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本文用震源力学理论和方法研究了徐淮地区从１９７０年以来构造应力场的方向和强度的时空变化过程．结果表明：以唐山地震为分界线，本区的应力场Ｐ轴取向由震前平均６１．８°变为震后平均７７．７°．如果将本区以宿北断裂为界分为南区和北区两个部分，则北区的Ｐ轴取向从６８．１°变到７１．２°，而南区的Ｐ轴取向由６２．５°变到８３．６°，南区的变化明显大于北区．对于水平剪切应力值来说，７６年前后应力值较高且变化剧烈，从７７年至８７年应力值缓慢下降，而从８７年开始应力值迅速上升并伴有起伏．上述应力场的时空分布特征可以解释为什么井筒破裂主要发生在宿北断裂以南地区，并且主要发生在幼年以后．因而我们认为，徐淮地区煤矿井筒破裂与构造应力场的变化有很大关系．
In this paper, the space-time variation of the direction and intensity of the tectonic stress field in the Xu-Huai region since 1970 is studied using the theory and method of the source mechanics. The results show that with the Tangshan earthquake as the boundary, the P-axis orientation of the stress field in this area changes from an average of 61.8° before the earthquake to an average of 77.7° after the earthquake. If the area is divided into two parts of the southern and northern districts by the boundary of the North of the Subei fault, the P axis orientation of the northern district changes from 68.1° to 71.2°, while the P axis of the southern district is oriented by 62. From 5° to 83.6°, the change in the Southern District was significantly greater than that in the North District. For the horizontal shear stress value, the stress value is high and changes violently before and after 76 years. From 77 to 87 years, the stress value decreases slowly, and from 87 years, the stress value rises rapidly with fluctuation. The spatial-temporal distribution of the above stress field can explain why the wellbore fracture mainly occurs in the area south of the Suobei fault, and mainly occurs after young age. Therefore, we believe that the wellbore fracture in the Xuhuai area is closely related to the change of tectonic stress field.