Experimental and theoretical analysis of the fall of a climber secured by a rope

Sportsko penjanje je ekstremni sport u kojem penjači penju isključivo opremljene smjerove. Da bi napredovao u visini penjač se koristi samo svojim tijelom, dok oprema služi isključivo kao osiguranje od pada. Iako kod sportskih penjača u fokusu nije visina već savladavanje teških detalja stijene, u ovom radu fokus je na proučavanju pada penjača osiguranog užetom. Obzirom da je uže elastično, prilikom pada penjača ono će amortizirati pad i na koncu zaustaviti penjača. U radu nas je zanimalo kako će na gibanje penjača prilikom pada i na silu koja se javlja u užetu utjecati različiti faktori poput krutosti užeta, duljine izvučenog užeta i visine pada. Za tu potrebu razvijen je fizikalni model s oprugama te je obrađena teorija slobodnih neprigušenih i prigušenih oscilacija. Rezultati modela uspoređeni su s eksperimentima iz literature koji su provedeni na umjetnoj stijeni s penjačima, te eksperimentima s krutim blokovima koji su specijalno za ovaj rad provedeni u Laboratoriju za konstrukcije Građevinskog fakulteta u Rijeci. U oba slučaja, primijećeno je da postoje odstupanja između fizikalnog modela i eksperimenata, što je uzrokovano time što model ne uzima u obzir određene efekte koji na koncu imaju važan utjecaj na gibanje penjača prilikom pada.Sport climbing is an extreme sport in which climbers climb exclusively equipped routes. To advance in height, climber uses only his body, while the equipment serves solely as a fall protection. Although in sports climbers the focus is not on mastering the difficult details of the rocks, in this paper the focus is on studying the fall of climbers secured with a rope. Since the rope is elastic, when a climber falls, it will cushion the fall and eventually stop the climber. In this paper, we were interested in how various factors such as the stiffness of the rope, the length of the pulled rope and the height of the fall will affect the movement of the climber during the fall and the force that occurs in the rope. For this purpose, a physical model with springs was developed and the theory of free undamped and damped oscillations was processed. The results of the models were compared with experiments from the literature presented on artificial rock with climbers, and experiments with rigid blocks presented especially for this work in the Laboratory for Structures of the Faculty of Civil Engineering in Rijeka. In both cases, it was observed that there is a discrepancy between the physical model and the experiment, which is caused by that the model does not take into account certain effects that ultimately have an important impact on the climber's movement during the fall