Effect of loading rate on splitting characteristics of weakly cemented sandstone

In order to study the influence of loading rate on the splitting characteristics of weakly consolidated sandstone, the Brazilian splitting test is carried out on weakly consolidated sandstone with six loading rates of 0.01-1 mm/min, and the acoustic emission monitoring system is used to collect the acoustic emission signals during the fracture process of rock samples.Digital image correlation (DIC) method is used to obtain the strain evolution of rock samples simultaneously.The results show that the tensile strength of weakly consolidated sandstone is closely related to the loading rate, and there is a positive correlation between the tensile strength and the loading rate.The polynomial fitting can well characterize the variation of the tensile strength with the loading rate.Weak cementation sandstone of acoustic emission counts curve can be divided into pressure, elastic, destroying three phases, and a surge of acoustic emission counts point is consistent with the sample of peak stress points, a large number of acoustic emission events at the instant of the rock’s damage, distribution of acoustic emission events and macro damage results, corresponding reduced gradually, and with the increase of loading rate events; the variation of loading rate has no great influence on the strain evolution of weakly consolidated sandstone during the splitting process, and the evolution law of strain field of rock samples under different rates is basically the same.The research results of this paper can provide reference for the deformation and failure analysis of weakly cemented soft rock roadway.