Investigation and modeling of deformation structures on ground surface caused by fault rupturing

一般而言，抗震设计方法通常考虑地震振动引起的结构破坏和液化引起的地面运动。然而，在1999年土耳其科卡里地震和台湾集集地震中，都出现了严重的断层破裂对工程结构的危害。2001年，有人提出了利用活动断层上软弱表层的缓冲作用来减轻断层破裂灾害的新设想。设计了各种形式的地面改进方法。本发明作为一种新的地基处理方法申请了专利，申请号为2001 - 316161。结果表明，由吸收层和刚性梁层组成的地基处理效果显著。此外，刚性梁层的抗弯刚度和锚杆的位置被证明是一些重要的设计参数。2003年，通过模型试验，探讨了倾斜滑动断层的合适的锚杆位置。将刚性梁层假定为弹性梁，梁上设置了弹簧，提出了设计计算方法。通过模拟试验结果的试算，验证了该设计模型的正确性。最后，尝试计算的原型行为假设一个铁路货车穿越走滑断层。计算结果表明，所提出的地基处理方法是有效的，以减少对铁路设施的结构损坏显着。

In general, earthquake resistance design methods typically thke into account the structural failures by earthquake vibration and ground movements by liquefaction. However, serious fault rupture hazards on engineering structures were seen in Cokaeri earthquake, Turkey, and Chi-Chi earthquake, Taiwan, in 1999. Thus, this study focuses on mitigation technology for fault rupture hazards.In 2001, a novel idea of mitigation measures was proposed that utilized the cushion effect of incompetent surface layer above active faults. Various forms of ground improvement methods were devised. This invention was patented claiming as a new ground improvement method, Application No.2001-316161.In 2002, a series of physical model tests and numerical analyses were conducted. The results demonstrated that the improved ground comprised of an absorption layer and a rigid beam layer showed remarkable performance. Furthermore, flexural rigidity of the rigid beam layer and locations of anchors were proved to be some of the important design parameters.In 2003, appropriate locations of anchors were investigated for dip-slip faults by the model tests. Design calculation method was also devised assuming the rigid beam layer as elastic beam resting on Whinkler's springs. Then, some trial calculations simulating the experimental results proved that this design model was adequate in predicting the behaviors of the improved ground. Finally, and attempt was made to calculate the prototype behavior assuming a railway truck crossing strike-slip fault. The computed results demonstrated that the proposed ground improvement method was effective in reducing the structural damages on the railway facilities significantly.