摘要
以在建的石家庄市曹家庄小净距公路隧道为例,采用离散元UDEC数值力学模型,研究偏压浅埋大跨小净距隧道失稳模式和支护要点。研究表明:在浅埋地形偏压条件下,浅埋侧隧道节理破坏是小净距隧道整体稳定性的关键控制部位。浅埋侧隧道拱肩岩块先沿结构面滑移,接着中夹岩柱失稳,然后深埋侧隧道坍塌,施工中应重点监测浅埋侧隧道拱肩和边坡地表变形。锚杆可有效控制结构面滑移,改善节理强度,从围岩内部进行加固。
By taking of Caojiazhuang small-distance highway tunnel in Shijiazhuang city, discrete element method UDEC was performed to investigate its instability mode and support technique. Inspection of results reveals that under shallow depth the most important part of small-distance tunnel is the shallower tunnel. The instability procedure begins with spandrel＇s shear slipping. Then interval pillar failures and sequentially the deeper tunnel collapses. In the process of construction, the deformation of spandrel of shallower tunnel and surface of slope should be paid more attention. Rock bolts can effectively control the shearing slipping of joints with the aiming at improving strength of joints, which could reinforce substantially inside surrounding rock.
出处
《建筑技术》
北大核心
2017年第4期346-349,共4页
Architecture Technology
基金
国家自然科学基金资助项目(51178399)
关键词
偏压
离散元
小净距隧道
失稳模式
节理岩体
unsymmetrical pressure
discrete element method
small-distance tunnel
instability mode
jointed rock
