深部地壳应力的测量,目前采用水力破碎方法。这种方法是根据在水力破碎时所测量的破碎压、龟裂开口压(再加压)或者是龟裂开口压(闭井压力)等的观测资料对地壳应力进行评价。也就是说,首先给出理论的上述观测资料和地壳应力关系,以资料评价方式进行并分析问题,通过实际范围实验所得到的观测数据来计算地壳应力。因此,采用该方法评价的地壳应力的可靠性,受该评价方式的影响很大。但是,当通过破碎压的研究(以应力评价为基础的观测数据),则可明确,实验所求得的方向应力未必与由破碎压评价或(以作用于井壁周方向应力理论为基础)所预测的相对应。例如、破碎压有井径越大则越小的现象,这一点若用以前的理论说明是很困难的。为此,提出详细研究水力破碎井壁发生龟裂机理的必要性。 Deep crustal stress measurement, currently using hydraulic crushing method. This method evaluates the crustal stress based on observed data such as crush pressure, cracked open pressure (re-pressurized), or cracked open pressure (closed pressure) measured during hydraulic crushing. In other words, the relationship between the above observations and the crustal stress is given first, the data are evaluated and analyzed, and the crustal stress is calculated from the observed data obtained from the actual range experiment. Therefore, the reliability of the crustal stress evaluated by this method is greatly affected by the evaluation method. However, when passing the study of crush pressure (observational data based on stress evaluation), it is clear that the directionally determined stress in the experiment is not necessarily proportional to the crush pressure (or to stress theory acting in the circumferential direction of the borehole) The predicted correspondence. For example, crushing pressure with the larger the smaller the phenomenon, which if the previous theoretical description is very difficult. Therefore, it is necessary to study in detail the mechanism of cracking in the wall of hydraulic fracturing.