Roots and buildings

摘要

Plants and especially trees enrich buildings. They give shade and improve the ambience, but also can cause damage to the buildings. Roots are biological soil anchorages. The wind load, which may amount to several metric tons and acts on lever arms that may exceed 50 meters in length, causes a high bending moment at the butt of the stem. This bending moment is distributed over the roots into the soil. Thereby, the roots often use structures in the surroundings of the tree like pipes, walls, etc., for anchoring and apply loads to these structures. Loading grows with tree height and root diameter, and when the loading caused by the roots exceeds the strength of the structure, it will fail. Structures of stone are especially sensitive against fatigue failure. In the present paper, examples of such root/building interactions will be given. Furthermore, results of a variant of the Soft Kill Option (SKO) will be presented. The method adapted to soil problems can be used for the optimization of technical soil anchors as well as for the simulation of mechanically stimulated root anchorage.