金塘海底隧道人工冻土力学特性研究  

Mechanical characteristics of artificial frozen soil of Jintang subsea tunnel

作　　者：刘华吉 Liu Huaji(China Railway Siyuan Survey and Design Group Co.,Ltd.,Wuhan 430063,China)

机构地区：[1]中铁第四勘察设计院集团有限公司,武汉430063

出　　处：《工程勘察》2021年第10期30-34,共5页Geotechnical Investigation & Surveying

摘　　要：为获取宁波至舟山铁路金塘海底隧道工程穿越的土层在人工冻结条件下的力学性质,勘察期间,在不同温度和不同含水率条件下,对选取的海底典型的粉质黏土和粉土地层重塑样品,开展了人工冻结条件下的单轴抗压强度试验。试验结果表明:人工冻土的力学性质受冻结温度的影响明显,冻结温度自-5℃降低至-20℃过程中,粉土层和粉质黏土层的人工冻土单轴抗压强度逐渐增大,其泊松比逐渐减小。含水率的不同对粉土层和粉质黏土层的力学性质有一定影响,粉土人工冻土的抗压强度在含水率为30%时最大,粉质黏土试样在含水率为34%时,其抗压强度最大。两种土层在人工冻结过程中均存在最优含水率,超过最优含水率时,人工冻土的强度将逐渐减低。研究成果可为金塘海底隧道冻结法设计和施工提供参考。In order to obtain the mechanical properties of the soil around Jintang subsea tunnel project of Ningbo-Zhoushan Railway under artificial freezing conditions,the uniaxial compressive strength tests are carried out on the selected typical silty clay and silt remolded samples with artificial freezing conditions under different temperatures and water contents.The test results show that the mechanical properties of artificial frozen soil are obviously affected by freezing temperature.When the freezing temperature decreases from-5℃to-20℃,the uniaxial compressive strength of the artificial frozen soil increases gradually,and the Poisson's ratio of artificial frozen soil decreases gradually.The different water content has a certain effect on the mechanical properties of silty soil and silty clay layer.The compressive strength of the artificial frozen silt in Jintang subsea tunnel is the maximum when the water content is 30%,and when the water content is 34%the uniaxial compressive strength of silty clay samples is highest.There is the optimal water content in the artificial freezing process of the two soil layers.The strength of the artificial frozen soil gradually decreases when the soil moisture content exceeds the optimal value.The study results can provide the reference for the design and construction of Jintang subsea tunnel with freezing method.

关 键 词：人工冻土 抗压强度 泊松比 含水率 

分 类 号：TU445[建筑科学—岩土工程]