改进复合形法及其在边坡稳定分析中的应用

基本复合形法寻优考虑了复形顶点目标函数的改进,但忽略了保持复形顶点的多样性,从而有可能使算法易陷入局部极优．为此,进行了以下改进：对每个顶点构造寻优直线,即该顶点与其余顶点几何中心的连线;在该直线上寻找该顶点的改善点并替换掉该顶点构造新的复形;在构造的多个新复形中,选择多样性最强的新复形作为本次迭代产生的复形;如此迭代直至没有新的复形产生．顶点多样性采用复形相似距度量．通过对1个复杂边坡最小安全系数的搜索证明,这些改进措施是有效的．     

Discontinuous flying particle swarm optimization algorithm and its application to slope stability analysis

A new version of particle swarm optimization (PSO) called discontinuous flying particle swarm optimization (DFPSO) was proposed, where not all of the particles refreshed their positions and velocities during each iteration step and the probability of each particle in refreshing its position and velocity was dependent on its objective function value. The effect of population size on the results was investigated. The results obtained by DFPSO have an average difference of 6% compared with those by PSO, whereas DFPSO consumes much less evaluations of objective function than PSO does.     

Practical electromagnetism-like mechanism algorithm

The function optimization principle of the original Electromagnetism-like mechanism (EM) algorithm and some problems of it are analyzed, such as large computation, low convergence rate, and pathological feature in the total force formula. A new pratical EM algorithm is proposed according to the problems above. The power formula is simplified by adopting the method for normalizing the objective function value. The correction factor is introduced into the total force formula, so that the pathological feature in the total force formula is eliminated, the impact of the distance factor on the force between population particles weakened, and the convergence rate increased. Experiments show that the improved algorithm has a faster convergence speed and higher solution accuracy.     

A new hybrid algorithm for global optimization and slope stability evaluation

A new hybrid optimization algorithm was presented by integrating the gravitational search algorithm （GSA） with the sequential quadratic programming （SQP）, namely GSA-SQP, for solving global optimization problems and minimization of factor of safety in slope stability analysis. The new algorithm combines the global exploration ability of the GSA to converge rapidly to a near optimum solution. In addition, it uses the accurate local exploitation ability of the SQP to accelerate the search process and find an accurate solution. A set of five well-known benchmark optimization problems was used to validate the performance of the GSA-SQP as a global optimization algorithm and facilitate comparison with the classical GSA. In addition, the effectiveness of the proposed method for slope stability analysis was investigated using three ease studies of slope stability problems from the literature. The factor of safety of earth slopes was evaluated using the Morgenstern-Price method. The numerical experiments demonstrate that the hybrid algorithm converges faster to a significantly more accurate final solution for a variety of benchmark test functions and slope stability problems.     

Improved electromagnetism-like mechanism algorithm

Based on the principle of the electromagnetism-like mechanism(EM) algorithm, the algorithm's optimization mechanism is studied. An improved electromagnetism-like mechanism algorithm is proposed to solve the problems of the original EM algorithm, such as non-uniform initial population, low search efficiency, and pathological feature in the total force formula. The new algorithm generates the initial population with the uniform design method, improves the local search algorithm with the hybrid chaotic pattern search method and calculates the total force between particles with the modified equation. Besides, an adaptive formula of movement is designed to update the locations of those particles. Experimental results show that the improved algorithm has a better convergence result and a higher solution accuracy.     

