桩土间负摩阻力计算研究

发布时间：2018-04-18 19:44

本文选题：负摩阻力 + 数学模型计算　；参考：《安徽理工大学》2017年硕士论文

【摘要】：改革开放以来,国家通过宏观调控的一整套连贯的国策牵引,以城市建设、交通拓展等一系列基础设施投入为先锋军,不断拓宽特、大、中型城市的城市群,不断刷新城市地标的新高度和建筑基础的新深度。面对越来越高、体量越来越大的建筑结构对基础的承载及稳定性的要求越来越高。桩基础选型设计方案,作为一种历史古老、技术及经验积累深厚的基本基础选型方案。在较大的竖向荷载及水平荷载条件,同时兼顾情况复杂的地基条件、高重大建筑的个性力学承载条件下,整体性、刚度都较大的桩基础选型,成为复杂地质条件下大体量建筑结构地基的首选基础选型方案。伴随着高层超高层建筑的迅猛发展,桩基础的应用范围也越加的广泛,单桩的长度也越来越长,在桩基应用初期影响可以忽略不计的桩土间负摩阻力的问题,也凸显出来,因在桩基施工过程中未能充分考虑到桩基负摩阻力问题而导致的工程事故也越来越常见;近年来引发了为数不少施工过程中甚至是建筑使用过程中的重、特大工程事故。但与之相对应的,桩基负摩阻力的相关理论研究至今仍旧相对滞后。对工程结构安全、生命财产安全产生了重大威胁。由此桩基负摩阻力的计算及理论探索逐渐成为基础-岩土工程相关研究的热点课题。桩-土之间在复杂的荷载环境、土层条件、外在影响环境下,桩-土之间产生了更为复杂的相互作用的力学机理。由于桩土作用机理的复杂性,目前对桩一土间相互作用的研究还很不够深入。本文从国内外相关桩基负摩阻力研究的现状出发,综合介绍了可能引发桩基负摩阻力的桩-土条件、桩基负摩阻力的主要几种计算方法、桩基负摩阻力研究中亟待解决的问题和不足、桩基负摩阻力的形成机理、桩基负摩阻力的相关计算思路,并选择了其中一种相对比较合理且实用性较好的计算方法,结合工程实例,建立相关的数学模型,进行了实例计算,最终通过对实际的计算结果进行对比分析,得出在相同的桩身截面以及桩周土体力学性质的条件下,不同桩顶荷载下,桩身负摩阻力的变化情况;以及桩截面面积相同,不同截面形状对于桩身负摩阻力的影响。通过以上两项的对比分析,为研究桩土间负摩阻力的影响因素提供一定的依据。
[Abstract]:Since the beginning of reform and opening up, the state has been drawing on a coherent set of national policies of macro-control, with a series of infrastructure inputs such as urban construction and transportation development as the vanguard army, constantly widening the urban agglomerations of special, large and medium-sized cities.Constantly refresh the new height of the city landmarks and the new depth of the building foundation.In the face of higher and higher volume of building structures, the requirements of the bearing capacity and stability of the foundation are becoming higher and higher.Design scheme of pile foundation selection is a kind of basic foundation selection scheme with ancient history and deep accumulation of technology and experience.Under the condition of larger vertical load and horizontal load, taking into account the complex foundation condition and the individual mechanics bearing condition of high important building, the pile foundation with larger integrity and stiffness is selected.It has become the first choice of foundation selection scheme for large-volume building foundation under complex geological conditions.With the rapid development of high-rise super high-rise building, the application range of pile foundation is more and more extensive, and the length of single pile is becoming longer and longer. In the initial application of pile foundation, the problem of negative friction between piles and soil which can be ignored is also highlighted.The engineering accidents caused by the failure to fully consider the negative friction of pile foundation in the construction process of pile foundation are more and more common, and in recent years, it has caused a large number of heavy and serious engineering accidents in the construction process and even in the course of building use.However, the theoretical research on the negative friction of pile foundation is still lagging behind.It is a great threat to the safety of engineering structure and life and property.Therefore, the calculation and theoretical exploration of negative frictional resistance of pile foundation has gradually become a hot topic in foundation-geotechnical engineering.In the complex load environment, soil layer condition and external influence environment, the pile-soil interaction mechanism is more complex.Because of the complexity of pile-soil interaction mechanism, the research on pile-soil interaction is not deep enough.Based on the present situation of the research on the negative friction of pile foundation at home and abroad, this paper introduces the pile-soil conditions which may lead to the negative friction of pile foundation, and the main calculation methods of the negative friction resistance of pile foundation.The problems and shortcomings to be solved urgently in the research of negative friction resistance of pile foundation, the formation mechanism of negative friction resistance of pile foundation, the related calculation thought of negative friction resistance of pile foundation, and a relatively reasonable and practical calculation method are selected.Combined with engineering example, the relevant mathematical model is established, and the example calculation is carried out. Finally, through the comparison and analysis of the actual calculation results, it is concluded that under the condition of the same pile cross-section and the mechanical properties of the soil around the pile, under different pile top loads,The change of negative friction resistance of pile and the influence of different cross-section shape on negative friction resistance of pile with the same cross-section area.Through the comparative analysis of the above two items, it provides a certain basis for studying the influence factors of the negative friction resistance between piles and soils.
【学位授予单位】：安徽理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU473.1

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