地表交通荷载下侧方溶洞对隧道影响研究

Study on influence of side karst cave on tunnel under surface traffic load

针对岩溶地区的地铁隧道建造问题,本文建立地表移动荷载作用下侧方溶洞-隧道耦合模型,分析不同荷载形式对侧方溶洞存在对模型应力场和位移场的影响,并对溶洞与隧道边距和溶洞洞径对隧道的影响进行了研究。研究结果表明:地表交通荷载作用下侧方溶洞对地基位移和应力场有显著影响,随着荷载移动速度增大显著增大;溶洞与隧道边距较小时,地表交通荷载下引起的附加动应力占比随溶洞洞径的增大而增大。地表移动荷载产生的铅垂向Z振级受溶洞与隧道边距影响,当边距不断增大时,振级逐渐减小;当超过环境振动标准规定的振动限值时需要对溶洞进行处理。

Aiming at the problem of subway tunnel construction in karst area,in this paper,the side karst cave-tunnel coupling model under the action of surface moving load is established,the influence of different load forms on the stress field and displacement field of the model is analyzed,and the influence of the edge distance between karst cave and tunnel and the diameter of karst cave on the tunnel is studied.The results show that under the action of surface traffic load,the lateral karst cave has a significant impact on the foundation displacement and stress field,which increases significantly with the increase of load moving speed;when the distance between karst cave and tunnel is small,the proportion of additional dynamic stress caused by surface traffic load increases with the increase of karst cave diameter.The vertical Z vibration level caused by surface movement load is affected by the edge distance between karst cave and tunnel.When the edge distance increases,the vibration level decreases gradually.When the vibration limit is exceeded,the karst cave needs to be treated.