Discussion of “a semi-empirical model for peak strain prediction of buried X80 steel pipelines under compression and bending at strike-slip fault crossings” by Liu et al. (2016)

In the paper presented by Liu et al. (2016), herein referred to as the original paper, a regression model was developed to estimate the compressive strain induced in X80 steel pipes crossing strike-slip faults. Later, a corrigendum (2018) was written by the original authors to correct the problems with the proposed equation and Fig. 14 of the original paper. However, there is still one problem remaining with the paper that limits the application of the proposed equation and makes it difficult for readers to understand the content. In this short paper, the discusser points out the issue and provides the readers with an explanation of the problem that exist with the proposed model.