摘要
冻岩隧道施工中,开挖、初衬、保温层和二衬等作业,产生的施工热量及洞内外空气的热交换,将影响冻土围岩原始地温场。这种地温场的扰动,破坏了冻土地层的热力学平衡,使其冻土的热物理力学性能发生改变,其中包括冻土的融沉性、冻土回冻过程的膨胀性以及隧道的稳定性等工程力学性能。因此,保护冻土、减少施工对冻土原始地温场的扰动是冻土隧道施工的重要控制因素之一。通过建立冻土围岩、支护衬砌结构、隔热保温层和洞内环境气体热力学模型,根据实际工况和实测洞内环境温度及地温,应用ANSYS有限元程序,对不同施工工况下围岩的温度场变化进行模拟,分别研究毛洞暴露时间、初衬施作时机、初衬持续时间等不同状况下,冻岩温度场的扰动规律、融化圈深度。根据不同施工方法下融化圈大小对洞室稳定性的影响,为冻土隧道施工控制和决策提供科学依据。
During the tunnel construction in permafrost regions, construction heat and heat exchange of air inside and outside the tunnel caused by excavation, primary lining insulation, and secondary lining will affect original ground temperature field of the surrounding rock. This influence will destroy thermodynamics balance of the permafrost stratum and change mechanical characteristics （thawing and sinking, dilatability, stability of tunnel, etc.） of permafrost. So, it is one of the important controlling factors during tunnel construction in permafrost regions to protect permafrost and to reduce the influence of original ground temperature field caused by construction. According to the establishment of thermal model of frozen surrounding rock, primary lining structure, insulation material and circumstance air inside the tunnel and on basis of construction method, surrounding temperature, and ground temperature, the surrounding rock temperature fields of different working procedures are simulated with finite element program ANSYS. The rules of surrounding rock temperature fields and the depths of thawing caused by uncovered time of gross tunnel and primary lining are analyzed. According to different constructions, the effects of stability of tunnel surrounding rock caused by the depth of thawing are studied, whieh can proyide theoretic basis and reference to the design and construction of similar projects,
出处
《岩石力学与工程学报》
EI
CAS
CSCD
北大核心
2005年第A02期5693-5697,共5页
Chinese Journal of Rock Mechanics and Engineering
关键词
隧道工程
冻岩
水化热
融化圈深度
围岩稳定性
tunneling engineering
frozen rock
hydration heat
depth of thawing range
stability of surrounding rock mass
