Dynamic parameters of lowering loads at gradual tree felling

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F62156489%3A43410%2F25%3A43926622" target="_blank" >RIV/62156489:43410/25:43926622 - isvavai.cz</a>

Výsledek na webu

<a href="https://doi.org/10.17221/66/2024-JFS" target="_blank" >https://doi.org/10.17221/66/2024-JFS</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.17221/66/2024-JFS" target="_blank" >10.17221/66/2024-JFS</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Dynamic parameters of lowering loads at gradual tree felling

Popis výsledku v původním jazyce

The lowering of loads at gradual tree felling is the riskiest activity performed by tree climbers. During this activity, great forces emerge and act on the felled tree, while the tree climbers use the tree itself to anchor and secure their stance. This research aims to find out whether certain methods of work or the use of certain rigging for lowering loads exhibit positive features in reducing the forces acting on the anchoring point of the rigging system. The work methodology consists of three operations: (i) the calculation of the coefficient of shear friction for the combination of 4 ropes and 5 lowering devices - altogether 20 combinations; (ii) the mathematical modelling of the maximum forces acting on the lowering loads of known weight; and (iii) the verification of mathematical modelling using a series of measured experiments of lowering loads of known weight. The research results present the calculation of the shear friction coefficient for 20 combinations of rigging rope and lowering devices. The maximum magnitudes of the forces which may act on the upper anchoring point of the rigging system at the known load weight were additionally calculated. A total of 240 force values were measured when a load of 12 kg in weight falls according to a predetermined model situation. The results indicate that the greatest influence on decreasing the impact force generated by the falling load is that of the load attachment, reduced load weight, shortened length of the fall or elongation of the total rope length in the rigging system. The differences in the coefficients of shear friction are apparent in the results of measurements, too.

Název v anglickém jazyce

Dynamic parameters of lowering loads at gradual tree felling

Popis výsledku anglicky

The lowering of loads at gradual tree felling is the riskiest activity performed by tree climbers. During this activity, great forces emerge and act on the felled tree, while the tree climbers use the tree itself to anchor and secure their stance. This research aims to find out whether certain methods of work or the use of certain rigging for lowering loads exhibit positive features in reducing the forces acting on the anchoring point of the rigging system. The work methodology consists of three operations: (i) the calculation of the coefficient of shear friction for the combination of 4 ropes and 5 lowering devices - altogether 20 combinations; (ii) the mathematical modelling of the maximum forces acting on the lowering loads of known weight; and (iii) the verification of mathematical modelling using a series of measured experiments of lowering loads of known weight. The research results present the calculation of the shear friction coefficient for 20 combinations of rigging rope and lowering devices. The maximum magnitudes of the forces which may act on the upper anchoring point of the rigging system at the known load weight were additionally calculated. A total of 240 force values were measured when a load of 12 kg in weight falls according to a predetermined model situation. The results indicate that the greatest influence on decreasing the impact force generated by the falling load is that of the load attachment, reduced load weight, shortened length of the fall or elongation of the total rope length in the rigging system. The differences in the coefficients of shear friction are apparent in the results of measurements, too.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

40102 - Forestry

Projekt

—

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2025

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Journal of Forest Science

ISSN

1212-4834

e-ISSN

1805-935X

Svazek periodika

71

Číslo periodika v rámci svazku

2

Stát vydavatele periodika

CZ - Česká republika

Počet stran výsledku

13

Strana od-do

86-98

Kód UT WoS článku

001427195800001

EID výsledku v databázi Scopus

2-s2.0-85218440553