摘要
利用GDS应力路径三轴仪测定了上海第(4)层软黏土的静止土压力系数K_0,并利用弯曲元测定了K_0状态下的土体剪切波速和最大剪切模量G0。同时,测定了等向固结应力状态下的剪切波速和最大剪切模量G0,建立了最大剪切模量G0和等向围压σ'_c的函数关系,推导出G0与静止土压力系数K_0的函数关系,并基于K_0状态下的G0值计算了静止土压力系数K_0,对比了三轴试验得到的K_0真实值及通过计算得到的K_0理论值,以研究利用最大剪切模量G0反算静止土压力系数K_0的可能性。试验研究表明,利用应力路径三轴仪测定K_0系数时,在达到设定围压后,需充分消散加载过程中的超静孔隙水压力来保证K_0值的准确性。同时,基于等向和K_0应力状态下的最大剪切模量G0的K_0反算值和实测值非常接近,这也为根据现场波速测试结合室内试验确定现场K_0提供了可行性。
The coefficient of lateral earth pressure at rest K_0 of Shanghai soft clay is measured by the GDS stress path triaxial device. The shear wave velocity and the corresponding small strain shear stiffness at K_0 state are also determined by the bender elements planned in the triaxial apparatus. The functional relationship between the maximum shear modulus G_0 and the isotropic confining pressure σ'_c is established, and then the functional relationship between G_0 and K_0 is deduced. The possibility of using G_0 to calculate K_0 is investigated. Meanwhile, the value of G_0 at isotropic stress state is also measured and that of K_0 is back calculated based on the values of G_0 at isotropic stress state and K0 stress state. The results indicate that the dissipation of the excessive pore water pressure during the K_0-measurement is very important to obtain the reliable value of K_0. Meanwhile, the back calculated values of K_0 based on the G_0-measurement agree well with the directly measured ones, which indicates the feasibility of K_0-determination based on the field shear wave velocity.
出处
《岩土工程学报》
EI
CAS
CSCD
北大核心
2017年第S2期212-215,共4页
Chinese Journal of Geotechnical Engineering
基金
国家重点研发计划(2016YFC0800202)
中国矿业大学深部岩土力学与地下工程国家重点实验室开放基金项目(SKLGDUEK1712)
关键词
静止土压力系数K0
应力路径三轴仪
弯曲元
剪切波速
K0试验
coefficient of lateral earth pressure at rest K0
stress path triaxial test
bender element
shear wave velocity
K0-test
