A construction method for steel-for-timber and formwork support poles

Abstract

This invention provides a steel-for-timber construction method for formwork erection. It selects appropriate main beam materials based on the floor slab thickness and load requirements; determines the spacing of the formwork erection poles based on the floor slab thickness and the performance of the main beam materials, and calculates and determines an economically reasonable pole spacing; utilizes the theoretical quantity calculation principle of formwork to calculate the formwork material requirements under specific floor slab area and floor height conditions; and adjusts for practical application: considering on-site construction conditions and actual problems encountered, the theoretical calculation values ​​are adjusted to ensure construction feasibility and safety; when erecting basement formwork, an appropriate pole spacing is selected and adjusted according to the slab thickness and dimensions; for standard floors above ground, a formwork layout diagram is drawn, and the formwork is erected according to the different requirements of precast and cast-in-place slabs; the formwork costs of different main beam materials and pole spacing schemes are compared, and the most cost-effective scheme is selected. This invention can improve construction efficiency, reduce costs, and ensure construction safety.

Description

Technical Field

[0001] This invention relates to the field of building construction technology, and in particular to a construction method for using steel instead of wood and for erecting formwork supports. Background Technology

[0002] With the rapid development of the construction industry, the requirements for construction speed and cost-effectiveness are becoming increasingly stringent. As a key temporary structure in construction, the design and implementation of formwork support systems directly impact project progress and cost. Existing formwork support systems often suffer from problems such as material waste, low construction efficiency, and insufficient safety. Summary of the Invention

[0003] In view of the above-mentioned defects of the prior art, the technical objective of the present invention is to solve the problems of high cost, low construction efficiency and insufficient safety of the existing formwork support system in actual construction.

[0004] To achieve the above technical objectives, this invention provides a steel-for-timber construction method and formwork support pole construction method, including the following steps: main beam selection and planning, determination of formwork support pole spacing, theoretical calculation of formwork quantity, actual construction application and cost comparison; main beam selection and planning: select appropriate main beam materials according to the thickness of the floor slab and load requirements;

[0005] Determine the spacing of the formwork uprights: Calculate and determine an economical and reasonable spacing of the uprights based on the floor slab thickness and the material properties of the main beams; Theoretical quantity calculation of the formwork: Calculate the material requirements of the formwork under specific floor slab area and floor height conditions using the theoretical quantity calculation principle of the formwork;

[0006] Practical application adjustments: Taking into account on-site construction conditions and actual challenges, the theoretical calculation values ​​are adjusted to ensure construction feasibility and safety;

[0007] Basement formwork erection: When erecting basement formwork, select appropriate upright spacing and adjust it according to the slab thickness and dimensions;

[0008] Erection of formwork for standard floors above ground: For standard floors above ground, draw a formwork layout diagram and erect the formwork according to the different requirements of precast slabs and cast-in-place slabs;

[0009] Cost Comparison: Compare the formwork costs of different main rib materials and upright spacing options, and select the most cost-effective option. Specifically, this includes the following steps:

[0010] (a) Determine the load: Calculate the uniformly distributed load on the floor slab, including static load and live load;

[0011] q = Uniformly distributed load on the floor slab

[0012] Determine the allowable stress: Determine the allowable stress value based on the properties of the pole material;

[0013] Determine the load-bearing capacity of the pole

[0014] A is the cross-sectional area of ​​the pole, f is the yield strength of the material, and g is the safety factor, which ranges from 1.5 to 2.5.

[0015] (ii) Calculate the load-bearing capacity of the upright: Calculate its load-bearing capacity based on the geometric dimensions and material properties of the upright;

[0016] Calculate the maximum permissible spacing: Use a mechanical model to calculate the maximum permissible spacing of the uprights while meeting safety requirements. L is the maximum allowable spacing of the uprights while meeting the load-bearing capacity requirements.

[0017] (III) Considering stability factors: The stability of the upright is affected by buckling, lateral support conditions and slenderness ratio; K is the effective length coefficient of the pole; E is the elastic modulus of the material; I is the moment of inertia of the pole section; Kcr is the critical load factor; f y It is the yield strength of the material;

[0018] (iv) Considering construction specifications, the following specific requirements apply to the spacing of the uprights:

[0019] L z =min(L,L w ,L g ), L z Lw represents the final spacing, Lg represents stability, and Lg represents the specification requirement.

