This paper uses GCTS dynamic hollow cylindrical torsional shear apparatus and two cyclic loading waveform of sine wave and square wave. It considers the confining pressure, the influence of the vibration amplitude, frequency and the minor factors. It studies the dynamic characteristics of structural soft clay. The test results show the follows. When the dynamic stress is below the yield stress of soil structure, waveform's influence on the overall shape of the dynamic stress-strain relationship curve is very small. When dynamic stress exceeds the structure yield stress, stress-strain relationship is softening type. The softening degree of square wave is higher. Under the same conditions, square wave accumulated deformation is always greater than that of the sine wave. Waveform has an effect on pore pressure changes. The values of pore pressure under sinusoidal wave action is always greater than that of the square wave. Amplitude for the performance of pore pressure change is as follows:when the rising speed of stable amplitude is quick, the value is greater than the critical type amplitude under the action of pore pressure value. Namely the critical type amplitude under the action of pore pressure hysteresis phenomenon is serious. Yield strain and dynamic strength decrease with the increase of the vibration time trend, eventually tend to a certain value. Finally numerical size is related to the waveform. The sine wave is less than the square wave, which is contrary to the sine wave is greater than the square wave.
. EXPERIMENTAL STUDY ON DYNAMIC PROPERTIES OF STRUCTURAL SOFT CLAY BASED ON TWO KINDS OF WAVEFORM[J]. Journal of Engineering Geology, 2017, 25(6): 1395-1404.
Behzadi G,Yandell W O. 1996. Determination of elastic and plastic subgrade soil parameters for asphalt cracking and rutting prediction[J]. Transportation Research Record, 1540 (1):97~104.
Cao Y,Kong L W,Yang A W. 2013. Waveform effect of cyclic loading of dynamic character and stiffness degradation characteristics of marine deposited natural soft clay[J]. Chinese Journal of Geotechnical Engineering, 35 (3):583~589.
Chen Y P,Huang B,Chen Y M. 2005. Deformation and strength of structural soft clay under cyclic loading[J]. Chinese Journal of Geotechnical Engineering, 27 (9):1065~1071.
Ding B Y,Zhang Y. 2012. Discussion on dynamic test and characteristics of structural properties of Quaternary soft clay in Hangzhou region[J]. Rock and Soil Mechanics, 33 (2):336~342.
Gong Q M,Liao C F,Zhou S H,et al. 2001. Testing study of dynamic pore water pressure under train loading[J]. Chinese Journal of Rock Mechanics and Engineering, 20 (S1):1154~1157.
Huang M S,Li J J,Li X Z. 2006. Cumulative deformation behaviour of soft clay in cyclic undrained tests[J]. Chinese Journal of Geotechnical Engineering, 28 (7):891~895.
Ishihara K,Takatsu H. 1979. Effects of overconsolidation and K0 conditions on the liquefaction characteristics of sands[J]. Soils and Foundations, 19 (4):59~68.
Jiang J,Chen L Z. 2001. One-dimensional settlement due to long-term cyclic loading[J]. Chinese Journal of Geotechnical Engineering, 23 (3):366~369.
Jiang Y. 2007. Dynamic behavior and mechanism analysis of structural clay under traffic loading[D]. Tianjin:Tianjin University.
Kabbajm M T,Tavenas F,Leroueil S. 1988. In situ and laboratory stress-stain relationships[J]. Géotechnique, 38 (1):83~100.
Lambe T W,Whitman R V. 1969. soil Mechanics[M]. New York:John Wiley & Sons Inc.
Larew H G,Leonards G A. 1962. A repeated load strength criterion[C]//Proc Highway Res Board, 41:529~540.
Lei H Y,Jiang Y,Lu P Y,et al. 2008. Experimental study of dynamic stress-strain relation of structural soft soil under traffic load[J]. Chinese Journal of Rock Mechanics and Engineering, 27 (S1):3052~3056.
Ling J M,Wang W,Wu H B. 2002. On residual deformation of saturated clay subgrade under vehicle Load[J]. Journal of Tongji University(Natural Science), 30 (11):1315~1320.
Tang Y Q,Wang Y L,Huang Y,et al. 2004. Dynamic strength and dynamic stress-strain relation of silt soil under traffic loading[J]. Journal of Tongji University(Natural Science), 32 (6):701~704.
Thiers G R,Seed H B. 1968. Cyclic stress-strain characteristics of clay[J]. Journal of Soil Mechanics and Foundations Division, 94:555~569.
Zhou J,Gong X N. 2000. Study on strain softening in saturated soft clay under cyclic loading[J]. China Civil Engineering Journal, 33 (5):75~78,82.