Experimental study on the permeability and seepage characteristics of bimsoils

Abstract

Bimsoils are a loose rock and soil system, and the occurrence of geological hazards is closely related to water. To investigate the permeability and seepage characteristics of bimsoils, factors on permeability are discussed in detail considering cementation state, and variable mass seepage is studied tentatively with self-developed apparatus. Results shown that the order of factors on permeability is rock content > cementation degree > rock size > Talbot index (describing the mass percentage for different particle size of sand), and there are significant differences between factors. Besides, permeability generally increases with the increase of rock content and decreases with the increase of cementing agent content, while increases slightly due to agglomeration effect at the clay content of 8%. It is more obvious for reducing the permeability of higher rock content bimsoils by strong cementing agent, however, it tends to be same eventually with cement content increasing. The seepage of bimsoils is dominated by fine particle losses, and the secondary inrush occurs under the larger particle radius ratio. Moreover, particle losses and the time needed for secondary inrush both increase with the increase of particle radius ratio. The results would provide consults for the preparation of similar materials and the prevention of tunnels and underground engineering disasters.