Earthquake-proof of Concrete Stave Silos with Structural Discontinuity

混凝土壁筒仓是分段式筒仓结构，由称为“壁”的预制混凝土块圆柱形组装而成，并由外部可调节的钢箍固定在一起。采用1/8比例的壁弹模型和圆柱壳模型进行了振动台试验。本文还研究了杆的连接和材料的储存对动力性能的影响。试验结果表明，混凝土壁仓的滞回恢复力特性除了受储料的阻尼作用外，还与结构的不连续有关。为了对具有这种结构不连续的混凝土壁仓进行动力分析，提出了一种新的离散模型——“壁仓单元”。提出了一种确定筒仓构件弹簧刚度的方法：首先计算连续筒壳的等效弹簧刚度，然后估计等效刚度的折减系数。为验证隔层筒仓单元及等效刚度及其折减系数方法的有效性，对某隔层筒仓模型进行了地震响应分析，并与试验结果进行了比较。达成了很好的协议。

Concrete stave silos are segmental silo structures which are cylindrically assembled from precast concrete blocks called "staves" and held together by exterior adjustable steel hoops.A series of shaking table tests was performed using a 1/8- scale stave sile model and a cylindrical shell model. The effects of the joints of staves and of a stored material on the dynamic behavior are also investigated. The experimental results reveal that the hysteretic restoring force characteristics of concrete stave silos are caused by not only the damping effect of a stored material but also their structural discontinuity.For dynamic analysis of concrete stave silos with such structural discontinuity, a new discrete model called "stave silo element" is developed. A method for determining spring stiffness in stave silo elements is also proposed : at first, the equivalent spring stiffness to the continuous cylindrical shell are calculated and then a reduction factor of the equivalent stiffness is estimated. To verify the validity of stave silo elements and the method of the equivalent stiffness and its reduction factor, seismic response analyses of a stave silo model are carried out and compared with its experimental results. A good agreement was obtained.