共查询到20条相似文献，搜索用时 62 毫秒
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环形超深基坑围护结构受力变形特性分析 总被引：5，自引：0，他引：5
结合上海世博500 kV变电站超深基坑实际工程,采用平面应变及轴对称弹性地基有限元分析模型对基坑围护结构的空间效应进行简化,分析了环形基坑空间效应、内衬墙以及水土压力模式对围护结构受力变形特性的影响,并与实测结果进行比较。结果表明,环形基坑围护结构的空间效应对其受力变形特性影响很大,在计算过程中必须考虑围护结构环向刚度对径向刚度的贡献;内衬墙作用类似于环形支撑,对地下连续墙受力及变形是有利的;地下连续墙水平位移实测值最接近于侧压力系数1.0的轴对称有限元分析结果;地下连续墙环向应力和弯矩实测值位于按规范水土分算与侧压力系数1.0的轴对称有限元计算结果之间。 相似文献
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基于空间协同作用的框架式抗滑桩力学分析模型考虑了桩、梁、岩土之间的相互作用及桩间土拱效应, 运用空间协同分析机理对框架式抗滑桩结构的内力和变形规律进行分析, 较好的弥补了当前主要采用桩土效应对多排抗滑桩进行受力分析的局限性.根据框架式抗滑桩受力模型的基本假定, 采用分段计算方法, 以框架式抗滑桩的滑动面为分界将桩体结构分为两段, 综合运用土拱效应、平衡协调原理及弹性地基梁方法, 分别建立框架式抗滑桩上下部分的受力计算方程, 给出该模型受力计算的数学解析方程组求解法, 并采用MATLAB对方程组进行编程计算, 结合工程实例的实验结果进行对比分析该数学解析法的正确性. 相似文献
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大断面宽幅盾构管片三维内力分布分析 总被引：2，自引：1，他引：1
以武汉长江隧道工程为例,采用三维壳-弹簧计算模型,对不同幅宽和不同环间接头剪切刚度的管片衬砌结构力学分布进行了分析,并与梁-弹簧模型结果在量值上做了全面比较。研究表明,全环最大弯矩发生在幅宽边缘部位;环间接头剪力对幅宽边缘影响较大,而对幅宽中央影响偏小;当环间接头剪切刚度为非无穷大时,壳模型的幅宽边缘最大弯矩值略微大于梁弹簧模型相应结果,而当无穷大时两者数值则基本相等;壳模型的幅宽中央的最大弯矩值介于梁模型错缝与通缝拼装的数值之间,并随幅宽加大而趋于接近通缝拼装的结果;大幅宽条件下,不宜将梁-弹簧模型的环间最大剪力结果作为环间接头抗剪设计的计算依据。 相似文献
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《中国煤炭地质》2015,(11)
环形支撑体系以环撑受压为主要特点,是内支撑体系中能充分发挥混凝土材料性能的合理支撑体系。环形支撑能优化支撑和竖向立柱数量,使支护体系具有土方开挖方便、主体结构施工空间良好、支撑拆除量少和施工周期短等显著效益。但是环形支撑体系受力复杂,尤其是平面双环支撑,对设计和施工都有较高要求。佛山融利大厦基坑周边用地紧张、基坑规模较大、支护难度大,经综合比选选取平面双环组合支撑+支护桩支护体系,相对于其它支护方案具有明显的经济效益。在对该工程概况、地质水文条件以及基坑支护方案设计论述的基础上,采用三维有限元和理正杆件整体计算方法,模拟分析了该基坑受力状况;结合基坑施工步骤及土方开挖过程中实际监测数据,对比分析与研究了环撑支撑体系的受力特征。研究结果不仅补充了软土地区大型复杂基坑采用双环支撑方式相关的理论内容,而且为今后类似条件下基坑支护方式的实施提供一定参考。 相似文献
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基于AutoCAD和OpenGL有限元可视化建模,利用Fortran语言对模型文件中的单元信息进行改写,提出了一种在地下厂房有限元模型中生成沥青单元网格的方法,显著减少了模型单元数与节点数,提高了建模与计算效率。采用隐式杆单元法模拟涂沥青锚杆,隐式柱单元法模拟普通锚杆,推导了其刚度矩阵及有限元迭代计算公式,并应用于地下厂房岩锚梁锚杆涂沥青段的有限元分析中。结果表明,吊车梁附近围岩破坏区减少,围岩深部锚杆应力增大,说明围岩受力特性得以改善,围岩和吊车梁整体安全度增大,符合工程实践经验。所提出的计算和单元再分方法可操作性和实用性大,可为类似工程有限元分析提供参考。 相似文献
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用于桩基础计算的Daubechies小波新型联系系数研究 总被引：1，自引：0，他引：1
基于小波函数特有的多分辨特性,Daubechies小波在处理工程中的应力大梯度、强非线性和奇异问题方面具有较强优势。限于联系系数的计算广度不够,目前Daubechies小波有限元法的应用仅限于杆、梁以及地基系数为常数的弹性地基梁等方面的计算中。在基于m法的桩基础计算中,假定地基系数为线性函数,故挠曲线微分方程中荷载项的地基系数为线性变量,但与此相关的联系系数的计算方法及计算结果尚未见文献报导,无法应用Daubechies小波法进行求解。针对桩基础计算模型的特点,提出和推导了一类基于m法的可用于桩基础计算的小波联系系数,首次将Daubechies小波应用于桩基础的计算中。并利用上述结果,对桩基础的典型模型进行计算。结果表明,所推导出的Daubechies小波新型联系系数结果正确,基于Daubechies小波有限元法可精确求解桩基础的受力。 相似文献
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Mathematical Geosciences - 相似文献
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Methodology for geohazard assessment for hydropower projects 总被引：1，自引：0，他引：1
Fjóla G. Sigtryggsdóttir Jónas Th. Snæbjörnsson Lars Grande Ragnar Sigbjörnsson 《Natural Hazards》2015,79(2):1299-1331
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Current methods of establishing suitable locations for onsite wastewater treatment systems (OWTS) are inadequate, particularly in light of the numerous cases of onsite system failure and the resulting adverse consequences. The development of a soil suitability framework for assessing soil suitability for OWTS allows a more practical means of assessment. The use of multivariate statistical analysis techniques, including Principal Component Analysis (PCA) and multi-criteria decision aids of PROMETHEE and GAIA, enabled the identification of suitable soils for effluent renovation. The