Construction of retaining walls: an overview of the types of structures and materials
Arrangement of land in complex terrain requires the construction of reinforcing structures. They will help to break the garden on the slopes, prevent soil collapse near the building and become a decorative ornament of the yard. Using retaining walls in landscape design, you can turn steep slopes into a landscaped system of terraces. The site is divided into zones with straight steps in the form of steps. Different materials are used for the construction of the structure, but in order for them to do their job 100%, it is necessary to follow precise calculations and a number of rules that we will talk about today.
Types and purpose of retaining walls
Retaining structures are divided into two types according to their functionality:
- decorative walls serve as the architectural decoration of the courtyard, being an element of landscape design. They are installed on flat or with a small bias of land;
- fortifications used in the improvement of terraces on natural slopes. The decorative functions of the facilities go by the wayside. Their main task is to keep the ground of steep slopes, increasing the useful area for planting trees and plants.
The practice of land planning shows that the mandatory construction of walls is required on a slope of more than 8%. Especially important is the construction in areas located near ravines and reservoirs. They will strengthen the slopes, preventing the ground from slipping from rain and melt water.
The main elements of the supporting structures
Decorative and fortifying walls differ from each other. Each of them plays a role, but they all have three main components:
- underground foundation of the wall - the foundation. It is to him that all the gravity of the pressure of the soil falls;
- ground structure - the body of the wall. The inner surface is in contact with the ground around the perimeter of the enclosed hill. The flat or oblique face of the wall serves as a decorative decoration for the landscape;
- protective structures - drainage and drainage. Communications contribute to the removal of moisture from the soil.Their presence is necessary, since the accumulation of water behind the inner surface of the wall can destroy it.
Factors affecting the stability of the structure
It is better to trust the construction of the wall to specialists, since it is a complex engineering structure. Having building skills, you can independently build a structure, the main thing to consider are the main factors affecting it:
- the installation should be done on a stable ground: sandy loam, clay, crushed stone and other;
- structural stability depends on the level of soil freezing, which should be no more than 150 cm from the ground;
- the minimum occurrence of groundwater should be at a depth of 1 m. The best indicator of water occurrence is 1.5 m;
- the ground part of a self-built wall should not exceed 1.4 m. Higher structures should be equipped by professionals, since complex calculations are required.
Increase wall resilience
When designing a retaining wall, it is necessary not only to pay attention to strength, but also to provide resistance to tipping or shifting from standstill. Achieve such indicators by the following activities:
- the inner side of the wall is constructed with an inclination towards the embankment of the earth to reduce pressure on it
- uneven edges of the inner side of the wall also reduce the pressure of the soil. It is possible to line up such edges in a concrete or reinforced concrete structure at the filling stage. To do this, the wooden formwork of each layer poured with concrete is shifted by 10 cm relative to each other. After concrete hardens, small chips are made on it. Masonry brick or stone walls perform with protrusions;
- necessarily equip the drainage;
- the console built on the outside of the wall will provide stability. This design has the form of a protrusion from the foundation;
- the lateral pressure of the wall is influenced by the specific weight of the filling soil. To reduce the pressure will help hollow granules zasypnogo insulation of polystyrene foam. They are added to the soil when filling the inner side of the wall;
- reduce the pressure installed to the inner side of the wall insulation boards. They are made of furniture filler or material for loosening the land used in agriculture;
- good result gives unloading platform.It is built in the central part of the wall from the inside. This protrusion uses the vertical forces of the soil above it, directing them to work, which increases the stability of the structure.
Retaining wall with unloading platform. 1-wall, 2-discharge area
Underground part - foundation
A wall more than 30 cm high requires the mandatory construction of the foundation. The higher the index of softness and instability of the soil, the deeper the foundation should be laid. The optimal proportions of the base depth and the height of the ground part, depending on the soil, look like this:
- the depth of the base in relation to the height of the above-ground part of the wall on solid soil is 1/4;
- for soil of medium friability - 1/3;
- the index on loose and soft soil is 1/2.
The base is filled with clay or cement mortar. As additives used crushed stone, gravel, pieces of concrete.
Drainage and waterproofing
To extend the life of the structure, you need to take care of waterproofing and drainage of water. Waterproofing make bituminous mastic, covering the inner side of the wall. For reliability, you can fix several layers of roofing material.Next, proceed to the construction of drainage. There are three types of them:
- transverse view consists of holes with a diameter of 10 cm left in the construction of the wall in every second or third row of masonry. It is also possible to punch holes in the finished wall, after which they are inserted into pieces of pipe. Through holes made under the slope of the water will flow out of the site;
- the design of the longitudinal drainage system consists of a perforated pipe with a diameter of 10–15 cm laid under the ground. From above the pipe is wrapped with geotextile tape. Flowing through geotextiles, water enters the pipe through the holes and is discharged into the drainage well;
- combined drainage consists of a transverse and longitudinal view.
To prevent the destruction of water above-ground part of the wall, on top of a slope or eave block is installed under a slope.
After arranging communications, they start filling the gap between the supporting wall and the slope. Backfilling is done in layers, ramming each of them. Construction waste of brick, stone, coarse sand, and gravel are well suited for the first layers.The top layer is covered with vegetable soil. To build strength gained, it is left without a load for a couple of weeks. Only then can begin to plant terraces planting vegetation.
The retaining wall of brick is not simple in construction, but it cannot be called complex. Masonry perform as in normal construction, only a smaller thickness. The wall height of 50-80 cm spread in half-brick. The construction of a height of 1 m is built in brick. Large walls with a height of more than 1 m lay out 1.5 bricks. The main rule of a brick wall is to observe the ratio of length to thickness 1/3. If the wall is not built from decorative brick, its front side is decorated with facing material.
The construction of stone buildings is carried out in two ways:
- dry laying of a stone implies its binding with garden soil. Such stitches are planted with ornamental plants;
- masonry cement mortar is more durable.