高邮凹陷南断阶东部阜宁期构造应力场及其对断层的控制作用

在断层级别划分的基础上分析断层的走向变化、组合规律及活动特征,建立地质模型,并确定SE152°~NW 332°为区域应力的加载方向,结合岩石力学试验确定岩石力学参数及加载应力值,采用有限单元法对工区阜宁沉积期构造应力场进行数值模拟,详细分析构造应力对断层的控制作用。结果表明:南断阶东部阜宁沉积期最小主应力均表现为张应力,沿真①断层在许庄地区和竹墩地区的向北凸出位置出现两个最小主应力高值区,断层发育密集;剪应力呈条带状右旋、左旋区域相间展布,右旋最大剪应力和最小主应力控制产生北北东向正断层,左旋最大剪应力和最小主应力控制产生近东西向正断层。

Structural stress field of Funing sedimentary period and its control on faults in the east of south fault terrace in Gaoyou sag

Based on the division of fault grade,fault strike changes,composition rules and fault activity characteristics were analyzed,the geological model was established,and the loading direction of regional stress was calculated as SE152°-NW332°.The rock mechanical parameters and loading stress values were determined on the basis of rock mechanism tests.The numerical simulation on structural stress field of Funing sedimentary period in the east of south fault terrace was done by finite element method,and the control of structural stress on faults was analyzed in detail.The results show that the minimum principal stress of Funing sedimentary period is tensile stress with two high value areas in the north convex parts of Xuzhuang and Zhudun areas along Zhen① fault with dense faults.The shear stress distribution is banding alternating dextrorotatory region with levorotatory region,and the development of north-northeast normal faults is controlled by dextrorotatory maximum shear stress and minimum principal stress.The development of near east-west normal faults is controlled by levorotatory maximum shear stress and minimum principal stress.