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Pile foundation buckling critical load analytical solution analysis method based on two-parameter foundation model

A foundation model and analysis method technology, applied in the field of geotechnical engineering, can solve the problem that the Winkler foundation model cannot consider the spread and deformation of stress

Inactive Publication Date: 2020-07-07
SHANGHAI UNIV
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  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

The solution process of this method is simple, and it is suitable for soils with very low shear strength or foundations with a relatively large plastic zone under the basement, but if this method is still used for calculations of soils with high shear stiffness, large errors will occur , and the Winkler foundation model cannot consider the stress diffusion and deformation, so this theory has a large defect in practical application

Method used

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  • Pile foundation buckling critical load analytical solution analysis method based on two-parameter foundation model
  • Pile foundation buckling critical load analytical solution analysis method based on two-parameter foundation model
  • Pile foundation buckling critical load analytical solution analysis method based on two-parameter foundation model

Examples

Experimental program
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Embodiment 1

[0091] In this example, see Figure 1-Figure 3 , a method for analytical solution analysis of pile foundation buckling critical load based on dual-parameter foundation model, the analysis method includes the following steps:

[0092] a) Based on the dual-parameter foundation model, an analysis method for the analytical solution of the pile foundation buckling critical load is proposed:

[0093] According to the Pasternak two-parameter foundation model, the deflection differential equation of the pile body under the two-dimensional plane strain condition is expressed as follows:

[0094]

[0095] EI is the bending stiffness of the pile section;

[0096] y is the deflection at any point of the pile body;

[0097] Gp is ​​the shear stiffness of foundation soil;

[0098] K is the foundation reaction modulus;

[0099] B is the calculated width of the pile body;

[0100] For the common circular section piles in engineering: when the pile diameter d≤1m, B=0.9(0.5+1.5d); when ...

Embodiment 2

[0117] This embodiment is basically the same as Embodiment 1, especially in that:

[0118] In this embodiment, the analytical solution analysis method of critical load of pile foundation buckling based on the two-parameter foundation model is solved by the energy method as follows:

[0119] (a) Based on the buckling analysis model of super-long rock-socketed piles, the total potential energy functional equation of the pile-soil system is established:

[0120] Such as figure 2 As shown, the total potential energy Π of the pile and soil should be calculated by the strain energy of the pile body U P , based on the elastic deformation energy U of the pile side soil under the dual-parameter foundation S , the load potential energy V of pile side friction f , the potential energy V of the self-weight load of the pile body g and the pile top external load potential energy V p Composition, namely:

[0121] Π=U p +U s +V f +V g +V p

[0122] Pile strain energy U P for: ...

Embodiment 3

[0170] This embodiment is basically the same as the previous embodiment, and the special features are:

[0171] In this embodiment, an analytical solution analysis method for pile foundation buckling critical load based on a two-parameter foundation model. In order to verify the correctness of the calculation method of the two-parameter foundation model, the following test results of the model pile are used for analysis and comparison. The boundary conditions are: the pile end is embedded and the pile top is free. The specific parameters are shown in Table 1, and the theoretical results of the calculated super-long pile buckling load are compared with the experimental results in the literature, as shown in Table 2.

[0172] Table 1. Calculation parameter list of test piles in this embodiment

[0173]

[0174] Table 2. Comparison table of calculation results of buckling critical load in this embodiment

[0175]

[0176] It can be seen from Table 2 that the actual mecha...

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Abstract

The invention discloses a pile foundation buckling critical load analytical solution analysis method based on a two-parameter foundation model. Aiming at the characteristic that overlong pile free sections such as a large-span bridge, a high-pile wharf and the like are easy to bend and damage when the slenderness ratio is overlarge; a constraint effect of soil around a pile is simulated accordingto a two-parameter foundation model, a total potential energy functional of a pile-soil system is established, a pile foundation buckling critical load analytical solution is obtained according to a potential energy standing principle and a variation method, and a reliable theoretical basis is provided for preventing engineering accidents caused by buckling damage of an ultra-long pile. Accordingto the method, the counter-force modulus and the shear modulus of foundation soil are fully considered, the dead weight of the pile foundation is considered, the total potential energy functional of apile-soil system is established, and the buckling critical load analytical solution of the pile foundation is obtained according to the potential energy standing principle and the variational method.Through comparison with the result of an example, the goodness of fit between the analysis result obtained by selecting the two-parameter foundation model and the test result of the pile test is high, and it is shown that the model can effectively reflect the actual stress characteristics and the constraint effect of soil around the pile when the pile foundation is bent.

Description

technical field [0001] The invention belongs to the field of geotechnical engineering and relates to pile foundation engineering technology, in particular to a method for calculating the analytical solution of pile foundation buckling critical load based on a double-parameter foundation model. Background technique [0002] Super-long rock-socketed piles are not only widely used in super high-rise buildings, but also a large number of highways, railway bridges, high-pile wharves, etc. also use pile foundations as their foundation forms. However, affected by the special topography and hydrogeological environment in mountainous areas, many road sections have to cross rivers and canyons in the form of viaducts, often resulting in too long free sections of foundation piles. The upper foundation pile is like a slender rod, which is prone to buckling instability failure, which often occurs suddenly and has serious consequences. Most current studies assume that the soil is a Winkle...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): G06F30/20G06F30/13E02D33/00G06F119/14G06F111/10
CPCE02D33/00
Inventor 姚文娟王雪明顾毛亮程泽坤顾文胤
Owner SHANGHAI UNIV
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