An improved calculation model for predicting the coefficient of restitution and maximum impact force of rockfalls
- PDF / 876,759 Bytes
- 10 Pages / 595.276 x 790.866 pts Page_size
- 74 Downloads / 235 Views
ORIGINAL PAPER
An improved calculation model for predicting the coefficient of restitution and maximum impact force of rockfalls Xuefeng Mei 1 & Xiewen Hu 1,2 & Zhenhua Zhou 3 & Gang Luo 1 & Jianli Wu 1 Received: 4 June 2020 / Accepted: 11 September 2020 # Saudi Society for Geosciences 2020
Abstract Rockfalls, which are a common natural hazard, collide and continuously bounce along slope surfaces during their movement; the coefficient of restitution (COR) and impact force are two important characteristic parameters related to the impact process of a rockfall. In this paper, considering the elastoplastic characteristics of the ground material, a theoretical model is proposed to obtain the normal COR and normal impact force at different stages of the impact process. Subsequently, the tangential COR and tangential force are calculated based on the improved friction theory. Finally, an engineering case is studied to illustrate the applicability of the proposed model. The calculation results show that the COR is positively correlated with the incident angle under the same incident velocity and negatively correlated with the incident velocity under the same incident angle; the impact force is linearly and positively correlated with the incident velocity. Under a given slope condition, the theory proposed in this paper can explain the locking phenomenon between the boulder and the slope during impact. Keywords Rockfall . Oblique impact . Energy principle . Impact force . Coefficient of restitution (COR)
Introduction As a kind of common geological hazard in alpine valley areas, rockfalls with the characteristics of uncertainty, randomness, and high energy pose a significant threat to life, housing construction, transportation, and environment (Crosta and Agliardi 2003). On July 25, 2009, a huge boulder with a volume of more than 50 m3 and a mass of more than 130 t destroyed the Chediguan Bridge in Sichuan, causing 6 deaths and 12 injuries (He et al. 2019; Li et al. 2016). Similarly, Nepal is one of the countries most affected by mountain disasters (Kharel and Dhakal 2013; Shroder and Bishop 1998; Responsible Editor: Zeynal Abiddin Erguler * Xuefeng Mei [email protected] 1
Faculty of Geosciences and Environment Engineering, Southwest Jiaotong University, Chengdu, Sichuan, China
2
Engineering Laboratory combined with national and local of spatial information technology of high speed railway operation safety, Southwest Jiaotong University, Chengdu, Sichuan, China
3
State Key Laboratory of Geomechanics and Geotechnical Engineering, Institute of Rock and Soil Mechanics, Chinese Academy of Sciences, Hubei Wuhan, China
Regmi et al. 2014). For example, during the monsoon of 2014, the Jure rock avalanche claimed the life of more than 150 people, completely destroyed 1.5 km of road, and damaged cultivation land (Regmi et al. 2016). In Italy, rockfalls represent a primary cause of landslide fatalities (Guzzetti 2000). In special, the largest rockfall disaster in recent European history occurred on October 12, 2007, and a
Data Loading...
