概率法与常用的概率统计法和PSD判别法作了比较，逆概率法的应用效果最好     

Design Water Levels in Tidal River Systems under the Influence of Typhoons

Water levels in tidal rivers are subject to the influence of both fluvial and tidal factors. The interaction between these factors is rendered more complex in regions affected by typhoons, which typically result in the combined occurrence of heavy rainfall and high sea levels.
Previous studies have outlined an analytical approach for calculating design water levels based on dividing the fluvial and tidal series into a typhoon and a non-typhoon component. This paper illustrates the steps involved in the analytical approach and describes its application to drainage basins in Hong Kong.
The approach provides a practical means for calculating design water levels, and is recommended for final design purposes. The results of using the full analysis may be approximated by using a sub-set of analytical results, and should prove satisfactory for the purposes of outline design.     

《岩土工程学报》1998～2004年刊载论文统计分析

通过检索1998～2004年《岩土工程学报》刊载的学术论文,按照文献计量学的原理对该期刊的载文量、作者的地区和单位分布、核心第一作者等做了初步的统计分析,还按照论文的研究方法即其偏重于理论或实验的程度做了分类和讨论分析,从一个侧面揭示了我国岩土工程科研领域一些特点和规律,并对今后的办刊方向提出了一些建议。     

Fragility analysis for ballistic design

Effective structural design to resist ballistic effects such as small arms or fragmenting weapons has been a goal since weapons were developed. Approaches currently in use for ballistic design are predominantly deterministic and allow designers to decide what wall thickness should be used to stop a prescribed projectile impacting at a predefined velocity. The research presented in this paper provides a framework for conducting reliability analysis of structures subjected to bullet and fragment demands. Thus, pseudo-fragility curves are developed for the limit states related to spall and perforation of wall panels, residual velocities of bullets and fragments, and injury to personnel. The pseudo-fragility analysis provides engineers and owners with a tool to quickly assess the reliability of a wall system subjected to high velocity, low mass projectiles. In particular, the proposed analysis method allows designers and owners to determine the probability of spall and perforation, residual velocity, and injury as a function of wall thickness or threat standoff distance.

Abbreviations: Cumulative distribution function (CDF): Gives the probability that a stochastic variable ‘X’, with a proper probability density function, is equal to or less than a value (x). Coefficient of variation (COV): The quotient of the standard deviation and the mean     

规则格网DEM粗差定位算法的比较

介绍了三种适用于规则格网DEM的粗差探测算法,分别是基于坡度信息的算法、基于参数统计的算法以及主成分分析法,并通过ZX铁路实测数据验证了上述算法的可行性和有效性。从试验结果可以看出,主成分分析法实施简单,运算速度快,具有较好的实用价值。     

建筑结构用钢丝束拉索和钢丝绳拉索抗力分项系数研究

收集了钢丝束拉索和钢丝绳拉索的试验数据 ,采用概率方法研究了拉索的抗力分项系数取值 ,提出了建筑结构设计中考虑长期荷载效应和短期荷载效应时拉索的设计计算方法及建议。     

论组合数行列式

组合数是基础数的概念,被普遍的使用.由组合数构成的行列式具有特色.本文研究了组合数行列式的独特、奇妙的性质,并给出了严密的证明。