1605年琼州大地震构造应力场的三维光弹实验

本文对1605年琼州大地震的构造应力场进行了三维光弹模拟实验,结果表明:(1) 在地下20公里左右,北东东走向的光村—铺前深断裂拦截北北西走向的塔市—演丰断裂的“拦截区”,是最大剪应力和主压应力的集中部位,是琼州大震的震源所在;(2) 因铅垂向外力作用的结果,应力矢量图中形象地显示出塔市—演丰断裂东侧(东寨港一带)一狭长地段呈“断块型倾侧式沉降”,光村—铺前断裂北侧(铺前湾、琼州海峡南侧一带)呈“断块型沉降”。实验结果与实际考察研究及其它有关资料的计算、分析结果相一致。

THREE-DIMENSIONAL PHOTOELASTIC SIMULATING EXPERIMENTS TO TECTONIC STRESS FIELD OF GREAT QIONGZHOU EARTHQUAKE OF 1605 IN HAINAN, CHINA

The three-dimensional photoelastic simulating experiments to tectonic stress field of great Qiongzhou earthquake of 1605 are made. The results indicate that the maximum shear stress and principal compressive stress are mainly concentrated in the depth of about 20km where the NNW trending Tashi-Yanfeng fault is intercepsted by the NEE trending. Guangcun-Puqian deep fault. The Qiongzhou earthquake of 1605 is formed in the intercepted region. Because of the influence of the vertical force, the stress vector diagram shows obviously a feature of the fault-block type dip-slip subsidence in the east of Tashi-Yanfeug fault (a narrow belt near Dongzhai port), and a feature of the fault-block type subsidence in the north of Guangcun-Puqian fault (from Puqian bay to the south of Qiongzhou strait), respectively. The results of tests are consistent with field survey as well as the analysis and calculation based on the other data.