CALCULATION OF ARMOCAMENE STRUCTURES

Calculation of compressed elements with mesh reinforcement at eccentric application of load at low eccentricities for a rectangular section (ℓ0 <017h) is carried out according to the formula

N≤mgφ1RskbA (1-2ℓ0 / h) ω, (19)

where Rskb≤R2 is the calculated resistance of reinforced masonry under eccentric compression, determined with a grade of solution 50 and higher by the formula

Rskb = R + 2μRs / 100 (1-2 l 0 / y). (20)

For eccentricities in rectangular sections ℓ0 <0.17h, as well as for λh> 15 or λ i > 53, mesh reinforcement should not be used. The percentage of reinforcement of masonry with mesh reinforcement is limited and should not exceed

μ = 50R / (1-2ℓ0 / y) Rs≥0.1.

Task 2.8. determine the carrying capacity of a brick pillar with a size in plan of 64 × 77 cm with an estimated height of Net = 8.4 m. the calculated longitudinal force, taking into account the reliability coefficient for the purpose N = 1200kN. Eccentricity of load application ℓ0 = 5 cm; height of the beam supported on the pole, 30 cm. Brick plastic extrusion brand M 200, solution brand M 75. Ng = 90kN-long-acting load.

Decision. The area of the column A = 64 * 77 = 4930 cm2. Elastic masonry characteristics according to the table. 3. equal to a = 1000; λh = 840/64 = 13,125 and table. 2.5 φ = 0.81. the calculated resistance of masonry (according to table. 1). R = 25 kg / cm2 = 2.5 MPa. The ultimate force in unreinforced masonry is determined by the formula (12)

N = mgωφAR (1-2ℓ0 / h) = 0.81 * 1.08 * 0.995 * 4930 * 2.5 (1-2 * 5/64) =

= 905.4 kN <1200 kN;

ω = 1 + ℓ0 / h = 1 + 5/64 = 1.08 <1.45;

η determined by the table. 6 with the percentage of longitudinal reinforcement 0.1;

mg = 1-ηNg / N = 1-0.062 * 90/1200 = 1-0.00465 = 0.995.

The strength of the masonry is not provided, so it must be reinforced with nets. Accept the grid of reinforcement class BP-I (used with a coefficient γs = 0.6). The value of the elastic characteristics for masonry with mesh reinforcement is calculated by the formula (2.6.)

Ask = a * Ru / Rsku; Rsku = kR + 2Rsnμ / 100.

We take in the first approximation the percentage of reinforcement μ = 0.15, then

Rsku = 2 * 2.5 + 2 * 350 * 0.15 / 100 = 6.05MPa <1.8 * Ru = 9MPa.

We calculate a sk = 1000 5.0 = 826.

6.05

With a sk = 826λh = l0 / h = (840-30) / 64 = 12.65

φ1 = 0.805.

Estimated compressive strength of the mesh-reinforced masonry,

Rsk = R + 2μRs / 10 = 2.5 + 2 * 0.15 350 = 3.55 MPa.

100

The bearing capacity of the column is determined by the formula (2.11)

N≤N sech = mgφ1RAcω;

N≤Nsech = 0.995 * 0.805 * 0.355 * 64 * 77 * 1.08 = 1401.3кН> 1200кН,

Accept rebar ø 4mm with f a = 0,126 cm2, mesh size 5 cm. When μ = 2 f a / cs = 0.15, the grid spacing is equal to

s = 2 f a / μc = 2 * 0.126 100 = 33.6 cm

0.15 * 5

Grid set through two rows of brickwork.

Table 1. Baseline data for task 1

Option number

Geometrical dimensions

HeightH, m

Brand solution

Type of masonry

Brand of stone

Type of overlap or method of support

a cm

b, cm

one

five

eight

ten

eleven

4.2

6.4

7.4

5.3

8.7

6.5

4.0

5.2

3.9

8.2

6,6

4.5

5.6

7,6

100

Silicate

Pressed plastic clay

Ceramic Stone

Concrete

Silicate

Cellular concrete

Clay hollow

Plastic pressing

Concrete with voids

Semi-dry clay pressing

Silicate

Ceramic Stone

Plain Clay Plastic Molding

150

250

125

100

125

100

300

125

100

200

125

Articulated

Precast Concrete

Monolithic overlap

Articulated

Free-standing construction

Precast Concrete

Articulated

Partial clamping on supports

Monolithic overlap

Articulated

Free-standing construction

Partial overlap

Precast Concrete

Table 2. Initial data for task 2

Option number

Geometrical dimensions a, cm

Floor height H, m

LoadN, kN

Type of overlap or method of support

Type of brick (stone)

