Compressive Capacity of Vortex-Compression Nodular Piles

Compared with traditional equal-section pile, the nodular parts of nodular pile expand the contact area between the pile and foundation soil, which can greatly improve the bearing capacity of pile foundation and increase the stability of pile body structure. In this paper, the mechanism of pile-soil interaction in the construction of vortex-compression nodular pile is studied with the purpose of evaluating the compressive capacity of nodular piles. Through the indoor model test and ABAQUS numerical simulation analysis, the compressive characteristics of 12 types of vortex-compression nodular pile are obtained, and the variation rules of the parameters of the compressive characteristics of vortex-compression nodular piles are quantitatively analyzed, including the failure pattern of foundation soil, load-settlement relationship, and load transfer law of vortex-compression nodular piles. The results showed that the compressive capacity of vortex-compression nodular piles has significant advantages over that of traditional equal-section piles. Based on the results of the indoor model test and numerical simulation, the calculation method and formula of the compressive capacity of vortex-compression nodular piles are given by modifying the corresponding calculation formula of traditional nodular piles. The new method and formula are more in line with the actual working conditions and provide theoretical and data support for the further engineering application of vortex-compression nodular piles.

Study on Bearing Capacity of Tank Foundation with Alternatively Arranged Vortex-Compression Nodular Piles

Types of tapered piles are widely applied in tank foundation consolidation, but their inherent deficiencies in design and construction limit their further promotion. Vortex compression pile is a novel nodular pile. Compared with the traditional equal-section pile, vortex compression nodular pile is featured by stronger bearing capacity and slighter settlement. In this paper, the model test results showed that vortex compression nodular pile can greatly improve the bearing capacity and reduce the settlement. Through the finite element software ABAQUS analysis the bearing characteristics of equal-section pile foundation and vortex-compression nodular pile foundation were compared. The three-dimensional solid model was established by ABAQUS finite element software. The impact of cushion modulus, cushion thickness, vertical load, pile modulus, soil modulus around the pile on the bearing capacity of the vortex-compression nodular pile foundation were studied.

Field Tests and Simplified Calculation Method for Static Drill Rooted Nodular Pile

In order to explore bearing characteristics of a new-type static drill rooted nodular pile foundation (SDRN), which is composed of PHC pile, bamboo joint pile, and cement soils, field tests of three piles were carried out by embedding internal rebar stress gauges to collect test data. The test results show that the SDRN piles were under elastic state and the load-settlement curves changed slowly before reaching the ultimate capacity. As pile head loads increased, the pile shaft frictions developed progressively, and axial forces gradually reduced along pile depths. Taking into account the interaction between the pile, the cement soils, and surrounding soils, a simplified method for calculating settlements and bearing capacity of SDRN piles was proposed. With corresponding parameters, the computing results obtained by the proposed method were compared with the field experimental data, which indicates acceptable agreements; thus, it is concluded that the applicability and predictive capability of the proposed method were verified.