This invention pertains to a Hollow Square Pile and its production method- JIAXING DONGJIN PRECAST COMPONENT CO., LTD.

This invention pertains to a Hollow Square Pile and its production method. The Hollow Square Pile comprises a steel reinforcement framework, square end plate with hoops, and concrete. The pile body features a circular through hole formed at its center; all elements of this construction are enclosed by dense concrete. A steel reinforcement framework sits atop this plate with hoops, wrapping around its periphery. Steel bars connected via spiral bars welded directly to end plates provide coverage at either end; as does dense concrete.

Hollow Square Piles provide several key advantages over pipe piles: They offer superior shear resistance and bearing capacity with the soil due to a larger contact area with it, and provide an effective foundation solution in difficult terrain. Their low self-weight helps lower construction costs; their compact form makes installation simple; high structural performance improves the seismic behavior of buildings and bridges. Furthermore, the Hollow Square Pile can be utilized across an array of applications.

Hollow Square Pile's ductility can also enhance its seismic performance, increasing reversal stiffness and dissipation capacity during earthquakes. To improve the shear resistance of this pile it is vitally important that its steel reinforcement ratio and shape of rebars be optimized, which has the power of increasing shear strength by over double and tripling its bending stiffness respectively.

Another approach for improving the shear resistance of Hollow square piles is using non-prestressed rebars, which will not only enhance shear resistance but also increase bending stiffness and reversal stiffness. Unfortunately, this approach may not apply to every project because additional equipment and time must be dedicated to manufacturing the rebars.

Hollow Square Piles provide superior load-bearing capacity compared to pipe piles, supporting more weight from buildings while being impact-resistant. Their axial load-bearing capacity increases as the depth of the pile increases; however, their lateral load-bearing capacity declines over depth.

For maximum load-bearing capabilities of Hollow Square Pile, strengthening of their core concrete should be undertaken. This may result in better load-bearing capabilities of PHS hollow piles. In this study, a series of full-scale PHS hollow piles were extracted through an uplift load test to investigate the effects of core concrete type, length, and internal thread on uplift load-bearing capacity. Acoustic emission data were continuously collected throughout the drawing process to monitor damage to core concrete. Results revealed that core concrete damage occurred primarily at the interface between the hollow pile and upper cap, with its inner wall sporting an internal thread that increased uplift load-bearing capacity.