Study of seepage-rheology coupling experiment of rocks

An effectual method of seepage-rheology coupling experiment was developed by the improvement on test apparatus and technics.The rheological properties of rock in seepage field under different stresses and water pressures were investigated by this method using porous limestone specimens.Based on the experimental results,the strain of specimen will increase along with the stress.The variation of vertical strain is larger than the other directions under lower stress;but when raising the stress level gradually,the strain of seepage direction will increase more remarkably.The results still show that the permeability coefficient and volume of the specimen have certain relation,the volume shrinkage of the specimen under lower stress will cause the decrease of permeability coefficient.When raising the stress to certain value,the volume of specimen will expand gradually;this so-called dilatancy effect will increase the permeability coefficient.If raising the water pressure,this variety of permeability coefficient and volume will be more notable.The rheological rate of specimen has deceleration and stable stage.The acceleration stage of rheological rate will appear and cause the specimen failure under certain high stress.