Pine piles are piling wood made of pine wood. They are mainly used to treat soft foundations, river embankments, etc. The raw material is pine. Pine wood is rich in rosin, and rosin can well prevent corrosion by groundwater and bacteria, causing "water logging" "Ten thousand years of pine" is said, so pine piles are suitable for working below the water table.

Pine wood is rich in rosin, and rosin has a good anti-corrosion effect. There is a saying that "water-soaked pine trees are ten thousand years old", so pine wood piles are suitable for working below the groundwater level. However, they are highly corrosive to groundwater or the groundwater level changes. In larger areas, pine stakes are not suitable.

According to the geological conditions of the construction site and the construction drawings, after the embankment is completed, the back of the embankment needs to be filled and compacted, and the other side of the embankment is the river bed. The river bed deposits thick silt and gravelly clay. If pine piles are used for gate foundation treatment, At this time, the pine piles are prone to horizontal displacement under the weight of the rubble embankment and the filling of soil, which affects the quality of the embankment; in addition, because the gate foundation is soft soil, its strength is very low and its compressibility is high, and the quality and specifications of the raw materials of the pine piles are difficult. Consistent, the penetration degree is difficult to control when piling, and cracks appear when the river embankment bears a large self-weight load;

Silt or silt soil has a high water content, low permeability coefficient and undrained shear strength. When a large number of pine piles are driven intensively, the pore water in the saturated soil has not had time to be discharged, and the pore volume does not change. All pressure The increment is completely borne by pore water, and the pressure between the particles of the gate foundation soil has not changed. Not only has the shear strength of the gate foundation soil not increased, it may also decrease due to construction disturbance. In addition, due to the , the silt between the piles does not need to be cleaned. When the disturbed silt is re-consolidated, the load of the retaining wall may be directly carried by the pine piles.

Pine wood piles are made of "logs" and should not be sawed into other shapes, especially not cut in half to form a semicircle. Semicircular piles will quickly become strongly bent and lose their effectiveness.

Don't promote "pine piles" as "cedar piles" or other piles. Most common woods are resistant to water and will quickly turn black, deformed and rotten in water. This is especially true for fir wood, which must not be used. Of course, there are also some Wood can also be "soaked in water for thousands of years", such as mahogany.

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

It is necessary to consider the impact force of pile sinking that pine piles can withstand. The impact force of pile sinking is within 300kg.m; no matter how large it is, even logs with a tail diameter of 400px cannot withstand it.

The horizontal resistance of foundation soil in silt areas is very small, and the upper ends of pine pile groups are prone to overall horizontal displacement, causing damage to ground facilities. Therefore, even if the need for earthquake horizontal loads is not considered, most of the time a stone layer is laid between the pine piles to raise the piles as high as possible. The horizontal stiffness of the group. The stone layer can only be laid manually, and the pine piles should be squeezed as tightly as possible one by one.