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针对目前抗滑桩设计中存在的计算结果主观性较大,且常规的有限元重度增加法的计算结果偏大的问题,基于理论推导对常规有限元重度增加法进行了改进,并将该改进方法应用于某边坡工程中,建立了自然边坡三维有限元模型,计算了该自然边坡的整体安全系数,并与极限平衡法和强度折减法进行对比分析,验证了改进方法的有效性,进而将其应用于抗滑桩加固边坡稳定性分析中,通过与相同安全系数下通用理正软件的计算结果相比,表明该改进方法在计算抗滑桩加固边坡稳定性中具有可行性。 相似文献
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屈服准则对边坡稳定有限元分析的影响研究 总被引:4,自引:1,他引:3
采用Mohr-Coulomb和Drucker-Prager准则分析了应用强度折减法进行边坡稳定有限元分析时屈服准则对计算结果的影响.分析表明,屈服准则对边坡稳定有限元分析结果影响显著,不同屈服准则计算的边坡位移场和应力场有显著差异.其中,Mohr-Coulomb准则计算的安全度偏小,但内接圆及等面积圆得出的安全度较合理,Drucker-Prager准则与参数α和 k的选取直接相关.该研究结果可为边坡稳定有限元分析合理选用屈服准则提供理论依据. 相似文献
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针对地震作用下边坡稳定分析方法之间的差异及其适用情况尚不明确的问题,以某三级均质土坡为例,基于Quake/w、Geo Studio、PLAXIS以及FLAC等软件,利用拟静力法、Newmark滑块分析法、动力有限元时程分析法、动力有限元强度折减法及有限差分强度折减法计算出安全系数,对比了5种方法的异同。结果表明,采用拟静力法获得的边坡抗震稳定性偏于安全;Newmark滑块分析法、动力有限元时程分析法计算的安全系数基本相同;动力有限元与有限差分强度折减法计算所得的安全系数相近,但在不同折减系数下计算的监测点位移相差较大。 相似文献
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基于FLAC/Slope模拟分析输电线路塔位边坡的开挖稳定性 总被引:1,自引:0,他引:1
塔位边坡的稳定性是输电线路基础设计考虑的一项重要内容.基于强度折减理论采用FLAC/Slope软件建立了输电线路典型塔位边坡的有限元分析模型,数值模拟了塔位边坡分步开挖施工过程,对各施工阶段的稳定性进行了评价分析,特别考虑了边坡稳定系数随边坡开挖步的变化规律.结果表明塔位边坡的坡脚或坡体分层处存在较大应力集中,且施工开挖步是影响边坡稳定系数变化的重要因素. 相似文献
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建筑能耗分析是建筑节能和建筑能效管理的基础。在分析常用建筑能耗分析方法的基础上,对比了计算机模拟法、度日法、温频法三种方法的优缺点,并简要介绍一些改进措施,使计算结果更符合实际情况,为建筑能耗计算及节能措施研究提供有益的参考。 相似文献
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国外页岩气资源储量评价方法分析 总被引:4,自引:0,他引:4
页岩气指储集在富含有机质的细粒碎屑岩中的天然气,全世界页岩气资源量估计为456×1012m3,主要分布在北美、中亚、中国、拉美、中东、北非和前苏联。目前,国内外页岩气发展势头强劲,明确页岩气资源规模,对于制定页岩气发展规划具有重要指导作用。通过研究分析,总结了国外计算页岩气资源常用的几种方法,包括类比法、体积法、测井分析法、物质平衡法、递减曲线法和数值模拟法等。其中,类比法主要用于页岩气新区、气田开发前和生产早期的资源评价。体积法是天然气资源量评估最常用的方法,它不依赖气井的生产动态趋势,是勘探开发前期和初期资源量及储量评估的最好方法之一。测井分析方法适用于钻井评价和开发期间,是以大量钻井、录井、测井及岩心分析工作为基础。物质平衡法在气田开发的中、后期应用十分普遍。递减曲线法适用于气田开发中、后期,以大量的生产数据为基础。数值模拟方法以生产数据为基础,适用于气藏开发阶段。我国页岩气资源的勘探开发刚刚起步,希望通过借鉴国外页岩气资源计算方法,对我国页岩气的资源开发有所帮助。 相似文献
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This paper critically reviews existing energy demand forecasting methodologies highlighting the methodological diversities and developments over the past four decades in order to investigate whether the existing energy demand models are appropriate for capturing the specific features of developing countries. The study finds that two types of approaches, econometric and end-use accounting, are commonly used in the existing energy demand models. Although energy demand models have greatly evolved since the early seventies, key issues such as the poor–rich and urban–rural divides, traditional energy resources and differentiation between commercial and non-commercial energy commodities are often poorly reflected in these models. While the end-use energy accounting models with detailed sectoral representations produce more realistic projections as compared to the econometric models, they still suffer from huge data deficiencies especially in developing countries. Development and maintenance of more detailed energy databases, further development of models to better reflect developing country context and institutionalizing the modelling capacity in developing countries are the key requirements for energy demand modelling to deliver richer and more reliable input to policy formulation in developing countries. 相似文献
