传统夯筑工艺夯筑质量及影响因素研究

Research on the rammed quality and influencing factors of traditional rammed technology

夯筑质量的量化指标的提出是夯筑工艺科学认知和质量控制前提,是传承和应用传统夯筑工艺的关键。采用传统夯筑工艺进行足尺现场试验样的夯筑,并通过取样实测单层和双层夯筑体在不同夯锤质量、铺土厚度和夯筑遍数的条件下的干密度、孔隙比、无侧限抗压强度及夯锤入土深度等参数,归纳总结了单层夯筑体和双层夯筑体在三变量不同工况条件下的质量特征。研究发现,干密度和无侧限抗压强度是控制夯筑质量的重要指标;增加夯筑遍数和夯锤的质量对夯筑体干密度和无侧限抗压强度具有增益效果;经8遍夯筑的单层夯筑体其密度、强度均收敛稳定;双层夯筑体叠加做功的压实效果明显,下层密度较上层提高4.33%,无侧限抗压强度提高39.52%。研究结果揭示了传统的"冲海窝、夯银锭"夯筑工艺在弥补夯层密实度的均匀性和逐层叠加夯筑方式增强密实度和强度的科学性。

The introduction of quantitative indicators of ramming quality is the premise of scientific cognition of ramming technology and quality control,and is the key to inherit and apply traditional ramming technology.This study adopted traditional ramming technology to ram full-scale field test samples;took samples and measured the parameters of single-and double-layer rammed body including dry density,porosity ratio,unconfined compressive strength,and the depth of rammer into the soil under the condition of different rammer mass,paved soil thickness,and ramming times;and summarized the quality characteristics of single-and double-layer rammed body under three variable different working conditions.The study found the dry density and unconfined compressive strength were the important indexes to control the quality of ramming.The increase of ramming time and rammer mass had a positive effect on the dry density and unconfined compressive strength of the ramming body.Single-layer rammed body after 8 times of ramming was convergent and stable in density and strength;the double-layer rammed body showed an obvious compacting effect of superimposed work,the density of the lower layer being increased by 4.33%compared to the upper layer and the unconfined compressive strength increasing 39.52%.The results revealed the scientificity of traditional ramming technology"chong haiwo"and"hang ying ding"in making up the uniformity of the compactness of rammed layer and enhancing the compactness and strength by layer-by-layer stacking method.