Buildings are in a constant exposure to the external as well internal forces that may cause damage. In order to stand against the threatening forces, the structures need to be designed safely and for this a continuous improvement in the construction techniques is necessary. With the advancement in the structural design and the capability, it becomes safer to inhabit in them.
The earthquake force that evolves and then reaches the foundation of building can transform into different forms of forces. The earthquake force might turn into tension, compression, shear, torsion forces or become momentum force that tends to create turning effects in the structure.(Adedeji, 2011)
Out of all the forces that evolve within the structure or are imposed on the outside of the structure, the most prominent of them is the horizontal force also known as shear loads that might get created due to the lateral earth pressure. These horizontal forces tend to cause a slip of the building foundation and hence the structures can slide past their original placement (Adedeji, 2011).
In addition to this, the horizontal forces that develop in the structural members on the top floors of a multi-storied building move towards the bottom of the structure and to the in-plane shear loads on the walls at the lowest level of the structure. In a similar way, just like the shear loads, there are uplift and toppling affects that impact the building. As these affects are originated, these move further onward towards the bottom to the corner of the wall and at this corner point, these forces try to lift and rotate the structural wall along the axis at which the lower corner of the wall lies.(Adedeji, 2011)
Keeping these drastic overturning phenomena in view, it is crucial that the pre-cast structural members such as the timber shear walls be designed with shear resistance with a value that is enough to resist against the natural/non-natural application of forces on the structure. The shear resistance of a wall plays a vital role in avoiding serious injuries and catastrophes as the chances of collapse and damage that might be imposed on the structure are mitigated. (Adedeji, 2011)