What Is a Foundation Wall?

The foundation wall is built below the ground and acts as a load transfer between the ground building and the foundation. The foundation wall generally refers to the wall above the foundation and below the elevation of the indoor floor as the foundation wall, which is the transition and connection between the house wall and the foundation. Generally, it is constructed with rough stone, brick or plain concrete. ^[1]

The foundation wall is the basement wall of the house. The basement space structure composed of the basement and the basement roof actually plays the foundation role of the above-ground part of the house. This space box structure not only bears all the vertical and horizontal loads of the house, and evenly transmits these loads to the foundation, but also serves as a reliable foundation for the rigid wall to ensure the safety and stability of the entire house. Therefore, sufficient attention should be paid to the design of the basement wall.

The basement wall is divided into exterior and interior walls, and the basement outdoor wall is a closed wall with a box foundation. In order to ensure that the external wall can interact with the load-bearing structure of the house without being disengaged from each other, the wall body should be designed with the foundation inserted in the structure, and necessary anchorage should be provided in the support area. This treatment is very beneficial to the structural scheme of the entire house (including the basement) built on the slab foundation, which can increase the support points for the foundation slab that bears the reaction force of the foundation and improve the stress conditions of the slab. The static effect of this kind of external wall is equivalent to a wall beam of limited height, and it also acts as a tie rod around the outer edge of the house. For this reason, the influence of the main tensile stress in the corresponding section needs to be considered when designing the wall, so that the wall thickness is adapted to it. In order to avoid weakening the overall rigidity of the basement box structure, the number and size of openings on the outer wall must be limited. It is best not to provide door holes in the two side spans at both ends of the house. If window holes are opened, the hole span must not exceed three One-half, and the entrance of the cave must have a lintel (beam section height should be about 60 cm after taking into account the floor thickness). The thickness of the wall is generally designed as an external wall in the range of 15 cm (for houses with less than 16 storeys with strip foundations) to 40 cm (for houses with less than 30 storeys with plate foundations), The concrete designation should be consistent with all basement load-bearing walls. ^[2]

After the axis and the foundation edge are ejected on the cushion, the foundation wall (the wall below ± 0.000) can be built. The height of the foundation wall is controlled by the base leather number. The basic leather pole is a wooden pole, which is marked with a height of ± 0.000, and the thickness of each leather brick and gray seam is drawn according to the design size, as well as the position of the moisture-proof layer and the elevation position where a hole is required to be reserved. When erecting a number of poles, a wooden pile is driven at the pole first, and the level is leveled according to the method of measuring the known elevation, and a horizontal line higher than a certain value (such as 0.1m) of the cushion is copied on the side of the pile. Then, align a line on the leather pole with the same height as the horizontal line on the stake and nail the leather pole with the stake with a large iron nail as the basis for controlling the elevation when laying the wall.

When the foundation wall is covered with bricks to the level of ± 0.000, the elevation of the moisture-proof layer shall be measured, and the allowable error is ± 5mm. Some moisture-proof layer is a layer of waterproof mortar on the foundation wall, also used as a smoothing layer before the wall is built. In order to make the elevation of the top of the moisture-proof layer consistent with the design elevation, a waterproof mortar gray pier can be made on the foundation wall about 10m away and at the corners. According to the method of measuring the known height, the level of the gray pier is leveled to make the upper surface of the gray pier The elevation is equal to the design elevation of the moisture-proof layer. Then, the construction staff will level the plaster of the moisture-proof layer according to the elevation of the gray pier. ^[3]

Able to bear the vertical load of the building;

It should be able to maintain (or support) horizontal earth pressure and water pressure in some places;

When used as a basement foundation wall, it must be able to prevent water from penetrating into the basement. ^[4]

All ordinary masonry materials, including stone, brick and concrete blocks, have been used as the foundation wall material. In the early part of this century, some areas of the Midwest have already used concrete to build such walls, and now concrete walls are increasing in other areas. In 1920 and 1930, the common foundation wall material was a hollow, fired clay block, which was particularly suitable for the construction of basement walls, not only because it had considerable ductility, but also because it had more properties Better insulation performance. Second only to this clay block (except for the Arctic region) is a bulky wooden block commonly used. This type of block wall is made of insect-resistant and anti-corrosive wooden blocks. In dry, cold climates, wood blocks may be the best material available today because of its good thermal insulation properties. ^[4]