In the field of pile foundation construction, the application of two innovative technologies is significantly improving the vertical bearing capacity and pullout resistance of single pile. Among them, by increasing the area of the pile end, the end bearing capacity of the pile is effectively improved. This method has been widely used in Japan, 95% of the pile holes are used to expand the bottom pile, not only saving 50% of the concrete usage, but also significantly improving the construction efficiency.

At the same time, as an innovative technology, the post-grouting method is gradually becoming the mainstream technology in pile foundation construction. By injecting cement grout, the hidden danger of the bottom of the pile is eliminated, the compactness of the pile and the soil around the pile is enhanced, and the bearing capacity of the single pile is significantly improved, and the increase range is up to 30 ~ 90%.

The effect of the post-grouting method is remarkable, and the cement slurry is combined with the sediment at the bottom of the pile to form concrete, eliminating the influence of the sediment on the bearing capacity of the pile bottom. At the same time, the slurry also fills the "virtual tip" and "dry slag stone" of the pile tip, which improves the strength of the pile tip concrete. In addition, the strength of the soil at the bottom of the pile is significantly improved after the compaction and consolidation of the cement slurry, thus further improving the pile end bearing capacity of the bored pile.

After the pile hole is drilled, the grouting pipeline is preset when the steel cage is placed, and the grouting is carried out after the concrete of the pile body is solidified. Before grouting, the clean water test was carried out to ensure that the pipeline was unblocked, and then the grouting operation was carried out in the order of first pile side and then pile bottom, first group perfusion and then group grouting.

The application of these two innovative technologies not only improves the quality and efficiency of pile foundation construction, but also provides a strong guarantee for the safety and stability of construction projects. With the continuous promotion and application of technology, it is believed that the field of pile foundation construction will usher in a broader development prospect.