Stability study of mature trees through numerical modelling

• Main Author: Zhang, Hanqing
• Other Authors: Harianto Rahardjo
• Format: Final Year Project
• Language: English
• Published: 2016
• Subjects: DRNTU::Engineering
• Online Access: http://hdl.handle.net/10356/67499
• Institution: Nanyang Technological University

The study of stability of mature trees is not a new topic but most of the studies conducted were from an arboricultural point of view and not enough studies were conducted from an engineering point of view. This project aims to use an engineering approach to explain the factors that could affect the stability of mature trees. Numerical models of matured tree were established to study the effects of various common geometrical and structural parameters on the stability of matured trees. One of the parameters studied was root flare. In this study, root flare of the tree model was reduced. The reduction of root flare resulted in a smaller critical wind load to break the (tension) windward root of the tree. Another parameter studied was the root architecture. Lateral roots were severed one or more at a time and the simulation results showed that the loss of tension roots has a much more significant impact towards tree stability. The third parametric study conducted was on lean angle of tree. The trunk of the tree model was rotated and critical wind velocity was determined. The result showed that trees are more prone to failure when subjected to wind load in the direction of the lean. The last parametric study conducted was defect study. Defect was added to the tree model and critical wind velocity was determined. The results from simulations showed that the location and size of defect have great impacts on the tree stability.