Today there is a joint venture for foundations for equipment. SP is a set of rules, whose number is 26.13330.2012. These rules establish all the necessary requirements that apply not only to the practical part of the foundation pouring, but also to the design 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 foundation will be exposed to aggressive environments, dynamic loads that will be created by industrial equipment, etc.
The foundation must comply with the following requirements:
- high strength threshold to withstand both static and dynamic loads that the device will create;
- the presence of such a property as inertness or, in other words, resistance to chemicals is necessary;
- the foundation for the equipment must have a huge mass so that it can absorb the vibration that the included mechanism will create;
- deviations from the planned sizes should be minimal, that is, the actual sizes should almost completely correspond to the calculated indicators;
- the area of the support should be larger than that of the apparatus installed on the base.
It is worth noting that strength and chemical resistance are those properties that directly affect the life of the foundation. Those substances that negatively affect the foundation are:
- lubricants;
- liquids for cooling devices;
- technical oils;
- fuel of various kinds.
Description of parameters
In addition to the two main properties, it is very important that the foundation for the equipment can successfully absorb 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 life of the unit. In some cases, this will adversely affect even neighboring devices. Vibrations per se arise due to the fact that unevenly spaced rotating parts constantly work in industrial machines.
As for coincidences with the project and the calculations, it is important to note here that in addition to the standard heights, lengths and widths, even the location of the equipment mounts must coincide. Only the smallest discrepancies between the design and the actual design are allowed.
Here we can add that the foundation device for equipment that weighs up to 2 tons and is considered small-sized, is not always necessary. If such a device, in addition to light weight, does not cause strong dynamic loads during operation, it can be mounted directly on a reinforced concrete floor. In some cases, you can install it on the floor.
Settlement Regulations
Above, the basic requirements that any foundation designed to install industrial equipment on it should be met. However, there are other requirements - for the foundation for equipment with dynamic loads, which it must meet.
- Design work, as well as the practical part on the arrangement of the foundation, should be carried out only by competent specialists who, in addition, have experience in carrying out this type of work.
- In order to create a correct and complete project, it is necessary that all the required data is available.
- During the installation of the foundation for the equipment, it is necessary to periodically conduct quality control.
- It is very important that the actions of all participants in the work process are strictly coordinated.
- 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.
- For construction, you can use only those materials that are suitable for design documentation.
- In the future, it is necessary to carry out maintenance of the foundation so that the structure is operated as long as possible.
- As fasteners, it is recommended to use the most simple parts. For example, it can be anchor bolts that are embedded in concrete.
Different types of units
When arranging the foundation for equipment, it is necessary 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 foundation according to its own rules and with different requirements.
Currently, there are the following types of groups for which you need to build a separate foundation.
- Units that have a crank mechanism. These include piston compressors, sawmills and more.
- A separate group are turbine units, for example, turbochargers.
- Some electrical equipment, such as motor generators, also need a base.
- A foundation is being set up for industrial equipment of a rolling type.
- A separate group are metal cutting machines and presses for various purposes.
Types of grounds
Next, various types of substrates that are used for the installation of various equipment will be presented:
- The simplest option is a foundation slab without a basement. There is a restriction, which consists in the fact that such a foundation can only be installed on the ground floor. In addition, the plate is quite expensive, since you have to spend a significant amount of money on building materials. However, there is a good advantage, which is that the foundation perfectly dampens vibration.
- The second option is a frame base, which is equipped with a beam of beams. This base is characterized by the fact that it is able to tolerate vibrations with high frequency. For this reason, it is very often used for mounting mechanisms in which the shock principle of action is observed.
- 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 transmitted by external walls, as well as partitions.
- The last kind of foundation for dynamic equipment is a foundation-ceiling with a basement. Such a foundation can only be equipped above the first floor. All the vibrations that the equipment will create, in this case, will be transmitted to the ceilings, that is, the ceilings of the frame. The foundation itself is able to withstand only minor fluctuations.
Today, bases that have springs or other type of vibration mounts are becoming quite popular. They are often used to install light and medium-sized mechanisms in weight. There is such a device as a damper, which is designed to damp vibrations. It is best suited for installation under the base frame type. It is worth noting that the foundation for technological equipment is divided into two types.
