Surface Spring Supports function of midas Civil is a feature to enter the soil boundary conditions which automatically calculates spring coefficient based on the shared sectional area. However, if the nodes you need to enter the geotechnical boundary conditions are multiple in number, it can become a very cumbersome task. If the geotechnical boundary conditions are to be entered only for a small number of nodes, you can enter as above, taking into account the contribution of each sectional area. Similarly at node 20 and 5, spring coefficient corresponding to the area 0.5m2 and 0.25m2 respectively, has to be entered. For the boundary conditions to represent the soil type at the bottom surface of the water tank, you must enter a value at node 17 to input the spring coefficient corresponding to the area 1m2. Ground Spring Coefficient = Section Area × Ground Reaction Force Coefficient In the figure below, on left, shows a three-dimensional shape with three nodes, and on the right is the plan of the figure, the bottom of the tank. Therefore, Point Spring Supports and Elastic Link has to consider the allotment area for each node to give the spring coefficients in the boundary condition. Point Spring Support is a boundary condition to be entered at a node, and Elastic Link is a boundary condition for entering between two nodes. Midas Civil has boundary conditions, in form of spring stiffness, namely Elastic Link and Point Spring Supports each with six degrees of freedom. Therefore, the boundary conditions of the soil must be in the form of spring having a stiffness rather than full constraints (Supports).

The structure may sink depending on the size and shape of the ground support and the load applied. Ground structure are those which rests on the ground. You can automatically enter a number of boundary conditions representing the ground at once. Surface Spring Supports function of midas Civil is a feature to enter the Soil boundary conditions that is automatically calculated based on the area section shared.

Midas civil boundary condition support