To probe into the influencing law of clay on the deformation response characteristics of low-permeability sandstones

the study of the influencing law of rich-clay sandstones is carried out. Based on the concept of the effective stress coefficient for permeability (ESCK)

it is found ESCK can reflect rock deformation and hence called as deformation response characteristic parameter. Meanwhile

According to the comparative analysis of the previous theoretical study

the relationship between ESCK and rock deformation response is constructed and one method diagnosing rock deformation is proposed. Besides

two samples’ permeability measurements under loading/unloading pore pressure with three different confining pressure cycles are made; data obtained with steady-state method are analyzed with the translation method and the ESCK are calculated accordingly. Results show that the values of ESCK are constant and greater than 1.0

the translation method is valid for calculating ESCK. In conclusion

the deformation characteristics of 31 rocks in present and previous papers are evaluated with diagnosing method; the diagnosing results illustrate that the type and content of clay mineral and rock microscopic pore structure are major factors affecting rock deformation.