自适应蚁群算法及其在边坡工程中的应用

蚁群算法目前多用于求解组合优化问题，为了让蚁群算法能求解复杂的边坡稳定性分析问题，对基本蚁群算法的结构形式和蚂蚁转移概率的计算进行了改进，针对蚁群算法在演化过程中存在停滞和过早收敛的现象，引入一种自适应搜索算子，改变蚂蚁的选择机制，提高蚂蚁选择的多样性，并由此构建了一种新的蚁群算法——自适应蚁群算法(AACA)，研究了AACA在边坡非圆弧临界滑动面搜索中的应用，所给出的算例结果表明：与基本蚁群算法相比，可有效地防止停滞和过早收敛现象，并总能搜索到问题的全局最优解，且搜索效率也有较大的提高。     

一种类电磁机制算法在锅炉主汽温系统的研究

针对主汽温控制对象的特点,改进类电磁机制算法的不足,对串级主汽温控制系统控制器参数进行优化,选定了3个稳定工况点模型进行仿真实验,改进后的控制系统具有较强鲁棒性,能适应现场复杂多变的情况,满足电厂控制的需求。     

Global analysis on slope stability and its engineering application

In hydraulic engineering, sometimes it is necessary to consider the stability of sliding bodies with lateral frictional boundaries. Neither the existing three dimensional limit equilibrium methods nor the commercial software products are able to treat such situations. The three dimensional factor of safety is accordingly underestimated; while the shearing strength based on the three dimensional back analysis is overestimated. In this study, the lateral boundaries are regarded as the part of the slip surface. Based on the expression of the normal pressure on the slip surface and the patch interpolation, a rigorous solution for the three dimensional limit equilibrium analysis is realized. Meanwhile, the proposed procedure is applied to the stability analysis of the slope with a cable platform on the right bank in Da Gang Shan hydraulic project under construction.     

Modified fuzzy point estimate method and its application to slope reliability analysis

A slope engineering system is a complex system, in which many uncertainties exist, including random uncertainties and fuzzy uncertainties. Traditionally, random uncertainties were often considered, while fuzzy uncertainties were ignored. Therefore, fuzzy-random methods should be proposed. A fuzzy point estimate method was proposed by Dodagoudar, that is, considering the effect of fuzzy-random factors, the fuzzy-random limit state function of slopes is changed to random interval limit state function by the A level cutting, then the moments of the function can be obtained by the Rosenblueth's method, and the stability state of slopes can be evaluated by synthesizing a group of moments. But in Dodagoudar's method, Rosenblueth's state function is composed of only two kinds of combinations of parameters rather than 2" kinds of combinations. So a modified fuzzy point estimate method is proposed by the authors, and it is used in a slope reliability analysis.     

一种采用类电磁机制算法的线性分类方法

根据最优超平面和类电磁机制算法的思想,提出了一种组合优化线性分类方法.该方法利用样本训练提取样本个体的类别特征,寻找到将类别分类的最优超平面,设计并实现了一种采用改进的类电磁机制算法的组合优化线性分类方法.试验取得了很好的分类效果,证实了组合优化线性分类方法的可行性.     

Search for circular and noncircular critical slip surfaces in slope stability analysis by hybrid genetic algorithm简

A local improvement procedure based on tabu search （TS） was incorporated into a basic genetic algorithm （GA） and a global optimal algorithm, i.e., hybrid genetic algorithm （HGA） approach was used to search the circular and noncircular slip surfaces associated with their minimum safety factors. The slope safety factors of circular and noncircular critical slip surfaces were calculated by the simplified Bishop method and an improved Morgenstern-Price method which can be conveniently programmed, respectively. Comparisons with other methods were made which indicate the high efficiency and accuracy of the HGA approach. The HGA approach was used to calculate one case example and the results demonstrated its applicability to practical engineering.     

复杂土坡稳定的电算分析

黏性土坡的稳定性分析因为滑裂面不能预先判定和土体受力的复杂性而使计算十分烦琐．为了能够手算,以往的计算模型都尽力简化．现在常用的3种分析方法,即条分法、泰勒法和毕肖普法,都只讨论了简单土坡,过多的简化使计算模型不能反映土坡的实际情况．用电算作土坡稳定分析可以使计算结果臻于精细．     

边坡稳定制约下土石坝截面优化遗传算法

为了实现土石坝的截面优化,基于坝体边坡极限平衡状态提出了一种易于施加特性约束条件和进行全局优化搜索的优化遗传算法.建立了以边坡稳定为约束条件的多工况条件下的土石坝截面优化模型,并在Matlab平台上编制了基于极限平衡理论的土石坝坝坡稳定性分析程序以及优化程序,实现了均质土坝在渗流和地震作用等约束下最优截面的搜索.算例结果证明了该优化方法具有一定的有效性和可行性.     

