活断层地表地裂缝变形特征试验

Experimental on ground fissure deformation characteristics of active faults

为研究不同沉积层厚度的活断层发震对地表变形和破裂的影响并对活断层活动进行探讨,结合活断层破裂基本原理,设计了活断层活动引发地表破裂的相似模型试验,模拟断层活动引起地表破裂过程,研究活断层沉积层厚度对地表破裂分布的影响.实验结果表明,断层错动时,地表的破裂以断层线为中心向两侧扩展形成一条破裂带,且带内以剪张破裂为主;随着沉积层厚度的增加,破裂带变宽,同时局部破裂带宽度增加,逐渐形成沿某条主裂缝的破裂带;沉积层厚度对分形维数影响不大,不同沉积层厚度地表破裂的分形维数均在0.95~1.05之间波动;地表裂缝分布间距、地表裂缝同破裂带中心线间斜交角度均随沉积层厚度的增加而增大.

In order to study the influence of active fault with different deposit thicknesses seismogenic on surface deformation and rupture and explore active fault activities, the similar model test of surface rupture caused by active fault creep movement was designed, combining with the basic principle of active fault rupture. The test simulated the process of surface rupture caused by active fault activities and studied the influence of the deposit thickness on the surface rupture distribution. The results show that the surface rupture is centering on the fault line to expand on both sides and become a fracture zone,and the rupture is given priority to shear tension fracture. With the deposit thickness increasing, the fracture zone broadens, at the same time, the local fracture zone width increases and formed a fracture zone along one of the main crack fracture zone gradually. All of the surface ruptures are range from 0.95 to 1.05, and has little to do with the deposit thickness. The separation distance of ground fissures distribution and the oblique angle between surface crack and centre line of fracture zone increase with deposit thickness.