[0020] Preferably, the main rib material is square steel pipe rather than fastener-type steel pipe.

[0021] Preferably, the spacing between uprights is 1200 / 1200mm as the main spacing for the erection of the basement formwork.

[0022] The beneficial effects of this invention are:

[0023] Cost-effectiveness: By optimizing the main beam material and the spacing between uprights, the amount of material used and rental costs are reduced.

[0024] Construction efficiency: Simplify the construction process and reduce erection time and difficulty.

[0025] Safety: Ensure the reliability and safety of the mold base design.

[0026] Adaptability: Suitable for the needs of different construction projects. Attached Figure Description

[0027] Figure 1 This is a diagram showing the arrangement of small-pitch uprights provided in this embodiment.

[0028] Figure 2This is a diagram showing the arrangement of large-spacing uprights provided in this embodiment. Detailed Implementation

[0029] The following will further explain the concept, specific structure, and technical effects of the present invention in conjunction with the accompanying drawings, so as to fully understand the purpose, features, and effects of the present invention.

[0030] Example:

[0031] Main beam selection planning

[0032] As the main load-bearing component of the formwork support frame, the selection of the main rib has a significant impact on the stability and economy of the entire formwork frame.

[0033] Material selection: Usually, you can choose steel pipes with fasteners, square steel pipes, etc.

[0034] Calculation and analysis: Based on the load of the floor slab and the mechanical properties of the main beam material, the safe spacing and quantity of the main beams are determined by mechanical calculation software or manual calculation.

[0035] Cost considerations: Compare the unit price of different materials, rental costs, procurement costs, and expected usage period.

[0036] Determining the spacing of the formwork uprights

[0037] Determining the spacing between poles requires consideration of safety, economy, and ease of construction.

[0038] Standard basis: Follow relevant building construction standards, such as the "Safety Technical Specification for Construction Coupler-type Steel Pipe Scaffolding".

[0039] Calculation and analysis: Perform structural calculations to ensure that the spacing between the uprights is maximized while meeting the requirements for strength and stability, so as to reduce the number of uprights.

[0040] On-site adjustments: Based on on-site conditions and construction experience, the theoretical calculation values ​​are adjusted appropriately.

[0041] Theoretical quantity calculation of formwork

[0042] Theoretical quantity calculation is used to estimate the total demand for mold base materials.

[0043] Parameter input: including pole spacing, main beam spacing, floor slab dimensions, floor height, etc.

[0044] Component quantity calculation: Calculate the quantity of components such as uprights, main beams, secondary beams, and horizontal beams based on the input parameters.

[0045] Material weight calculation: Calculate the total weight based on the number of components and the material density.

[0046] Cost estimation: Estimate the total cost based on material weight and market price.

[0047] Practical construction applications

[0048] Applying theoretical designs to actual construction requires consideration of site conditions and feasibility.

[0049] Construction plan: Develop a detailed formwork erection plan, including construction steps, personnel arrangements, and material transportation.

[0050] On-site implementation: Erect the structure according to the construction plan, ensuring that every step of the operation complies with safety regulations.

[0051] Quality inspection: After the formwork is erected, a comprehensive inspection is carried out to ensure its stability and safety.

[0052] Cost comparison

[0053] Cost comparison is to select the most economical construction plan.

[0054] Scheme Comparison: List all feasible mold base design schemes.

[0055] Cost calculation: Detailed cost calculations are performed for each option, including material costs, labor costs, and machinery usage fees.

[0056] Economic analysis: Compare the total cost and cost-effectiveness of different options, and select the option with the lowest cost that meets the safety requirements.

[0057] Specific implementation steps

[0058] Information gathering: Collect information related to the project, such as design drawings, construction specifications, and material prices.

[0059] Parameter determination: Determine the load on the floor slab and the mechanical performance parameters of the main beam material.

[0060] Mechanical calculations: Using mechanical principles and calculation software, the optimal spacing between the main beam and the uprights is determined.

[0061] Material requirements calculation: Calculate the required material quantity based on the spacing between uprights and the spacing between main beams.

[0062] Cost estimation: Based on the quantity of materials and market prices, estimate the construction cost.

[0063] Solution evaluation: Evaluate the technical feasibility and economic viability of different solutions.

[0064] Construction drawing design: Draw construction drawings for the formwork erection, including the arrangement of uprights and main beams.

[0065] On-site implementation: Erect the structure on-site according to the construction drawings and construction plan.

[0066] Safety inspection: After the installation is completed, a safety inspection will be conducted to ensure that it meets safety standards.

[0067] Cost accounting: After the construction is completed, cost accounting is carried out and compared with the estimated cost.

[0068] By following the steps above, we can ensure that the design and construction of the formwork support system are both safe and economical.

[0069] Specifically, project overview

[0070] The total land area of ​​this project is 47,693 square meters. The total building area is 125,945.71 square meters (excluding the area of ​​the elevated floor (not included in the floor area ratio) of 3,202.05 square meters), of which the above-ground building area is 85,847.4 square meters and the underground building area is 40,098.31 square meters. The above-ground part mainly consists of 16 individual buildings and podiums, consisting of 11 buildings of 14 floors, 2 buildings of 13 floors, 1 building of 12 floors, and 2 buildings of 11 floors, with a height not exceeding 49.90 meters; there are two underground floors in some areas.

[0071] Buildings 1-16 are cast-in-place reinforced concrete shear wall structures, buildings G1 and G2 are steel structures, and buildings S1-4 and the underground parking garage are cast-in-place reinforced concrete frame structures.

[0072] Floor slab distribution overview

[0073] Based on the structural model provided by the company, a floor slab schedule was generated to analyze the distribution of floor slab thickness in the project.

[0074] In the basement area, slabs with a thickness of 250mm or less accounted for 67.90%, slabs with a thickness of 300mm accounted for 31.94%, and slabs with a thickness of more than 300mm accounted for only 0.15%.

[0075] Taking Building #1 as an example, cast-in-place slabs account for 20.77% of the total, with 87.25% of the cast-in-place slabs being 120mm or less in thickness; precast slabs account for 79.23%, with 94.42% of the precast slabs being 130mm or less in thickness. Analysis shows that cast-in-place slabs thicker than 120mm and precast slabs thicker than 130mm are both located in the elevated floor and roof area.

[0076]

[0077]

[0078] Main beam selection overview

[0079] The formwork materials are divided into four types: formwork frame body, main beams, secondary beams, and formwork. The frame body adopts Hangzhou strong push disc buckle frame, the secondary beams adopt square timber (40*90mm) to facilitate turnover between projects, and the formwork adopts conventional 13-15mm wooden formwork.

[0080] Meanwhile, calculations show that the selection of main rib materials and the spacing of secondary ribs are key variables for adjusting the spacing of the disc-lock frame, which in turn affects the material cost of the formwork erection.

[0081] The project plans to use fastener-type steel pipes (A48mm) and square steel pipes (50*100mm) as the main ribs, and conducts planning and analysis.

[0082] The main material parameters and unit price of the mold frame are detailed below:

[0083] Material type weight / volume unit price Chinese knot 0.00555t / m 3.5 / t / day Timber 0.0036m³ / m 1012 yuan / m3 (usage cost) square steel pipe 0.00685t / m 35 yuan / ton / day steel pipe 0.0033t / m 3 yuan / ton / day

[0084] Note: Timber was purchased at 2012 yuan / m. 3 The allocation is approximately 1000 yuan / m. 3 The selection of the rib type does not affect the formwork laying area, so it will not be considered for the time being.

[0085] Spacing between formwork uprights

[0086] Based on the overall floor slab distribution of the project, a selection and planning analysis of main ribs was conducted using 120mm, 250mm, and 300mm thick cast-in-place slabs and 130mm thick precast slabs. Calculations yielded the most economical formwork spacing for different main rib materials, as detailed in the table below:

[0087]

[0088] 2.3 Theoretical Calculation Principle of Rectangular Plate Lower Mold

[0089] Taking a 20*20m slab area and a floor height of 3.5m as an example, the calculation and comparison are performed as follows:

[0090] Under ideal conditions, the uprights are 3.5m long and there are 3 rows of horizontal bars. The number of components with a length of 20m at different spacings is detailed below:

[0091]

[0092] Taking a pole spacing of 0.9m x 1.2m, a main joist (two steel pipe fasteners) spacing of 1.2m, and a secondary joist spacing of 0.25m as an example, the calculation is performed according to the table above:

[0093] Number of poles = 23 * 17 = 391;

[0094] Length = 391 * 3.5 = 1368.5m;

[0095] Weight = 1368.5 * 0.00555 = 7.60 tons;

[0096] Number of horizontal bars = 23 + 17 = 40;

[0097] Length = 40 * 20 * 3 = 2400m;

[0098] Weight = 3200 * 0.00555 = 13.32 tons;

[0099] Number of main beams = 17;

[0100] Length = 17 * 20 * 2 = 680m;

[0101] Weight = 680 * 0.0033 = 2.24 tons;

[0102] Number of secondary beams = 81;

[0103] Length = 81 * 20 = 1620m;

[0104] Volume = 1620 * 0.0036 = 5.83 m3.

[0105] The cost can be calculated as: (7.6 + 13.32) * 3.5 + 2.24 * 3 = 79.94 yuan / day, and the purchase amount of timber is (5.83 * 1012) = 5902 yuan.

[0106] Calculation table

[0107] Based on the theoretical calculation principles, the calculation table is as follows:

[0108]

[0109] The yellow-filled items are input items. The number of poles can be determined by actual values. The final calculation will be based on the calculated value or the larger of the actual values.

[0110] The system automatically outputs daily costs and timber usage costs based on the actual input data, and allows you to select the required data according to the main beam material.

[0111] Comparison of mold frame cost theories

[0112] Based on the calculation table, the costs are as follows:

[0113]

[0114] in conclusion:

[0115] 1. The main rib material is made of square steel pipe, which saves 30%-50% of the daily rental cost compared to steel pipe with fasteners. However, the cost of using secondary rib materials will increase accordingly.

[0116] 2. The selection and planning of main beams should comprehensively consider the formwork rental period and the cost of using square timber. Taking the main beam material (1 or 2 square steel pipes) as an example:

[0117] The cost is more favorable when the rental period exceeds 1136 days, provided that the main rib material (2 square steel pipes) is used; conversely, the cost is more favorable when the main rib material (1 square steel pipe) is used.

[0118] In the above embodiments, the main beam selection planning is only a comparative selection planning under ideal conditions. In practical applications, the following problems exist:

[0119] 1. During on-site construction, there are cases where the large panel size does not meet the formwork erection conditions for a large spacing between uprights (1500 / 1500mm, 1800 / 1800mm), which is quite common in standard floors above ground.

[0120] 2. The 1500 / 1500mm and 1800 / 1800mm upright spacing is difficult to offset from the 600, 900 and 1200mm upright spacing under the beam. A larger upright spacing under the slab will increase the number of uprights under the beam to ensure the reliable connection of the frame.

[0121] 3. The spacing between the 1500 / 1500mm and 1800 / 1800mm uprights is relatively large, making it difficult for scaffolders to erect the scaffolds as they have no leverage points.

[0122] 4. Square steel pipes weigh twice as much as steel pipes with fasteners, making it more difficult for scaffolders to move and erect them.

[0123] Field application status

[0124] 1. Basement formwork: Considering the thickness and dimensions of the slab on site, as well as theoretical costs and on-site safety, a pole spacing of 1200 / 1200mm is selected as the main spacing for the basement formwork erection.

[0125] 2. Formwork for Standard Floors Above Ground: Taking the standard floor of Building 6 as an example, draw a formwork layout diagram and conduct cost comparisons.

[0126] Taking the standard floor of Building 6 (mostly precast slabs) as an example, the spacing of the uprights under the beams (in the form of supporting beams) is 900mm. The spacing of the uprights under the slabs is divided into small spacing (600-900mm, with double-coupler steel pipes for the main ribs) and large spacing (1500-1800mm, with double-sided steel pipes for the main ribs). The upright layout is drawn for each. Figure 1-2 As shown:

[0127] The small-spacing pole arrangement has a total of 339 poles; the large-spacing pole arrangement has a total of 263 poles, which is 76 fewer than the small-spacing pole arrangement.

[0128] Analysis shows that the only difference between the two pole arrangement schemes is the number of poles under the slab in large open-plan rooms:

[0129] 3.8*5.0 meters (3 pieces), the larger bay (3*4 rows) reduces the number of uprights by 18 compared to the smaller bay (5*6 rows);

[0130] 2.9*4.1 meters (1 piece), the larger bay (3*3 rows) has 11 fewer uprights than the smaller bay (4*5 rows);

[0131] 2.8*3.2 meters (2 pieces), the larger bay (3*3 rows) requires 7 fewer uprights than the smaller bay (4*4 rows);

[0132] 2.8*2.4 meters (2 pieces), the larger bay (3*2 rows) requires 6 fewer uprights than the smaller bay (4*3 rows);

[0133] 2.6*3.3 meters (1 piece), the larger bay (3*3 rows) requires 7 fewer uprights than the smaller bay (4*4 rows);

[0134] 2.5*2.35 meters (1 piece), the larger bay (3*3 rows) requires 3 fewer uprights than the smaller bay (4*3 rows);

[0135] 2.2*2.5 meters (1 piece), the larger bay (2*2 rows) requires 8 fewer uprights than the smaller bay (3*4 rows);

[0136] 3.5*2.2 meters (1 piece), the larger bay (3*2 rows) requires 6 fewer uprights than the smaller bay (4*3 rows).

[0137] In summary, the number of support poles under the slab is reduced by 115 for the large-span layout and the small-span layout.

[0138] Based on the comparison of the total number of uprights, the number of uprights under the beams increases by (115-76) = 39 for the larger span arrangement and the smaller span arrangement.

[0139] Cost comparison of standard floors above ground

[0140] Selection Background:

[0141] 1. The formwork under the standard floor beams adopts the formwork support beam type. Therefore, the length of the uprights under the beams is the same as the length of the uprights under the slabs. The length of the uprights is tentatively set at 2.6 meters, and there are 3 rows of horizontal bars.

[0142] 2. A fixed spacing of 300mm is arranged for the horizontal beams under the beam. The cost of the horizontal beams and support beams under the beams is not considered in this comparison.

[0143] 3. Standard floors are mostly precast slabs, so the cost of timber and formwork will not be considered in this selection process.

[0144] In summary, the cost differences between the large-bay and small-bay selection options are detailed below:

[0145] 1. Reducing the number of uprights by 76 = 76 * 2.6 * 0.00555 * 3.5 = 3.84 yuan / day

[0146] 2. Reduce the horizontal bar by (3 * (4.2 * 2 + 3.3 * 2))

[0147] +(3.6+2.1*2)+2*(2.7+2.1)+2*(1.8+2.1)+(2.7+2.1+1.8+1.8+1.5*2

[0148] 2.7 + 1.5) * 0.00555 * 3.5 = 2.78 yuan / day

[0149] 3. Length of the main beam in the large span = (3*5*3 + 3*4.1 + 3*3.2*2 + 3*2.4*2 + 3*3.3 + 3*2.35 + 2*2.5 + 3*2.2)*2 = 238.9 meters

[0150] Length of main beam in small bay = (5*5*3+4*4.1+4*3.2*2+4*2.4*2+4*3.3+4*2.35+3*2.5+4*2.2)

[0151] *2 = 350.2 meters

[0152] Cost savings = 350.2 * 0.0033 * 3 - 238.9 * 0.00685 * 3.5 = -2.26 yuan / day, total cost savings

[0153] =3.84 + 2.78 - 2.26 = 4.36 yuan / day

[0154] The main beam selection plan is only a comparative selection plan under ideal conditions. In practical applications, the following problems exist:

[0155] 1. During on-site construction, there are cases where the large panel size does not meet the formwork erection conditions for a large spacing between uprights (1500 / 1500mm, 1800 / 1800mm), which is quite common in standard floors above ground.

[0156] 2. The 1500 / 1500mm and 1800 / 1800mm upright spacing is difficult to offset from the 600, 900 and 1200mm upright spacing under the beam. A larger upright spacing under the slab will increase the number of uprights under the beam to ensure the reliable connection of the frame.

[0157] 3. The spacing between the 1500 / 1500mm and 1800 / 1800mm uprights is relatively large, making it difficult for scaffolders to erect the scaffolds as they have no leverage points.

[0158] 4. Square steel pipes weigh twice as much as steel pipes with fasteners, making it more difficult for scaffolders to move and erect them.

[0159] Field application status,

[0160] 1. Basement formwork: Considering the thickness and dimensions of the slab on site, as well as theoretical costs and on-site safety, a pole spacing of 1200 / 1200mm is selected as the main spacing for the basement formwork erection.

[0161] 2. Formwork for Standard Floors Above Ground: Taking the standard floor of Building 6 as an example, a formwork layout diagram is drawn, and a cost comparison is conducted. In summary,

[0162] 1. The theoretical calculation table is applicable to large open spaces in basements and can be used as a reference for formwork calculation.

[0163] 2. Square steel pipes have better material properties than fastener-type steel pipes. As the main rib material, they free up more space for the disc buckle uprights and reduce the amount of disc buckle scaffolding used.

[0164] 3. The performance of the 40*90mm square timber secondary rib material restricts the final cost calculation. Increasing the spacing between the uprights of the disc buckle will lead to a decrease in the spacing between the secondary ribs. The cost calculation process needs to balance the material usage of the disc buckle, main ribs and secondary ribs.

[0165] 4. During the erection of large-spacing disc buckles, there are difficulties such as the excessive weight of the square steel pipes and the lack of leverage points for scaffolders.

[0166] 5. The 1500 / 1500mm and 1800 / 1800mm upright spacing is difficult to offset from the 600, 900 and 1200mm upright spacing under the beam. A larger upright spacing under the slab will increase the number of uprights under the beam to ensure the reliable connection of the frame.

[0167] 6. For small rooms on the ground floor, the spacing of the uprights should be selected according to the actual size of the room.

[0168] The preferred embodiments of the present invention have been described in detail above. It should be understood that those skilled in the art can make numerous modifications and variations based on the concept of the present invention without creative effort. Therefore, all technical solutions that can be obtained by those skilled in the art based on the concept of the present invention through logical analysis, reasoning, or limited experimentation on the basis of existing technology should be within the scope of protection defined by the claims.

Claims

1. A steel substitute wood and formwork support frame vertical pole construction method, characterized in that, The steps include: Main beam selection planning, determination of module frame stand rod spacing, module frame theoretical calculation, actual construction application and cost comparison; Main beam selection planning: select appropriate main beam material according to the thickness and load requirements of the floor; Determine the spacing of the module frame stand rod: according to the thickness of the floor and the performance of the main beam material, calculate and determine the economic and reasonable stand rod spacing; Module frame theoretical calculation: use the principle of module frame theoretical calculation to calculate the module frame material demand under the condition of specific floor area and floor height; Actual application adjustment: consider the construction conditions and actual challenges encountered, adjust the theoretical calculation value to ensure the feasibility and safety of construction; Basement module frame erection: select appropriate stand rod spacing when erecting the basement module frame, and adjust according to the thickness and size of the plate; Erecting module frame for standard floors above ground: for standard floors above ground, draw a module frame arrangement diagram, and erect the module frame according to the different requirements of precast and cast-in-place slabs; Cost comparison: compare the module frame costs of different main beam materials and stand rod spacing schemes, and select the scheme with the highest cost-effectiveness; The steps include: (I) determine the load: calculate the uniform load of the floor, including static load and live load; q = uniform load of the floor, determine the allowable stress: determine the allowable stress value according to the characteristics of the vertical rod material; determine the vertical rod bearing capacity ; A is the cross-sectional area of the vertical rod, f y is the yield strength of the material, g is the safety factor, g is 1.5 to 2.5; (2) Calculate the bearing capacity of the stand rod: calculate the bearing capacity of the stand rod according to its geometric dimensions and material properties; Calculate the maximum allowable spacing: use the mechanical model to calculate the maximum allowable spacing of the vertical rod under the safety requirements ; L is the maximum allowable spacing of the vertical rod under the bearing capacity requirements (3) Consider stability factors: the stability of the pole is influenced by factors of buckling, lateral support conditions and slenderness ratio; ; K is the effective length factor of the pole; E is the modulus of elasticity of the material, I is the moment of inertia of the pole section, Kcr is the critical load factor, f y is the yield strength of the material; (4) Considering the construction specification, the distance between the vertical rods has the following specific requirements: , L z is the final distance, Lw is the stability, and Lg is the specification requirement.

2. The steel substitute wood and formwork support frame stand pole construction method according to claim 1, characterized in that, The main beam material is square steel pipe with fastener type steel pipe.

3. The steel substitute wood and formwork support frame stand pole construction method according to claim 1, characterized in that, The stand rod spacing of 1200 / 1200mm is used as the main spacing for the erection of the basement module frame.

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