共查询到20条相似文献，搜索用时 15 毫秒
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The foundation pit deformation of a commercial building in Hangzhou is calculated by using calculation method related to foundation pit deformation. The calculation results by m method show that the maximum deformation is 29.2mm and the real maximum deformation is 174.6mm. The deformation character obtained by foundation coefficient method is different from the real deformation. There are lots of factors influencing foundation deformation. According to practical engineering condition, in this study, the influencing factors for soil parameters, bracing condition, condition for insertion of retaining wall into soil and construction speed are determined. The calculation method used is analyzed and modified. Finally, a useful and valid method for calculating foundation deformation is presented, by which the foundation pit deformation in practical project can be forecasted and analyzed. 相似文献
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Zhang Yongxing Li Bo Wang Guilin 《保鲜与加工》1999,(2):1-4
Based on the practical project a study on analysis methods for rock slope foundation stability of highrise-building project criterion transfer coefficient method, rotation limit equilibrium method (Sweden slices method) and finite element method was carried out.The authors found that safety factor of criterion transfer coefficient method is larger than that of rotation limit equilibrium method, but is similar to the results of finite element method. So, when rockslope foundation stability of highrise building is to be analysed,the rotation limit equilibrium method is suggested to use. 相似文献
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流固耦合的多元结构深厚覆盖层透水地基的力学特性 总被引：3，自引：0，他引：3
深厚覆盖层多元结构坝基在渗流过程中各土层力学差异明显,分析时关注的具体问题也不尽相同,需要深入研究。基于比奥固结理论,考虑土体的非线性流变以及土体固结变形过程中孔隙度、渗透系数、弹性模量及泊松比的变化;借助ADINA流固耦合模块来模拟西藏达嘎水电站坝基渗流场与应力场耦合过程,分析各层力学特性及相互作用。研究表明,透水性较强的表层土体是渗流主要通道,也是渗流进出区和沉降变形体现区,应在上游采取措施提高其压缩模量,下游区域增设反滤层和排水设施;坝基中的粉细砂层是坝基沉降的主要原因,对坝基沉降起主导作用,同时应注意其液化特性对坝基的不利影响;坝基中的承压含水土层对下游上部结构产生向上顶托力,若位置较深,则破坏性较小;坝基深部土层对整个坝基的渗流破坏影响较小,但对沉降和渗流量的影响不可忽视;表层砂卵砾石层和粉细砂层的渗透系数相差较小时,土层间不会发生接触冲刷。此外,还发现坝基孔隙水压力在快速衰减阶段被消散,期间土体固结较快。垂直防渗墙能有效降低渗透坡降和渗流量,将坝基沉降变形控制在防渗墙上游区域,但上游坝基变形对防渗墙产生较大的水平推力,应加大防渗墙尺寸或者采用辅助渗控措施。 相似文献
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A new efficient method named matrix method is presented based on the traditional calculation methods of stabilizing force. The method is derived from the thrust force method and designed to address the deficiency of traditional method. It cannot only get the best pile location with minimum stabilizing force when is applied to the design calculation of single row anti slide piles, but also be applied to the optimal calculation of multi row anti slide piles. The cases comparing results show the method is more reasonable. For major projects of landslide control, the combination of matrix method and finite element method can make the result safer and more accurate. 相似文献
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跨越农业信息化“最后一公里”之路径分析 总被引：3，自引：0，他引：3
在跨越农业信息化“最后一公里”时，决定技术和组织管理路径选择的基本因素是“经济可行性”。在边际收益有限的情况下，性能卓越但成本高昂的计算机网络手段存在更为突出的“最后一公里”问题，有成本优势的技术创新得到优先使用；作为技术手段的配套或补充，可降低成本的信息服务的组织管理创新陆续出现；组织管理手段应与农业信息化的技术手段配套和协调。“三网合一”的技术选择与农业合作化的组织管理创新是新形势下跨越农业信息化“最后一公里”的现实选择。 相似文献
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中国"以工补农"政策的地区适用性初探 总被引：2，自引：1，他引：2
