Conceptual design of a building with columns and shear walls

1.

Criteria		a	b	c
Restraint of floor shrinkage	observation	full restraints at all corners	corners are left free but restraints along the edges	non-uniform retraints
	conclusion	option (a) will have high restraint to shrinkage , thus lead to cracks in floor	its average	it will not effectively restraint the shrinkage ,so possibly less cracks
The lateral stiffness	observation	comparatively lower lateral stiffness in both x & y	uniform & comparatively higher lateral stiffness in both x & y	non uniform lateral stiffness in both x & y
	conclusion		it will provide higher lateral stiffness for pure seismic acceleration in X & y direction
torsion with respect to vertical axis	observation	corner walls provide more resistance to twist	edge walls provide good resistance to twist	irregular walls provide poor resistance to twist
	conclusion	its is best		its worse
vertical reinforcement for similar base capacity	observation	walls are subjected to nominal flexural and heavy twisting moment	walls are subjected to nominal twisting moment	walls are subjected to heavy flexural and heavy twisting moment
	conclusion		it requires least	it requires higher vertical reinforcement
static eccentricty	observation	structurally symmetric	structurally symmetric	un symmetric
	conclusion			it will have static eccentricity & its significant
system redundancy	observation	uniform placements of lateral load supports in both axes	uniform placements of lateral load supports in both axes	concentrated lateral load supports in both axes
	conclusion	its more redundant	its more redundant	less redundant
foundation system	observation	Due to L shaped walls , geometry of foundation and design will be critical	walls are in line. Easy to fix the geometry and design of foundation	walls are in line & conentrated . Easy to fix the geometry and design of foundation
	conclusion	it recommended to have peripherical box foundation	it should be incorporated with isolated /strip footing	it should be incorporated with isolated /strip footing
Architectural constraints	observation	walls obstruct only corners	walls obstruct the faces of the building	vertical wall will not allow passage
	conclusion	its preferred	subjected to discussion	not recommended

2. issue in the given framing plan:

Indirect lateral load transfer in X & Y directrions: The beam is connected to another beam which are ineffective during lateral load transfer. in such conditions, primary beam is prone to shear failure.

Eccentricity :

The longer the distance between center of mass and center of stiffness , the higher the torsional moment of the building. As per the given plan eccentricity , the building is subjected to higher torsional moment (torsional flexibility) in both X & Y direction

Strong beam Weak column possibility

The sizes of column majorly mentioned as 25cm*25cm , but all the beams have much deeper sections 50cm. Inertia of beams is visually higher than the column. if the column reinforcement is adequatelt greater than that of the beams , it ok and since we do not have reinforcement details , this is doubtful. it is recommended to have slightly bigger sizes of column.

3. floor plan - The floor plan of the 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 interanl columns- Since internal columns are random , they are unable ton transfer lateral loads effectively and can not achieve desirable building response . so we have to assume and design those columns for only gravity loads

Floor to Floor variations in partition walls and beams- partition walls provide an important mass control in a building and beams play key role in shear transfer from floor to beam. All these elements are not in order. So heavy distortion and distribution of lateral loads will hapen.

Suggestions on lateral load system &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 left side than the right side (irregular quadrilateral) . So corner shear walls on the left side should be heavier than the right.

corner shear walls shall preferably be supported over a box foundation. Shear walls should be connected by link beams to transfer shear from one to other.

The internal columns shall be supported by isolated footing. Those isolated footing can be connected with shear walls through tie beams.