Laboratory work 1. Determination of the value of the angle of renunciation and an angle of natural sloping of grainy lump

Purpose of work.Determine the magnitudes of the angle of natural slope and the angle of reninking of the grainy lump.

Theoretical States . The grain-lining material lying on the inclined plane (for example, on the inclined plane of the hopper, on the inclined belt conveyor, etc.), with a certain angle of inclination of this plane, it starts to be replaced by it. Such an extreme angle of inclination is called a replication angle.

Depending on the shape of pieces, you can observe two types of movement of lumpy material on the plane of the replication: sliding and rolling. Slide is observed with slices with developed flat faces; Moving pieces here prevents the friction of sliding between pieces of pieces and a replacement plane. Swinging is observed in the shape of pieces close to the ball. In this case, the movement of a piece is happening as rolling it, with rolling friction resistance.

The limit state of resting layer of lump material on the inclined plane takes place when the friction force F. equal to the projection M. Forces of gravity G. on this plane (Figure 1). On the other hand, the same friction force is proportional to the normal pressure of lump material on the inclined plane

F.= M.= fN.,

where did f \u003d m / n \u003d tgα

where f -the friction coefficient determined by the properties of the material itself equaltGA;

α – the viewing angle of the grainy lump.

Picture 1

If we consider the entire layer of a bulk material that moves along a smooth inclined plane, then here, even in the case of pieces of a spherical shape, a slip of the material on the plane is rather than rolling, since the entire material "flows" with a solid mass.

The viewing angle depends on the coefficient of the friction of the material on the plane of the renunciation, on the shape and size of pieces, from the surface structure, according to which the renunciation occurs (the surface may be smooth, rough, ribbed, etc.), as well as it humidity itself.

If you pour the grain-lousy material on the horizontal plane, then it is located on it as a cone. The angle between the forming of this cone and the horizontal plane is called the corner of the natural sloping of the grainy lining material.

The angle of natural slope is always larger than the area of \u200b\u200bthe replication (for the same material), since the presence of irregularities on the surface of the material prevents the rolling, and even more so slipping pieces. The angle of natural slope to a large extent depends on the fractional composition of the lump material, for the latter determines the overall structure of the cone surface. This heterogeneity of the size of pieces causes the preferential rolling of large pieces of material to the edge of the pile of pile, due to the fact that the surface irregularities have a smaller resistance to rolling largeslices than small (Figure 2). Uneven distribution of pieces for size must be considered when loading nozzle absorbers, mine furnaces, etc., as in the location of large pieces, i.e. on-peripherals, it turns out a greater cross-section of channels and gas will be predominantly on these channels having a smaller Hydraulic resistance.

Sufficiently crushed materials have a greater angle of natural slope, i.e. less flowable, due to the more developed friction surface.

Figure 2.

The angle of natural sloping significantly depends on the moisture content of the material, because water, located on the surface of pieces, causes an adhesion of them and thus makes it difficult to move the movement of individual pieces. The smaller the pieces of the material, the more the influence of humidity is manifested; But excessive moisturizing leads to an increase in the layer-by-layer fluid flow between the pieces of the material, and the angle of the natural slope decreases again (Table 1).

Table 1

Breed	Corner of natural slope, hail, for breed
dry	wet	wet
Sand large	30 – 35	32 – 40	25 – 27
Sand Middle	28 – 30
Sand small		30 – 35	15 – 20
Gravel	35 – 40

The angle of natural slope and the area of \u200b\u200bthe pivoting decrease sharply when the material and the plane moves on which it lies. When shocking or vibrations, the material is intensively crumpled, spreads, trying to take a horizontal position, since with vibrations in certain moments, mutual friction on the surface of contacting pieces with each other and pieces with a plane decreases. This is based on the use of vibrated vehicles, vibrators to facilitate unloading bins, dump trucks and metering devices.

Knowledge of corners of natural sloping and renovation is necessary when designing warehouses, conveyors, mining furnaces, where they deal with bulk materials. The inability to take into account theoretically of all factors determining the magnitude of these angles leads to the need to experimental determination.

