为得到低强度、低弹性模量,能够在离心机振动台试验中产生破坏现象的模型材料,采用正交试验方法对不同配合比石膏材料进行研究,根据试验结果选出适合土–结构离心机振动台破坏性试验的石膏配合比。并进一步对该配合比石膏进行耐水性研究,结果表明,试验中的防水处理效果显著。对于振动模型试验,相似关系设计是很重要的环节,在试验前期关系到模型尺寸的大小与材料的选取,在试验结束后则关系到试验数据的处理。基于Bockingham定理,采用量纲分析法对土–结构动力相互作用的离心机振动台试验进行模型相似关系设计。在相似设计中,主要考虑要在试验中能够激发出与原型相似的土–结构动力相互作用,因此需要保证土–结构刚度比、结构惯性力满足相似关系。由此,根据相似关系要求,分别得到石膏材料及微粒混凝土材料试验模型结构,并对2种材料模型进行分析。
In order to obtain model material with low strength and low modulus which can be used to make dynamic centrifuge model to study damage phenomena in the dynamic centrifuge shaking table test, orthogonal experimental design method to investigate plaster performance with different mixing proportion are studied. Based on the experiment results, an appropriate plaster mixture is selected to make the model for centrifuge shaking table tests. Furthermore, the plaster is treated by waterproof measures and underwent waterproof test. The results show that the waterproof plaster buried in moist soil can maintain strength and modulus. Similitude design of a model test concerns the size and materials of the model in prophase of a test and also concerns the management of data after the test, so it is very important for shaking table tests. Similitude design of the dynamic soil-structure interaction test on shaking table system for geotechnical centrifuge is carried out by means of dimensional analysis method, which is based on theorem of Bockingham π. The main aim of the similitude design in the system is to induce strong soil-structure interaction as in the prototype. So the similitude design should maintain similar relative stiffness and inertial force between soil and structure as in the prototype. Based on the required similitude, plaster model and micro-concrete model are designed, and the analysis about the two models is conducted.