Foundations for equipment: special requirements, types, design, calculation formulas and application features

2024 Author: Howard Calhoun | [email protected]. Last modified: 2023-12-17 10:16

Today, there is a joint venture for foundations for equipment. The joint venture is a set of rules, the number of which is 26.13330.2012. These rules establish all the necessary requirements that relate not only to the practical part of pouring the foundation, but also to the calculation part and design.

Foundation Requirements

The foundation for the equipment must meet certain requirements so that it can be successfully operated. It is very important to comply with them, since usually the base will be exposed to aggressive environments, dynamic loads that industrial equipment will create, etc.

The foundation must meet the following requirements:

• high threshold of strength to withstand both static and dynamic loads that the device will create;
• must have a property such as inertness or, in other words, resistance to chemicals;
• the foundation for the equipment must have a hugemass so that it can dampen the vibration that the included mechanism will create;
• deviations from the planned dimensions should be minimal, that is, the actual dimensions should almost completely correspond to the calculated indicators;
• The footprint must be larger than the base unit.

It is worth noting that strength and chemical resistance are the properties on which the service life of the foundation directly depends. Those substances that negatively affect the foundation are:

• lubricants;
• liquids for cooling devices;
• technical oils;
• fuel of various kinds.

Description of parameters

Besides the two main properties, it is very important that the foundation for the equipment can successfully dampen the vibrations that the working mechanism creates. This is a very important function, since if vibrations constantly affect the base and the unit, this will reduce the service life. In some cases, this will even negatively affect neighboring devices. Vibrations themselves arise from the fact that unevenly spaced rotating parts are constantly working in industrial machines.

As for the coincidence with the project and calculations, it is important to note here that in addition to the standard height, length and width, even the locations of the equipment mounts must match. Only the most minimal discrepancies between the project and the actual design are allowed.

Here it can be added that a foundation for equipment that weighs up to 2 tons and is considered small-sized is not always necessary. If such a device, in addition to its low weight, also does not cause strong dynamic loads during operation, then it can be mounted directly on a reinforced concrete floor. In some cases, you can install it on the floor.

Regulations for Arrangement

Above were considered the basic requirements that any foundation must meet, designed to install industrial equipment on it. However, there are other requirements - for the foundation for equipment with dynamic loads, which it must meet.

1. Design work, as well as the practical part of arranging the foundation, should be carried out only by competent specialists who, in addition, also have experience in this type of work.
2. In order to create a correct and complete project, it is necessary that all the required data be available.
3. Quality control should be carried out periodically during the installation of the foundation for equipment.
4. It is very important that the actions of all participants in the workflow are strictly coordinated.
5. Those foundations that have already been erected should only be operated with the equipment for which they are intended. There is technical documentation for this.
6. For construction, you can use only those materials that are suitable for the designdocumentation.
7. In the future, it is necessary to carry out maintenance of the foundation so that the structure is used as long as possible.
8. It is recommended to use the simplest parts as fasteners. For example, these can be anchor bolts that are embedded in concrete.

Different types of aggregates

When building a foundation for equipment, you need to understand that at present there are a huge number of different machines that are combined into groups. For each group, it is necessary to create a base according to its own rules and with different requirements.

Currently, there are the following types of groups that require separate foundations.

1. Units that have a crank mechanism. This includes reciprocating compressors, sawmill frames, and more.
2. Turbo units, for example, turbochargers, are a separate group.
3. Some electrical equipment such as motor generators also need a base.
4. The foundation for rolling-type industrial equipment is being built.
5. Machines for cutting metal and presses for various purposes are a separate group.

Types of bases

Following will be presented different types of bases that are used for mounting various equipment:

1. The simplest option is a foundation slab without a basement. There is a limitation herelies in the fact that such a foundation can only be installed on the first floor. In addition, the stove turns out to be quite expensive, since you have to spend a significant amount of money on building materials. However, there is also a good advantage, which is that the foundation perfectly dampens vibrations.
2. The second option is a frame base, which is equipped with a grillage of beams. This base is characterized by the fact that it is able to tolerate high frequency vibrations well. For this reason, it is very often used for mounting mechanisms that have an impact principle of operation.
3. The third option is a stepped support. Such a foundation is being built only from the second floor. In this case, the load from the equipment will be transferred by external walls, as well as partitions.
4. The last type of foundation for dynamic equipment is a floor foundation with a basement. It is possible to equip such a foundation only above the first floor. All vibrations that the equipment will create, in this case, will be transmitted to the ceilings, that is, to the ceilings of the frame. The foundation itself can only withstand slight vibrations.

Today, bases that have springs or other types of vibration mounts are becoming quite popular. They are often used to install mechanisms that are light to medium in weight. There is such a device as a damper, which is designed to dampen vibrations. It is best suited forinstallation under frame-type bases. It should be noted that the foundation for technological equipment is divided into two types.

The first type is a basement-free foundation. It almost completely lacks the part that is located above the floor. The second type is the basement, in which this part is developed quite strongly.

