What should I do if the rings of the drain pit sink?

To strengthen the walls of the drain pit, standard factory-made reinforced concrete rings are used. During operation of the building, cases of subsidence of concrete rings sometimes occur. The design slowly goes underground, making the owners of the house nervous. This problem arises as a result of hydrological and physical-mechanical changes occurring in the lower layers of the soil, after which its bearing capacity is weakened. In addition, changes in soil properties can be caused by construction work in the immediate vicinity of the drain pit.

If the rings are not stapled together, a structural break may occur. At the same time, the lower elements sag, and the upper ones, tightly held by the soil on the sides, remain in their places. As a result, not only the tightness of the structure is violated, but the sewer pipe brought into the tank is also significantly deformed. What to do if the rings of the drain pit sink? What actions can be taken?

Determine the type of displacement - temporary or permanent?

The process of settling of reinforced concrete rings may be temporary. At the same time, the sagging walls of the structure freeze at a new level, leaning on a solid layer of soil, after which their movement is no longer observed. In this case, the structure is built up with an additional ring made to order, or the gap is laid with red brick.

The problem of continuous “drowning” of rings is much more complicated. In this case, more serious measures must be taken to stop this process. Establish the true cause of what is happening under the power of specialists. Often, it is not possible to completely eliminate the causes of subsidence of a structure; it is only possible to fix the existing position of concrete rings and suspend their further displacement.

Important! Often a drain pit settles down without a bottom. This is done intentionally in order to reduce the cost of pumping and disposing of liquid household waste. However, increasing the reference area of ​​the structure reduces the pressure of its structural elements on the ground. Therefore, professionals recommend using a finished ring with a bottom or pouring a concrete pillow before lowering the sewer rings into the pit. Remember that the concrete solution must be given at least a week to harden.

How to stop design subsidence?

• Before setting up a concrete bottom in an operating drain pit, it is necessary to pump out all waste and clean out all solid deposits.
• Then a layer of crushed stone is poured, the thickness of which can vary from 5 cm to 30 cm.
• After they perform bottom reinforcement with a mesh made of reinforcing bars, the diameter of which should be at least 10 mm. The pitch between the rods is 200 mm. To fix the reinforcement in the body of the concrete ring, holes are drilled with the same step at 2/3 of the wall thickness around the entire perimeter.
• Metal rods are inserted into the holes made, the ends of which are pre-painted to prevent corrosion.
• The rods are fixed to each other with a knitting wire.
• The reinforcing mesh is poured with concrete mortar.

Important! If you do not want to make a sealed bottom, then you can put a metal mesh on the rubble, inserted into a steel frame of two hoops. Through the locking pins inserted into the holes made in the wall of the ring, pressure is transferred to the shield mesh. Liquid waste seeps through the mesh cells and the crushed stone layer into the lower layers of the soil, undergoing natural filtration.

Structural layout of laying a fine-mesh mesh shield: A - Reinforced concrete ring; B - Crushed stone layer; B - metal mesh; D - Lock pins; D - The hole for the pin, sealed with cement mortar.

Important! For the manufacture of locking pins, you can take pipe cuts or metal rods, the diameter of which can be 8-12 mm. The length does not matter.

How to lock the bottom ring?

To lock the bottom ring, it is necessary to make four holes in the walls of the reinforced concrete product at a distance of 50-60 cm from the bottom surface. In these holes, pieces of thick-walled metal pipes are installed, the diameter of which should be at least 50 mm, and they are driven into the ground. The length of the pipes is equal to half the diameter of the ring or slightly less. This length facilitates the process of driving the pipe into the soil. Slots around clogged pipes are covered with cement-sand mortar. From the same solution, plugs are made into pipes to prevent runoff from entering the soil.

As an option, drive pipes into the ground - they will play the role of specific supports

How to close up the space between the rings after they break?

To reduce the likelihood of rupture of concrete rings, it is necessary to use special reinforced concrete products equipped with a “lock”. True, the price of such structures is more expensive than ordinary sewer rings.

Therefore, the connection of adjacent elements is carried out using metal brackets or steel plates bolted. The space formed between the rings after they break, it is better to lay brickwork. The surface of the resulting brick wall must be plastered by mixing a solution of one part of cement and three parts of sand for this.

The space between the concrete rings in the event of their rupture is laid with a brick

Important! While inside the drain pit, workers should be mindful of the safety precautions for such work.

Now you know what you can do if the rings of a drain hole located on a personal plot have subsided. Necessary work can be done independently with a partner or entrusted to a team of professionals to solve the problem.