Load-bearing standard and load-bearing calculation method of computer room

Preface:

As we all know, the room is the operation of electronic equipment, and electronic equipment, large size, and very heavy, so the room to have a higher load-bearing capacity, to meet the load-bearing requirements of equipment, but now many buildings are not built for the engine room, its load-bearing can not meet the requirements of the room, so in the construction of the engine room The following details of the room load-bearing standards, as well as the computer room load calculation and calculation methods.

Civil buildings above the second floor load-bearing load design are 250-500kg/m2 load, office building in the construction of floor load in 300-500kg per square meter, machine room due to cabinets and equipment, as well as the weight of UPS is often relatively large, usually the standard of their own floor load in 800-1000kg per square meter.

When designed into a computer room, if you want to meet the room specifications, you should consider doing a loose load-bearing bracket under the cabinet, the bottom of the bearing bracket to increase the contact area by one time to achieve decentralized floor bearing gravity, when the cabinet, air conditioning, UPS and other equipment weight, more than the floor load, In order to ensure that the structure of the building itself and the general seismic requirements of the machine room, then you need to the cabinet, air conditioning, UPS battery cabinets and precision air-conditioning production load-bearing loose frame, the bulk load bearing support can disperse floor bearing capacity of the floor to meet the design value requirements.

Room load-bearing loose force frame reinforced general steel beams, according to equipment location plus. such as groove steel, angle, support at both ends of the load-bearing structure of the beam (wall), specifically to see the actual need for load-bearing situation. For example, in the Machine column location add two transverse 50*50 angle, or 100*50 groove steel, this column position load can reach 5000~7000n.

Calculation basis:

⑴ "Code for design of Concrete structures" (GB 50010-2002)

⑵ "Building Structure Load Code" (gbj9-87), "Building Structure Load Specification" (GB50009-2001)

⑶ "prestressed long-direction circular orifice Plate Atlas" (Beijing 92g42), "prestressed short-bore plate atlas" (Beijing 92g41)

Calculation of equivalent uniform live load on building floor

The standard value of the live load of the shovel, such as the building surface, shall be calculated according to the weight of the electronic equipment provided by the process, the size of the bottom, the arrangement of the installation and the layout of the building structure, according to the principle of internal force equivalence, in accordance with the current representative telecommunications equipment weight, Arrangement method and the calculation of various beam and plate layout determine the equivalent average live load value of the building floor of the computer room:

Note:

(1) The table load is applicable to the one-way board reinforcement of the cast-in-situ plate and the plate cross-direction and the rack arrangement direction (the long side of the loading surface) perpendicular to the prefabricated floor structure, according to the two-way plate reinforcement of the cast-in-situ board can also be referenced to use;

(2) The table load does not include the wall, ceiling load;

(3) due to the heavy power supply equipment, the design can also be in accordance with the weight of the equipment, the size of the bottom, the arrangement of the equipment in the role of the floor structure treatment;

(4) When the Wall, column and foundation are designed, the load value of the main girder in this table may be used in the live load value of the floor.

(5) The load of the computer room, does not consider the decentralized power supply when the battery into the room increased load.

equivalent uniform live load of floor area of computer room

The equivalent average live load value of the building floor of the computer room, according to the existing representative communication equipment weight, arrangement and structure of the different beam plate layout, according to the internal force (bending moment, shear) equivalent principle of calculation to determine, computer room values, also applicable to the wireless paging room.

Note:

(1) The table load is applicable to the one-way board reinforcement of the cast-in-situ plate and the plate cross-direction and the rack arrangement direction [The long side of the load surface] perpendicular to the prefabricated floor structure, according to the two-way plate reinforcement of the cast-in-situ board can also be referenced to use;

(2) The table load does not include the wall, ceiling load;

(3) due to the heavy weight of the uninterruptible power supply equipment, the design can also be based on the weight of the power equipment, the size of the bottom, the arrangement of the floor of the plant to deal with the structure;

(4) When handling a machine with a heavier weight, the strength of the slab structure along the way is fulfilled;

(5) When designing the wall, column and foundation, the live load of the table-column floor can be loaded with the same load as the design main girder.

computer room prefabricated load calculation standard

1. Calculation content

(1) The maximum bending moment value of the floor span of the machine room under the load of the original equipment;

(2) The maximum bending moment value of the floor slab across the machine room under the load of all equipment is added to the machine room.