Description of installation. To determine the angle of natural slope, a smooth horizontal plane is used with dividing in centimeters and a short metallic cylinder; To determine the angle of the replication, the device consisting of a shaft 1 to which the cord is confrontated, the bracket 2, through which the cord is connected to the lifting board 3, and the tilter 4 installed at the axis of rotation of the lifting board. The lifting board is equipped with a pointer shown on the angle of its lift (Figure 3). To collect the reputable mass, a box is supplied. The work also uses a ruler, scales and a rectangular metal frame.

Figure 3.

Conduct experience and write observations. When determining the angles of natural slope and the refline, the bulk material of two or three varieties of size is used.

A. Defining an angle of natural slope

1. Install a metal cylinder in the center of the horizontal plane,

2. To dial with a bulk material and pour it into the cylinder.

3. Slowly lift the cylinder, providing the material to crumble freely on the plane.

B. Definition of the angle of the replication

1. To put a rectangular metal frame on the lifting board and completely fall asleep with its bulk material.

2. Remove the rectangular frame and, slowly rotating the shaft, bring the lifting board to the inclined position.

3. When the material begins to reflect, stop the boards and record the angle of inclination. Transfer all the material from the lifting board and its stand on a sheet of paper, weigh the material, add a specific amount of water (specified by the teacher), mix and make the same definition with a wet material (steps A, 1 - 4 and B,

The results of the experiments add to Table 2.

table 2

Name of the material under study	The angle of natural slopes	Square angle
dry Material	wet material	Dry Material	Wet material
		tG α.				tG α.

Processing the results of experience. Using the ratio to determine the amounttG α. and on the tables to find the corresponding value α.

font-Size: 14.0PT; Font-Family: "Times New Roman\u003e where α is an angle of natural slopes, hail.;

H is the height of the pile of material, cm;

D - the diameter of the pile of material, cm;

font-Size: 14.0PT; Font-Family: "Times New Roman\u003e - radius of a full heap of material, cm,

1) Summary of the theory and purpose of work.

2) Installation scheme.

3) Table 2.

4) Conclusion for work.

Task for preparing for laboratory work .

1) Grinding solid materials and their classification.

2) Grinding, screaming and dosing of solid tel.

Control questions .

1) Explain the concept of "the angle of the repinction".

2) Types of movement of lump material on the plane of the replication.

3) Name the factors on which the magnitude of the reninking angle of the grain-lining material depends.

4) Explain the concept of the "corner of the natural sloping of the grain-piece material."

5) Name the factors on which the magnitude of the angle of natural slope depends.

6) Tell me what value is more - the angle of the repinction or an angle of natural slopes, explain why.

7) How is the magnitude of the angle of representation and an angle of natural slope when the material moves and the plane on which it lies?

8) How does the angle of natural slope depends on the humidity?

9) Thin or large grinding material has a greater angle of natural slop?

10) What is necessary to know the corners of the natural slope and the replication?

purpose of work:

Determine the angle of the natural slope of the test soil in laboratory conditions in a dry state and under water.

The essence of the method:

Corner of the natural slope of the sand - This is an extreme angle of free slugging of sand, in which the ground mass is in a steady state. This indicator is defined both in a dry state and under water.

The angle of the natural slope of the soil test is determined in the laboratory conditions to determine the angle of natural discovery, which is part of the Litvinova PLL-9 field laboratory.

The corner of the natural slope of sand in a dry state is equal to the corner of the inner friction of this sand

Equipment:

Instrument for determining the angle of natural slope;

Funnel;

A knife with a straight blade;

Measuring vessel.

Fig.5. Device for determining the corner of the natural slope of the sands

1- retractable sash;

2- Small compartment.

Determination of the corner of the natural slope of the sands in a dry state

Operating procedure:

3. Sand to dissolve with a knife.

4. After that, gradually raise the retractable sash, following the shocks; At the same time, the device hold the hand.

5. The sand is partially smashed into another compartment, until the position of a steady equilibrium occurs; The angle between the plane of the free slope and the horizontal plane is the angle of natural slope.

