Research on mechanical characteristics and energy dissipation of traditional ramming technology

Abstract

The ramming technique is a traditional method used to improve the compactness of soil with impact and vibration energy. Based on the measured data of ramming force transmission and dissipation, this study reveals the mechanism of energy transfer and dissipation of single-layer ramming as well as the law of variation with ramming quality, laying thickness, and ramming times. It also establishes the ramming model and empirical formula of ramming quality, laying thickness, and ramming times, introduces the ramming layer changes associated with the constitutive relationship (elastic to elastoplastic parts) as a function of ramming times, and determines the influence depth and horizontal range based on real-time data monitoring. It was found that as the mass of the rammer increases, the range of influence of the impact stress inside the earth also increases proportionally, and this effect is more pronounced vertically. However, the dissipation rate of energy in horizontal direction is much greater than in the vertical direction. The traditional stacked ramming technique of “chong hai wo, hang yin ding” can effectively eliminate the defects of horizontal reversal upwelling impact and unevenness of the ramming layer during the ramming process. The research results provide a theoretical basis for evaluating the quality of the traditional ramming technique.