Reduction of Extreme Earthquake Motions with Sliding Base Foundation

对混凝土基础的滑动特性进行了动力试验和分析，测量了摩擦系数，制定了简单的节点滑动细部。在2011年的试验中，混凝土与混凝土接缝的摩擦系数为0.6 ~ 0.8，而与钢板的摩擦系数则降至0.4。混凝土与混凝土的动摩擦系数为0.66 ~ 0.77，钢板与混凝土的动摩擦系数为0.41 ~ 0.69。在2012年的试验中，采用二硫化钼粉对新的节理细部进行了试验，使节理处的摩擦系数降至0.2 ~ 0.1，稳定降至0.05 ~ 0.07。试验和地震反应分析表明，采用经济可行的基础节点结构，可以使上部结构在极端地震运动下的反应不仅小于安全极限，而且小于破坏控制极限，从而达到理想的失稳抗震体系。

Dynamic tests and analysis were conducted on sliding behavior at the base of concrete foundation to measure the friction coefficients and to develop simple joint details to slide. In 2011 tests, the friction coefficients were 0.6 to 0.8 in case of concrete to concrete joint, while reduced to 0.4 in case with steel plate. Dynamic friction coefficients were 0.66 to 0.77 in case of concrete to concrete, while 0.41 to 0.69 in case with steel plates. In 2012 tests, new joint details were tested with molybdenum disulfide powder so that the friction coefficients at the joints could be reduced to 0.2 to 0.1, down to 0.05 to 0.07 stably. It may be concluded from the tests and earthquake response analyses that the fail-safe earthquake-resistant system could be idealized with economical and feasible joint details at the bases, by which the responses of the superstructures could be reduced less than not only within safety limit but also damage control limit against extreme earthquake motions.