Experimental Study on the Effects of Initial Shear Stress and Vibration Frequency on Dynamic Strength of Saturated Sands

Abstract

The cyclic triaxial system is used to investigate the effects of confining pressure, initial shear stress, cyclic stress ratio, and vibration frequency on the dynamic strength characteristics of saturated sand in the Wenchuan area. Results show that when the vibration frequency is constant, the dynamic strength of sand increases with the increase of the consolidation ratio. However, when the consolidation ratio exceeds a certain value, the dynamic strength of sand decreases or increases slowly. The dynamic internal friction angle first increases and then decreases with the increase of consolidation ratio, and the dynamic internal friction angle under different initial shear stresses differs by a maximum of about 12%. When the failure cycles are constant, the dynamic strength and the dynamic internal friction angle of the sand increase with the increase of vibration frequency, and the dynamic internal friction angle at different frequencies differs by a maximum of about 7%. When the cyclic stress ratio is constant, the higher the vibration frequency, the greater the cycles required to achieve the failure. As the cyclic stress ratio decreases, the influence of the vibration frequency on the failure cycles is gradually reduced.

Experimental investigation on dynamic behavior of silt-rich fly ash using cyclic triaxial and bender element tests

“…Taking into consideration of the aforementioned condition, 1 Hz and 0.1 Hz frequency are generally preferred for coarse-grained soil (sandy type) and fine-grained soil (silty type), respectively [62,63]. Based on the analysis of seismic events, Zhang et al [64] also adopted frequency starting from 1 to 3 Hz for saturated sand. However, many studies on dynamic properties of soil considered frequency range in between 0.5 and 2 Hz [65][66][67].…”

Experimental Investigation on the Behavior of Gravelly Sand Reinforced with Geogrid under Cyclic Loading

“…Much research has been conducted on the behavior of sand under cyclic loading using cyclic triaxial tests, with the focus being on the effects of confining pressure, loading amplitude and frequency, over-consolidation ratio, fine particle content, and relative density, etc. [2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20]. Sharma and Maheshwari [21] conducted cyclic triaxial tests on sands with different degrees of saturation and found that the damping ratio of saturated sand is greater than that of dry sand and partially saturated sand.…”

Effect of Initial Shear Stress on the Undrained Shear Behavior of Normally Consolidated Kaolin Clay

“…Bu zemin elemanları herhangi bir ilave gerilme öncesinde de kayma gerilmelerine maruz durumdadırlar. Özellikle drenajsız şartlar altında, kumlu zeminlerin tekrarlı yükler altındaki davranışları üzerinde başlangıç statik kayma gerilmesinin etkileri sıvılaşma direnci açısından oldukça önemli bir konu olup günümüzde halen birçok araştırmacı tarafından ele alınmaktadır [2,[4][5][6]. Bu çalışmalar, başlangıç statik kayma gerilmesi varlığının, doygun kumların dinamik özelliklerini etkileyen önemli bir faktör olduğunu ortaya koymakta ve bu etkiyi yansıtabilmek için düzeltme faktörleri (Kα) önermektedirler.…”