6. On divisions on the bottom and side wall count the height and locking of the slope and calculate the tangent of the angle of natural slop. The counts lead with an accuracy of 1 mm.

7. Tests are carried out twice.

8. The numerical value of the tangent of the corner of the natural slope is defined as the arithmetic average of the results of the two measurements.

9. The results of the definitions are recorded in Table 5.

Determination of the corner of the natural slope of the sands in the underwater state

Operating procedure:

1. The device is put on a table or a different horizontal surface. The retractable sash at the same time is lowered to the bottom.

2. In a small separation of the device, sand is poured by small portions through a floss to the clove with the edges.

3. Sand to dissolve with a knife.

4. After the small branch of the device is embarrassed in the small separation of the device, the ground is poured to the top water.

5. After that, the retractable sash raise a few millimeters so that water can penetrate into a small compartment.

6. When the soil is soaked with water, gradually raise the retractable sash, following the shocks; At the same time, the device hold the hand.

7. The sand is partially smashed into another compartment, until the position of a steady equilibrium occurs; The angle between the plane of the free slope and the horizontal plane is the angle of natural slope.

8. According to divisions on the bottom and side wall, they count the height and locking of the slope and calculate the tangent of the angle of natural slop. The counts lead with an accuracy of 1 mm.

9. Tests are carried out twice.

10. The numerical value of the tangent of the corner of the natural slope is defined as the arithmetic average of the results of the two measurements.

11. The results of the definitions are recorded in Table 5.

Table 5 The results of the definitions of the angle of natural slope.

Laboratory work number 6

Definition of the Filtration Coefficient of Sand Soil

Purpose of work:

Determine the filtering coefficient of the test sandy soil in laboratory conditions.

The essence of the method:

Filtration coefficient To F. - This is the numerical characteristic of the water permeability (soil ability to filter water). It is the filtration rate and is usually expressed in cm / s or m / day.

The filtration coefficient is determined on the soils of impaired addition at optimum humidity and the maximum standard density, the values \u200b\u200bof which are pre-determined in laboratory work No. 4.

The filtering coefficient is used when counting groundwater reserves, determining the flow of water into construction pitchers and mining, when calculating water leaks from reservoirs, designing drainage structures and filters, as well as in a number of other calculations.

In this laboratory work, the procedure for determining the filtering coefficient of sandy soils and construction sands used in construction was established.

Equipment:

Device of the Union of PKF-SD;

Scales with an accuracy of 0.01 g.;

Metal cups with a capacity of at least 5 l;

Cylinders are measured with a spacing capacity of 100 and 500 ml;

Vopatochka - trowel;

Metal line 30 cm long;

Stopwatch;

Thermometer;

Rubber pear.

Figure 6. General view of the devicePKF-CD to determine the filtering coefficient.

1- work cylinder; 2 piezometer; 3- perforated bottom;

10- anvil; 11-drummer; 12-hand.

The device consists of the following main parts: a filtration tube assembly, boot funnel, stand, a flexible device, glass, and bath.

The filtration tube assembly includes a working cylinder 1, on which a piezometer is placed 2. From the bottom to the cylinder, the perforated bottom 3 with the mesh 4. After the soil seal, the filtration tube is installed on the stand 6. The rubbing device consists of a guide rod 9, anvil 10, drumming 11 mass. 500 gr and handles 12.

To carry out experience in determining the filtering coefficient To F.with hydraulic gradient i \u003d 1,the filtration tube with the stand is placed in a glass 7. With a hydraulic gradient i \u003d 2.The filtration tube with the stand is placed directly in the bath 8.

Operating procedure:

Sample formation

1. Fall asleep the first hollow to the working cylinder, insert rubbing into it (the weight of the cargo 0.5kg, the height of the cargo drop is 0.3 m), carry out 40 shocks by sealing soil.

2. Measure using a ruler with an accuracy of 1 mm at three points distance from the surface of the compacted soil to the top of the cylinder. The results of measurements are recorded in Table 6.2 and determine the mean value.

3. Understand the surface of the compacted layer with a knife to a depth of 1-2mm. Fall asleep into the working cylinder the second sample, repeat the sample seal and measure the distance from the surface of the compacted soil to the top of the cylinder. The results of measurements are recorded in Table 6.2 and determine the mean value.

