相似性原理在构造应力场数值模拟中的应用

APPLICATION OF SIMILARITY THEORY IN THE NUMERICAL SIMULATION OF TECTONIC STRESS FIELD

论述了在构造应力场模拟中相似性原理的重要性,指出地质原形与数值模型在材料、组合形式、边界条件、受力方式和破裂准则等方面必须相似,模拟的结果才具有真实性.并利用相似性原理,对贵州赤水宝元嘉五1古构造应力场和岩体破坏程度进行了模拟预测.根据模拟结果可知,嘉五1层岩石最大破坏程度系数达到1.62,一般地区岩体的破坏程度系数在0.85～0.98之间,接近破裂临界值.破坏程度系数最高的分布区带除了断裂带外,还有高木顶、宝元构造的核部,这些地区岩体破坏接近程度系数普遍高于1.42;在上述地区的外围岩体破坏系数也比较高,一般大于1.03,这说明嘉五1层岩体的破坏程度较高,裂缝比较发育.

In the paper, on the basis of expounding the importance of similarity theory in the numerical simulation of tectonic stress field, it is pointed out that, only by making the numerical model be similar to the geological prototype in material, combination pattern, boundary condition, loading mode and cracking criterion, etc., may the simulation result be real. The ancient tectonic stress field of T 1j 5 1 (the first submember of the fifth member of Jialingjiang Formation, Lower Triassic) reservoir in Baoyuan structure, Chishui, Guizhou, and the cracked degree of its rocks were simulated and predicted by applying the similarity theory. The simulation results indicated that the coefficient of maximum cracked degree of the rocks in T 1j 5 1 reservoir was up to 1.62 but the coefficients of cracked degree of the rocks in ordinary regions ranged from 0.85 to 0.98, being approximate to the cracking critical value. The distribution areas of the high coefficients of cracked degree of the rocks are located at the crests of Gaomuding structure and Baoyuan structure besides the fault belts, where the coefficients of cracked degree of the rocks are commonly greater than 1.42 and those around the above-mentioned areas are relatively high, being more than 1.03 in general, which shows that the cracked degree of the rocks in T 1j 5 1, reservoir is relatively great and the fractures in it are relatively developed.