Development of fast-operating servo-controlled loading frame for studying earthquake generating processes

本研究项目的主要任务是(1)开发一种新的快速响应的伺服控制加载系统，用于研究断层的组织性质，同时控制不稳定的断层运动；(2)通过对断层内过程的分析，并通过高温实验产生与深部断裂带相同的过程，建立真实的断层模型；(3)开展岩石流变性的基础研究，提出岩石圈和板块边界的流变学模型。在本项目正式投入使用期间，设计并建造了一台可在500kN动态载荷下进行200 Hz循环试验的新型伺服控制试验机，该试验机现可用作高温(至1000ﾟC)双轴试验机，与其他资金建造的卧式压力机和加热炉相结合。该机现已扩展为传统的三轴试验机，具有良好的渗透率测量能力和w…为研究深断裂的本构性质开辟了更多不合理的途径。其他结果如下：(1)研究了岩盐和岩盐-方解石混合剪切带在温度随断层法向应力(地温梯度)的线性增加时，在极端剪切作用下从脆性变形到中塑性变形到全塑性变形的完全转变。否定了以往的断裂模型，提出了新的断裂与板块边界模型。(2)流变学模型揭示了岛弧岩石圈的独特特征，解释了日本岛屿的构造和地震活动。提出了一种新的俯冲板块边界的流变学模型，以解释比较俯冲学揭示的板间逆冲型地震的极端变化。(3)基于已有的包括矿物在内的各种材料的实验数据，提出了Harper-Dorn蠕变。将清水的非平衡态热力学理论推广到晶内扩散蠕变，并将其应用于晶内扩散蠕变。较少

The main task of the present research project has been (1) to develope a new fast-response servo-controlled loading system for studying fault constitive properties while controlling unstable fault motion, (2) to establish a realistic fault model through the analyzes of intrafault processes in fault rocks and through high temperature experiments producing the same processes as recognized in deep fault zones, and (3) to perform basic researches on rock rheology and propose rheological models for the lithosphere and plate boundaries. A new servo-controlled testing machine capable of 200Hz cyclic testing under the dynamic loading to 500kN was designed and built during the official period of this project, and the machine can now be used as a high temperature (to 1,000ﾟC) biaxial machine combined with a horizontal press and a furnace that were built with other funds. The machine is extended now as a conventional triaxial testing machine with good capability of permeability measurements and w … More ill open ways for studying constitutive properties of deep faults. Other results are as follows.(1) Complete transition from brittle, through intermediate, to fully plastic deformation under extreme shear has been studied for halite and halite-calcite mixed shear zones at temperatures increasing linearly with an increase in the normal stress to the fault (as in the case of geothermal gradient). Previous fault models were all denied and a new fault and plate-boundary model was proposed.(2) Rheological model has revealed unique features of island arc lithosphere and explains tectonics and seismicity of Japanese islands. A new rheological model of subducting plate boundaries was proposed so account for the extream variation of interplate thrust-type earthquakes as revealed by comparative subductology.(3) Harper-Dorn creep was proposed based on existing experimental data on various materials including minerals. Predictions from power-law creep will be changed substantially if this is the case.(4) Shimizu's theory of non-equilibrium thermodynamics was extended and applied to intracrystalline diffusion creep. Less