地质力学模型新技术研究——用离心机作静力结构模型试验

A New Technique of Geomechanic Model Experiment-Use of Centrifuge for Structural Model

在一个物理模型上,同时完成应力测验和破坏试验,以及在同一模型上,作强度储备安全系数试验,是实验力学工作者,长期试图解决的一项技术难题。问题的难点是:高容重、低弹模的地质力学模型材料,不能定量地测出应力,而应力模型材料,又不能满足破坏阶段的本构关系,而且,要在物理模型上同时满足外荷载和坝身、基岩自重同步增加,也存在困难。论文作者,在满足物理模型相似条件的基础上,提出了用离心机作为加载工具的办法,解决了上述的困难问题,成功地在同一模型上实现了应力和破坏试验,并获得了强度储备安全系数,从而,提高了模型试验精度,缩短了提供成果周期,节省了试验经费和人力、物力。在“讨论”一节中,作者对一些通常认为有疑虑的问题,作了论证和说明。

In the field of physical model experiment, the technicians of experiment mechanics have long been tempted to solve two problems:One is that stress measurement and failure test could be conducted simultaneously in one model.The other is that the safety factor of strength reserve could be provided in physical model.The main difficulties consist in that stress can't be measured quantitatively in geomechanic model made of materials with high density and low elastical modulus, while materials of stress model do not permit satisfaction of constitutive relation in failure stage. Besides, it's difficult to be realized that water load and the self weight of dam and rock mass increase at a same step.Based on satisfaction with conditions of mechanical similitude, the writer applied centrifuge as loading tool to solve these difficulties. These, tests succeeded in combining stress measurement and failure test in one model and obtained the safety factor of strength reserve. Consequently, the accuracy of model test is improved, the circle of providing test results is shortened, expenses for experiment cost and manual power as well as for materials are reduced. In the section of discussion, some controversial questions are proved and interpreted too.