滚石冲击荷载作用下土体屈服特性研究

 滚石冲击压力是滚石防护结构设计的重要参数，当不考虑被冲击材料的弹塑性特性时，获得的冲击压力非常大，几乎不能用于工程设计。而实际岩土材料均为弹塑性体，在滚石冲击压力下，会产生很大的塑性变形，为此，必须研究土体的初始屈服压力作为判断土体是否开始进入屈服的条件。以Hertz接触力学为基础，假设土体服从莫尔–库仑屈服准则，研究土体在滚石冲击荷载作用下的初始屈服压力和初始屈服冲击速度。研究结果表明：土体初始屈服冲击速度非常小，其中黏聚力对其有较大影响，而内摩擦角对其影响相对较小。

RESEARCH ON YIELD PROPERTY OF SOIL UNDER ROCK-FALL IMPACT

The impact pressure of rock-fall is an important parameter for shield structure design. While not considering the elastoplastic properties of impacted object，the value of impact pressure becomes extremely high and can¢t be used in project design. However，the actual rock-soil materials are all elastoplastic bodies and will produce great plastic deformation under the rock-fall impact. For this purpose，the initial yield pressure should be studied and serve as a basis for judging whether the materials begin to yield or not. Based on the Hertz contact mechanics，under the assumption that the soil obeys the Mohr-Coulomb yield criterion，the initial yield pressure and the corresponding impact velocity of soil are studied. The result shows that the impact velocity of initial yield is very small for the soil，and the cohesion has an obvious influence on it while the internal friction angle does relatively small.