不同加固方式对深基坑变形影响的数值分析

发布时间：2018-01-07 08:40

本文关键词：不同加固方式对深基坑变形影响的数值分析　出处：《天津大学》2014年硕士论文　论文类型：学位论文

【摘要】：随着我国城镇化建设进程的加快,基坑工程的规模越来越大,若基坑设计不合理,会影响基坑的稳定性及其周围环境的安全和正常使用。坑底加固可以改善土体的物理力学参数,抑制基坑的变形,增强基坑的稳定性,但其费用较高,因此,确定合理的加固范围、选择合适的加固方式及其组合十分重要。本文运用有限元软件ABAQUS建立三维弹塑性模型,模拟了深基坑内坑底加固对基坑变形的影响,讨论了坑底加固不同影响因素及不同坑底加固方式对坑底隆起和围护结构侧向位移的影响,并探讨了(坑底加固+工程桩)对基坑变形的影响,得出了一些结论和规律,主要的研究内容和成果如下:1、分析了加固体刚度、宽度、位置变化等影响因素对坑底隆起和围护结构侧向位移的影响,结果表明:坑底隆起和围护结构的侧向位移随加固体刚度、宽度的增大而减小,但存在一个合理的加固范围;基坑变形随加固体离坑底距离的增大而增大,坑底土体应从坑底开挖面处开始加固。2、讨论了满堂、裙边、抽条、格栅等四种不同加固方式对坑底隆起和围护结构侧向位移的影响,结果表明:在抑制坑底隆起的效果上,由大到小依次是满堂、格栅、抽条、裙边加固,裙边加固可以有效提高加固范围之内土体的抗隆起作用;在抑制最大侧向位移的效果上,四种不同加固方式相差不大。3、探讨了满堂加固、工程桩、(满堂加固+工程桩)、(裙边加固+工程桩)这四种不同加固方式对基坑变形的影响,结果表明:在抑制坑底隆起的效果上,由大到小依次是(满堂加固+工程桩)、(裙边加固+工程桩)、工程桩、满堂加固;工程桩对抑制围护结构侧向位移的作用要小一些,而其他三种不同加固方式在抑制最大侧向位移的效果上相差不大。4、对于不同地区的工程地质条件和基坑变形的控制要求,使用合理的加固方式以及不同加固方式的组合,不仅可以保证基坑的安全和环境影响的要求,而且还可以降低成本。5、通过对实际的基坑工程进行模拟计算分析,得出有限元模拟值与计算值、实测值基本吻合,验证了有限元模型的合理性以及数值模拟分析所得的规律的正确性。
[Abstract]:With the process of China's urbanization accelerated, increasing the size of the foundation pit design, if not reasonable, will affect the stability of the foundation pit and the surrounding environment safety and normal use. Foundation reinforcement can improve the physical and mechanical parameters of soil deformation, inhibition of foundation pit, foundation stability enhancement, but its high cost, therefore sure, the reasonable reinforcement scope, select the appropriate reinforcement and combination is very important. This paper uses finite element software ABAQUS to establish three-dimensional elastoplastic model, simulation of the deep foundation pit of foundation reinforcement effect on the deformation of foundation pit, the influence of different factors and different foundation reinforcement foundation reinforcement in displacement and lateral heave retaining structure the discussion, and discussed the (+ pile foundation reinforcement engineering) the influence of pit deformation, draws some conclusions and rules, the main research contents and results are as follows: 1 points. Analysis of the solid stiffness, width, impact, influence of location changes on the heave and displacement of retaining structure. The results showed that the lateral displacement and heave retaining structure with solid stiffness, width increases, but there is a reasonable range of deformation of foundation pit reinforcement; with the increase of solid increases from the bottom distance increases, the bottom soil from the excavation surface at the beginning of reinforcement.2, discusses the full skirt, pumping, influence, grid four different reinforcement method of heave and displacement of retaining structure. The results showed that: in the suppression of lateral uplift effect, from large to small in turn is full, grille pumping, skirt, skirt reinforcement, reinforcement can effectively improve the range of soil heave reinforcement; in the suppression of the maximum lateral displacement effect, four different reinforcement has little difference with.3, discusses the full reinforcement engineering Cheng (full pile, reinforcement engineering pile, (+) + skirt reinforcement engineering pile) these four different ways of strengthening the results show that the influence of the deformation of foundation pit in inhibiting uplift effect, from large to small in turn is (a + pile reinforcement (reinforcement), skirt + pile), engineering the role of engineering pile, reinforcement; pile retaining structure on the inhibition of lateral displacement is smaller, while the other three kinds of reinforcement has little difference in the inhibition of the maximum lateral displacement of the.4 effect, for the control of different parts of the engineering geological conditions and deformation requirements, reasonable use of reinforcement method and combination of different ways of strengthening. Not only can guarantee the safety and environmental impact of excavation requirements, but also can reduce the cost of.5 was simulated through the analysis of the actual excavation engineering, the finite element simulation and calculated values and measured values coincide, verify the Co. The reasonableness of the metamodel and the correctness of the numerical simulation analysis.

【学位授予单位】：天津大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TU753

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