(3) After the calculation of the above data, the relevant data into the "six provided by the special-shaped plate program calculation base station floor load-bearing idiot book" To carry out the load-bearing conclusion analysis.

2. Calculation steps:

The load-bearing calculation of precast slab is much more complicated than the load-bearing calculation of cast-in-situ slabs, and the following steps must be strictly observed in calculation to ensure that the prefabricated panels can achieve load-bearing safety requirements.

(1) The slab length and plate width should be evaluated before the precast panel calculation.

(2) when the precast plate load-bearing calculation, select the most dangerous board for calculation (basically the main equipment more than a single block of prefabricated panels). If the number of main equipment on multiple boards at the same time, more than one board is required to carry out load-bearing calculation.

(3) After the calculation if the room reliability grade B and B level, then the room load to meet the requirements, such as less than Class B, you need to replace the equipment location, and in the replacement position after the precast floor re-accounting, such as still can not reach a reliable level, it is necessary to strengthen the treatment.

(4) Can not determine the direction of the plate and the width of the board, the general recommendation of the battery "L" type placed, the size of the plate according to the most adverse to take value, usually the board length to take the shortest side, the board width of 900mm, and then to calculate, such as the calculation results do not meet the load-bearing requirements, it

calculation parameters of the tool box

(1) Slab Thickness: Short plate (board length of 1.8M-4.2M) plate thickness take 130mm, long plate (board length of 4.5m-6.6m) plate thickness take 185mm.

(2) Prefabricated floor size value: Prefabricated floor calculation width =1200mm (wide plate) or 900mm (narrow plate), by the site survey decision (judging results directly affect the results of the calculation), when the plate width is not determined to keep the small value to ensure safety.

Prefabricated floor length = actual measurement of the wall distance +300mm (when the board length is not an integer, the value is in multiples of 3 of the specified board length)

(3) The boundary form of the slab: the short side adopts simple support method, and the long side adopts the free way.

(4) The load form of the action: partial load.

The calculation of the maximum bending moment value parameter of the floor slab of the machine room when the load of all equipment is calculated (if there is a reserved equipment, you need to calculate the original equipment load effect of the machine room floor of the maximum bending moment value, and then calculate all the equipment load when the machine room floor of the maximum bending moment value):

(1) All Bu Heng load the standard value to take 1.0 kn/m2

(2) The standard value of the average live load is taken 0.6 kn/m2

(3) Short width plate (plate width of 1200mm, board length of 1.8m-4.2m) volume 1.97 (check Atlas)/15.15kn/m3

Short narrow plate (plate width is 900mm, board length is 1.8m-4.2m) bulk weight Take 16.1kn/m3

Long width plate (plate width is 1200mm, board length is 4.5m-6.0m) bulk weight Take 15.33kn/m3

Long Narrow plate (plate width is 900mm, board length is 4.5m-6.0m) bulk weight Take 15.46kn/m3

Ultra-long wide plate (plate width of 1200mm, board length of 6.3m-6.6m) capacity to take 15.62kn/m3

Ultra-long narrow plate (plate width of 900mm, the board length is 6.3m-6.6m) 16.12kn/m3 length range is greater than 6.6m of the precast board length, it is necessary to refer to the National Precast prefabricated atlas for calculation.

(4) The coefficient of the constant live load is taken 1.2

(5) Live load quasi-permanent value coefficient take 0.5

standard for evaluation of structural reliability

After the above steps have been calculated, the allowable bending moment design value R (Note: R value must be the corresponding bending moment design value of the plate number mantissa is. 1) and the calculated design value R is compared with the bending moment value calculated by the γ0s, according to the Atlas standard.

According to the provisions of 3rd 3.3 of the standard for reliability appraisal of civil buildings, the evaluation criteria for reliability evaluation of structural components are:

Class A reliability conforms to the requirements of grade A, i.e., r/γ0s≥1.0, does not affect the overall carrying function and the use function, can not take measures;

B-level reliability is slightly lower than the identification standard A-level requirements, that is, 1>r/γ0s≥0.9, but does not significantly affect the overall load-carrying function and the use of functions, there may be a few or very few members should take measures;

C-Class reliability does not meet the requirements of the identification standard A-0.9>r/γ0s≥0.85, which significantly affects the overall load-carrying function and the use of functions, should take measures, and may have individual components must take immediate action;

D-class reliability does not meet the requirements of the identification standard A-level, that is, the 0.85>r/γ0s, significantly affect the overall load-carrying function and the use of functions, must take immediate action, while not considering the new equipment.

