Plumbing

Recommendations for the design of retaining walls and basement walls. Recommendations for the design of retaining walls and basement walls Calculation and design of retaining walls

CENTRAL RESEARCH

AND DESIGN AND EXPERIMENTAL INSTITUTE OF INDUSTRIAL BUILDINGS AND CONSTRUCTIONS (TsNIIpromzdaniy) of the State Construction Committee of the USSR

REFERENCE AID

to SNiP 2.09.03-85

Retaining wall design

and basement walls

Developed for SNiP 2.09.03-85 “Construction of industrial enterprises”. Contains the main provisions for the calculation and design of retaining walls and basement walls of industrial enterprises from monolithic and prefabricated concrete and reinforced concrete. Calculation examples are given.

For engineering and technical workers of design and construction organizations.

FOREWORD

The manual was compiled for SNiP 2.09.03-85 “Constructions of industrial enterprises” and contains the main provisions for the calculation and design of retaining walls and basement walls of industrial enterprises from monolithic, prefabricated concrete and reinforced concrete with calculation examples and the necessary tabular values of the coefficients that facilitate the calculation.

In the process of preparing the Handbook, certain calculation prerequisites of SNiP 2.09.03-85 were clarified, including taking into account soil cohesion forces, determining the slope of the sliding plane of the collapse prism, which are supposed to be reflected in addition to the specified SNiP.

The manual was developed by the Central Research Institute of Industrial Buildings of the Gosstroy of the USSR (candidates of technical sciences A. M. Tugolukov, B. G. Kormer, engineers I. D. Zaleschansky, Yu. N. M. Gersevanova of the State Construction Committee of the USSR (Doctor of Technical Sciences E. A. Sorochan, Candidates of Technical Sciences A. V. Vronsky, A. S. Snarsky), Foundation Project (engineers V. K. Demidov, M. L. Morgulis, I. S. Rabinovich), Kiev Promstroyproekt (engineers V. A. Kozlov, A. N. Sytnik, N. I. Solovyova).

1. GENERAL INSTRUCTIONS

1.1. This Manual was compiled to SNiP 2.09.03-85 "Constructions of industrial enterprises" and applies to the design of:

retaining walls erected on a natural basis and located on the territories of industrial enterprises, cities, towns, access and on-site railways and roads;

industrial basements, both detached and built-in.

1.2. The manual does not apply to the design of retaining walls of main roads, hydraulic structures, retaining walls for special purposes (anti-landslide, anti-landslide, etc.), as well as to the design of retaining walls intended for construction in special conditions (on permafrost, swelling, subsidence soils, in undermined territories, etc.).

1.3. The design of retaining walls and basement walls should be carried out on the basis of:

master plan drawings (horizontal and vertical layout);

report on engineering and geological surveys;

technological task containing data on loads and, if necessary, special requirements for the designed structure, for example, requirements for limiting deformations, etc.

1.4. The design of retaining walls and basements should be established on the basis of a comparison of options, based on the technical and economic feasibility of their use in specific construction conditions, taking into account the maximum reduction in material consumption, labor intensity and construction costs, as well as taking into account the operating conditions of structures.

1.5. Retaining walls constructed in settlements should be designed taking into account the architectural features of these settlements.

1.6. When designing retaining walls and basements, structural schemes should be adopted that provide the necessary strength, stability and spatial invariability of the structure as a whole, as well as its individual elements at all stages of construction and operation.

1.7. Elements of prefabricated structures must meet the conditions of their industrial production at specialized enterprises.

It is advisable to enlarge the elements of prefabricated structures, as far as the carrying capacity of the assembly mechanisms, as well as the conditions of manufacture and transportation, allow.

1.8. For monolithic reinforced concrete structures, unified formwork and overall dimensions should be provided, allowing the use of standard reinforcing products and inventory formwork.

1.9. In prefabricated structures of retaining walls and basements, the structures of the nodes and the connection of the elements must ensure reliable transmission of forces, the strength of the elements themselves in the joint zone, as well as the connection of the additionally laid concrete in the joint with the concrete of the structure.

1.10. The design of structures of retaining walls and basements in the presence of an aggressive environment should be carried out taking into account the additional requirements of SNiP 3.04.03-85 “Protection of building structures and structures from corrosion”.

1.11. The design of measures to protect reinforced concrete structures from electrocorrosion should be carried out taking into account the requirements of the relevant regulatory documents.

1.12. When designing retaining walls and basements, as a rule, unified standard structures should be used.

The design of individual structures of retaining walls and basements is allowed in cases where the values of the parameters and loads for their design do not correspond to the values accepted for standard structures, or when the use of standard structures is impossible, based on local construction conditions.

1.13. This Handbook deals with retaining walls and basement walls filled with homogeneous soil.

2. STRUCTURAL MATERIALS

2.1. Depending on the adopted design solution, retaining walls can be built from reinforced concrete, concrete, rubble concrete and masonry.

