Calculation method of load transfer function for the study of load transfer mechanism of super-long piles

Abstract

The invention discloses a load transfer function calculation method used for research of a load transfer mechanism of a super-long pile. The calculation method comprises the following steps of collecting pile test data of the super-long pile in a soft soil area, researching a law of change of side frictional force of the super-long pile along with shear displacement of a pile side soil body, and obtaining an actually measured load transfer tau-s curve; then according to the actually measured load transfer tau-s curve, obtaining a load transfer function of a non worked and softened pile soil interface and a load transfer function of a worked and softened pile soil interface; by reference to a matrix displacement method, based on the actually measured load transfer functions, performing numerical solving on a load transfer basic differential equation of the super-long pile; performing calculation by adopting an iterative method, and compiling calculation software; and simulating a complete loading process of the super-long pile by utilizing the calculation software. The method has the advantages that the load transfer functions can ideally simulate characteristics of the load transfer mechanism of the single pile; asynchronous characteristics of bearing capacity of different soil layers in a pile body range of the super-long pile are intuitively reflected; and the method has advantages in the aspect of super-long pile theory analysis.

Description

technical field [0001] The invention belongs to the technical field of geotechnical engineering, and in particular relates to a load transfer function calculation method for studying the load transfer mechanism of super-long piles. Background technique [0002] The load transfer function is a mathematical model that characterizes the relationship between the shear displacement of the pile side soil and the value of the side friction resistance. Theoretically, for soil layers with the same engineering properties and the same distribution depth in different sites, the load transfer function should be unique. But for super-long piles, which are mainly cast-in-place piles, the function is complex and not unique due to the influence of hole quality, pile technology, pile material quality and other factors. Especially after the post-grouting process is adopted, the pile-soil interface is improved and strengthened to varying degrees, and the load transfer function is more complicat...

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Problems solved by technology

[0002] The load transfer function is a mathematical model that characterizes the relationship between the shear displacement of the pile side soil and the value of the side friction resistance. Theoretically, for soil layers with the same engineering properties and the same distribution depth in different sites, the load transfer function should be unique. However, for super-long piles dominated by cast-in-situ piles, the function is complex and not unique due to the influence of factors such as hole-forming quality, pile-forming technology, and pile material quality.

Especially after the post-grouting process is adopted, the pile-soil interface is improved and strengthened to varying degrees, and the load transfer function is more complex

Based on the collection of published scientific research results, there are few studies on the load transfer function of super-long piles in Shanghai. On the one hand, it is difficult to obtain the pile displacement test results in practice, and on the other hand, the pile side friction resistance is affected by various factors. Large, relying on the existing data is not enough to obtain the understanding of the regularity in the statistical sense

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