孔隙度变化对充填体动载冲击变形的影响

Influence of porosity variation on dynamic load impact deformation of backfill

采用核磁共振仪测定不同浓度充填体试件在饱水状态下的孔隙度,并对充填体进行了动载冲击试验,结果表明:充填体的孔隙度与浓度存在关联,增加充填体的浓度可以有效减小其孔隙度;充填体处于弹性变形阶段时,孔隙度不同,其弹性模量也不同;充填体达到变形破坏时,屈服点应力值随孔隙度的增加而减小;而孔隙度越大,充填体达到变形破坏的时间越短,其峰值应力随孔隙度的增大而减小。

The porosity of backfill specimen of the different concentrations at saturation was measured using Nuclear Magnet- ic Resonance and the dynamic load impact test was conducted on backfill. The result showed that a correlation exists between po rosity and concentration of the backfill and the increase of concen tration of the backfill can effectively reduce its porosity. When the backfill is in the elastic deformation stage, porosity is different and its modulus of elasticity is varied too. When the backfill is de- formed and broken, the stress value of yield point decreases with the increase of porosity and the larger porosity,the shorter time it is for the backfill to become deformed and broken. The peak stress will decrease with the increase of porosity.