2.2. The choice of structural material is determined by technical and economic considerations, durability requirements, work conditions, the availability of local building materials and mechanization.

2.3. For concrete and reinforced concrete structures, it is recommended to use concrete with a compressive strength of at least class B 15.

2.4. For structures subjected to alternate freezing and thawing, the design must specify the grade of concrete for frost resistance and water resistance. The design grade of concrete is set depending on the temperature regime that occurs during the operation of the structure, and the values of the calculated winter temperatures of the outdoor air in the construction area and is taken in accordance with Table. 1.

Table 1

Conditions	Estimated	Concrete grade, not lower
structures	temperature	frost resistance			in terms of water resistance
freezing at	air, ° С	Building class
variable freeze and thaw
In water-saturated	Below -40	F 300	F 200	F 150	W 6	W 4	W 2
state (for example, structures located in a seasonally thawing layer	Below -20 up to -40	F 200	F 150	F 100	W 4	W 2	He is normalized
soil in permafrost areas)	Below -5 to -20 inclusive	F 150	F 100	F 75	W 2	Not standardized
	5 and above	F 100	F 75	F 50	Not standardized
In conditions of episodic water saturation (for example, above-ground structures that are constantly exposed to	Below -40	F 200	F 150	F 400	W 4	W 2	He is normalized
atmospheric influences)	Below -20 to -40 inclusive	F 100	F 75	F 50		W 2 He is normalized
	Below -5 to -20	F 75	F 50	F 35*	He is normalized
	inclusive 5 and above	F 50	F 35*	F 25*	the same
In conditions of air-humidity in the absence of episodic water saturation, for example,	Below -40	F 150	F 100	F 75	W 4	W 2	He is normalized
structures permanently (exposed to the ambient air, but protected from the effects of atmospheric precipitation)	Below -20 to -40 inclusive	F 75	F 50	F 35*	He is normalized
	Below -5 to -20 inclusive	F 50	F 35*	F 25*	the same
	5 and above	F 35*	F 25*	F 15**

______________

* For heavy and fine-grained concrete, frost resistance grades are not standardized;

** For heavy, fine-grained and light concrete, frost resistance grades are not standardized.

Note. The calculated winter temperature of the outside air is taken as the average air temperature of the coldest five-day period in the construction area.

2.5. Prestressed reinforced concrete structures should be designed mainly from class B 20 concrete; At 25; B 30 and B 35. Concrete of class B 3.5 and B5 should be used for concrete preparation.

2.6. The requirements for rubble concrete in terms of strength and frost resistance are the same as for concrete and reinforced concrete structures.

2.7. For reinforcement of reinforced concrete structures made without prestressing, hot-rolled bar steel of a periodic profile of class A-III and A-II should be used. For mounting (distribution) fittings, it is allowed to use hot-rolled fittings of class A-I or ordinary smooth reinforcing wire of class B-I.

When the design winter temperature is below minus 30°C, reinforcing steel of class A-II grade VSt5ps2 is not allowed to be used.

2.8. As prestressed reinforcement of prestressed reinforced concrete elements, heat-strengthened reinforcement of the At-VI and At-V classes should be mainly used.

It is also allowed to use hot-rolled rebar of class A-V, A-VI and thermally hardened rebar of class At-IV.

When the calculated winter temperature is below minus 30°C, reinforcing steel of class A-IV grade 80C is not used.

2.9. Anchor rods and embedded elements should be made of rolled strip steel of class S-38/23 (GOST 380-88) grade VSt3kp2 at a design winter temperature of up to minus 30°C inclusive and grade VSt3psb at a design temperature of minus 30°C to minus 40°C. For anchor rods, steel S-52/40 grade 10G2S1 is also recommended at a design winter temperature of up to minus 40°C inclusive. The thickness of the strip steel must be at least 6 mm.

It is also possible to use reinforcing steel of class A-III for anchor rods.

2.10. In prefabricated reinforced concrete and concrete structural elements, mounting (lifting) loops must be made of class A-I grade VSt3sp2 and VSt3ps2 reinforcing steel or grade AC-II grade 10GT steel.

When the design winter temperature is below minus 40°C, the use of VSt3ps2 steel for hinges is not allowed.

3. TYPES OF RETAINING WALLS

3.1. According to the constructive solution, retaining walls are divided into massive and thin-walled.

In massive retaining walls, their resistance to shear and overturning when exposed to horizontal soil pressure is mainly ensured by the own weight of the wall.

In thin-walled retaining walls, their stability is ensured by the own weight of the wall and the weight of the soil involved in the work of the wall structure.

As a rule, massive retaining walls are more material-intensive and more labor-intensive to erect than thin-walled ones, and can be used with an appropriate feasibility study (for example, when they are built from local materials, the absence of precast concrete, etc.).

3.2. Massive retaining walls differ from each other in the shape of the transverse profile and material (concrete, rubble concrete, etc.) (Fig. 1).