Mark brick (stone)

one

four

five

eight

ten

eleven

5.2

4.6

7.4

4.8

5.3

6.3

8.7

4.2

5.7

10.1

8.2

6,6

7.4

5.2

140

235

200

400

120

180

260

540

100

320

280

198

Prefab

Articulated

Monolithic overlap

Partial clamping on supports

Articulated

Also

Free-standing construction

Articulated

Prefab

Free-standing construction

Articulated

Monolithic overlap

Articulated

Silicate

Clay plastic pressing

Ceramic Stone

Ceramic hollow

Concrete

Also

Silicate

Cellular concrete

Clay hollow semi-dry pressing

Concrete with voids

Semi-dry clay pressing

Silicate

Ceramic Stone

Ceramic hollow

Silicate

150

250

125

100

125

100

300

125

100

200

100

150

Table 3. baseline data for task 3

Option number

Geometrical dimensions a, cm

Floor height H, m

Type of brick

Brand of brick

Brand solution

load

Long ng, kN

TotalN, kN

one

four

five

eight

ten

eleven

thirty

5.6

6.4

7.2

4.8

10.2

9.1

11.2

5.4

6.8

7.5

6.2

10.2

8.2

6.4

7.0

Aerated Concrete Stone

Silicate

Clay plastic pressing

Ceramic Stone

Ceramic hollow

Cellular concrete

Clay hollow semi-dry pressing

Silicate

Concrete stones with voids

Semi-dry clay pressing

Silicate

Clay hollow semi-dry pressing

Semi-dry clay pressing

Silicate

200

250

100

200

125

150

125

100

300

125

100

200

100

230

140

180

240

120

100

250

110

160

450

240

120

300

420

160

100

350

180

510

180

210

320

Table 4. initial data for problem 4.

Option number

Geometrical dimensions, cm

LoadN, kN

Type of brick (stone)

Brand solution

Mark brick (stone)

ℓ0

one

four

five

eight

ten

eleven

121

119

120

110

116

142

120

116

142

119

121

102

116

102

103

102

103

116

102

100

eight

thirty

eight

ten

sixteen

200

350

120

300

420

160

250

180

400

100

360

Silicate

Clay plastic pressing

Aerated Concrete Stone

Concrete stone

Semi-dry clay pressing

Silicate

Clay hollow plastic extrusion

Clay plastic pressing

Ceramic Stone

Ceramic hollow stone

Aerated Concrete Stone

Brick hollow semi-dry pressing

Silicate

Concrete stone

Silicate

100

125

200

150

100

300

100

250

150

100

150

100

150

Table 5. baseline data 5

Option number

Geometric dimensions of the cross section of the column, cm

Height H m

Loads

Eccentricity ℓ0, cm

Brand of brick

Brand solution

Dimensions of reinforced concrete slab, cm

Ng, kN

N, kN

one

four

five

eight

ten

eleven

4.8

7.2

6.4

5.2

10.2

8.3

9.6

11.5

8.6

6.8

7.5

4.2

5.4

6.0

8.2

230

140

180

240

120

100

250

1100

260

450

240

120

300

420

160

100

350

180

510

360

480

160

eight

five

four

eight

ten

five

eleven

eight

150

250

125

100

125

100

300

125

100

200

125

100

sixteen

thirty

sixteen

Table 6. baseline data 6.

Option number

Geometrical dimensions, cm

load

Floor height, N, m

Type of brick (stone)

Brand solution

Mark brick (stone)

N, kN

M, kN m

one

four

five

eight

ten

eleven

121

119

120

110

116

142

120

116

142

119

121

102

116

102

103

102

103

116

102

380

120

420

340

600

250

180

230

100

280

460

260

400

300

150

200

120

100

160

150

110

4.5

8.2

7,8

6.3

5.0

5.6

8.4

10.1

6.8

7.3

8.6

4.6

9.3

7.0

6.1

Silicate

Clay plastic pressing

Cellular concrete

Ceramic Stone

Concrete stone

Semi-dry clay pressing

Silicate

Clay hollow plastic extrusion

Clay plastic pressing

Ceramic Stone

Ceramic hollow stone

Also

Aerated Concrete Stone

Ceramic hollow semi-dry pressing

Silicate

125

100

125

200

150

300

100

150

250

150

100

150

Table 7. baseline data for task 7.