The first type is a baseless foundation. He has almost completely no part, which is located above the floor. The second type is the basement, in which this part is developed quite strongly.
Foundations of group and individual type
To date, the foundations for the installation of equipment can be individual or group.
As for the group view, this foundation is designed to accommodate several industrial units of light or medium weight - up to 8 tons. Moreover, they should have a rigid bed, normal accuracy, and they should be operated mainly in static mode. The thickness is usually from 150 to 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 the 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, usually such mechanisms are characterized by dynamic loads of medium or significant class. Such a base not only dampens vibrations successfully, but also isolates the aggregates from each other. This is important, since in this case there is no oscillation between them.
We can add that machines that have medium or light weight, and are also characterized by a static period of operation, are often mounted directly on a reinforced concrete floor or ceiling. If such a foundation is necessary, it can be further reinforced with a concrete screed so as not to flood 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 to get a good foundation. To ensure the result, the following consumables are used:
- 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 high-quality cement for the basement and basement foundation. If light units will be installed, then you can use the brand M200 or M300. If you plan to install a heavy industrial unit, you must use the M400 brand. 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 feedstock. Rarely, but still sometimes found a foundation of a brick type. That is, bricks are laid on a cement base. It is very important that the groundwater is deep enough. Most often, this basis is used only for those machines whose mass does not exceed 4 tons. The thickness of the foundation is usually at least 50 cm. It is important to add that in this case, the use of silicate brick is excluded.
In the past, light cars were often installed on a wooden floor, but now this is practically impossible. The main disadvantage is that the tree is warped too much, and very quickly, because of which the shape of the base changes. A wooden floor can be used, but only as a temporary basis.
As for the attachment of equipment to the base, in this case, the bolted connection that is prescribed in the joint venture is always used. It should only be noted that if the unit is characterized by high shock loads or strong vibrations during operation, then at least 42 mm bolts and a removable type are used. It is also very important that the distance from the lower end of the bolt to the bottom 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 following factors are the initial data for design work:
- soil characteristics, for example, freezing depth, groundwater location, structure, etc .;
- static load;
- vibration force or dynamic load;
- reference area of the bed of the equipment itself;
- An important role is played by the temperature regime at which the base will be operated.
Another 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 conduct a hydrogeological engineering study of the soil to find out its characteristics. If the soil is considered loose, then the foundation should be more massive.
Settlement work
The calculation of the foundation for the equipment is the next stage of its construction. The basis of the calculations in this case will be two factors. The first of them is the bearing capacity of the soil, and the second is the static and dynamic load that the mounted device will have. In this case, it is necessary to calculate everything so that the sum of the static and dynamic loads that will be transmitted through the base of the foundation to the ground 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 mass of equipment. As for the dynamic load calculations, it is calculated by the pressure that affects the foundation grill. It should be noted that the pressure that occurs due to the mass of the machine must be adjusted using the following factors:
- constant working conditions, which starts from 0.5 for a forging hammer and amounts to 1.0 for a screw-cutting lathe;
- constant soil sediment from 0.7 to 1.0, which varies depending on soil moisture.
Knowing all three necessary components, it is not difficult to carry out all the required calculations in order to obtain the exact characteristics necessary for the foundation of a particular machine.
Foundation reinforcement for equipment
In order to qualitatively and correctly conduct the reinforcement of the foundation, it is necessary to know several basic points:
- To achieve maximum strength from reinforcement, it is necessary to fix the rods in the "cell".
- In this case, it is recommended not to use welding to connect the rods, but to fasten them with a wire. Thus, the number of joints and more fragile joints can be reduced.
- It is possible to make the structure even more durable if reinforcement is bent at the corners of the structure. In addition, the connection itself is best done with an overlap.
It is also worth noting that the reinforcement of the foundation of a different type is carried out by different methods. The most laborious is the process of reinforcing the strip foundation. It requires the most costs and building materials. It is possible to reinforce the slab foundation. However, this process is quite complex, and also requires highly qualified specialist. In addition, it is recommended to have experience in such work.