X型正断层地应力分布规律影响因素分析

通过使用RFPA(Rock Failure Process Analysis System)二维模拟软件,分别研究了断层相交角度θ、破碎带宽度、关键层强度、破碎带强度、埋深5个参数对X型正断层交汇处垂直和水平方向应力场分布的影响。研究表明,这些因素在不同范围内,都对断层交汇处地应力场的分布有不同程度的影响,且这些因素对垂直和水平两个方向的主应力影响程度并不是完全一致的。相交角度不同时,垂直应力可能表现为应力集中或应力降低,而水平应力只表现为应力降低;破碎带宽度不同时,垂直应力只表现为应力集中,而水平应力可能表现为应力集中或应力降低;破碎带强度越小对垂直应力的影响越大,而对水平应力的影响则呈线性关系;埋深较浅对垂直应力的影响较大,而随着埋深增加,埋深对水平应力的影响不变;关键层强度对垂直和水平方向应力的影响程度却极为相似。

Influencing Factors Analysis of the Ground Stress Distribution Regularity of X-pattern Normal Fault

Effect of parameters including fault intersecting angle, width of the shattered zone, strength of the key layer, strength of the fracture zone and buried depth on the distribution of vertical and horizontal stress field of X-pattern normal fault are studied respectively adopting the two-dimensional simulation software RFPA(Rock Failure Process Analysis System). Studies show that: All of these factors have different influences on the ground stress distribution of faults interchange, and the influence of these factors on the vertical and horizontal principal stress is not complete consistent. Vertical stress may show stress concentration or stress reduction with different intersecting angles, while horizontal stress only reduce. Vertical stress only concentration, but horizontal stress may concentration or lower with different fracture zone width. The smaller the fracture zone intensity, the greater its influence on the vertical stress, while the relationship between fracture zone intensity and horizontal stress is linear. The influence of buried depth on vertical stress is great, while with the increases of buried depth, its influence on horizontal stress does not change. The influence of key layer strength is similar on vertical and horizontal stress.