Protogyakonov's coefficient of rock strength

例句：

1. 1. The engineer used the Protogyakonov's coefficient to calculate the stress in the concrete beam.
   工程师使用普朗格-雅科诺夫系数来计算混凝土梁中的应力。
2. 2.The researcher discovered a new method to estimate the Protogyakonov's coefficient based on experimental data.
   研究者发现了一种基于实验数据的新方法来估计普朗格-雅科诺夫系数。
3. 3. The engineer used the Protogyakonov's coefficient to optimize the design of the bridge for maximum load capacity.
   工程师使用普朗格-雅科诺夫系数来优化桥梁的设计，以实现最大的承载能力。