Treatment of weak soil by bamboo pile method

The use of foundation treatment technologies is practiced by a professional organization to rehabilitate weak ground after geological drilling. In the treatment methods of ownership use bamboo piles for reinforcement. Similarly, is it safe, and how do people do it? We advise to consult questions.

The benefits of bamboo piles for project foundation treatment

Function of bamboo piles

Bamboo piles, cajuput piles are the traditional way of technology to treat the foundation of small load works on weak ground. This is the secret of reinforcing weak or used earth. In folk are often used under the foundation of small load (foundations under the culvert, the foundation...). Bamboo stakes or piles are often used by the south. The pile length of 1.5 - 6m was built to strengthen the ground bearing the criterion of decreasing settlement and increasing load.

Do not place them on sandy soils because sandy soils do not retain water, usually only in clay with water. People play 16-25 piles / m2 because it is easy to divide (20-25 cm distance).

Bamboo pile is to reduce the hollow coefficient, increasing the density of the soil leading to higher load capacity of the soil. For bamboo not to rot, they can only be placed in wetlands. In dry land without water, the bamboo decomposes and then causes soil depletion.

How to calculate the bearing capacity of the pile: In the design, assume that after the foundation treatment reaches a density (through the coefficient of hollow) from which the load capacity of the ground is calculated. For nail design (can assume the bearing capacity of the ground after reinforcement). It is necessary to estimate the bearing strength and subsidence of the foundation of the pile by means of daily calculations.

Asked and the number of reinforced concrete floor with bamboo sticks secret, the result: adjacent houses are built and used but not see the crack. However, there is a small settlement (but will stabilize evenly at the foundation line). Only if the building owns a good number of floors and undergoes good loading. The use of loose materials (sand, stone) can only be used to improve the strength of making the soil compact by using bamboo poles.

When piling up to check the load capacity of the ground against the assumed load bearing capacity, there is no need to modify the design (in fact, some tests are tested but mainly based on experience. business).

Where is the use of bamboo poles?

Bamboo piles are used in wet, flooded areas. Assuming they work in moist soil, longevity will be high (used as the roof of the old days or the columns of the buildings, 50-60 years and longer: the ancients often choose bamboo in the mud, when it will be black but anti. get termites). For example, they work in wetlands, dry irregularities, broken piles, very fast bites or damage (thus damaging the foundation).

Bamboo piles are used to reinforce the ground for works with good transmission load or reinforced wall embankments.

Selection of bamboo piles

The number of piles per m2 is determined by the formula:

Poor soil has a density of> 0.80, bearing capacity r0 <0.5 kg / cm2 with 36 piles per square meter.

Weak density = 0,7 ÷ 0,8, load intensity suddenly r0 = 0,5 ÷ 0,7 kg / cm2 possesses 25 piles for 1m2.

Weak soil with densities of 0.55 ÷ 0.60, natural loading strength r0 = 0,7 ÷ 0,9 kg / cm2 with 16 piles for 1m2.

At 22tcn 262-2000, bamboo piles are 25 piles / 1m2, pile 16 piles / 1m2.

The length of each pile is 1.5 - 2.5 m. The pile length is longer than the design length of 20-30cm.

At the top of the pile (always taken to the base) is sawn perpendicular to the pile shaft and 50mm from the bamboo eye, the lower end is gradually reduced in the 200mm and 200mm range in the eye area to the pile head.

Bamboo piles must be over 2 years old, straight and fresh, minimum diameter of over 6cm (usually 80-100mm), without bending over 1cm / 1md pile. Using bamboo is the best. The thickness of the bamboo tube is not less than 10mm. If the bamboo is bare, the minimum thickness of bamboo tube is 10 - 15mm, so the distance in bamboo gut is as small as possible. The distance between bamboo eyes should not exceed 40cm.

Method of piling bamboo

Map down pile

For example, piles or reinforced concrete piles then proceed from the middle out. If it is a pile of strips or rows of piles, then close it sequentially. For piles, the hole is fixed in the pile to the edge of the hole to dig.

Treatment of pile foundation by machine

This secret is used today because of mobility, ease of transfer.

You can use the bucket to put up with the body. In some places, a line of concrete hammers have been improved by taking a lid to place bamboo poles. Each type of compressor uses a small capacity, compressive pressure of about 4-8atm, a compressor can be used simultaneously for 5-6 drivers. This method makes the work quick and difficult and can bind bamboo in the pit with less than 20cm of water.

Pile foot and hand

Use solid wood with a weight of 8-10kg / person or two to close. To avoid crushing the end of the pile. Once the piles are finished, they must be cut off, such as not being able to close the pile. In the case of weak ground, when the pile's hold is lifted, it must be lowered by vibration-laden load. This is a difficult task, it takes a lot of work and time.