Tree wind load measurement method

Abstract

The invention discloses a tree wind load measurement method. The measurement method comprises the steps of measuring a bending moment, a torque and wind force generated by a tree trunk under the action of a wind pressure, and an acting point position of the wind force. A wind load is obtained by the steps of mounting deformation sensors at different positions and azimuthal angles of the tree trunk and performing measurement to obtain a relationship (epsilon max=f(v2)) among a maximum linear strain, a maximum shear strain and a wind speed generated by the tree trunk under the action of strong wind; then under the no-wind condition, performing a manual tension test on a tree, and establishing a relationship (M=g(epsilon max)) among the bending moment, the maximum linear strain and the shear strain; and finally according to the two formulae, establishing a relationship (M=g(epsilon max)) between the bending moment and the wind speed, wherein the relationship is called as a wind-induced bending moment characteristic equation. For the selected tree, the wind-induced bending moment characteristic equation of the tree has specificity and conditional uniqueness. Based on this, a wind load on a tree crown and an acting point position also can continue to be determined. The method solves the difficult problem of difficulty in determining the wind load of the tree, and can be used for monitoring / predicting wind damage resistance of trees in forest regions, urban street trees and ancient and rare trees in gardens.

Description

technical field [0001] The invention belongs to the technical field of forest wind disaster monitoring / prediction, and can accurately evaluate the safety of trees under different wind speeds by measuring the magnitude of the wind load formed by wind pressure on trees and the position of the action point. Background technique [0002] Since the wind force or wind bending moment formed by the wind pressure on the trees will be affected by many factors such as the shape and size of the canopy, the characteristics of the leaves, the height and width of the forest belt, the ventilation coefficient, the topography, the wind direction, and the wind speed, etc., how to quantify the wind pressure The wind force or wind bending moment acting on the trees in the forest area is a problem that has not been well solved so far, and thus affects the accuracy of the risk assessment of trees breaking and lodging under strong winds. Although many influencing factors have been simplified in the...

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Problems solved by technology

[0002] Since the wind force or wind bending moment formed by the wind pressure on the trees will be affected by many factors such as the shape and size of the canopy, the characteristics of the leaves, the height and width of the forest belt, the ventilation coefficient, the topography, the wind direction, and the wind speed, etc., how to quantify the wind pressure The wind force or wind bending moment acting on the trees in the forest area is a problem that has not been well solved so far, and thus affects the accuracy of the risk assessment of trees breaking and lodging under strong winds

Although many influencing factors have been simplified in the existing foreign methods for measuring wind loads on trees, there are still many parameters that are not easy to determine in the relationship between wind bending moment and wind speed.

Due to the inconvenient or rough acquisition of parameters, it not only affects the effectiveness and convenience of tree safety assessment, but is even difficult to implement

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