广州地铁隧道冻结工程冻土力学特性试验研究  

Mechanical Properties Study of Artificially Frozen Soil in Tunnel Engineering of Guangzhou Metro

作　　者：郑波[1] 张建明[2] 常小晓[2] 邓友生[2] 顾同欣[2] 

机构地区：[1]中铁西南科学研究院,成都610031 [2]中国科学院寒区旱区环境与工程研究所冻土工程国家重点实验室,兰州730000

出　　处：《地下空间与工程学报》2007年第5期893-897,908,共6页Chinese Journal of Underground Space and Engineering

基　　金：中国科学院寒区旱区环境与工程研究所知识创新工程项目(2004104);中国科学院知识创新工程重要方向性项目(KZCX3-SW-351)联合资助

摘　　要：人工冻结工程中,天然岩土变为冻岩土,其物理力学性质会发生显著变化,而隧道冻结工程的冻土力学参数,是冻结壁设计和隧道开挖的依据。据此展开室内试验,研究结果表明,在相同的土质条件下,温度越低,冻土的单轴抗压强度越高;当蠕变应力小于冻土长期强度时,可用方程ε=AσBtC描述冻土的蠕变过程;而当蠕变应力较大时,上述蠕变方程不适用;在加载应力作用初期,冻土的强度衰减很快,在设计中必须考虑冻土的长期强度,而不能用瞬时强度代替长期强度;在有补给水源的情况下,粉质粘土的冻胀率及融沉系数最大,分别可达26.88%和17.19%。In the ground freezing, natural soil becomes frozen soil, and its mechanical properties have a remarkable change. The mechanical parameters of frozen soil in metro tunnel are the basis of freezing wall design and tunnel excavation. Analyses of the test results show： （ 1 ） Under the same soil condition, the lower the temperature, the higher the uniaxial compressive strength. （ 2 ） When the creep stress is less than the long - term strength of frozen soil, the creep equation can be expressed as ε = Attarc , but when the creep stress is greater ,this equation is invalid. （3）The diminishing of the frozen soil strength is quick in the initial stage of loading, therefore, the long -term strength of frozen soil in the design must be considered, and it cannot be replaced by the instantaneous strength. （ 4 ） In the open system, the frost heave and thaw strain of silty clay is the greatest with a value of 26.88%, 17.19%, respectively.

关 键 词：人工冻结 地铁隧道 力学特性 

分 类 号：TU411.3[建筑科学—岩土工程]