基于GIS的边坡三维稳定性计算

根据高速公路高边坡的钻孔资料,利用ArcMap建立进行三维边坡稳定性分析的TIN数据层和栅格数据层,将栅格数据模型的各层对应栅格块视为一个滑坡单元体,通过读取相应栅格值进行稳定性计算.针对顺层滑坡的特点,采用ArcGIS集成的VBA开发环境,提出了一种三维折线法分析边坡的稳定性.该方法通过对栅格数据的重采样,可以计算任意滑动方向三维边坡的安全系数,通过选择最小安全系数来确定边坡的主滑动方向.结合某高速公路大型岩质滑坡的工程实例,通过比较三维折线法计算结果与某典型剖面的二维不平衡推力法计算结果,讨论该方法对工程滑坡治理的指导意义.     

开挖边坡变形和稳定性有限元分析

采用有限元方法对边坡开挖进行数值计算,得到开挖后边坡的变形情况,并通过抗剪强度折减技术对开挖后的边坡材料进行强度折减,得到边坡破坏时的临界滑面和安全系数。有限元方法的计算结果不但能评价边坡的稳定性,还可得到潜在的危险区域,对边坡开挖施工有一定指导意义。     

土坡稳定可靠度分析

简述了可靠度分析的“ＪＣ”法,介绍了一种典型的土坡稳定分析模型的极限状态方程,编写了一套完整的计算程序,并结合算例,对该法应用中的一些问题进行了讨论     

岩质边坡稳定分析三维与二维的比较

提出岩质边坡沿软弱结构面滑移一剪切的三维稳定分析方法。在分析模型中,下滑体沿滑动面下滑,在其他的面上则产生剪切破坏。在结构面上满足莫尔库伦破坏准则,把剪切面上的摩阻力向下滑方向投影,由下滑体的力学平衡条件求解出未知力,通过迭代可以求得稳定系数。同时推导了摩阻力倾向与倾角的计算式,编制了相应的程序,并利用这个程序,研究了边坡长度、岩层与坡面夹角等因素对边坡稳定系数的影响,比较了三雏分析与二维分析的差别。     

各向异性土坡稳定性的极限平衡遗传算法

本文将Mohr-Coulomb破坏准则推广得到各向异性土的破坏准则 ,在Bishop简化法基础上推导出考虑各向异性的边坡安全系数公式 ,并结合遗传算法得到真正最危险滑动面和全局最小的安全系数     

金堆城排废场人工填土高边坡稳定性数值分析

采用有限元数值法，通过对研究边坡的模拟计算，分析了关键部位应力、应变大小及分布规律，得到了金堆城北沟排土场人工填土高边坡的变形、破坏方式、破坏部位及破坏规模．     

容重增加法在边坡稳定性分析中的应用

通过逐步增加容重的方法使边坡达到极限平衡状态,基于D-P准则,采用关联流动法则,用非线性有限元法进行数值模拟.将坡顶水平位移随容重增加系数的变化关系曲线上位移陡然增大作为边破的破坏标准,用一个区间描述边坡稳定安全系数.该法无须事先对滑动面的位置和形状作出任何假定,能够考虑土体的材料非线性和几何非线性,有助于了解边坡的破坏机理.同时由于用一个区间描述边坡稳定安全系数,避免了数值计算中真实安全系数的丢失.算例分析表明,用容重增加法得到的安全系数与传统方法相近,并建议安全系数区间的长度取为0.03.