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论述了岩石力学传统的研究方法的局限性,指出了岩石力学数值研究方法的优势与作用,同时探讨了岩石力学数值方法、数值分析软件当前存在的问题及不足,分析了21世纪岩石力学数值方法所能承担的及应该承担的任务。 相似文献
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Two methods were examined for the formation of poly-Si films. One is flux method and the other is Cat-CVD method. Flux method was used for forming poly-Si seed films on glass substrates covered with rear electrode. Poly-Si films of a few μm grain size and of mainly (1 1 1) crystalline orientation were obtained at less than 600°C. To make the seed films function as BSF layer for solar cell, boron doping was applied and carrier concentration of 2×1019/cm3 was obtained which is suitable for highly efficient solar cells. Cat (catalytic)-CVD method was examined for forming poly-Si photo-active layers on the seed films. The films showed deposition gas pressure-dependent crystalline orientations and there was no amorphous incubation layer in (1 1 1) oriented films by Cat-CVD method when deposited on (1 1 1) oriented seed films prepared by Flux method. The electrical properties of the film are insufficient at present, may be due to high defect density and the film structure which allows impurity contaminations of oxygen and carbon after film deposition. Although the film quality needs to be improved, poly-Si films whose crystal fraction is more than 85% were obtained at deposition rate of up to around 40 Å/s. This result indicates high potential of Cat-CVD method for high throughput photo-active formation process necessary for low production cost thin film silicon solar cells. 相似文献
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In this paper, coupled nonlinear equations governing the flow for magnetoconvection in a vertical channel for open and short circuits are solved. The calculations are carried out by using differential transformation method (DTM) which is a semi‐numerical–analytical solution technique. By using DTM, the nonlinear constrained governing equations are reduced to recurrence relations and related initial conditions are transformed into a set of algebraic equations. The principle of differential transformation is briefly introduced, and then applied for the aforementioned problems. The current results are then compared with those derived from the finite difference method (FDM) and perturbation method (PM) in order to verify the accuracy of the proposed method. The findings reveal that the DTM can achieve more suitable results in predicting the solution of such problems. © 2013 Wiley Periodicals, Inc. Heat Trans Asian Res; Published online in Wiley Online Library (wileyonlinelibrary.com/journal/htj). DOI 10.1002/htj.21035 相似文献
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目前煤炭开采技术得到了前所未有的发展,煤炭产量迅猛提高,煤炭作为重要的工业能源,在为中国经济增长做出贡献的同时,也带来了诸多社会问题。煤炭资源大量开采造成地表塌陷、地下水位下降等环境问题日益凸显,许多地方的生态环境遭到破坏,村庄的房屋、建筑由于地下开采出现了裂缝,地表河流出现断流甚至枯竭,地下水位下降转移,人们的生存条件及安全受到了严重威胁。 相似文献