井架模型极限载荷试验

Ultimate load test of derrick model

为了研究井架承载至破坏整个过程,利用相似模型进行井架试验是非常必要的。应用相似理论制作了1∶13.3的JJ315/43—A型井架相似模型,在该模型上进行了井架安全承载试验与井架压溃破坏试验。由井架安全承载试验结果可知:井架上段为受力较大部位;井架立柱测试应力与大钩作用载荷呈线性关系。井架压溃试验发现:井架破坏发生在井架上段;实测井架模型大钩极限载荷为19.0kN,与双重非线性有限元分析计算结果基本一致,其相对误差在5.0%以内,证明以这种方法预测井架原型极限载荷是可行的。

To make clear the overall process of derrick loading and collapse, it is necessary to make a test of the derrick by using the similar model. So the model of JJ315/43-A was made by taking the scale proportion of 1: 13.3 on the basis of the similarity theory, and safety bearing capacity test and collapse test were completed by means of this model. The safety bearing capacity test shows that, the upper portion of the derrick is an area loaded heavily, and the measured stress on the derrick stand is linear to the hook load. The collapse test shows that the breakdown occurred on the upper portion the derrick. The measured ultimate load of the derrick hook is 19.0 kN, which is nearly equal to the value calculated by double nonlinearity FEM method, with a relative error of less than 5.0%. This proves the feasibility of this method for forecasting the ultimate bearing capacity of real derrick.