Rice. 1. Massive retaining walls

a - in- monolithic; d - e- block

Rice. 2. Thin-walled retaining walls

A- corner console; b- corner anchor;

V- buttress

Rice. 3. Pairing of prefabricated front and foundation slabs

A- using a slotted groove; b- with the help of a loop joint;

1 - front plate; 2 - base plate; 3 - cement-sand mortars; 4 - embedding concrete

Rice. 4. Construction of a retaining wall using a universal wall panel

1 - universal wall panel (UPS); 2 - monolithic part of the sole

3.3. In industrial and civil construction, as a rule, thin-walled retaining walls of the corner type are used, shown in Fig. 2.

Note. Other types of retaining walls (cellular, sheet pile, shells, etc.) are not considered in this Manual.

3.4. According to the manufacturing method, thin-walled retaining walls can be monolithic, prefabricated and prefabricated-monolithic.

3.5. Thin-walled cantilever walls of the corner type consist of front and foundation slabs rigidly connected to each other.

In prefabricated structures, the front and foundation slabs are made from prefabricated elements. In prefabricated monolithic structures, the front slab is prefabricated, and the foundation slab is monolithic.

In monolithic retaining walls, the rigidity of the nodal junction of the front and foundation slabs is ensured by the appropriate location of the reinforcement, and the rigidity of the connection in prefabricated retaining walls is ensured by the device of a slotted groove (Fig. 3, A) or loop joint (Fig. 3, 6 ).

3.6. Thin-walled retaining walls with anchor rods consist of front and foundation slabs connected by anchor rods (ties), which create additional supports in the slabs, facilitating their work.

The interface of the front and foundation plates can be hinged or rigid.

3.7. Buttress retaining walls consist of an enclosing front slab, a buttress and a foundation slab. In this case, the soil load from the front plate is partially or completely transferred to the buttress.

3.8. When designing retaining walls from unified wall panels (UPS), a part of the foundation slab is made of cast-in-situ concrete using a welded joint for the top reinforcement and an overlap joint for the bottom reinforcement (Fig. 4).

4. LAYOUT OF THE BASEMENTS

4.1. Basements should, as a rule, be designed as one-story. According to technological requirements, basements with a technical floor for cabling are allowed.

If necessary, basements with a large number of cable floors are allowed.

4.2. In single-span basements, the nominal size of the span, as a rule, should be taken as 6 m; a span of 7.5 m is allowed, if this is due to technological requirements.

Multi-span basements should be designed, as a rule, with a grid of colonies 6x6 and 6x9 m.

The height of the basement from the floor to the bottom of the ribs of the floor slabs must be a multiple of 0.6 m, but not less than 3 m.

The height of the technical floor for cable distribution in tan areas should be taken at least 2.4 m.

The height of the passages in the basements (clean) should be set at least 2 m.

4.3. Basements are of two types: free-standing and combined with building structures.

Unified schemes of detached basements are given in Table. 2.

4.4. Basement structures (ceilings, walls, columns) are recommended to be made of precast concrete elements.

4.5. As a rule, it is not necessary to place tan marks in the zones of influence on the floor of the workshop of temporary loads with an intensity of more than 100 kPa (10 tf / m 2).

4.6. Evacuation exits from basements and rooms of categories C, D and D, stairs from tan to these rooms, fire safety requirements for category B basements or warehouses of combustible materials, as well as fireproof materials in combustible packaging should be provided for according to SNiP 2.09.02-85 "Industrial buildings".

4.7. Cable basements and cable floors of basements should be divided by means of fire partitions into compartments with a volume of not more than 3000 m 3, while providing for volumetric fire extinguishing equipment.

4.8. From each compartment of the basement, cable basement or cable floor of the basement, at least two exits must be provided, which should be located on different sides of the room.

Exits should be located so that the length of the dead end is less than 25 m. The length of the way for service personnel from the most remote place to the nearest exit should not exceed 75 m.

The second exit is allowed to be provided through the adjacent room (basement, basement floor, tunnel) located on the same level (floor) of categories C, D and D. When exiting to category C rooms, the total length of the evacuation route should not exceed 75 m.

4.9. Exit doors from cable basements (cable floors of basements) and between compartments must be fireproof, open in the direction of the nearest exit and have self-closing devices.

Door porches must be sealed.

table 2

Unified Schemas	Dimensions, m
one-story basements	L	H

Notes: 1. The step of the columns in the longitudinal direction with a live load on the floor of the workshop up to 100 kPa (10 tf / m 2) 6 and 9 m, with a live load of more than 100 kPa (10 tf / m 2) - 6 m.

2. Size c is assumed to be 0.375 m.

4.10. Evacuation exits from oil cellars and cable floors of cellars should be carried out through separate staircases that have direct access to the outside. It is allowed to use a common staircase leading to the above-ground floors, while for the basements a separate exit from the staircase at the level of the first floor to the outside must be arranged, separated from the rest of the staircase to the height of one floor by a blank fire partition with a fire resistance limit of at least 1 hour.

