行人荷载下乐山大佛九曲栈道赋存岩体稳定性研究

Stability analysis of the occurrence rock mass in Jiuqu Plank Road of Leshan Giant Buddha under tourist load

针对乐山大佛九曲栈道地形崎岖多变、长年游人如织的特点,为分析行人荷载对九曲栈道赋存岩体稳定性的影响,建立了九曲栈道区域的精细化模型,采用数值计算方法研究了行人静、动荷载作用下九曲栈道赋存岩体的受力状态及变形特征。结果表明,九曲栈道满载行人时赋存岩体整体稳定,仅局部表层岩体发生破坏。静荷载下L1裂隙底部、L15中下部及栈道底部佛龛的表层岩体受拉破坏;栈道中下部两转角处崖壁、佛脚平台及临江面底部凸出部位的表层岩体易发展为受拉破坏。动荷载下栈道赋存岩体的振动速度均超过规范容许值,在行人动荷载长期作用下易疲劳破坏;栈道上部转角处凸出部位的表层岩体还可能发生瞬时受拉破坏。研究结果对掌握行人荷载下九曲栈道赋存岩体的稳定性现状及预防性加固有指导意义。

The rugged terrain of Jiuqu Plank Road experiences heavy tourist traffic year-round.To assess the impact of tourist loads on rock mass stability,a refined model was established,using numerical simulations to analyze stress and deformation under static and dynamic loads.The results indicate that when the Jiuqu Plank Road is fully loaded with pedestrians,the rock mass is generally stable,with only partial damage to the surface rock mass.Under static load,the surface rock mass of L1 crack bottom,L15 middle and lower parts,and the Buddha niche at the bottom of the plank road are subjected to tensile failure,and the surface rock mass at the two corners of the middle and lower parts of the plank road,the Buddha foot platform,and the protruding part facing the river are prone to tensile failure.The vibration velocities of the rock mass in the boardwalk under dynamic load all exceed the specification allowable value,and it is prone to fatigue failure under long-term pedestrian dynamic load.The surface rock mass at the protruding corner of the upper part of the plank road may experience instantaneous tensile failure.These findings are essential for monitoring stability and guiding preventive reinforcement efforts.