摘要
木寨岭铁路隧道穿越软弱围岩高地应力区,施工中产生强烈变形和严重破坏。变形突发性强,水平变形快,持续时间长,初期支护喷射混凝土开裂严重,部分支护钢架折断,局部边墙挤出侵线,甚至二次衬砌开裂掉块。从岩性条件、地应力、支护刚度、时间因素方面分析了该隧道大变形的原因,按水平收敛值,结合变形特征对大变形等级进行了划分,通过应力释放技术研究,采用预留变形量+三台阶法开挖将高地应力转移,放抗结合,先释放应力,再强支护,及时施作仰拱,隧道支护体系就成为闭合的受力结构,与围岩共同形成受力体系,适时构筑二次衬砌,采取应力释放对解决大变形十分必要。
Muzhailing tunnel pass through stress zone of soft surrounding rock highland,intense deformation and serious failure happened in construction.Deformation of sudden strong,horizontal deformation fast,long duration,initial support of sprayed concrete cracking is serious,part supporting steel snapped,local wall extrusion intrusion line,and even the two lining cracking off block.Analysis of the causes of the tunnel with large deformation,stress from lithology conditions,supporting stiffness,the factor of time,according to the horizontal convergence value,combined with the deformation characteristics of large deformation are divided by grade,stress release technology research,using the reserved deformation+three bench excavation will high stress transfer,put anti binding first,stress release,and strong support,timely applied to do the inverted arch lining,timely build two,take the stress release is necessary to solve the large deformation.
作者
吴发展
WU Fazhan(China Railway Tunnel Group Co.,Ltd.,Luoyang,He’nan 471009,China)
出处
《施工技术》
CAS
2018年第A04期1326-1330,共5页
Construction Technology
关键词
隧道工程
软弱围岩
大变形
地应力释放
tunnel engineering
soft rock
large deformation
stress release
