泡沫轻质混凝土作为铁路路基填料的动静力特性研究

Study on Dynamic and Static Characteristics of Foamed Lightweight Concrete as Railway Subgrade Filler

通过将室内静力学试验与数值模拟动力分析相结合,研究了新型路基填料泡沫轻质混凝土的动静力特性,静力学分析中研究了其组成材料发泡剂的泌水量和沉降距随稀释倍数的变化情况,得出沉降距与泌水量随稀释倍数增大呈现先增大后减小的规律。同时研究了在最佳稀释倍数下的泡沫轻质混凝土其抗压强度、抗劈裂强度随泡沫掺量、粉煤灰的变化规律,从中确定最优配合比。在数值模拟的动力分析中,分别将最优配合比的泡沫轻质混凝土与传统A、B组填料作为路基填料,通过记录对应位置的动应力,得出泡沫轻质混凝土对动应力的衰减与A、B组填料相似,但相比于A、B组填料在基床表层中衰减慢,在基床底层中衰减快。

The dynamic and static characteristics of a new type of road-filled foam lightweight concrete were studied by combining the indoor static test with the numerical simulation dynamic analysis.The hydrodynamic analysis and the sedimentation distance of the foaming agent of the constituent materials were studied in the static analysis.The change situation shows that the settlement distance and the bleeding volume increase first and then decrease with the increase of the dilution factor.At the same time,the compressive strength and anti-cracking strength of foam lightweight concrete under optimal dilution ratio were studied with the change of foam content and fly ash,and the optimal mix ratio was determined.In the dynamic analysis of numerical simulation,the foamed lightweight concrete with the best mix ratio and the traditional A and B packs were used as the roadbed fillers.By recording the dynamic stress at the corresponding position,the attenuation of the dynamic stress of the foamed lightweight concrete was obtained.The fillers of group A and group B are similar,but the attenuation of the fillers in group A and group B is slower in the surface layer of the bed,and the attenuation is faster in the bottom layer of the bed.