1911年红海湾6级地震前珠江三角洲及其邻区的区域构造应力场

本文包括：（１）通过拟合区内断层错动方式确定区域边界上作用的远场构造应力；（２）根据发震前震中所在断层段要进入塑性状态，确定１９１１年红海湾地震前区内构造应力场．两个应力场均采用正交设计法与弹塑性有限元方法快捷地得到．结果表明：该区远场最大主压应力σ３的方向为Ｎ６８°Ｗ，σ３＝－２００ＭＰａ，最小主压应力σ１＝－８０ＭＰａ；算得的红海湾地震前区内应力场的特点是除滨海断裂的红海湾段已进入屈服状态外，其余断裂均处于弹性状态．

THE STRUCTURE STRESS FIELDS OF ZHUJIANG DELTA AND PROXIMAL AREA BEFORE HONGHAI BAY EARTHQUAKE IN 1911

This paper includs two parts: （1）Determining the outside structure stresses actting on the boundary of the calculation area by means of fitting the regmatic directions of faults in this area.（2） According to that the stress on the hazad section of the fault at which the earthquake will be going to happen should enter into the plastic yield state, determining the inside structure stress field before Honghai Bay earthquake in 1911.Both stress fields are determined by orthogonal design method and elastic-plastic finite element method.The result indicats that the direction of the main stress σ3 of the outside structure structure stress is N68°W,σ1=-80MPa,The character of the inside structure stress field before Honghai Bay earthquake is that all of the stress on the faults are still in elastic state but on Honghai Bay section of the Binhai fault gets yet into plastic yield state.