outcome of the multivariate analysis, together with soil permeability and drainage characteristics permitted the establishment of a framework for assessing soil suitability based on three main soil functions: (1) the ability of the soil to provide suitable effluent renovation, (2) the permeability of the soil, and (3) the soils drainage characteristics. The developed framework was subsequently applied to the research area, Gold Coast, Queensland, Australia, and the use of standard scoring functions were utilised to provide a scoring system to signify which soils were more suitable for effluent renovation processes. From the assessment, it was found that Chromosol and Kurosol soils provided the highest level of effluent renovation, closely followed by Ferrosol and Dermosol, Kandosol and Rudosol soil types. Tennosol and Podosol soil types were found to have a significantly lower suitability, with Hydrosol soils proving the least suitable for renovating effluent from OWTS. 相似文献
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湘南地区蕴藏着丰富的锡矿资源,锡及锡多金属矿矿床(点)分布广泛,类型复杂,它们的形成除与花岗质侵入岩体直接相关外,同时还受到区域地层和地质构造等因素的共同制约。通过对锡矿的地质背景、分布特征、矿床特征与矿化规律、矿床成因及找矿信息和标志的研究,把湘南地区锡矿的找矿归纳为:"划带、圈区、寻体、定位"的找矿模式,不仅从宏观上提出了或解决了锡矿找矿方向的问题,而且近几年来的地质找矿工作得到了实践应用,并取得了丰硕的找矿成果。 相似文献
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A new approach for calculating strain for particulate media 总被引：1，自引：0，他引：1
Discrete element modelling is a viable alternative to conventional continuum‐based analysis for analysing problems involving localized deformations of particulate media. However, to aid in the interpretation of the results, it is useful to express the results of discrete element analyses in terms of the continuum parameters of stress and strain. A number of homogenization methods have been proposed to calculate strain in discrete systems; however, two significant limitations of these methods remain. First, none of these methods incorporate particle rotation effects satisfactorily, although significant particle rotation occurs in shear bands in both physical tests and numerical simulations of granular materials. Additionally, observations of the particle displacement fields in shear bands in granular materials indicate that the displacements within the localizations are erratic. Consequently, existing linear, local interpolation approaches produce substantial variations in the strain values calculated in adjacent elements in the region of localization, hindering clear visualization of the strain localization as it evolves. A new method of domain discretization for calculating strain is proposed. This method is capable of capturing particle rotation and employs a non‐local meshfree interpolation procedure capable of smoothing the erratic displacements in strain localizations, which better defines their evolution. The proposed method is validated for problems involving both two and three dimensions. A number of methods are compared with the proposed method and pertinent insights are made. Copyright © 2003 John Wiley & Sons, Ltd. 相似文献
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Acta Geotechnica - The hypoplastic model for sands proposed by Wolffersdorff (Mech Cohes Frict Mater 1: 251–271, 1996) combined with the intergranular strain anisotropy by Fuentes and... 相似文献
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