If it is not possible to arrange exits directly to the outside, it is allowed to arrange them in rooms of categories D and D, taking into account the requirements of clause 4.6.

4.11. In oil cellars, regardless of area and in cable cellars with a volume of more than 100 m 3, it is necessary to provide automatic fire extinguishing installations. In cable cellars of a smaller volume, there should be an automatic fire alarm. Cable basements of power facilities (NPP, CHPP, SDPP, TPP, HPP, etc.) should be equipped with automatic fire extinguishing installations, regardless of their area.

4.12. It is allowed to provide free-standing one-story pumping stations (or compartments) of categories A, B and C, buried below the planned ground elevations by more than 1 m, with an area of \u200b\u200bno more than 400 m 2.

These rooms should include:

one emergency exit through a stairwell, isolated from the premises, with a floor area of not more than 54 m2;

two emergency exits located on opposite sides of the premises, with a floor area of more than 54 m 2 . The second exit is allowed by a vertical staircase located in a shaft isolated from rooms of categories A, B and C.

4.13. The device of thresholds at the exits from the basements and differences in the floor level is not allowed, with the exception of oil basements, where thresholds 300 mm high with steps or ramps should be arranged at the exits.

5. GROUND PRESSURE

5.1. The values of the characteristics of soils of natural (undisturbed) composition should be established, as a rule, on the basis of their direct testing in field or laboratory conditions and statistical processing of test results in accordance with GOST 20522-75.

Soil characteristics values:

normative - g n , j n and With n;.

for calculations of foundation structures for the first group of limit states - g I , j I , and c I ;

the same for the second group of limit states - g II , j II and c II.

5.2. In the absence of direct tests of the soil, it is allowed to take the standard values of specific adhesion With, angle of internal friction j and deformation modulus E according to the table 1-3 app. 5 of this Manual, and the normative values of the specific gravity of the soil g n equal to 18 kN / m 3 (1.8 tf / m 3).

The calculated values of the characteristics of the undisturbed soil in this case are taken as follows:

g I \u003d 1.05 g n; g II \u003d g n; j I = j n g j ; j II = j n ; With I= With n/1.5; c II = With n

where gj - the reliability coefficient for the soil, is taken equal to 1.1 for sandy and 1.15 for dusty clay soils.

5.3. The values of the characteristics of backfill soils ( g¢ , j¢ and With ¢ ), compacted in accordance with regulatory documents with a compaction factor k y not less than 0.95 of their density in natural composition, it is allowed to establish according to the characteristics of the same soils in natural occurrence. The ratios between the characteristics of backfill soils and soils of natural composition are as follows:

g¢ II \u003d 0.95 g I; j¢ I = 0.9 j I ; With¢ I = 0,5With I, but not more than 7 kPa (0.7 tf / m 2);

g¢ II \u003d 0.95 g II; j¢ II \u003d 0.9 j II ; With¢ II =0.5 c¢II , but not more than 10 kPa (1 tf / m 2).

Note. For structures with a laying depth of 3 m or less, the limit values for the specific cohesion of the backfill soil With ¢ I, should be taken no more than 5 kPa (0.5 tf / m 2), and With ¢ II no more than 7 kPa (0.7 tf / m 2). For structures less than 1.5 m high With ¢ I should be taken equal to zero.

5.4. Load safety factorsg I when calculating for the first group of limit states, they should be taken according to Table. 3, and when calculating for the second group - equal to one.

Table 3

Loads	Load safety factor g I
Permanent
Self weight of the structure
Soil weight in natural occurrence
Backfill weight	1,15
Bulk soil weight
The weight of the road surface of the carriageway and sidewalks
The weight of the canvas, railroad tracks
Hydrostatic groundwater pressure
Temporary long
From the rolling stock of the SK railways
From columns of AK cars
Load from equipment, stored material,

Temporary short-term
From wheeled PK-80 and caterpillar NG-60 load
From loaders and cars
From the columns of cars AB

5.5. The intensity of the horizontal active soil pressure from its own weight R g, at a depth at(Fig. 5, A) should be determined by the formula

P g=[ gg f h l - With (K 1 + K 2)] y/h, (1)

Where K 1- coefficient taking into account the cohesion of the soil along the sliding plane of the collapse prism inclined at an angle q 0 to the vertical K 2- the same, on a plane inclined at an angle in to the vertical.

K 1=2 l cos q 0 cos e /sin(q 0 + e); (2)

K2= l + tg e , (3)

where e - angle of inclination of the design plane to the vertical; - the same, the backfill surface to the horizon; q 0 - the same, sliding planes to the vertical; l - coefficient of horizontal soil pressure. In the absence of adhesion of the soil to the wall K2 = 0.

