How to Drive Prefabricated Piles for House Subsidence

Driving prefabricated piles for house subsidence requires pile foundation reinforcement methods, carried out by a professional team following standardized procedures, with a focus on controlling pile position, verticality, and drop hammer height, suitable for scenarios with soft soil layers or severe subsidence.

I. Construction Preparation

1. Positioning and Layout: Based on the on-site axis control piles, use a total station to measure and set out the building axis grid according to the construction drawings, and then use a steel tape to determine each pile position. Pile position markers should be made by punching holes with a steel chisel (depth ≤ 200mm), filling the holes with lime, and inserting steel rods to ensure that the allowable deviation of pile positions in a group is ≤ 20mm. If this requirement is not met, re-measurement is necessary.
2. Pile Driver Positioning: Determine the pile driving sequence based on on-site conditions, move the rented pile driver to the designated position, align it with the pile position, and adjust the verticality to ensure that the pile driver remains stable and does not tilt during construction.

II. Hoisting and Stabilizing Piles

1. Lifting and Alignment: Use a sling to bundle the lifting ring at the upper end of the prefabricated pile, slowly lift it to align the pile tip with the center of the pile position, and vertically insert it into the soil. After securing the pile cap on the pile top, fill elastic material (such as a rubber pad) between the pile cap and the pile top to prevent the pile top from being crushed, and then release the sling.
2. Initial Hammering and Verticality Correction: After the pile tip has penetrated 1-2 meters into the soil, use a small drop distance cold hammer to strike it 1-2 times, and then correct the verticality of the pile body. The verticality deviation should be ≤ 0.5%. This can be monitored in real-time by drawing black lines on both sides of the pile body and setting up two total stations (with horizontal braking and lenses that only rotate vertically) to ensure that the pile body does not deviate during pile driving.

III. Pile Driving Process Control

Drop Hammer Height Management: During pile driving, strictly control the drop hammer height to avoid pile body breakage or pile position deviation due to excessive impact force. The specific height should be adjusted according to geological conditions, pile type, and design requirements, usually determined by on-site technicians based on test pile results.

IV. Key Construction Requirements

1. Professional Team Operation: Pile driving for house subsidence should be carried out by a qualified construction team to ensure the verticality of the pile foundation, connection strength, and construction safety.
2. Applicable Scenarios: This method is suitable for houses with soft soil layers (such as silty soil) and severe subsidence, significantly improving the bearing capacity and stability of the foundation and reducing the risk of uneven subsidence.

Tip: Before construction, conduct a geological survey to clarify the soil layer distribution and bearing capacity characteristics, providing a basis for pile foundation design; after construction, conduct a bearing capacity test to ensure that the reinforcement effect meets regulatory requirements.