Pine wood is rich in rosin, and rosin can well prevent groundwater and bacteria from corroding it. There is a saying that "water-soaked pine trees are ten thousand years old". Therefore, pine wood piles are suitable for river slope protection projects below the groundwater level. But for groundwater In areas where the water level changes greatly or the groundwater is highly corrosive, pine piles should not be used.

The soft soil foundation reinforced with pine piles is a composite foundation. The composite foundation is composed of natural foundation soil and pile body. Compared with other composite foundations, the pine pile composite foundation is similar except for the different materials of the piles. , its reinforcement mechanism: First, the supporting role of the pile body: the pine pile composite foundation uses pine piles to replace the low modulus, low strength soil with the same volume as the pile body. When receiving external loads, the stress in the foundation is based on the stress of the pile soil. The ratio is redistributed. The stress gradually concentrates towards the pile body, and the stress received by the soil around the pile is reduced accordingly. Most of the load is accepted by the pine pile. Because the strength and deformation resistance of the pile are better than those of the soil, the composite foundation formed The bearing capacity and modulus are also better than those of the original soil, thus achieving the effect of reducing deformation and improving bearing capacity.

So some of the issues you need to pay attention to when using pine piles are as follows:

1. Pine wood piles are made of "logs" and should not be sawed into other shapes, especially not cut in half to form a semi-circle. Semi-circular piles will quickly bend strongly and lose their effectiveness.

2. The planning method of pine pile composite foundation is similar to that of ordinary composite foundation, except that the pile center distance is often very small.

3. It is necessary to consider the pile-driving impact force that pine wood piles can withstand. The pile-driving impact energy is within 300kg\/m; if it is larger, even a log with a tail diameter of 16cm cannot withstand it.

4. The horizontal resistance of the foundation soil in the silt area is very small, and the upper ends of the pine pile groups are prone to overall horizontal displacement, causing damage to the above-ground equipment. Therefore, even if the earthquake horizontal load requirements are not considered, most of the time a stone layer is laid between the pine piles, as much as possible. Increase the level of the pile group. The stone layer can only be laid manually, and the pine piles should be squeezed one by one as tightly as possible.