当前中国经济发展总体上已经进入了工业化中期阶段,具备了工业反哺农业的条件和能力。但并不意味着全国各个地区都进入了工业化中期阶段,统一的"以工补农"模式和政策在全国各个地区也不一定都适用。运用钱纳里和赛尔昆等设计的标准模型,分析了2005年中国不同地区的经济发展水平。结果表明:仍有皖、豫、湘、桂、琼、黔、滇、藏、甘九省区与全国进入工业化中期阶段的总体判断不符;而京、津、沪、苏、浙五省市则明显超越全国平均水平,已基本进入大规模反哺期。需要针对区域的工业化进程分类研究其工农关系和"以工补农"政策措施。因此,判断中国区域工业化进程发展阶段,研究"以工补农"政策的地区适用性和对策,将为中国"以工补农"政策的科学制定提供有益的参考。 相似文献
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"三农"问题由来已久,是长期"二元经济社会结构"、城乡分治、过度汲取农业剩余牺牲发展工业的结果;近年来日趋严重与我国国际贸易环境的恶化密不可分,全面解决的难度是非常大的,笔者认为现阶段必须有清晰的解决问题的路径,采取多种富有针对性的措施,才有可能在较短的时间内解决好"三农"问题,实现全面建设小康社会的宏伟目标. 相似文献
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Zhong Jingxiao 《保鲜与加工》1989,(4)
This paper introduces the metod of optimal design of municipal water distribution,The main points are the theory,mathematical model,program frame figure and example in practice of the optimal method of hydraulics.The
program is applicable to the design and calculation of the pipe network in a city. It gives a simple and convenient calculation method for multiple-scheme design and scheme cmparison of water supply system. 相似文献
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Based on the simplified elastoplastic constitutive model of soil, the calculation method for the laterally loaded single pile with large deflection was submitted. The coefficient of subgrade reaction was presumed to increase linearly with depth, which simulates the soil resistance close to ground well. The relevant program was then developed using FORTRAN language. The examples show that (1)the displacement and bending moment increase nonlinearly when the lateral load and the moment load increase. (2)The pile displacement decreases with depth. (3)The pile displacement at the point which is over ten times pile diameter from ground is so small that can be neglected. (4)The pile head condition is the key factor, which influences the distributions of pile responses along depth. (5)By improving the mechanical properties of soil around pile, the maximum lateral displacement and bending moment can be decreased efficiently. The calculation results are in good agreement with the field test results and are better than those obtained using the pre existing solutions, which shows the presented solutions are reliable. 相似文献
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In order to investigate the issue in the field of the application of CFG pile application of CFG pile composite foundation technology in deep embedded secret passage of such special structure ground treatment, the settlement deformation of CFG pile composite foundation according to deep are studied and detailed analysis are given in the field test and indoor model test of the gravel cushion with different thickness. Moreover it points out that the cushion compressive deformation must be taken into account, and that the settlement deformation calculation cannot simply consider the amendments of composite foundation. The amendments of cushion deformation must be considered. The effect of the different thickness of cushion on pile-soil stress ratio, total settlement of composite foundation, cushion compression and axial stress of pile body were analysed by using ABAQUS finite element method. Through the analysis of the field test, indoor model test and the numerical simulation of CFG piles-gravel cushion composite foundation of the deep embedded secret passage, a settlement deformation monitoring method has been described and the selection principle of the cushion has determined so as to provide the cushion design basis in the process of composite foundation design. 相似文献