4. Fill to the working cylinder the third hitch, repeat the operations on the seal, the measurement. Record the results in Table 6.2 and determine the average value.

5. After completion of the soil seal operations, the working cylinder with a soil to weigh up to 1gr. Weighing results to put in Table 6.2.

6. On the surface of the compacted soil in the working cylinder, fill the gravel with a particle size of 2-5mm so that the thickness of the gravel layer was 5-10mm.

Sample saturation with water.

1. Filtering tube with a compacted soil Place a metal glass 7, the height of which corresponds to the top level of soil in the working cylinder. Fill this glass with water on 2/3 of the height and to withstand before carrying out the next operation within 15 minutes.

2. To transfer the glass with a filtration tube placed in a tank with water with a capacity of 8-10 liters and bring the water level in this tank to a height of 10-15 mm above the top edge of the glass.

3. To withstand the glass in the water tank until the water mirror appears above the gravel layer and secure the saturation time of the soil with water in Table 6.2.

Testing.

1. Carefully add water into the inner cavity of the filtration tube on 1/3 of its height and transfer the device together with a metal glass to the bath for measuring the duration of filtration, placing it in such a way that the zero marker of the water tube is located at the eye level.

2. To add water to the inner cavity of the filtration tube to a level greater than at least 0.5 cm zero marking of the water tube (each division on the water tube corresponds to 0.5 cm).

3. Check the water level in the metal glass and, if necessary, fill it with water up to top.

4. Install in a metal glass thermometer for measuring water temperature during testing.

5. To carry out the first measurement of the filtering duration in the stopwheel, turn on the latter at the moment when the water level in the water tube reaches zero division, and turn off when it is set at 5 cm, and to register the water temperature at the same time. The water level in the filtration tube during the testing process should not be released below the surface of the gravel layer.

6. In the event that the filtering duration exceeds 2 minutes, the second measurement is carried out when the water level falls to 2 cm. Otherwise, all the subsequent measurements are carried out when the level falls to 5 cm, in all cases registering the loss of water. The water level in the filtration tube during the testing process should not be released below the surface of the gravel layer.

7. In case the filtering duration of the previous point exceeds two minutes, all subsequent measurements are carried out when the water level drops to 1 cm. Otherwise, all subsequent measurements are carried out with a drop of level to 2 cm, in all cases registering the temperature of the water. The water level in the filtration tube during the testing process should not be released below the surface of the gravel layer.

8. In case the filtering duration by the previous paragraph exceeds 10 minutes, the pressure gradient during testing must be taken equal to 2. To do this, the filtration tube along with the stand must be removed from the metal glass and install it in the bath without a glass.

9. The results of each measurement and the temperature of the water registered in its process to be put in Table 6.2.

Processing results:

where k 10 is the filtering coefficient, M / day;

I - the height of the filtering layer of sand, defined as the difference between the total height of the filtration tube N O and the distance from the top end of the tube to the surface of the soil H 3, see

t M is the average filtering duration, sec;

T CP - water temperature, ˚С;

The value of the water level drop function determined by Table 6.1;

S is the drop in the water level in the water tube, see;

h O is the height of the initial pressure of water in the device from its bottom to zero division of the water tube, equal to 10 for a pressure gradient 1 or 20 for a pressure gradient 2.

2. Apply the obtained values \u200b\u200bin Table 6.2 with rounding results up to 0.1 m / day, if the filtration coefficient is less than 5m / day, and rounding results to integers if the filtering coefficient is more than 5m / day.

3. After calculations, compare the results obtained with the averaged values \u200b\u200bof the filtering coefficient of various types of soils:

Pynes pure ................................. more than 100 m / day;

Penette with sandy aggregate .. ......... 100-200 m / day;

Sands pure differentities ............... 50-2 m / day;

Sands clay, squeeze ......................... 2-0.1 m / day;

Suglinki .............................. ... ............ less than 0.1 m / day;

Clay ................................. ... ............ ..ee 0.01 m / day.

