地温对冻土动力特性及其场地地震动参数的影响

地温是影响冻土力学性质的重要参数之一。本文基于对2001年11月14日昆仑山口西8．1级大震在多年冻土区所造成的地表变形与地震破坏特征的定量调查结果，通过冻土的振动三轴实验，研究了地温对冻土动本构关系、动弹性模量、阻尼比、动强度等动力特性参数的定量影响规律；进而利用青藏铁路沿线4个冻土剖面和该区50年超越概率分别为63％、10％和2％的场地基岩地震动时程，分析计算了不同地温下冻土场地地震动参数的特征，研究了地温对冻土地面地震位移、速度、加速度和反应谱等的定量影响，为冻土区工程地基、路基以及地下工程震害防御提供了科学依据。

The Influence of Earth Temperature on Dynamic Characteristics of Frozen Soil and the Parameters of Ground Motion on the Sites of Frozen Soil

Earth temperature is one of the most important factors of influencing the mechanical property of frozen soil. Based on the field investigation to the characteristics of ground deformation and ground failure caused by the west of Kunlun mountain pass M8.1 earthquake, the influence of temperature on dynamic constitutive relationship, dynamic elastic modulus, damping ratio and dynamic strength of frozen soil were quantitatively studied by means of dynamic triaxial test. Moreover, the characteristics of ground motion on frozen soil site under different temperatures were analyzed for the four profiles of frozen soil along the Qingzang Railway using the time histories of ground motion acceleration with 3 exceedance probabilities of the Kunlun mountain area. The influences of temperature on seismic displacement, velocity, acceleration and response spectrum on frozen ground were quantitatively studied. A scientific basis was presented for earthquake disaster mitigation of grounds of structures and highways and underground engineering in the frozen soil areas.