Experimental Study on the Dynamic Characteristic of Soft Soil under Cyclic Loads

Abstract

To study the change law of the dynamic characteristics of soft soil, particularly the inadequate bearing capacity of highway and railway roadbeds induced by traffic loads, the soft soil in Yingkou area was taken as the research object. A series of dynamic strength and dynamic modulus tests were performed under different dynamic stress amplitude amplitudes, consolidation ratios, confining pressures, dynamic stress amplitudes, consolidation confining pressures, consolidation ratios, vibration frequencies, soft soil dynamic strains, dynamic strengths, dynamic backbone curves, dynamic moduli, and dynamic damping ratios. The results show that (1) Yingkou soft soil has a significant structural property. A strain turning point was found in the εd-N and dynamic curves. The deformation of soil increases rapidly when the strain is larger than this turning point. (2) Dynamic strength increases as consolidation confining pressures increase, but the influence of consolidation ratio and vibration frequencies on soft soil dynamic strength is not limited to an increase or decrease. (3) The dynamic modulus increases as consolidation confining pressure, consolidation ratio, and vibration frequencies increase, whereas dynamic damping ratio decreases with increasing pressure and ratio but increases with increasing vibrational frequency. The above results provide a theoretical basis for studying the insufficient bearing capacity of highway and rail roadbeds caused by long-term cyclic loads.