Foundation is the fundamental part of a building or structure. The durability and quality of absolutely any building will depend on it. It is necessary to correctly calculate the volume of earthworks so that there are no problems in the future. Usually this is done by people who have received the necessary knowledge in colleges or universities, who have a specialized diploma and experience. But anyone wondering how to calculate the amount of earthwork can figure it out.
What you need to count
To correctly calculate the volume of earthworks, you need to have:
- Foundation drawing.
- Formulas.
What type of excavation is needed for different types of foundations
If you plan a tape monolithic or prefabricated foundation in a building with a large number of load-bearing walls,it is necessary to plan the digging of the pit.
If there are few load-bearing walls or they are located far from each other, a trench will do.
If the foundation is columnar, digging of special recesses is provided.
Pit
Only having a project drawing at hand, you can make all the calculations for digging pits.
This is due to the fact that there are many technological nuances of the final design. List of formulas you need to know to determine the volume of earthworks:
if the shape of the pit is rectangular with slopes:
OK=N/6 {AkBq+AkvBkv+(Ak+Akv)(Bq+Bkv)};
where, OK - an indicator of the volume of the pit, in meters;
Ak - width indicator along the bottom, in meters;
Bq - bottom length indicator, in meters;
Akv - width above, in meters;
Bkv - length indicator on top, in meters;
H - depth indicator, in meters.
if the shape is polygonal with slopes:
OK=N/6(F1+F2+4Fsr);
where, Ф1 - bottom area indicator, in square meters;
Ф2 - top area indicator, in square meters;
Fsr - an indicator of the cross-sectional area in the middle of the height, in square meters.
square:
OK=N/38(F1+F2+√F1F2).
Trench
To calculate the volume of earthworks when digging a trench, you must use the following formulas:
if the trench has vertical walls:
Neg=Atr(H1+H2)B/2;
where, Atr - width, in meters; H1 and H2 - depthssections.
or
Neg=(F1+F2)L/2;
where, F1 and F2 - cross-sectional areas; B is the distance between them.
sloping trench:
F1, 2=(Atr+M8H1, 2)H1, 2;
where M is the slope factor.
Parameters of various soils
For the development of pits and trenches, it is important to consider what kind of soil is being developed.
The ground can be rocky or non-rocky.
Rocks are called rocks that occur as a continuous massif. This type of soil is difficult to develop. It can only be mined by blasting, jackhammers and wedges.
Non-rocky ones are easier to develop, but there are also difficult types among them, for example, scrap clay. Soil composed of sandy and dusty particles is the easiest to develop.
What properties do soils have that dictate the complexity of the work:
- density;
- humidity;
- clutch.
When working with soil, its volume becomes larger. This is called "initial loosening". This happens because soil compaction occurs due to the influence of the weight of the layers of earth that lie above, as well as due to wetting by precipitation and the weight of vehicles moving through the area of the future development.
Counting volumes, it is necessary to draw up a statement of volumes of earth masses, which includes:
- soil of the planned area;
- displaced ground;
- excess during leavening;
- removable soil;
- fertile soil.
Calculating all these parameters,it is necessary to take a compaction correction of 0.02 and calculate the total amount of soil. With this data, it is already possible to calculate the volume of earthworks.
What else needs to be considered
Before earthworks, it is necessary to prepare the area where construction will be carried out. Preparation includes:
- fencing the future building area;
- site clearing;
- demolition of unnecessary buildings;
- rerouting of interfering engineering networks;
- Protection of the site from scouring by surface water;
- laying communications;
- arrangement of temporary structures: change houses, warehouses, administrative buildings (if this is the construction of some large object);
- installing a cast-off;
- carrying out geodetic works.
If you plan to buy a land plot and build a manor house on it, you should take a soil analysis to find out the type of soil. This procedure should be carried out before purchasing a site to make sure that there will be no problems during excavation.
Before calculating the volume of earthworks, it is necessary to calculate the width of the base of the foundation and the depth of soil freezing. Such calculations are made after the architectural part of the project is ready.
The sole of the foundation is laid 30 centimeters below the freezing depth of the soil.
In addition, it is worth strengthening the soil to avoid the collapse of the upper part of the slopes.
The best time for excavation is early autumn and summer. In these seasonsthe ground is soft and easy to dig.
When removing the surface layer, in addition to the area of the future pit, it is necessary to take into account the area of the blind area of the building being erected. To do this, you can simply add a meter to the width of the boundaries of the trench or pit.
The height of the fertile soil layer is approximately 30 centimeters. This parameter will vary individually depending on each plot allocated for development.
The waste soil should be taken out immediately, in the process of work, otherwise this land will take up a lot of space.
Digging with special mechanisms
If the building for which earthworks are being carried out has a basement or ground floor, then special earthmoving machines will not work.
What types of development exist:
- mechanical - soil is separated from the main mass by machines;
- hydromechanical - the soil is eroded or sucked in by a dredger;
- explosive - on the construction site, wells are drilled into which special explosives are laid; this method of excavation is practiced far from the city or in rocky soils.
Mechanisms:
- loosen the soil;
- develop;
- sleep off;
- transport;
- level the ground;
- compact;
- plan slopes and squares.
What machines are used in earthworks:
- bulldozers;
- single-bucket excavators;
- excavators continuousactions;
- loaders;
- bulldozer-loosening machines;
- trailed scrapers;
- self-propelled scrapers;
- trailed rollers.
Earthmoving mechanisms are needed to remove soil in layers, transport and unload into an embankment/dump.
Scrapers are used in hydraulic engineering construction.
Front shovel excavators are then needed to develop the soil and load the waste soil into the back of a car. The face should be located above the excavator parking lot, and the machine that is used to transport the waste soil should be higher.
Backhoes must be at the same level as the machine, and the face must be below their parking.
When connecting mechanisms to work, you need to check if there are power lines, underground utilities and groundwater in the territory of work.
The very choice of transport for such work depends on the parameters of the soil and work.
Manual work
You can dig the soil manually when the volume is small - the foundation is small in area and height. But, even if the work with the soil is carried out in a mechanized way, you have to manually clear the bottom. When working with an excavator, you need to leave a small amount of earth so as not to “get too much”, because if you scoop deeper than it should, it will be wrong to lay the soil back, because it tends to loosen.
Howearthworks in progress
Excavation sequence includes:
- Removing the surface layer.
- Removal of soil mass.
- Installation of the foundation.
- Backfill soil.
Did you have any difficulties in calculating the volume of earthworks?