Table 6.1. The dependence of the size of the water level from the initial pressure.

S / H 0	φ (S / H 0)	S / H 0	φ (S / H 0)	S / H 0	φ (S / H 0)	S / H 0	φ (S / H 0)
0,01	0,010	0,26	0,301	0,51	0,713	0,76	1,427
0,02	0,020	0,27	0,315	0,52	0,734	0,77	1,470
0,03	0,030	0,28	0,329	0,53	0,755	0,78	1,514
0,04	0,040	0,29	0,346	0,54	0,777	0,79	1,561
0,05	0,051	0,3	0,357	0,55	0,799	0,8	1,609
0,06	0,062	0,31	0,371	0,56	0,821	0,81	1,661
0,07	0,073	0,32	0,385	0,57	0,844	0,82	1,715
0,08	0,083	0,33	0,400	0,58	0,863	0,83	1,771
0,09	0,094	0,34	0,416	0,59	0,892	0,84	1,838
0,1	0,105	0,35	0,431	0,6	0,916	0,85	1,897
0,11	0,117	0,36	0,446	0,61	0,941	0,86	1,966
0,12	0,128	0,37	0,462	0,62	0,957	0,87	2,040
0,13	0,139	0,38	0,478	0,63	0,994	0,88	2,120
0,14	0,151	0,39	0,494	0,64	1,022	0,89	2,207
0,15	0,163	0,4	0,510	0,65	1,050	0,9	2,303
0,16	0,174	0,41	0,527	0,66	1,079	0,91	2,408
0,17	0,186	0,42	0,545	0,67	1,109	0,92	2,526
0,18	0,196	0,43	0,562	0,68	1,139	0,93	2,659
0,19	0,210	0,44	0,580	0,69	1,172	0,94	2,813
0,2	0,223	0,45	0,593	0,7	1,204	0,95	2,996
0,21	0,236	0,46	0,616	0,71	1,238	0,96	3,219
0,22	0,248	0,47	0,635	0,72	1,273	0,97	3,507
0,23	0,261	0,48	0,654	0,73	1,309	0,98	3,912
0,24	0,274	0,49	0,673	0,74	1,347	0,99	4,605
0,25	0,288	0,5	0,693	0,75	1,386	-	-

Table 6.2. The results of determining the filtering coefficient.

op.

Soil humidity, w,%

Mass, gr.

The height of the filtration tube, see

Soil density, g / cm 3

Filtration time, sec.

Falling the water level in the tube, see

Water temperature, ˚С

Gradient head

Filtration coefficient, M / day.

Cylinder

Cylinder with soil

Soil

Initial, H 0.

Over a compacted sample of soil, H 3.

Wet

Dry

Separate measurement

Mean

Separate measurement

Mean

Measuring the filtering duration with the selected levels of water drops and the head gradient should be carried out at least 2 times, calculating the average value after that.

Laboratory work number 7.

The angle of the natural slope of the soil is the highest value of the angle, which forms the surface of the soil with a horizontal plane, dumplessly; Shocked and oscillations.
The angle of natural slope depends on the resistance of the soil shift. To establish this dependence, imagine the soil body dissected by the plane A - A, inclined to the horizon at an angle A (Fig. 22).

Part of the soil is higher than the plane of A - A, considered as a single array, can remain alone or to move under the action of P - own weight and the impact of the structures erected on it.
We decompose P into two forces: n \u003d p cos A, directed normally to the plane A - A and the force T \u003d P SIN A, parallel to the plane A - a. The force T seeks to move the cut-off part, which is held by the clutch and friction by the plane A - a.
In a state of marginal equilibrium, when the shift force is backed by the friction resistance and clutch, but when there is no shift yet, equality is performed 26, that is, T \u003d N TG F + CF.
In clay soils, the shift is mainly counteracting the clutch.

