TY - JOUR T1 - Research Note: Observed Symmetry and Force of <em>Plantanus</em> × <em>acerifolia</em> (Ait.) Willd. Roots Occurring Between Foam Layers Under Pavement JF - Arboriculture &amp; Urban Forestry (AUF) SP - 35 LP - 40 DO - 10.48044/jauf.2011.006 VL - 37 IS - 1 AU - Jason C. Grabosky AU - E. Thomas Smiley AU - Gregory A. Dahle Y1 - 2011/01/01 UR - http://auf.isa-arbor.com/content/37/1/35.abstract N2 - Root damage to infrastructure is common in the urban environment. Many problems could be avoided if more were known about tree root growth patterns and the forces involved. This study looks at the growth symmetry and forces from four roots to aid in the development of a computer model.Two primary roots, each from two trees, that were growing between two foam layers under pavement for 10 years were harvested and sectioned to measure radial growth symmetry to assist in the development of a computer simulation of root growth under pavement. The indentations in the foam created by the root growth were replicated using a universal loading press to estimate the radial growth pressure. Root growth was offset upward when close to the tree trunk, but shifted to a downward offset within 1 m from the trunk. Load penetration testing of the foam suggested a minimal load of 0.35–0.40 MPa to replicate the foam deformation. ER -