5.6. The coefficient of horizontal soil pressure is determined by the formula

, (4)

where d - the angle of friction of the soil in contact with the calculated plane (for a smooth wall d = 0, rough d = 0.5 j , stepped d = j ).

Coefficient values l given in appendix. 2.

Rice. 5. Soil pressure diagram

A- from its own weight and water pressure; b - from a continuous uniformly distributed load; V- from a fixed load; G- from strip load

5.7. The angle of inclination of the sliding plane to the vertical q 0 is determined by the formula

tg q 0 = (cos - h cos j )/(sin - h sin j ), (5)

where h = cos (e - r )/ .

5.8. With a horizontal backfill surface r = 0, vertical wall e =0 and the absence of friction and adhesion to the wall d = 0, K 2= 0 lateral earth pressure coefficient l , coefficient of intensity of adhesion forces K 1 and the angle of inclination of the sliding plane q0 are determined by the formulas:

(6)

For r = 0, d ¹ 0, e ¹ 0 value of the angle of inclination of the sliding plane to the vertical q 0 is determined from the condition

tg q 0 = (cos j - )/sin j . (7)

5.9. Intensity of additional horizontal ground pressure due to the presence of groundwater P w, kPa, at a distance w, from the upper groundwater level (Fig. 5, A) is determined by the formula

Pw = y w{10 - l[g -16.5/(1 + e)]) g f , (8)

Where e- soil porosity; g f- load safety factor is taken equal to 1.1.

5.10. The intensity of the horizontal pressure of the soil from a uniformly distributed load q located on the surface of the collapse prism should be determined by the formulas:

with a continuous and fixed location of the load (Fig. 5, b,c)

Р q = q g f l; (9)

with a strip arrangement of the load (Fig. 5, G)

Pq = q g f l /( 1 + 2 tg q 0 at a/b 0). (10)

Distance from the soil surface of the backfill to the beginning of the diagram of the intensity of the soil pressure from the load at a, is determined by the expression at a = a/(tg q 0 +tg e ).

The length of the diagram of the intensity of soil pressure in height b at a fixed load (see Fig. 5, V) is taken equal to b=h- yA.

With strip load (see Fig. 5, G) the length of the pressure diagram in height yb =(b 0 + 2tg q0 y a)/(tg e + tan q 0), but no more than the value b £ h - y A.

5.11. Live loads from mobile transport should be taken in accordance with SNiP 2.05.03-84 “Bridges and pipes” in the form of load SK - from the rolling stock of railways, AK - from motor vehicles PK-80 - from wheel load, NG-60 - from caterpillar load.

Notes: 1. SC - conditional equivalent uniformly distributed standard load from the rolling stock of railways per 1 m of track, the width of which is assumed to be 2.7 m (along the length of the sleepers).

2. LK - standard load from vehicles in the form of two lanes.

3. NK-80 - standard load, consisting of one wheeled vehicle weighing 785 kN (80 tf).

4. NG-60 - standard load, consisting of one tracked vehicle weighing 588 kN (60 tf).

5.12. Loads from mobile vehicles (Fig. 6) are reduced to an equivalent uniformly distributed band load with the following input data:

for SC - b 0 = 2.7 m, and the intensity of the load q== 76 kPa at the level of the bottom of the sleepers;

for AK - b 0 = 2.5 m, and the intensity of the load, kPa,

q = TO (10,85 + y a tg q 0)/(0.85 + y a tg q 0 ) 2.55, (11)

Where TO= 1.1 - for main trunk roads; TO= 8 - for internal economic roads.

Rice. 6. Scheme of bringing loads from mobile transport to the equivalent band load

for NK-80 - b 0 = 3.5 m, and the intensity of the load, kPa,

q = 112/(1,9 + y a tg q0); (12)

for NG-60 - b 0 = 3.3 m, and load intensity, kPa,

q = 90/(2,5 + y a tg q0). (13)

5.13. The normative vertical load from the rolling stock on the roads of industrial enterprises, where the movement of vehicles of especially large carrying capacity is provided for and which are not subject to restrictions on the weight and overall parameters of general-purpose vehicles, should be taken in the form of columns of two-axle vehicles AB with the parameters given in Table. 4.

5.14. In the absence of specific loads on the surface of the collapse prism, a conditional normative uniformly distributed load with an intensity of 9.81 kPa (1 tf / m 2) should be taken.

5.15. The dynamic coefficient from the rolling stock of railways and road transport should be taken equal to one.

Table 4

Options	Type of two-axle vehicle
	AB-51	AB-74	AB-151
Axle load of a loaded vehicle, kN (tf):
back	333(34)	490(50)	990(101)
anterior	167(17)	235(24)	490(50)
Distance between axes (base) of the car, m
Width dimensions (along rear axle wheels), m
Wheel track width, m:
rear			3,75
front
The size of the contact area of the rear wheels with the pavement of the roadway, m:
by lenght		0,45
in width			1,65
Wheel diameter, m

"Design of retaining walls and basement walls".

