hi does anybody has info. about the subgrade modulus coefficient, k (t/m3) can be used for the settlement amount? if the mat foundation system is rigid and the layer below it is sandy silty clay; as far as i know it can not be used for the settlement calculations. it is only used for differencial deformations.? empric correlations recommended for the k coefficient is 1500-2000 t/m3 for this soil structure. But if you calculate that from the formula (Braja Das. "princ. of foun. engng.)it will be app. 150-200 t/m3.
and consequently: if you use emprical values the settlement value is 1-2 cm. and if the other, the sett. is 12-13 cm. if i calculate the settlement by classical stress distribution method, it will be 15 cm.
i use this modulus as a soil parameter to the SAP2000 programme.
would you tell me that which value is reliable? and can i calculate the settlement amount by this way?.. thanks..
thank you Paul, i have two things that i need more info? 1st as far as i understand, the subgrade reaction coefficient Kh (t/m3) can not be used for the setllement analysis. it is only used for deflection of the foundation.? is settlement only determined by E (t/m2) layer by layer?
2nd if i derive Kh (t/m3) by Kh=E/b(1-u2) it is app. 100-150 t/m3 but emprical correlations give 1500-2000 t/m3. in addition, 1st value represents very soft and slime soil condition? but it is not really. what is the difference betw. them.?