摘要
为保证浅埋深富水软弱地层的盾构隧道安全始发,采用人工冻结法进行端头加固。通过在室内进行冻土单轴抗压试验,得到可靠的冻土力学参数,并采用正交试验的方法分析冻结深度、冻结宽度和冻结温度对地表沉降和管片拱顶沉降的影响规律和影响程度,选取确定最优冻结加固方案。结果表明:相同冻结温度下中粗砂抗压强度最大,其次是粉细砂、粉质黏土、黏质粉土,杂填土抗压强度最小;土体冻结温度越低,抗压强度越大;对地表沉降和管片拱顶沉降的影响排序为冻结深度>冻结宽度>冻结温度;最优冻结方案为冻结宽度6 m,冻结深度15 m,冻结温度-20℃。
To ensure the safe start of shield tunnels in shallow,deep,and water-rich soft strata,artificial freezing method was used to reinforce the end of shield tunnels.A uniaxial compressive test of frozen soil was conducted in laboratory,in which reliable mechanical parameters of frozen soil were obtained.In addition,orthogonal test method was used to analyze the influence and degree of frozen depth,frozen width,and frozen temperature on surface settlement and segment vault settlement;and the optimal freezing reinforcement scheme was selected.Results show that under the same freezing temperature,the compressive strength of medium coarse sand is the largest,followed by silty fine sand,silty clay and clayey silt,and the compressive strength of miscellaneous fill is the smallest.The lower the freezing temperature of soil,the greater the compressive strength.The order of the influence on surface settlement and segment vault settlement is freezing depth>freezing width>freezing temperature.The optimum freezing scheme iss freezing width of 6 m,freezing depth of 15 m,and freezing temperature-20℃.
作者
李晓刚
高波
赵育飞
LI Xiao-gang;GAO Bo;ZHAO Yu-fei(CCCC Fourth Highway Engineering Co.,Ltd.,Luoyang 471000,China)
出处
《科学技术与工程》
北大核心
2020年第27期11259-11265,共7页
Science Technology and Engineering
关键词
盾构始发
人工冻土
单轴抗压试验
优化设计
正交试验
shield launching
artificial frozen soil
uniaxial compression test
optimal design
orthogonal test
