Longitudinal dynamic characteristics of a defective tapered pile with exposed cap in layered soil

Abstract

The longitudinal dynamic characteristics of a defective tapered pile embedded in layered soil is investigated considering that an exposed cap is connected with the pile top rigidly. According to the layered condition of the surrounding soil and the variable cross-section of the tapered pile, the pile-soil system is discretized into multiple segments. By employing the complex stiffness transfer mechanism (CSTM) to simulate the construction disturbance, the complex stiffness of the surrounding soil was solved. The vertical reaction of the surrounding soil on the annular projections at the interfaces of adjacent pile segments is generalized as a Voigt model, while the exposed cap is regarded as an expanding segment of the pile. The analytical solution to the dynamic impedance of a defective tapered pile with exposed cap subjected to a vertical excitation is then derived by means of the Laplace transformation and the amended impedance function transfer method (AIFTM). Based on the presented solution, the influences of the pile-soil system parameters on the velocity response at the cap top are investigated in detail. Some conclusions derived from this study could provide practical guidance for the engineering practice of tapered pile.

Keywords:

• Dynamic characteristics
• defective tapered pile with exposed cap
• construction disturbance
• amended impedance function transfer method (AIFTM)
• low-stain test

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This research was supported by the National Natural Science Foundation of China (Grant Nos. 52178358 and 51779217).