Foshan Chengye Building's Large-tonnage Single Pile Load-bearing Anchor Bolt Static Pressure Steel Pipe Pile Reinforcement Project

The Chengye Building, located in Nansha District, Foshan City, was originally designed as a 10-story structure. The pile foundation is now complete, and the owner has decided to increase the building to 15 stories. Due to the addition of 5 floors, the upper load has increased, and the uniaxial compressive strength of some pile foundations does not meet the design requirements. Foundation reinforcement is necessary. Design calculations indicate the need for an additional 47 steel pipe piles, with each pile having a design bearing capacity of 1225KN, reaching 2450KN under double the pressure. Such a high-tonnage single pile bearing capacity is a first in our industry.

Solution Process

Based on the site conditions, geological conditions, and load, it was determined to reinforce the foundation section using reverse construction anchor bolts and statically compressed steel pipe piles.

2. Calculate the single pile bearing capacity requirements for the additional piles and the number of supplementary piles based on load requirements.

3. Calculate the increased size and reinforcement requirements for the foundation based on load requirements and pile parameter specifications.

4. Our company has successfully addressed technical challenges with two new proprietary processes: "The vertical pile replacement reinforcement method for the thick plate foundation structure of buildings" and "A special foundation reinforcement treatment system for buildings."

Overall construction sequence

Due to the original灌注桩's bearing capacity being sufficient to support construction up to the 10th floor, and through calculations, the self-weight load of the upper structure will meet the reaction requirements of the anchor bolt static pressure pile after the construction of the upper structure reaches the 5th floor.

The initial foundation pad enlargement work has been completed, with pile holes and anchor bolts pre-set. Once the upper structure reaches the 5th floor, simultaneous anchor bolt static pile construction can commence.

Heavy-duty pile driving frame

Specialty steel pile tips

To better penetrate sand layers and isolated rock layers, the pile body has been improved.

Drilling pilot holes to penetrate sand layers and individual shallow foundation boulders.

The single pile is designed for a bearing capacity of 1225KN, which can reach 2450KN with double the pressure applied. Such a high-tonnage single pile bearing capacity is a first in our industry.

Due to the larger bearing capacity of single piles, higher requirements are placed on the static pressure pile anchoring technique. As a result, our company has upgraded and improved this process.

Partial pile design drawings

Our project incorporates two of our patented technologies.

Vertical pile replacement reinforcement method for thick plate foundation structure of buildings (Patent No. ZL200910235342.0)

A Special Foundation Reinforcement Treatment System for Buildings (Patent No. ZL201726966765.2)

Engineering Implementation Summary

The project employs the reverse construction method, effectively resolving the issue of the original pile bearing capacity not meeting the requirements, while also not affecting the overall construction schedule of the project, thereby creating time and economic value for the client.

2. The anchor pile static pressure piles in this project are generally of small diameter, but we have adopted large-tonnage anchor pile static pressure piles, which is also a breakthrough in the technology of anchor pile static pressure piles.

3. The scope of this project includes, for instance, houses under construction with altered plans, or those completed and requiring additional construction, as well as those with limited working space. This method can be employed when the foundation bearing capacity is insufficient. The reinforcement of both the upper structure and foundation can be carried out simultaneously, saving both time and construction costs.