地基基础剪切作用对水平受荷桩的影响研究

发布时间：2018-05-30 11:04

本文选题：桩 + 模型试验　；参考：《西南交通大学》2017年硕士论文

【摘要】：关于水平受荷桩的理论计算方法原则上有多种,其中线弹性地基反力系数法概念简单,计算结果偏于安全,因而在国内外得到广泛应用,我国规范推荐的m法和c法均属于此类方法。但弹性线地基反力系数没有考虑桩身剪切变形的影响,并且在建立方程时采用温克尔地基模型,忽略了岩土介质间的横向剪切力,这些因素都将导致计算结果与实际产生偏差。针对该问题本文进行一系列研究,具体工作如下:(1)在规范推荐的聊法和c法的基础上,引用可以考虑桩剪切变形的铁木辛克两广义位移梁理论,建立相应微分方程,利用幂级数法对其进行推导求解,求得初参数方程。结合实例,通过对比推导理论与原有理论计算结果间的差异,得到剪切变形对计算结果影响的结论,同时对桩的剪切模量进行了敏感性分析。(2)对吴氏双参数法进行修正,解决其理论推导时桩长指数值取值矛盾的问题,为建立一个统一计算公式,在此基础上引入可以考虑桩剪切变形的铁木辛克梁理论和考虑岩土介质间剪切作用的Pasternak双参数地基模型,使理论更加严谨。采用幂级数法对方程求解,得到该一般式的初参数方程,为计算方便,编写相应matlab计算程序。新理论能更全面反映桩的实际受力情况,且通过调节参数使其应用于更广泛的范围。最后结合实例,验证推导理论计算方法的正确性,同时对地基的剪切模量进行敏感性分析。(3)开展室内模型试验得到不同桩径、不同岩土介质水平受荷桩沿桩深的内力和变形分布曲线,对结果进行分析。(4)根据推导通式的解得到考虑剪切变形和岩土介质间剪切作用时m法微分方程的解。以模型试验结果为参考,通过m法与几种计算方法(1.考虑桩剪切变形不考虑岩土介质间剪切作用;2.考虑岩土介质间剪切作用不考虑桩剪切变形;3.同时考虑桩剪切变形和岩土介质间剪切作用)结果的对比,探究桩径和岩土介质变化时各种计算方法间的差异,并对结果分析,得到一些有用结论。
[Abstract]:There are many theoretical methods for calculating horizontally loaded piles in principle. Among them, the linear elastic foundation reaction coefficient method is simple in concept and safe in calculation results, so it is widely used at home and abroad. The m method and c method recommended by our country's norm belong to this kind of method. However, the reaction coefficient of elastic line foundation does not take into account the influence of pile shear deformation, and the Winkler foundation model is used to establish the equation, and the transverse shear force between rock and soil is neglected. These factors will lead to the deviation between the calculation results and the practice. In this paper, a series of research on this problem is carried out. The specific work is as follows: (1) on the basis of the recommended chat method and c method, the corresponding differential equation is established by introducing the theory of two generalized displacement beams of Tomusink considering the shear deformation of piles. The power series method is used to derive and solve the initial parameter equation. Combined with an example, by comparing the difference between the theory and the calculation results of the original theory, a conclusion of the influence of shear deformation on the calculation results is obtained. At the same time, the sensitivity analysis of the shear modulus of the pile is carried out, and the Wu's two-parameter method is modified. To solve the problem of the contradiction of pile length index value in theoretical derivation, in order to establish a unified calculation formula, On this basis, the theory of Fermuxink beam which can consider the shear deformation of pile and the Pasternak two-parameter foundation model considering the shear action between rock and soil are introduced, which makes the theory more rigorous. The power series method is used to solve the equation and the initial parameter equation of the general formula is obtained. For the convenience of calculation, the corresponding matlab calculation program is compiled. The new theory can reflect the actual force of pile more comprehensively, and it can be applied to a wider range by adjusting the parameters. Finally, a practical example is given to verify the correctness of the theoretical calculation method. At the same time, sensitivity analysis of the shear modulus of the foundation is carried out. (3) different pile diameters are obtained through laboratory model tests. The distribution curves of internal force and deformation along the pile depth of different horizontal loaded piles with different rock and soil media are analyzed. 4) the solution of m method differential equation considering shear deformation and shear action between rock and soil media is obtained according to the general formula. Based on the model test results, m method and several calculation methods are used. Considering the shear deformation of pile, the shear action between rock and soil is not considered. The shear deformation of pile is not considered when considering the shear action between rock and soil media. At the same time, considering the comparison of the results of pile shear deformation and the shear action between rock and soil media, the differences between various calculation methods of pile diameter and variation of rock and soil media are explored, and some useful conclusions are obtained by analyzing the results.
【学位授予单位】：西南交通大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU473.1

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