摘要
为了研究不同超前支护方式和参数下软岩隧道施工的围岩及结构安全性,基于实际工程,分析了超前大管棚环向间距和超前小导管长度对隧道围岩的变形、塑性区扩展和结构受力情况,得出了以下结论:对于大管棚支护而言,随着大管棚环向间距的增大,隧道受力和变形也逐渐增加。在计算范围内,仰拱隆起变形最大为40.1 mm、塑性区最大为4.19×10^(4) m^(3)、最大拉应力为0.203 MPa。对于小导管支护而言,随着小导管设计长度的增大,隧道受力和变形也逐渐减少。在计算范围内,仰拱隆起变形最大为39.1 mm、塑性区最大为3.79×10^(4) m^(3)、最大拉应力为0.185 MPa。计算范围内,超前小导管的控制效果较好。当大管棚环向间距>0.35 m、超前小导管长度<4 m时,隧道变形、结构受力和塑性区均会大幅度增大,不利于隧道稳定性和安全性。
In order to study the surrounding rock and structural safety of soft rock tunnel construction under different advance support methods and parameters,based on actual engineering,the deformation,plastic zone expansion and structural stress of tunnel surrounding rock caused by the circumferential distance of the advance large pipe shed and the length of the advance small pipe were analyzed,and the following conclusions were drawn:For the support of large pipe shed,the stress and deformation of the tunnel increase gradually with the increase of the annular distance of large pipe shed.In the calculated range,the maximum deformation of invert uplift is 40.1 mm,the maximum plastic zone is 4.19×10^(4) m^(3),and the maximum tensile stress is 0.203 MPa.For the small conduit support,with the increase of the design length of the small conduit,the stress and deformation of the tunnel are gradually reduced.In the calculated range,the maximum deformation of invert uplift is 39.1 mm,the maximum plastic zone is 3.79×10^(4) m^(3),and the maximum tensile stress is 0.185 MPa.In the calculation range,the control effect of the advanced small catheter is better.When the annular distance of the big pipe shed is>0.35 m and the length of the leading small pipe is<4 m,the tunnel deformation,structural stress and plastic zone will increase greatly,which is not conducive to the stability and safety of the tunnel.
作者
廖勇军
LIAO Yongjun(Lushan Branch of Jiujiang Highway Development Center,Jiujiang,Jiangxi 332900,China)
出处
《黑龙江交通科技》
2025年第5期96-100,共5页
Communications Science and Technology Heilongjiang
关键词
软岩隧道
超前大管棚
超前小导管
变形受力
塑性区
soft rock tunnel
advanced large pipe shed
advanced small catheter
deformation and stress
plastic zone