Developed for SNiP 2.09.03-85 "Construction of industrial enterprises". Contains the main provisions for the calculation and design of retaining walls and basement walls of industrial enterprises from monolithic and prefabricated concrete and reinforced concrete. Calculation examples are given.
For engineering and technical workers of design and construction organizations.

FOREWORD

The manual was compiled for SNiP 2.09.03-85 "Constructions of industrial enterprises" and contains the main provisions for the calculation and design of retaining walls and basement walls of industrial enterprises from monolithic, prefabricated concrete and reinforced concrete with calculation examples and the necessary tabular values of the coefficients that facilitate the calculation.

The manual was developed by the Central Research Institute of Industrial Buildings of the Gosstroy of the USSR (candidates of technical sciences A. M. Tugolukov, B. G. Kormer, engineers I. D. Zaleschansky, Yu. N. M. Gersevanova of the State Construction Committee of the USSR (Doctor of Technical Sciences E. A. Sorochan, Candidates of Technical Sciences A. V. Vronsky, A. S. Snarsky), Fundamental Project (engineers V. K. Demidov, M. L. Morgulis, I. S. Rabinovich), Kiev Promstroyproekt (engineers V. A. Kozlov, A. N. Sytnik, N. I. Solovieva).

1. GENERAL INSTRUCTIONS

1.1. This Manual was compiled to SNiP 2.09.03-85 "Constructions of industrial enterprises" and applies to the design of:
retaining walls erected on a natural basis and located on the territories of industrial enterprises, cities, towns, access and on-site railways and roads;
industrial basements, both detached and built-in.

1.3. The design of retaining walls and basement walls should be carried out on the basis of:
master plan drawings (horizontal and vertical layout);
report on engineering and geological surveys;
technological task containing data on loads and, if necessary, special requirements for the designed structure, for example, requirements for limiting deformations, etc.

1.5. Retaining walls built in settlements should be designed taking into account the architectural features of these settlements.

1.7. Elements of prefabricated structures must meet the conditions of their industrial production at specialized enterprises.
It is advisable to enlarge the elements of prefabricated structures, as far as the carrying capacity of the assembly mechanisms, as well as the conditions of manufacture and transportation, allow.

1.8. For monolithic reinforced concrete structures, unified formwork and overall dimensions should be provided, allowing the use of standard reinforcing products and inventory formwork.

1.10. The design of structures of retaining walls and basements in the presence of an aggressive environment should be carried out taking into account the additional requirements of SNiP 3.04.03-85 "Protection of building structures and structures against corrosion".

1.11. The design of measures to protect reinforced concrete structures from electrocorrosion should be carried out taking into account the requirements of the relevant regulatory documents.

1.12. When designing retaining walls and basements, as a rule, unified standard structures should be used.
The design of individual structures of retaining walls and basements is allowed in cases where the values of the parameters and loads for their design do not correspond to the values accepted for standard structures, or when the use of standard structures is impossible, based on local construction conditions.

1.13. This Handbook deals with retaining walls and basement walls filled with homogeneous soil.

2. STRUCTURAL MATERIALS

2.1. Depending on the adopted design solution, retaining walls can be built from reinforced concrete, concrete, rubble concrete and masonry.

2.3. For concrete and reinforced concrete structures, it is recommended to use concrete with a compressive strength of at least class B 15.

Compiled for the chapters of SNiP 11-15-74 and 11-91-77 and contain the main provisions for the calculation and design of retaining walls made of monolithic and prefabricated reinforced concrete using the calculation and the necessary tabular values of the coefficients that facilitate the calculation, as well as recommendations for calculating the walls of the basements of industrial and civil buildings.

For engineering and technical workers of design and construction organizations.

1. GENERAL PROVISIONS

1.1. The guidelines apply to the design of gravity retaining walls for industrial and civil buildings built on natural foundations, as well as to the design of basement walls for industrial and civil buildings.

1.2. The Guidelines do not apply to the design of retaining walls of main roads, hydraulic structures, retaining walls for special purposes (anti-landslide, anti-landslide, etc.), as well as to the design of retaining walls intended for construction in special conditions (permafrost swelling, subsidence soils, in undermined territories, etc.).

1.3. The design of retaining walls and basement walls should be carried out on the basis of:

master plan drawings (horizontal and vertical layout);

report on engineering and geological surveys;

technological task containing data on loads, if necessary, special requirements for the designed structure, for example, requirements for limiting deformations, etc.

1.4. The design of retaining walls and basement walls should be established according to the comparison of options, based on the technical and economic feasibility of their use in specific construction conditions, taking into account the maximum reduction in material consumption, labor intensity and construction cost, as well as taking into account the operating conditions of structures.

1.5. Retaining walls constructed in settlements should be designed taking into account the architectural features of these points.

