柔性落石防护系统丝束环形网拉-弯刚度协调模型  

Tensile-bending stiffness coordinated model for wire-ring nets in flexible rockfall protection system

作　　者：金云涛 余志祥[1,2,3] 郭立平 骆丽茹 张丽君 廖林绪 JIN Yuntao;YU Zhixiang;GUO Liping;LUO Liru;ZHANG Lijun;LIAO Linxu(School of Civil Engineering,Southwest Jiaotong University,Chengdu,Sichuan 610031,China;Research Center of Protection Structures Against Natural Hazards,Southwest Jiaotong University,Chengdu,Sichuan 610031,China;National Engineering Laboratory for Prevention and Control of Geological Disasters in Land Transportation,Chengdu,Sichuan 611756,China)

机构地区：[1]西南交通大学土木工程学院,四川成都610031 [2]西南交通大学防护结构研究中心,四川成都610031 [3]陆地交通地质灾害防治技术国家工程实验室,四川成都611756

出　　处：《岩石力学与工程学报》2023年第3期698-707,共10页Chinese Journal of Rock Mechanics and Engineering

基　　金：四川省科技计划项目(2022YFG0141);2020年度交通运输行业重点科技项目(2020–MS3–101);江西省交通运输厅科技项目(2020H0005)。

摘　　要：常用于柔性防护系统的环形网由离散的高强钢丝束编制而成,广泛用于落石灾害防护。既有研究中,环形网常等效为等截面积的圆截面梁单元,该方法无法解决网环的拉–弯刚度协调及失效预测难题。为此,引入网环离散丝束截面的抗拉、抗弯刚度修正系数及拉–弯刚度协调因子,构建了网环的拉–弯刚度协调模型。开展单环和环链拉伸试验以明确模型等效参数,同时揭示了网环接触区失效机制。进一步开展网片冲击试验,比较分析冲击变形、冲击力和网片极限承载能量等关键动力响应指标,分析结果显示,模型的预测误差分别为3.0%,6.6%和5.9%,相较既有等截面模型,对网片极限承载能量的预测精度平均可提高20.4%。拉–弯刚度协调模型能够实现环形网加载刚度和失效点的准确预测,可显著提升落石柔性防护系统的设计精度。Wire-ring nets,consisted of discrete wire bundles,are commonly used for flexible protection system in the field of rockfall disaster protection.The wire-ring nets’numerical models in existing research simplify the discrete wire-bundle section into a circular section with equivalent area,which can’t realize the equivalent tensilebending stiffness of the ring section and is still difficult to accurately predict the failure of wire-ring nets.In this paper,a tensile-bending coordinated model was hereby established by introducing the tensile,bending stiffness correction factors and tensile-bending stiffness coordinated factor of the ring’s discrete wire-bundle section.The tensile tests of single rings and ring chains were carried out to determine the model parameters,and the failure mechanism of the wire-rings in contact area was revealed.The nets impact tests were further carried out,and the key indexes such as impact displacement,impact forces and ultimate bearing energy were analyzed,with relative error 3.0%,6.6%and 5.9%respectively.Compared to the existing area equivalent model,the ultimate capacity prediction accuracy of the new model can be increased by 20.4%in average.The tensile-bending coordinated model can predict the loading stiffness and failure accurately,which improves the design accuracy of flexible rockfall protection system.

关 键 词：防护工程 落石柔性防护 环形网 拉–弯刚度 失效机制 极限承载力 

分 类 号：U41[交通运输工程—道路与铁道工程]