石灰固化泥液塑限及不排水剪切强度试验研究

Experimental Study on Atterberg Limits and Undrained Shear Strength for LimeSolidified Sediments

针对某港口海相淤泥试样进行了室内落锥试验和十字板试验等,开展了确定液、塑限及不排水剪切强度的试验研究。结合试验结果分析了石灰掺入对阿太堡界限的影响,并对比了落锥试验和十字板试验确定的剪切强度。结果表明:对于原状淤泥,石灰掺入引起液限明显增大,但随着石灰掺量的增加,固化泥液限值逐渐减小;落锥法测定固化泥液限值总体上高于碟式仪测定的液限值;石灰掺入导致淤泥塑限明显增大,且固化泥塑限随石灰掺量的增加而逐渐增大;传统搓条法测定的塑限值低于落锥法测定的塑限值;石灰固化泥的塑性指数随石灰掺量的增加而减小;对比落锥法和十字板剪切法,两者在淤泥塑限附近的不排水剪切强度较为一致,而液限附近对应的不排水剪切强度相差较大。

An experimental study on Atterberg limits and undrained shear strengths had been carried out by using fall cone tests and vane shear tests on certain marine sediments. The effect of lime content on Atterberg limits was studied, and the shear strengths determined by fall cone and vane shear tests were compared. The results show that： for raw sediments, liquid limit increases due to lime addition but decreases with an increase in lime content; liquid limits determined by fall cone are generally higher than those determined by Casagrande apparatus; lime addition leads to an increase in plastic limit, and then plastic limit increases with lime content; plastic limits determined by thread rolling method are lower than those determined by fall cone tests; plasticity index of lime-based sediments decreases with an increase in lime content; the undrained shear strengths measured by fall cone tests and vane shear tests are comparable at plastic limits, but they are greatly different at liquid limits.