1.6. When designing retaining walls and basement walls, structural schemes should be adopted that provide the necessary strength, stability and spatial immutability of the structure as a whole, as well as its individual elements at all stages of construction and operation.

1.7. Elements of prefabricated structures must meet the conditions of their industrial production at specialized enterprises.

It is advisable to enlarge the elements of prefabricated structures, as far as the carrying capacity of the assembly mechanisms, as well as the conditions of manufacture and transportation, allow.

1.8. For monolithic reinforced concrete structures, unified formwork and overall dimensions should be provided, allowing the use of standard reinforcing products and inventory formwork.

1.9. In the controversial structures of retaining walls and basement walls, the structures of the catch and the connections of the elements must ensure reliable transmission of forces, the strength of the elements themselves in the joint zone, as well as the connection of the additionally laid concrete in the joint with the concrete of the structure.

1.10. The design of structures for retaining walls and wall basements in the presence of an aggressive environment should be carried out taking into account the additional requirements imposed by the head of SNiP II1-23-78.

1.11. The design of measures to protect reinforced concrete structures from electrocorrosion should be carried out taking into account the requirements of SN 65-76 "Instructions for the protection of reinforced concrete structures from corrosion caused by stray currents."

1.12. When designing retaining walls and basement walls, as a rule, unified standard structures should be used.

The design of individual structures of retaining walls and basement walls is allowed in cases where the parameters and loads for their design exceed the parameters and loads for standard structures, or when the use of standard structures is impossible based on local construction conditions.

1.13. The Guidelines deal with retaining walls and basement walls when backfilled with homogeneous soil.

2. MATERIALS FOR RETAINING WALLS

2.1. Depending on the adopted design solution, retaining walls can be built from reinforced concrete, concrete, rubble concrete and masonry.

2.2. The choice of material for retaining walls is determined by technical and economic considerations, durability requirements, work conditions, the availability of local building materials and mechanization.

2.3. Reinforced concrete and concrete retaining walls are recommended to be designed from concrete of a design grade in terms of compressive strength:

for prefabricated reinforced concrete structures - M 200, M 300, M 400;

for monolithic reinforced concrete and concrete structures - M 150, M 200,

Prestressed reinforced concrete structures should be predominantly designed from concrete of the MZOO, M 400, M 500, M 600 grades. Concrete of the M 50 and M 100 grades should be used for concrete preparation.

2.4. For brick retaining walls, well-burnt red brick of a grade of at least M 200 should be used for a mortar grade of at least M 25, and for very wet soils - at least M 50. The use of silicate brick is not allowed.

2.5. Rubble and rubble concrete masonry for retaining walls should be made of stone of a grade of at least 150-200 on Portland cement mortar of a grade of at least 50.

2.6. For structures subjected to alternate freezing and thawing, the design must specify the concrete grade for frost resistance. The design grade of concrete for frost resistance for reinforced concrete structures of retaining walls is assigned depending on the temperature regime of their operation in accordance with Table. 1. The temperature mode of operation is set based on the value of the calculated winter temperature of the outdoor air in the construction area.

Requirements for rubble concrete and masonry in terms of frost resistance are the same as for concrete and reinforced concrete structures.

2.7. For reinforcement of reinforced concrete structures made without prestressing, hot-rolled reinforcing steel of a periodic profile of classes A-III and A-P according to GOST 5781-75 should be used. For mounting (distribution) fittings, it is allowed to use hot-rolled fittings of class A-I according to GOST 5781-75 or ordinary reinforcing smooth wire of class B-I according to GOST 6727-53*.

At the design winter temperature below minus 30 ° Reinforcing steel of class A-P grade VSt5ps2 is not allowed for use.

2.8. As prestressed reinforcement of prestressed reinforced concrete elements, heat-strengthened reinforcement of classes At-VI and At-V according to; GOST 10884-78.

It is also allowed to use hot-rolled rebar of classes A-V, A-IV in accordance with GOST 5781-75 and heat-strengthened rebar of class At-IV in accordance with GOST 10884-81) At the design winter temperature below minus 30 ° C, reinforcing steel of class A-IV grade 80C is not allowed to be used.

2.9. Anchor rods and embedded elements should be made of rolled strip steel of class C 38/23 (GOST 380-71 *) grade VstZkp2 at a design winter temperature of up to minus 30 ° C inclusive and grade VStZpsb at a design temperature of minus 30 ° C to minus 40 ° C. For anchor rods, steel 1^S 52/40 grade 10G2S1 is also recommended at design winter temperatures down to minus HOX inclusive. The thickness of strip steel should be taken at least 6 mm. It is also possible to use reinforcing steel of class A-III for anchor rods.

2.10. In prefabricated reinforced concrete and concrete elements, mounting (lifting) loops must be made of reinforcing steel of class A-I (grades VStZsp2 and VStZps2) or steel of class A-P 1 (grade YuGT). When the calculated winter temperature is below -40 ° C, the use of VStZps2 steel for hinges is not allowed.

