Question:
How do I enter member elastic foundations? The question arises for a bored pile that is oriented in the global Z-direction and has different horizontal foundations in the global X- and Y-directions.
Answer:
The parameters for entering the elastic member foundations are based on the coefficients of the surface foundations.
The coefficients always refer to the local member axes (x, y, z). The coefficients C-1,x, C-1,y, and C-1,z describe the translational spring values in the direction of the local member axes (x, y, z).
The value C-φ expresses a rotational restraint of the member about its longitudinal axis.
The values C-2,x, C-2,y, and C-2,z affect the consideration of the shear resistance of the foundation soil in the direction of the local member axes (x, y, z).
The entry always refers to a width of 1 m. If the member has a smaller width, you need to consider this in the coefficients; for example: in the case of a member with a width of 30 cm, C-1,z = 10,000 kN/m³ × 0.3 m = 3,000 kN/m².
To enter different horizontal foundations in the global X- and Y-directions, you should first consider the local axes of the member. Then, you can enter the spring constants according to the directions.