In order to approach the failure criterion of sand, an experiment of independent control three-dimensional stress of sand has been performed with some simpler device.
为了探索砂土的破坏条件，曾利用比较简单的设备进行了一种砂土的控制三向压力试验。
2
Based on the failure analysis of the fracturing pump valve chamber, a model for calculating its reliability under three-dimensional stress is established, and a computing program is worked out.
基于压裂泵阀箱的失效分析，建立了在三向应力作用下计算阀箱可靠性的模型，设计了计算程序。
3
According to the failure mechanism of horizontal convex slopes, this paper proposed a three-dimensional limit equilibrium method which is adapted for calculating the stability of the slopes.