基于崩塌滚石运动特征的防护网动态响应规律

Dynamic Response Laws of Flexible Rockfall Barriers Based on Movement Characteristics of Rockfall

为获取被动柔性防护网在不同崩塌滚石运动特征下的动态响应规律,以鲁甸803地震震后崩塌滚石造成防护网损坏现场为例,通过无人机倾斜摄影技术实现地质调查,采用Rockyfor3D获取研究区落石的运动特征,并通过被动柔性防护网有限元模型,对不同落石冲击形式下防护网的动态响应规律进行研究.研究显示区内落石弹跳高度普遍在1~2 m,优势路径上的落石会形成稍高速低弹跳的范围冲击.在范围落石冲击下,防护网绳索最大拉力增加可达123.7%;在低弹跳落石冲击下,绳索最大拉力增加可达181.2%.范围落石冲击会导致防护网网面耗能的降低,并导致上拉锚绳拉力的增大.防护网下一级支撑绳对不同落石弹跳高度的响应较为敏感,部分高弹跳落石会对上拉锚绳和上一级支撑绳产生影响.

In order to obtain the dynamic response laws of the flexible rockfall barriers under different rockfall movement characteristics,taking the site where the flexible barriers were damaged by rockfall after the Ludian 803 earthquake as an example,the geological survey was carried out through the UAV tilt photogrammetry technology,Rockyfor3D was used to obtain the movement characteristics of the rockfall in the study area.And through the finite element model,the dynamic response laws of the flexible barrier under different rockfall impact forms are studied.The research shows that the bounce heights of rockfall in the area is generally between 1-2 m,and the rockfall on the dominant path will form a scale impact with slightly high speed and low bouncing.Under the scale rockfall impact,the maximum tensile force of the flexible barrier rope can be increased by 123.7%;under the low-bounce rockfall impact,the maximum tensile force of the rope can be increased by 181.2%.The scale rockfall impact will reduce the energy consumption of the flexible barrier net and lead to the increase of the tensile force of the upslope anchor rope.The lower primary support rope of the flexible barrier is more sensitive to the response of different rockfall bounce heights,some high-bounce rockfall will affect the upslope anchor rope and the upper primary support rope.