Bored foundation

Asbestos-free cement pipes with a diameter of 200 mm were selected as a shell and fixed formwork for a bored pile. According to the formula and data from reference sources. the bearing capacity of a pile is the construction of a soil uniformity coefficient (0.7) on the normal soil resistance under the lower end of the pile (this is a separate indicator for each type of soil) multiplied by the pile cross-sectional area (0.03 m2).

Plus the perimeter of the pile (0.63 m) multiplied by the conditional work coefficient (0, and multiply by the normal soil resistance on the lateral surface along the entire pile shaft (1,3). Substituting the data from the directories in the formula, we get: 0.7x1x (40x0.03 + 0.63x0.8x (0.3x2 + 0.7x1) = 1.34t. That is, one pile can withstand 1.34 tons of weight. at home by the amount of building material used and we multiply the result by 3 (furniture, household utensils, etc.), I got about 10,500 kg, dividing by the load-bearing capacity of one pile we get 16 bored piles for such a house is enough.

Speed ​​and ease of construction

Pretty big cost

You can do it yourself. And if the only way out is to hire a team of builders, then you need to carefully calculate how much to manage not only materials but also the construction process itself.

• For example, take our house 9x11m. whose walls are made of aerated concrete.
• A pipe with a diameter of 150 mm and a length of up to 2 m is taken as piles.
• A total of 36 bored piles are planned. The cost of one such pile is 3000 rubles. and the total cost is 10,800 rubles.
• Yamobur rental 12 thousand rubles per day;
• D300 sand-family mix worth 2.5 thousand rubles / 1 m3. total 13 m3 of concrete are needed;
• Excavation work for excavation under bored piles will amount to 800 lips / m3, with a volume of 10 m3 the total amount will amount to 8 thousand rubles

In total, the cost of installing a bored foundation will amount to 163.7 thousand rubles. Moreover, if the company is fully responsible for the construction of the foundation, from the purchase of raw materials to its use they take at least 250 thousand rubles ..

Average labor and financial costs;
Prompt execution

Performed on most civilized worlds

There was an idea to make a bathhouse a 3x3 meter log house. A base with another 3 meter outlet. A friend advised to make a permanent formwork from a pressureless asbestos-cement pipe with a diameter of 200 mm, wrapping it with roofing material on the outside. After my reasonable question, why not just pour concrete into the selected hole, and limit the last 50 cm with a pipe.The answer was that adhesion of the soil to a smooth asbestos pipe, also wrapped with roofing material, will significantly reduce the effect of heaving soils on the pile. Therefore, a depth of 1.5 m was chosen with a freezing level of 1.2 m.

As a reinforcing cage, a spatial lattice was chosen with 6 vertical rods of 8 m diameter and horizontal dressings at a distance of 60-70 cm. In principle, reinforcement of 4 10-12 mm or 3 12-25 mm of rods was allowed, but for a cylindrical shape, the load distribution to the external side more productive.

Relatively low cost with considerable strength
Average labor costs.

Not suitable for all types of soil.

When planning to build a small house for himself, 4x7 task became his choice on a pile foundation because construction was supposed to be on a relief terrain. And since the soils in the area are solid loam, strongly compacted with depth, I chose a type of bored foundation. Using a mobile drilling rig (motorized drill) he chose the ground from the pits of 600 mm in diameter and up to 2 and in depth. He poured gravel into the pit and rammed it.

He poured concrete with vertical reinforcement - 3 rods up to 10 mm in diameter. The height of the pillow was 20 cm. The formwork was made of roofing material based on the diameter of the pile 200 mm. Having installed the reinforcing cage, concrete was poured into the formwork and simultaneously poured sand between the roofing material and the pit wall so that the soft formwork would not be torn or distorted.

A reliable foundation that can be installed on problematic soils

Wasteful.