Group and individual foundations

Today, the foundations for the installation of equipment can be individual and group.

As for the group type, this foundation is intended to accommodate several industrial units of light or medium weight - up to 8 tons. At the same time, they should have a rigid frame, normal accuracy of work, and they should be operated mainly in a static mode. The thickness is usually between 150 and 250 mm. A rigid bed is considered to be one in which the ratio of length to height is no more than 2 to 1.

As for the construction of a foundation for equipment of an individual type, in this case a mechanism is installed on the foundation, the mass of which allows it to be classified as medium or heavy class. In addition, such mechanisms are usually characterized by dynamic loads of a medium or significant class. Such a base not only successfully dampens vibrations, but also isolates the units from each other. This is important, because in this case there is no oscillation between them.

It can be added that machines that are of medium or light weight, and also characterized by a static period of work, are often mounted directly on a reinforced concrete floor oroverlap. If such a base is necessary, it can be further reinforced with a concrete screed so as not to pour a separate foundation.

What materials are used for construction

Since the foundation must be very strong, resistant to vibrations, as well as to chemicals, the consumables must be of high quality in order to get a good foundation. To ensure the result, use the following consumables:

• prefabricated reinforced concrete blocks, during construction they are bandaged with each other;
• reinforced concrete itself, which can be obtained by pouring a reinforcing cage in the formwork;
• you will need high-quality metal if you need to create pile structures with grillages in the form of a frame.

It is very important to use quality cement for basement and non-basement foundations. If light units are installed, then the M200 or M300 brand can be used. If you plan to install a heavy industrial unit, then you must use the M400 brand. The cement must belong to class B15.

It is worth noting that when arranging the foundation in a private workshop or in a home workshop, rubble stone can be used as a raw material. Rarely, but still sometimes there is a foundation of a brick type. That is, the bricks are laid on a cement base. Here it is very important that the groundwater is deep enough. Most often, such a basis is used only for those machines whose mass does not exceed 4tons. The thickness of the foundation is usually at least 50 cm. It is important to add that in this case the use of sand-lime brick is excluded.

It used to be quite common to put light cars on a wooden floor, but now it's almost out of the question. The main disadvantage is that the tree warps too much, and very quickly, due to which the shape of the base changes. A wooden floor can be used, but only as a temporary base.

As for fixing the equipment to the base, in this case, a bolted connection is always used, which is prescribed in the joint venture. It should only be noted that if the unit is characterized by high shock loads or strong vibrations during operation, then bolts of at least 42 mm are used, and of a removable type. It is also very important that the distance from the lower end of the bolt to the base of the foundation is at least 10 cm. Today, chemical anchoring has become popular.

Design

Designing foundations for equipment is the initial stage of all work. In this case, the initial data for design work are the following factors:

• characteristics of the soil, such as freezing depth, location of groundwater, structure, etc.;
• static load;
• vibration force or dynamic load;
• supporting area of the bed of the equipment itself;
• The temperature regime at which the base will be used plays an important role.

One morean important requirement that the designer must take into account is the impact of aggressive environments, as well as protective measures. Before starting construction, it is necessary to carry out a hydrogeological engineering study of the soil in order to find out its characteristics. If the soil is considered loose, then the foundation should be more massive.

Settlement work

Calculation of the foundation for equipment is the next stage of its construction. In this case, two factors will be the basis of calculations. The first of these is the bearing capacity of the soil, and the second is the static and dynamic load that the device to be mounted will exert. In this case, it is necessary to calculate everything so that the sum of the loads of the static and dynamic type, which will be transmitted through the sole of the foundation to the soil, is equal to the bearing capacity of the soil.

When calculating the foundation for equipment, it is important to calculate the static load. It depends on the weight of the equipment. As for the calculations of the dynamic load, it is calculated from the pressure that acts on the foundation grillage. It is worth noting that the pressure that occurs due to the mass of the machine must be corrected using the following coefficients:

• constant working conditions, which starts from 0.5 for a blacksmith hammer and is up to 1.0 for a screw-cutting lathe;
• constant ground settlement from 0.7 to 1.0, which varies with soil moisture.

Knowing all three necessary components, it is not difficult to carry out all the required calculations in order to obtain accuratecharacteristics required for the base of a particular machine.

Reinforcing the foundation for equipment

In order to qualitatively and correctly reinforce the foundation, you need to know a few basic points:

1. To achieve maximum strength from reinforcement, it is necessary to fix the rods in the "cell".
2. In this case, it is recommended not to use welding to connect the rods, but to fasten them with wire. In this way, the number of seams and more fragile joints can be reduced.
3. You can make the structure even more durable by bending reinforcement at the corners of the structure. In addition, the connection itself is best done with an overlap.

It is also worth noting that different types of foundation reinforcement are produced by different methods. The most time-consuming is the process of reinforcing the strip foundation. It requires the most costs and building materials. It is possible to carry out reinforcement of the slab foundation. However, this process is quite complicated, and also requires a highly qualified specialist. In addition, it is recommended to have experience in such work.