During or after drilling, varying degrees of borehole wall collapse, continuous air bubbles in the discharged mud, or a sudden drop in the water level inside the casing are all signs of borehole collapse.#spiral drill rig#
Analysis of the causes of borehole wall collapse in rotary drilling piles:
1. Loose soil, poor casing installation, and low water level inside the casing.
2. Inadequate mud wall protection.
3. Deformation of the reinforcing cage or rubbing against the borehole wall during installation, causing thinning of the mud wall protection.
4. Excessive waiting time or excessive grouting time after drilling can easily lead to collapse of the lower part of the borehole.
Prevention measures:
1. In loose and easily collapsible strata, appropriately bury the casing at the required depth, compact the backfill soil, and pay attention to replenishing the mud to maintain the required level.
2. Use high-quality mud to increase its specific gravity and viscosity.
3. Ensure the quality of the reinforcing cage fabrication and prevent deformation. During installation, align the hole with the specified position, hoist it upright and stabilize it, and lower it slowly to prevent collision with the hole wall.
4. After hole formation, the waiting time for grouting should generally not exceed 3 hours, and the grouting speed should be accelerated as much as possible to shorten the grouting time.
Treatment methods for pile hole collapse:
1. If the reinforcing cage has not been lowered into the hole, backfill the hole with a mixture of sand and clay to a position 1-2 meters above the collapse site and re-drill the hole, or backfill the entire hole and compact it before cleaning the hole with the original drill bit and high-quality mud.
2. If the reinforcing cage hits the hole wall and causes a slight collapse, use a drill bit with a diameter smaller than the inner diameter of the reinforcing cage to clean the hole with high-quality mud or use a guide pipe to clean the hole.#spiral drill rig#
Shandong Liqiang Machinery is committed to the production and sales of small rotary drilling rigs, crawler pile drivers, long spiral drilling rigs, diesel hammer pile drivers, and excavator-modified rotary drilling rigs. Adhering to the philosophy of pragmatism, progress, and innovation, the company has been working hard in the small rotary drilling rig market for more than 10 years, and the quality of its products has won widespread praise from customers. #spiral drill rig#