Option number

Floor height H, m

Load

The height of reinforced concrete slab, cm

Type of brick

Brand solution

N, kN

M, kN m

one

four

five

eight

ten

eleven

4.8

7.2

6.4

5.2

10.2

8.3

9.6

11.5

8.6

6.8

7.5

4.2

5.4

6.0

8.2

380

120

420

340

600

250

180

230

100

280

460

260

400

300

150

200

120

100

160

150

110

sixteen

thirty

sixteen

thirty

Silicate, 125

Clay plastic molding, 200

Stone of cellular concrete, 75

Concrete Stone, 150

Clay semi-dry pressing, 100

Silicate, 300

Clay hollow plastic extrusion, 100

Clay plastic molding, 250

Ceramic Stone, 150

The stone is ceramic hollow, 100

Stone of cellular concrete, 50

Brick hollow semi-dry pressing, 150

Silicate, 100

Concrete Stone, 150

Silicate, 150

125

100

Task 7. Determine the bearing capacity of the stone pillar under central and eccentric loading according to the table. 7

Task 6. Determine the geometric dimensions of the stone column of rectangular cross-section with a different method of support according to the table. 6

Task 5. Determine the required brand of brick for masonry T-section eccentric-loaded according to the table. 5 (see fig. 2.2).

Task 3. Determine the strength of the laying of the inner bearing wall according to Table. 3

Task 4. Determine the strength of the eccentric-loaded masonry of the T-section according to the table. 4 with an eccentricity - in the direction of the edge (see figure 2.2).

Task 1. Determine the strength of a centrally loaded stone pillar with different support for it, taking into account the brutal design of the building according to the table. one

Task 2. Determine the width of the brick pier at a given thickness according to Table. 2

Questions for self-test

on the topic "Stone and Arkamkamen

constructions "

1. Materials for stone and reinforced stone structures.

2. Types of masonry and their characteristics.

3. Advantages and disadvantages of stone structures.

4. Types of artificial stones and characteristics and differences.

5. Types of natural stones, brand, scope.

6. Types of solutions, brand, method of application.

7. Requirements of strength and durability for stone materials.

8. Stages of masonry work in axial compression.

9. Factors affecting the strength of the masonry.

10. Determination of the average tensile strength (temporary resistance) of masonry in compression.

11. Deformative properties of masonry.

12. The modulus of deformation and its value.

13. The phenomenon of creep during prolonged loading masonry.

14. The work of masonry under tension and shear.

15. determining the temporal resistances.

16. What are the stresses experienced brick (stone) in the masonry during compression.

17. What are the stages of the work of the centrally compressed masonry.

18. Constructive strength of masonry and its dependence on the strength of the stone.

19. What are the deformation properties of masonry?

Determination of the modulus of deformation of the masonry.

20. Types of design limit states of the clutch.

21. How are the limits of strength and design resistance of masonry in compression, tension, shear and bending?

22. Determination of flexibility of compressed elements.

23. Accounting for the effect of flexibility on the carrying capacity of compressed elements.

24. The work of masonry in non-central compression.

25. What are the features of laying and bending?

26. Work masonry with local compression. As determined in this case, the calculated resistance of the masonry.

27. Types of reinforced structures, their characteristics and applications.

28. Mesh reinforcement.

29. Work of grids at the central and eccentric compression.

30. Longitudinal reinforcement. Features work masonry.

31. Calculation of longitudinal reinforcement.

32. How is the calculated resistance to compression of reinforced masonry determined?

33. How is the elastic characteristic and coefficient of buckling of the masonry with mesh reinforcement determined?

34. What are complex structures? Their device and work.

35. Ways to strengthen the clutch clips. Influence of clips on the work of masonry in compression?

36. Ways of making connections between elements of a building.

37. What are the signs distinguish buildings with a rigid structural scheme.

38. The actual and design scheme of the building with a rigid structural scheme.

39. How is the flexibility of walls and pillars determined?

40. The design scheme of the building with an elastic structural scheme.

41. In which cases the building is dismembered by temperature-shrinkable seams?

42. Construction of expansion joints.

43. Types of winter laying.

44. Features of winter laying.

45. Quality control and masonry effort.

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CALCULATION OF ARMOCAMENE STRUCTURES

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