In the dry sand, the clutch is almost no and the state of the limit equilibrium is characterized by the ratio T \u003d N TG F. Substituting the values \u200b\u200bof N and T, we obtain p sin a \u003d p cos a Tg F or TG A \u003d TG F and A \u003d F, i.e., the angle A corresponds to the angle of internal friction of the soil f in the state of the maximum equilibrium of the solidness of the incoherent soil.
The definition of the corner of the natural slope of the sand is shown in Fig. 23. The angle of natural sand slope is determined twice - for the state of natural humidity and under water. To do this, in a glass rectangular vessel puffed sandy soil, as shown in Fig. 23, a. Then the vessel is tilted at an angle of at least 45 ° and carefully returned to the previous position (Fig. 23, b). Next, the angle and between the resulting sloping sandy soil and horizontal are determined; The magnitude of the angle A can be judged by the ratio of HL equal to TG a.

In recent years, a number of new methods have been proposed to determine the characteristics of soil resistance: according to the test of soils in stabilometers (see Fig. 11), by pressing the ball stamp to the soil (Fig. 24), similar to the determination of the hardness of Brinell and others.
The test of the soil by the ball sample (Fig. 24) is to measure the shaker of the ball S under the action of the permanent load p.
The value of the equivalent grip of the soil is determined by the following formula:

where P is full load on
D - the diameter of the ball, see;
S - Sharch sediment, see

The magnitude of the clutch of the SS takes into account not only the strength of the grip of the soil, but also inner friction.
To determine the specific adhesion with the value of the SS, is multiplied by the coefficient K, which depends on the angle of internal friction F (hail).

In recent years, the method of ball samples began to apply in the field. In this case, hemispherical stamps are used in size up to 1 m (Fig. 25).
The characteristics of the shift F and C are called the strength and accuracy of their definition is of great importance when calculating the foundations of structures on strength and stability.

The angle of natural slopes- this is the largest angle that can be formed by slope freely washed soilin a state of equilibrium with a horizontal plane.

The angle of natural slope depends on the particle size and form of particles. With a decrease in grain size, the corner of the natural slope becomes position.
In the air-dry state, the angle of natural slope of the sandy soil is 30-40 °, under water - 24-33 °. For soils that do not have adhesion (bulk), the angle of natural slope does not exceed the angle of internal friction

To determine the corner of the natural slope of the sandy soil in air-dry state, the device of the UVT ( fig. 9.11, 9.12), under water - VIA ( fig. 9.13).

According to fig. 9.12. With the slope of the sand drawer, it crepts and loosened, forms a slope with an angle that can be determined by the transport or by the formula

Concept of obligation angle of natural slopes It only applies to dry bulk soils, and for connected clay, it loses any meaning, since the latter it depends on the humidity, the height of the slope and the magnitude of the load on the slope and can vary from 0 to 90 °.

Fig. 9.11. Device WTT-2: 1 - scale; 2 - reservoir; 3 - measurement table; 4 - clip; 5 - support; 6 - Sample Sand

Fig. 9.12. Determination of the angle of natural slope by the rotation of the capacity (A) and the slow removal of the plate (b): A - axis of rotation of the container

Fig. 9.13. VIA device: 1 - Box VIA; 2 - sample sand; 3 - water tank; 4 - transport; 5 - axis of rotation; 6 piezometer; 7- tripod

When developing and shrinking loose soilrecesses and embankments form natural slopes of various steepness. The greatest steepness of the flat slopes of earthworks, trenches and pitchers, suitable without fasteners, should be taken according to table. 9.2. When providing natural rescue steepness ensures the stability of earth embankments and recesses.

Table 9.2. The greatest steepness of slopes of trenches and catlovanov, hail.

Soils	Crudyness of slopes at the depth of the excavation, M (the ratio of height to the mortgage)
	1,5	3,0	5,0
Unpleasant bulk	56(1:0,67)	45(1:1)	38(1:1,25)
Sand and gravel wet	63(1:0,5)	45(1:1)	45(1:1)
Clay:
Spring	76(1:0,25)	56(1:0,67)	50(1:0,85)
loam	90(1:0)	63(1:0,5)	53 (1:0,75)
clay	90(1:0)	76(1:0,25)	63(1:0,5)
Lesters and Ledsovid Dry	90(1:0)	63(1:0,5)	63(1:0,6)
Moray:
Sand, sulace	76(1:0,25)	60(1:0,57)	53 (1:0,75)
Suglinist	78(1:0,2)	63(1:0,5)	57(1:0,65)

The slopes of permanent structures perform more gentlemen than the slopes of the recess.

