Conceptual design of a building with columns and shear walls

1.

In this question we have to compare the 3 plans

Here let me name it as Option A, Option B and Option C

                  Option A

                Option B

              Option C

2.

Issues in the given framing plan

Indirect lateral load transfer in x and y direction:- The beams are connected to another beam which is ineffective during lateral load transfer, In such conditions, the primary beam prone to shear failure.

Improper transfer of lateral load in x- direction

 Improper transfer of lateral load in y- direction

Eccintricity:- The longer the distance between the center of mass and center of stiffness, the higher torsional moment of building. As per the given plan eccintricity, the building is subjected to higher torsional moment (Torsional flexibility) in both x nad y directions.

• Here red arrow indicates the torsional innfluence during X - direction excitation
• Here blue arrow indicates the torsional innfluence during Y - direction excitation

Strong beam and week column possibility 

The size of the column is majourly mentioned as 25cmx25cm. But all the beam have deeper sections (50cm). Inertia of beam is visually higher than column. If the column reiforcement is adequatly greater than that of beam, we are okay and since we do not have the reinforcement details, this is doubtful. It is recommended to have slight bigger sizes for column

Here the column size is 250x250mm and beam size is 250x500mm this leads to strong beam and weak column

Alternate scheme

• Here all the columns and beams should aligned in straight
• Here beams can be projected from the column to get a chejja / Projected slab

This is the drawing given in the question 

• In this question there is a problem in Improper transfer of lateral load, Eccintricity, and Strong beam and week column
• To avoid this problem the column andd beam placement should be in proper manner

By using this plan all the problems like Improper transfer of lateral load, Eccintricity, and Strong beam and week column can be controlled

3.

Observation in the given framing plan

Floor Plan :- The floor plan of building is not either uniform or symmetric. So Naturally any lateral load induced in the floor will not have 100% influence in same direction. Definitely a special lateral load resisting system for these torsional moments should be accomodated.

Random internal columns :- Since the internal columns are random, they are unable to transfer the lateral load efficiently and cannot achieve desirable building response. So we have to assume and design those column for only gravity load 

Floor to floor variation in partition walls and beams:- Partition walls provides an important mass control in a buildings and beams can play a key role in shear transfer from floor to beam. All these elements are not in order. So heavy distortion and distribution of lateral load will happen.

Suggested on lateral load system and its foundation

• Heavy torsional forces should be controlled by respective lateral load system. So corner shear walls are suggested
• The proportion of floor area is greater on the left side than the left side (irregular quadrilateral). So the corner shear walls on the left side should be heavier than the right
• Corner shear walls preferably supported over a box foundation. Shear walls should be connected by link beams to transfer shear from one to the another
• The internal columns shall be supported by isolated footings. Those isolated footings can be connected with shear wall through tie beam

Proposed schematic plan 

• In the super structure the corner shear walls and link beams are provided to withstand the lateral load 
• In the sub structure the box foundation are provided to extend the corner RC shear wall, tie beams are used to connect between columns, and isolated footings are provided to place and extend the columns

This is the AutoCAD model for super structure

 This is the AutoCAD model for sub structure