Foundation Interaction

Whenever a mechanical system is placed on a foundation, on or partly on the top layer of the ground, the question remains whether the loads it exerts exceed the maximum allowable loads. Especially dynamic effects by the system are relatively hard to predict. MungosWorks has been asked to develop a measuring system to determine the force interaction with the mechanical system and the foundation, which can be places within the current system.

From our analyses it seemed that, in order to get reliable data:

• four measuring positions have to be present within the system
• the measuring equipment has to have a similar stiffness to the current structure

Within all boundary conditions four measuring sticks were used which could easily be integrated temporarily in the current system. By executing every measuring stick in such a way that it could be fitted inside a foundation post, a measuring system was created which was easy to assemble.

Every measuring stick contains to fundamental elements:

• a sensor area capable of measuring deformations
• a measuring unit capable of storing data and sending it to a pc

In order to get complete data about the direct interaction between the ground and the mechanical system, two angle meters are also present. These angle meters measure the rotation of the foundation. It is expected that in case the ground is very hard (concrete/dry clay) the post will hardly rotate. If a softer soil is used, rotations will certainly take place and they will be recorded.

The maximum sample rate is 25 Hz with an accuracy of 0.1 kg horizontally and 1 kg vertically. Both angle meters measure angles between -18° and 18° with an absolute accuracy of 0.2°.

From computer model to real-life product