(1. Dunhuang Academy,Dunhuang,Gansu 736200,China;2. School of Civil Engineering and Mechanics,Lanzhou University,Lanzhou,Gansu 730000,China;3. National Technological Research Center for Conservation of Ancient Wall Paintings and Earthen Heritage Sites,Dunhuang,Gansu 736200,China;4. Key Laboratory Conservation of Ancient Wall Paintings and Earthen Sites,Gansu Province,Dunhuang,Gansu 736200,China;5. Gansu Mogao Grottoes Cultural Heritage Conservation Design and Consultation Co.,Ltd.,Dunhuang,Gansu 736200,China;6. College of Cultural Heritage,Northwest University,
Xi′an,Shaanxi 710069,China)
Abstract: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.