In the last posts about mat foundation, we have discussed many parameters that are used in analysis and design of mat foundation. Say these parameters are:
a. Es=modulus of elasticity of soil
b. µ =Poisson’s ratio
c. Ks=q/δ=Modulus of subgrade reaction in vertical direction
Many parameters with this parameters cannot be predicted accurately as their have many difficulties. To account this problem, geotechnical engineers and structural engineers together perform a study called parametric study.
In this parametric study engineers vary the values that are used in foundation design. There have a range of variation. This is
(1/2 X furnished value) to (10Xfurnished value)
With this wide range of variations in parameters, the geotechnical engineers carefully review the results through the whole design process.
When engineers are not satisfied with solutions, then it is assumed appropriate adjustments are done in development concept. Now we will know what the adjustments are. The adjustments are:
1. Reduction in weight of structure
2. Enlarging mat foundation area
3. Reducing net pressure changing mat base area
It should keep in mind that, the adjustments should take in presence of both structural and geotechnical engineers.