METHODS TO CALCULATE THE FAULT-RELATED STRAIN
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摘要:
本文介绍了断裂引起的应变量计算方法。断裂作用可导致连续应变和非连续应变。连续应变与断裂位移断裂长度比值及断裂面上有效应力成正相关关系。影响非连续应变的因素有:断裂几何形态、断裂的旋转性、断裂规模。已经提出三种断裂旋转机制:刚性旋转, 垂直剪切和斜向剪切。对于这三种机制, 我们分别建立了断裂非连续应变的计算公式。这些公式与断裂的旋转角度和位移大小相关。刚性旋转时, 断块内部没有任何塑性变形, 因此地层的长度没有变化。它引起的非连续应变最小。垂直剪切作用使断块内地层变形, 但水平方向的地层长度不变。推算的公式表明, 对于相同的原始数据, 它引起的非连续应变比刚性旋转机制引起的非连续应变大。斜向剪切也使断块内地层变形, 但水平方向的长度也不变。在同等条件下, 它引起的非连续应变比垂直剪切机制引起的非连续应变大。
Abstract:This paper presents some methods for calculation of fault strain. The faulting can produce continuous and discontinuous strain. The continuous strain has positive relationship with the ratio of fault displacement vs fault length and with the effective stress on the fault plane. When calculating the discontinuous fault strain, we should consider three factors that affect the establishment of equations: fault geometry, fault rotation, and fault size or fault displacement. There have been three mechanisms of fault rotation: rigid-body, vertical shear, and oblique shear. For these models, the calculation equations are established, respectively. These equations are related to the rotation angle and displacement of fault. For the rigid-body model, the fault has no internal deformation, thus the bed remain its length after rotation. The discontinuous strain due to this mechanism is smallest. The vertical shear produces bed deformation, whereas the horizontal length of bed does not change.The established equation indicates that, using the same data, the discontinuous fault strain is larger than that for the rigid-body model. Similarly, the oblique shear also causes bed deformation, but the horizontal length of bed remains constant. The obtained equation implies that the discontinuous fault strain is larger than that for the vertical shear model in the same condition.
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Key words:
- fault /
- fault strain /
- fault rotation /
- vertical shear /
- oblique shear
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