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以干法制备和腌制的腊八蒜为试材,在25℃下存放12 d,定期测定腊八蒜的色素底物、色素中间体、蓝色素和黄色素含量,以期研究色素的变化规律。结果表明,乙酸熏蒸组和乙酸+20%CO2组底物蒜氨酸质量分数分别减少了51.37%和46.89%,对照组降低了81.8%;色素中间体大蒜素含量缓慢减少。货架期中后期熏蒸组的黄色素含量显著高于浸泡组;乙酸+20%CO2组蓝色素含量与乙酸浸泡组无显著差异。12 d后,浸泡腌制的腊八蒜呈蓝绿色,乙酸+20%CO2熏蒸制备的腊八蒜呈淡绿色,乙酸熏蒸制备的腊八蒜呈墨绿色。 相似文献
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在综合分析现有水平荷载作用下桩基分析方法的基础上,建立了考虑桩侧土体受力状态的斜坡刚性桩力学模型;根据极限平衡原理,建立横向荷载作用下斜坡刚性桩弯矩和应力平衡方程;引入考虑斜坡影响的p-y曲线方法,提出了综合考虑桩侧土体极限承载力与水平抗力系数沿深度呈线性增加的侧向极限承载力与土体抗力承载力系数计算方法,同时,将该方法应用于计算实例,通过与已有有限元和理论计算方法对比分析,计算结果验证了本文方法的合理性与可行性;并利用该方法,分析了斜坡坡角、桩土接触面系数以及地基水平抗力系数对斜坡刚性桩承载特性的影响因素。分析表明:斜坡的坡角、桩土接触面系数对侧向荷载作用下斜坡刚性桩的荷载位移曲线影响明显,而桩侧土的抗力系数对侧向荷载作用下斜坡刚性桩的荷载位移曲线影响不明显。 相似文献
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Considering the relationships of coupling movement and compatible displacement among bonding layer, piezoelectric layer, damping layer, and base structure, a finite element dynamic model of coupled systems for vibration reduction plates is established. The model combined with piezoelectric theory, finite element theory and ADF model of viscoelastic damping material can be suitable for vibration model of complex SCLD structure. The dynamics parameters for clamped-clamped steel plate with partially treated smart constrained layer damping are obtained by theoretical calculation, ANSYS modal analysis and modal experiment. The results show that theoretical values are closer to the test results and ANSYS analysis, and the methods proposed is more accurate and effective. 相似文献
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Fast algorithm for apparent resistivity calculation based on back propagation neural networks 总被引：1，自引：1，他引：0
To avoid the complex numerical calculation for the electromagnetic field and determine underground abnormality, a neural network based method is proposed. In consideration of turn off transmitter current, the effect of a linear ramp turn off current on transmitter is corrected. The characteristics of transient expression and the traditional calculation algorithm for apparent resistivity are analyzed, and a predigest structure of network is obtained based on the kernel expression. The three layer back propagation(BP) neural network is trained by using sample data in homogeneous half space, and its number in hidden layer was determined. The method proposed is compared with two traditional calculation methods with simulation experiments. The result demonstrates that BP neural network has a high speed of processing data and is useful in explanation of the transient electromagnetic method. 相似文献
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河南平原区烤烟“前膜后秸”覆盖栽培效果初报 总被引：17，自引：1，他引：17
研究了河南省平原区典型烟田几种覆盖栽培方式对烤烟生育、产质量建成以及土壤水温动态的影响。结果表明，“前膜后秸”一体化覆盖的栽培方式，能够促进烟株早发快长，形成适宜的烟叶产量，获得最佳的烟叶等级构成，中上等烟比例，尤其是上等烟的大幅增加，烟叶含钾(K2O)量大幅增加，达1.84%，而含氯量最低，仅0.38%，钾氯比达到适宜比例，为4.84。与无覆盖烟田相比，其它各种覆盖措施的烟叶中，虽然通过提高烟叶产量来增加了产值，但其中上等烟比例和内在品质相对下降。与优化的低起垄、深栽烟、培土技术相结合，“前膜后秸”覆盖栽培能够在烟草生育期内保持良好的土壤水分和热量条件，同时促进烟株形成分层、发达的架状根系，有利于对土壤水肥营养的吸收和土壤水肥气热关系的协调，是该区烤烟生产“提钾降氯”、无公害栽培的有效途径。 相似文献
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JIANG Gang 《保鲜与加工》2006,(1):71-73
The deformation and stress induced by the loading of building on the foundation will cause the settlement and incline.If the foundation settlement isn't a uniform one,it will decline and affect the safety of the building.The consolidation coefficient is the main factor for the settlement of foundation.At present,the method for the consolidation coefficient such as logarithm of time and square root of time methods couldn't overcome the jamming.However the Genetic Algorithm can diminish the jamming and a precise result can be gained. 相似文献