3. TYPES OF RETAINING WALLS

3.1. Retaining walls according to the constructive solution are divided into massive and thin-walled.

In massive retaining walls, their resistance to shear under the influence of horizontal soil pressure is provided mainly by the own weight of the wall.

In thin-walled retaining walls, their stability is ensured by the own weight of the wall and the weight of the soil involved in the work of the wall structure.

3.2. Massive walls can be built from in-situ concrete, precast concrete blocks, rubble concrete and masonry. According to the cross-sectional shape, massive walls can be:

with two vertical faces (Fig. 1a);

vertical front and inclined back face (Fig. 1.6),

with an inclined front and vertical back face (Fig. 1, c),

with two faces inclined towards the backfill (Fig. 1, d),

with a stepped back face,

with a broken back edge.

3.3. Walls with sloping edges (variable section, thinning upwards) are less material-intensive than walls with two parallel edges.

In the presence of a back face inclined away from the backfill, the work of the retaining wall includes the mass of soil located above this face. In walls with two faces inclined towards the backfill, the intensity of the horizontal pressure of the soil decreases, but the construction of walls of such a section is more difficult. Walls with a stepped back face are mainly used in the construction of massive walls from precast concrete blocks.

3.4. In industrial and civil construction, as a rule, thin-walled retaining walls of the corner type are used:

console (Fig. 2, a),

with anchor rods (Fig. 2,.b),

buttress (Fig. 2, b).

Note. Other types of retaining walls (cellular, sheet pile, shells, etc.) are not considered in this Guide.

3.5. According to the manufacturing method, thin-walled retaining walls can be monolithic, prefabricated and prefabricated-monolithic.

3.6. Thin-walled cantilever walls of the corner type consist of front and foundation slabs rigidly connected to each other. In prefabricated walls, the front and foundation slabs are made from prefabricated elements. In prefabricated-monolithic - the front slab is prefabricated, and the foundation is monolithic.

In monolithic retaining walls, the rigidity of the nodal interface of the front and foundation slabs is ensured by the appropriate arrangement of the reinforcement.

In prefabricated and prefabricated-monolithic retaining walls, the rigidity of the interface is ensured by the device of a slotted groove (Fig. 3, a) or loop (Fig. 3, b) joint.

3.7. In prefabricated-monolithic thin-walled retaining walls, the front slab is prefabricated, and the foundation slab (which does not require scaffolding and complex formwork) is monolithic.

Prefabricated-monolithic retaining walls are made in the case when the dimensions of the prefabricated foundation slab are insufficient, and an additional monolithic anchor slab is attached to it (Fig. 4).

3.8. Thin-walled retaining walls with anchor rods consist of front and foundation slabs connected by flexible steel sulfur rods (ties), which create additional supports in the slabs, facilitating their work. The interface of the front and foundation plates can be hinged or rigid.

3.9. Thin-walled buttress retaining walls consist of three elements: front slab, rigid buttress and foundation slab. In this case, the load from the front plate is partially or completely transferred to the buttress.

...

CENTRAL RESEARCH

AND DESIGN AND EXPERIMENTAL INSTITUTE OF INDUSTRIAL BUILDINGS AND CONSTRUCTIONS (TsNIIpromzdaniy) of the State Construction Committee of the USSR

REFERENCE AID

Retaining wall design

and basement walls

Developed for "Construction of industrial enterprises". Contains the main provisions for the calculation and design of retaining walls and basement walls of industrial enterprises from monolithic and prefabricated concrete and reinforced concrete. Calculation examples are given.

For engineering and technical workers of design and construction organizations.

FOREWORD

The manual was compiled for “Constructions of industrial enterprises” and contains the main provisions for the calculation and design of retaining walls and basement walls of industrial enterprises from monolithic, prefabricated concrete and reinforced concrete with calculation examples and the necessary tabular values of the coefficients that facilitate the calculation.

In the process of preparing the Handbook, certain calculation prerequisites were clarified, including taking into account the cohesive forces of the soil, determining the slope of the slip plane of the collapse prism, which are supposed to be reflected in addition to the specified SNiP.

The manual was developed by the Central Research Institute of Industrial Buildings of the Gosstroy of the USSR (candidates of technical sciences A. M. Tugolukov, B. G. Kormer, engineers I. D. Zaleschansky, Yu. N. M. Gersevanova Gosstroy of the USSR (Dr. Technical Sciences E. A. Sorochan, candidates of technology sciences A.V. Vronsky, A. S. Snarsky), foundationproject (engineers V.K. Demidov, M. L. Morgulis, I. S. Rabinovich), Kiev Promstroyproekt (engineers V.A. Kozlov, A. N. Sylovtnis? N. I. Solovyev).

1. GENERAL INSTRUCTIONS

1.1. This Manual has been drawn up for “Constructions of industrial enterprises” and applies to the design of: