Hey, are you a civil engineering final year student and interested in RCC building project? If you are in confusion about how and from where to begin, then you are in right place to learn. Here you will learn about the procedure to do from beginning to the end of building project.

Steps to follow for building project

You can choose any types of building like residential, commercial, institutional or others. The basic requirements before the structural design of building are architectural drawing and soil exploration data.

Architectural drawing:

Architectural drawing should contain plans, sections and elevations with clearly visible dimensions. You can manage architectural drawing from seniors, teachers, consultancy or from different other sources. You can also draw yourself, as your interest, which should meet certain criteria. If you want to make architectural drawing then you should have sound knowledge of drawing software, bylaws and local rules and regulation.

It would be better if you choose building having

1. all structural members including shear wall, cantilevers, lifts/elevators, ramp and basement.
2. Plinth area greater than 2500 sq. ft.
3. More than 5 storey

Soil exploration data (optional)

            Soil exploration data is needed for seismic analysis and for design of sub-structure. You can get rough data from local authorities of that area and from local people who have built before. As an engineer, you should have soil data of same plot. But now you can assume suitable data so I keep this as optional.

Here I assume you have architectural drawing and sound knowledge about the soil type and bearing capacity of soil. Now we can begin the structural part. Following things to be considered first before going to design portion. These are,

• Grade of concrete
• Grade of steel
• Material used for partition walls
• Flooring material

For structural member, we can’t use concrete mix less than M20. You should choose M20 or above depending upon load intensity. There is no fixed rule to choose the grade of mix but it should be kept in mind that lower grade will result greater size of structural member. Higher size of structural means high self-weight and higher self-weight will cause problems during seismic analysis. I recommend you to use M30 if you building is more than 6 storey.

Also there is no fixed rule to choose grade of steel. But there are some restriction. In design and construction of RCC building in seismic Zones III and above, elongation more than 14.5% should be used. The elongation of normal HYSD bar greater than 415 has lesser elongation. If you want to use higher grade of steel then you have to choose special types of steel like 500D, 550D, 500S, etc. But, they may not available in your area and may be economical unfeasible. I recommend you to use Fe 415 or Fe 500D.

You can choose any partition walls material and flooring materials depending upon your project suitability.

Structural design of building

Different codes are used in designing the building project. Since our country accept indian codes so we have to use IS 456:2000, IS 875, IS 1893, IS13920, SP 16 and some other codes & handbooks.

The design of each structural member begin with its preliminary design. The design begins from slab. The step by step process is as follows:

1. Preliminary design of slab

It is the first step of design. For this you should select some critical slabs and do preliminary design. The critical slab means that slab which have greater area or the slab which encounter greater load.

2. Detailed design of slab

Since there is negligible effect of lateral load on slab, it can be design in detail after completion of preliminary design. You can design the slab either do manually or by using software like SAFE. The design of one-way and two way was already discussed before.

3. Design of staircase/ramp

After slab design you can either design staircase or you can do it after preliminary design of beam and column.

4. Preliminary design of beam and column

As you have done detailed design of slab, you have also fixed the alignment of secondary beam (if any). Then select some critical beams then find out its depth and width from preliminary design of beam. For preliminary design of column you have to know about the loading pattern. Always select some critical columns of lowest floor for design. It is already discussed in preliminary design of column before.

5. Detailed design of beam and column

After completion of complete design of slab, staircase and preliminary design of beam and column, you can go to design of beam and column. For this, it is better to use structural software like ETABS, SAP2000, STAAD PRO. In final year project, we are allowed to use only shear from and flexural moment from design software. From this, you have to do manually to find the area of reinforcement and its details. While taking size and reinforcement, it should be kept in mind about dynamic loading cases.

6. Design of shear wall

Before design of shear wall, you should be familiar about it provisions. Shear walls must be used around lifts and some other place such that building experience negligible torsional effects.

7. Analysis for dynamic load

After complete design of superstructure for static condition, you should check for dynamic cases. If the structure is in allowable limit then its ok otherwise revise the dimension.

8. Design basement wall

Basement wall is constructed to retain the earth and to prevent moisture from seeping into the building. The basement wall should be designed for lateral soil pressure and surcharge load.

9.Design of foundation

From complete analysis of superstructure, you will get force and moment from all column. Then you can go for foundation design. Based on loading intensity, the bearing capacity of soil, select suitable types of footing. After selecting footing, you can design it either manually or using design software like SAFE, STAAD foundation.

10.Design outputs

The design output are drawings. After completing all, you have to prepare complete report of structural analysis.

 Note: Some of the topic had discussed before in detail, you can reached there just in one click in blue underlined text. The remaining portion will be uploaded in upcoming days.

For motivating me to prepare this topic, special thanks to

Ebin Nakarmi, a final year Civil Engineering student

IOE, Pulchowk Engineering Campus

 Lalitpur, Nepal