捆绑式抗滑桩的力学特性及抗震性能研究

发布时间：2018-04-22 03:39

本文选题：捆绑式抗滑桩 + 地震　；参考：《重庆大学》2016年硕士论文

【摘要】：基础设施大力发展,边(滑)坡稳定性问题是常见的工程问题,同时也是地震产生次生灾害的主要组成部分之一。大型边(滑)坡屡见不鲜,仅靠增大单桩截面积显得不太实用,各种新型抗滑桩亟待出现,捆绑式抗滑桩的出现解决了大型边(滑)坡的支护难题。捆绑式抗滑拥有抗弯性能好、机械化施工、工期短等优越性。捆绑式抗滑作为边(滑)坡新型的支挡结构,为概念型桩,目前未在工程中应用。随着抗滑桩施工机械化施工程度的提高,捆绑式抗滑桩必然成为边(滑)坡支挡结构的新趋势。地震频发引发众多次生灾害,造成巨大经济损失。地震工况下,支挡结构失效与否直接关乎人民生命财产安全,基于此,对捆绑式抗滑桩和矩形截面桩进行对比分析,探讨捆绑式抗滑桩在静力条件下的力学性能及地震荷载作用下的抗震性能具有重要意义。本文对土质边(滑)坡的抗滑桩支挡结构做了以下研究:(1)本文对矩形截面桩及捆绑式抗滑桩的研究现状做了简要阐述,对FLAC3D有限差分软件相关计算原理做了简要概述。利用FLAC3D建立模型进行有限差分计算,对捆绑式抗滑桩和矩形截面桩在桩身变形、位移、弯剪及桩身应力等方面做了详细研究,研究表明同单桩相比捆绑式抗滑桩在这几个方面都具有一定的优越性。(2)基于有限差分原理在静力条件下对捆绑式抗滑桩的桩身截面尺寸、桩间距、桩内距、嵌岩深度、不同地基刚度等因素进行了研究,探讨了各因素的重要性及相应的取值范围。研究表明桩身截面尺寸、桩间距、嵌岩深度、不同地基刚度对桩身的变形、弯剪、桩身应力影响大,桩内距对桩身的力学特性无太大贡献。(3)利用汶川地震卧龙站测得的50s地震加速度时程对等截面换算的矩形截面桩和捆绑式抗滑桩进行动力分析,研究结果表明在动力条件下,捆绑式抗滑桩的力学性能优越于矩形截面桩。(4)捆绑式抗滑桩的优越性决定了它的使用范围比矩形截面单桩广。捆绑式抗滑桩在不同的桩间距、桩内距、不同地基刚度等条件下桩身的力学性能如何亟待解决,故利用卧龙地震加速度时程作为动力荷载施加,对相关影响因素建模计算,研究了捆绑式抗滑桩在动力条件下不同影响要素的取值范围。(5)基于实际工程实例对捆绑式抗滑桩和矩形截面单桩进行对比分析,捆绑式抗滑桩节约材料,经济价值高,适应性强,相对矩形截面单桩而言捆绑式抗滑桩将会减少约1/2的工程造价。捆绑式抗滑桩的研究成果可为工程中桩身设计和静力学特性分析夯实基础,对更好的研究捆绑式抗滑桩的设计要素及抗震性能做了铺垫,对后续的理论求解提供参考。
[Abstract]:With the development of infrastructure, slope stability is a common engineering problem, which is also one of the main components of secondary disasters caused by earthquakes. Large side (slide) slope is not uncommon, only by increasing the cross-section area of single pile is not very practical, various new anti-slide piles need to appear urgently. The emergence of bundled anti-slide pile solves the support problem of large side (slide) slope. Strapped anti-slip has the advantages of good bending resistance, mechanized construction, short construction period and so on. As a new type of retaining structure of side slope, bundled anti-slide is a conceptual pile, which has not been applied in engineering at present. With the improvement of construction mechanization degree of anti-slide pile, bundled anti-slide pile is bound to become a new trend of side (slide) slope retaining structure. Frequent earthquakes cause many secondary disasters, resulting in huge economic losses. Under the earthquake condition, the failure of retaining structure is directly related to the safety of people's life and property. Based on this, the comparative analysis of strapped anti-slide pile and rectangular cross-section pile is carried out. It is of great significance to discuss the mechanical properties of strapped anti-slide piles under static conditions and seismic behavior under seismic loads. In this paper, the following research is done on the anti-slide pile retaining structure of the soil side (slide) slope. In this paper, the research status of rectangular cross-section pile and bundled anti-slide pile is briefly described, and the related calculation principle of FLAC3D finite difference software is briefly summarized. The finite difference calculation is carried out by using the FLAC3D model. The deformation, displacement, bending shear and stress of the pile body are studied in detail, such as the deformation of the pile body, the displacement of the pile, the bending shear and the stress of the pile body. The research shows that the bundled anti-slide pile has some advantages in these aspects compared with the single pile. Based on the finite difference principle, the pile cross-section size, pile spacing, pile inner distance, and rock-socketed depth of the bundled anti-slide pile under static conditions are studied. The factors of different foundation stiffness are studied, and the importance of each factor and the corresponding value range are discussed. The results show that the deformation of pile body, bending shear and pile body stress are greatly affected by the size of pile cross-section, the distance between piles, the depth of rock-socketed rock, and the stiffness of different foundation. The internal distance of pile has no great contribution to the mechanical properties of pile body.) the dynamic analysis of rectangular cross-section pile and strapped anti-slide pile is carried out by using the 50 s acceleration time history measured by Wolong station in Wenchuan earthquake. The results show that under the dynamic conditions, The mechanical performance of strapped pile is superior to that of rectangular cross-section pile. 4) the superiority of bundled pile determines that its application range is wider than that of single pile with rectangular section. How to solve the mechanical properties of bundled anti-slide pile under the conditions of different pile spacing, pile inner distance and different foundation stiffness is urgently needed to be solved. Therefore, the acceleration time history of Wolong earthquake is used as dynamic load to model and calculate the relevant influencing factors. This paper studies the value range of different influencing factors of strapped anti-slide pile under dynamic condition. Based on practical engineering examples, the paper makes a comparative analysis of strapped anti-slide pile and rectangular cross-section single pile, which saves material and has high economic value. Strong adaptability, compared to rectangular section of single pile, bundled anti-slide pile will reduce the engineering cost by about 1 / 2. The research results of bundled anti-slide pile can be used to lay a solid foundation for the design of pile body and the analysis of static characteristics in engineering. It also provides a basis for better research on the design elements and seismic performance of bundled anti-slide pile, and provides a reference for the subsequent theoretical solution.
【学位授予单位】：重庆大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TU473.1

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