Experimental study on expansion and creep characteristics of high flow sealed grouting material
In order to investigate the expansion law of high flow grouting material and the creep mechanical properties and pore structure of coal after grouting,a new nonlinear viscoplastic element was created and a creep mechanical model was constructed.Firstly,the high flow grouting material was prepared and injected into the coal body to simulate the coal body grouting around the borehole.Secondly,mercury injection experiment and uniaxial fractional loading creep test were used to test the pore structure of the coal after grouting and the creep performance of the coal under different stress levels,and the strain variation law of the coal at different creep stages was obtained.Finally,based on the creep test results,a new nonlinear viscoplastic element was constructed and introduced into the Boedin-Thomson model.Finally,the relevant parameters of the creep model were obtained by inversion,the reliability of the model was verified,and the creep instability failure law of the coal after grouting was obtained.The results show that the expansion rate of high flow grouting material is 92％ higher than that of ordinary cement material,which effectively improves the shrinkage problem of cement-based grouting material after curing.After the high flow grouting material is injected into the coal body,the critical load of instability failure of the coal body is 15.3 MPa,which improves the stability of the coal body to some extent.
high flow stategrouting materialmaterial expansioncreep characteristicsgraded loadingpore structure
万方数据
维普