General provisions

Appointment and types of earthworks

The volume of earthworks is very large, it is available in the construction of any building and facilities. Of the total labor intensity in construction, earthworks are 10%.

The following main types of earthworks differ:

Planning site;

Pit and trenches;

Earth canvas;

Dams;

Channels, etc.

Earth structures are divided into:

Constant;

Temporary.

The constant belongs to bellows, trenches, embankments, recesses.

Requirements for permanent earth facilities:

Must be durable, i.e. resist temporary and permanent loads;

Sustainable;

Well resist atmospheric influences;

Well resist erosex actions;

Must possess immune.

Main building properties and classification of soils

Soil is called rocks that occur in the upper layers of the earth's crust. These include: vegetable soil, sand, soup, gravel, clay, loamy lounge, peat, various rocking soils and flooded.

On the size of mineral particles and their mutual communication distinguish the following soils :

Connected - clay;

Unconnectable - sandy and bulk (in dry condition), large-grass unprovered soils containing more than 50% (by weight) of crystalline fragments of more than 2 mm in size;

Rock - erupted, metamorphic and sedimentary breeds with tough bond between grains.

The main properties of soils affecting the production technology, the complexity and the cost of earthworks include:

Bulk mass;

Humidity;

Blurring

Clutch;

Looseness;

Angle of natural slope;

The bulk mass is called the mass of 1 m3 of soil in a natural state in a dense body.

The bulk mass of sandy and clay soils of 1.5 - 2 t / m3, rockless not loosened to 3 t / m3.

Humidity - the degree of saturation of the soil of water

g B - G C - ground soil before and after drying.

With humidity up to 5% - soils are called dry. With humidity from 5 to 15% - soils are called alignments. With humidity from 15 to 30% - the soils are called wet.
With humidity more than 30% - the soils are called wet.

The clutch is the initial resistance of the soil shift.

The grip strength of the soils: - sandy soils 0.03 - 0.05 MP-clay soils 0.05 - 0.3 MP semi-flux of 0.3 - 4 MPasal more than 4 MPa.

In frozen soils, the clutch force is much larger.

Breakfast - This is the ability of the soil to increase in the scope in the development, due to the loss of communication between particles. An increase in the volume of the soil is characterized by a loosening coefficient to p. After sealing the loosening soil is called residual breakdown to the or.

The angle of natural slopes Characterized by the physical properties of the soil. The magnitude of the angle of natural discovery depends on the angle of internal friction, the clutch forces and pressure of the overlying layers. In the absence of clutch forces, the extreme angle of natural slope is equal to the angle of internal friction. The slope of the slope depends on the angle of natural slope. The steepness of the slopes of recesses and the mound is characterized by a height ratio M is the slope coefficient.

The angles of the natural slope of the soil and the ratio of the height of the slope to the attachment

Soils	The value of the angles of natural slope and the relationship of the height of the slope to its embedding with different humidity of the soils
Dry	Wet	Wet
Corner in hail		Corner in hail	The ratio of height to the downstream	Corner in hail	The ratio of height to the downstream
Clay		1: 1		1: 1,5		1: 3,75
Suglink Middle		1: 0,75		1: 1,25		1: 1,75
Suglink easy		1: 1,25		1: 1,75		1: 2,75
The sand is fine-grained		1: 2,25		1: 1,75		1: 2,75
Sand range		1: 2		1: 1,5		1: 2,25
Sand coarse sand		1: 1,75		1: 1,6		1: 2
Vegetable primer		1: 1,25		1: 1,5		1: 2,25
Bulk sad		1: 1,5		1: 1		1: 2
Gravel		1: 1,25		1: 1,25		1: 1,5
Galka		1: 1,5		1: 1		1: 2,25

Blurry soil - UROS particles of fluid water. For small sands, the highest water velocity should not exceed 0.5-0.6 m / s, for large sands 1-2 m / s, for clay soils 1.5 m / s.