Device parameter table: (direct input when calculating)

Network Cabinet Steel beam calculation:

Steel beam at both ends of the frame beam, network cabinets A total of 7 units weight 1500Kg, steel beam span 3m and 4m, the use of cold-formed thin-walled steel 2c160x70x20x3.0 back-to-rear section. Steel beam bottom surface height 40mm from floor surface. Geometric data and calculation parameters:

Cross-medium bending moment adjustment factor: 1.00

Support Bending moment adjustment factor: 1.00

g1:1.35 of the permanent load sub-coefficients under permanent load control

g2:1.20 of the permanent load sub-coefficients under variable load control

Variable load sub-term coefficient q:1.40

Variable load combination value coefficient c:0.70

Variable load quasi-permanent value coefficient q:0.40

Load data Live load diagram:

Internal force and reinforcement, shear envelope diagram:

Bending moment enveloping diagram:

Steel beam calculation:

Steel Grade: 235

Component Length (m): 3.000

Component cross section: cold-formed thin-walled steel 2c160x70x20x3.0 back-cross section

Limb back Pitch (mm): 0

Out-of-plane calculation length: 3.000

Strength Calculation net cross-sectional factor: 1.000

Seismic design: No seismic design

Design internal force:

Design values for the x-axis bending moment Mx (KN.M): 5.400

Design value of bending moment around y-axis My (KN.M): 0.000

Shear Design Value V (KN): 8.2800

Component checking:

1. Calculation of section characteristics

Full cross-sectional characteristics

A =1.8900e-003; Xc =7.0000e-002; Yc =8.0000e-002; Ix =7.4728e-006;

Iy =2.1432e-006; IX =6.2880e-002;iy=3.3675e-002; w1x=9.3420e-005;

w2x=9.3420e-005;  w1y=3.0618e-005; w2y=3.0618e-005;

Effective Section:

2. Calculation results of flexural strength of pure bending members

Considering the strength design value of cold bending effect (n/mm2): 222.493

Maximum stress calculation for component strength (N/MM2): 74.938 < f=222.493

The strength checking of component is satisfied.

3. Calculation results of shear strength of pure flexural members

Calculated points (centroid points) above the median and axial area moment (m3): Sx =5.7744e-005

Calculation of maximum shear stress of beam members (N/MM2): 8.371 < fv=120.000

The shear calculation of beam member is satisfied.

4. Overall stability checking results of pure bending member

Out-of-plane calculation length (m): 3.000

Plane Foreign Minister fine ratio λy:89

Flexural integral stability factor φb:0.977

Maximum stress calculation for integral stability of components (N/MM2): 76.733 < f=205.000

The overall stability checking of the component is satisfied.

calculation of steel beam of battery:

Steel beams at both ends of the frame beam, battery cabinet battery each 500Kg, steel beam span 3m, the use of cold-formed thin-walled steel 2c160x70x20x3.0 back-cross section. Steel beam bottom surface height 40mm, geometrical data and calculation parameters:

Cross-medium bending moment adjustment factor: 1.00

Support Bending moment adjustment factor: 1.00

g1:1.35 of the permanent load sub-coefficients under permanent load control

g2:1.20 of the permanent load sub-coefficients under variable load control

Variable load sub-term coefficient q:1.40

Variable load combination value coefficient c:0.70

Variable load quasi-permanent value coefficient q:0.40

Load data Live load diagram

Internal force and reinforcement, shear envelope diagram:

Bending moment enveloping diagram:

Steel beam calculation:

Steel Grade: 235

Component Length (m): 3.000

Component cross section: cold-formed thin-walled steel 2c160x70x20x3.0 back-cross section

Limb back Pitch (mm): 0

Out-of-plane calculation length: 3.000

Strength Calculation net cross-sectional factor: 1.000

Seismic design: No seismic design

Design internal force:

Design values for the x-axis bending moment Mx (KN.M): 10.130

Design value of bending moment around y-axis My (KN.M): 0.000

Shear Design Value V (KN): 7.500

Component Checking

1. Calculation of section characteristics

Full cross-sectional characteristics

A =1.8900e-003;  Xc =7.0000e-002; Yc =8.0000e-002;

Ix =7.4728e-006;     Iy =2.1432e-006; IX =6.2880e-002;

Iy =3.3675e-002;  w1x=9.3420e-005; w2x=9.3420e-005;