二灰砂在软弱路基分层回填工程中的试验研究

Experimental study on lime fly ash and grains of stone in layered backfill project of weak subgrade

软弱路基在现代交通工程施工建设当中越来越常见,分层回填强夯法是处理此类地基的有效方法之一。结合某工程现场实际情况,采用室内外试验及数值模拟相结合的分析方法,探究了分层回填过程中,二灰砂配合比以及回填速率对路基工程力学特性、孔隙水压力以及沉降变形等的影响。研究结果表明:采用白灰、粉煤灰、碎石配合比为1∶2∶7,回填速率为0.2 m/d时,各项工程力学特性表现最好,回填变形最大,工后沉降最小且均匀,表明其回填加固效果最佳。在工期紧张时,可考虑将回填速率提升至0.5 m/d,既可保证相应的工程要求也可缩短工期,达到经济合理的效果。

Weak subgrade is becoming more and more common in modern traffic engineering construction.Layered backfill dynamic compaction method is one of the effective methods to deal with such ground.Combined with the actual situation of a project site,the effects of the mixture ratio of lime fly ash and grains of stone and the backfilling rate on the mechanical properties of subgrade engineering,pore water pressure and settlement deformation in the process of stratified backfilling were investigated by the combination of indoor and outdoor experiments and numerical simulation.The results showed that,the lime flyash gravel mixture ratio is 1∶2∶7,the backfill rate is 0.2 m/d,the mechanical properties of the project was the best;the backfill deformation is the largest and the post construction settlement is the smallest,which indicates that the backfill reinforcement effect is the best.In tight deadlines,the filling rate can be increased to 0.5 m/d,which can ensure the corresponding engineering requirements,but also can shorten the construction period,to achieve reasonable economic effect.