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长期循环荷载下,结构性软土的力学变形特性已被广泛研究。但以往的研究主要集中在一种循环荷载波形下结构性软土的动力特性,而原状软土地基实际上承受着不同的外部循环荷载,如地震、高速交通、波浪荷载、油罐及水库液面的升降等,其等效的循环波形不同。通过应力控制式动三轴试验,分别在方形波、三角形波和正弦波3种循环荷载作用下,考虑加载次数、振动幅值、振动频率等因素的影响,对海积结构性软土的动力特性与变形特征进行分析,并类比了在不同循环荷载波形下软土刚度软化性状;通过借鉴由循环剪切模量定义的软化指数,分析出3种波形下软化指数随着振动次数的变化规律,得出在3种循环荷载下海积结构性软土的刚度软化过程。
Under long-term cyclic loading, the mechanical deformation characteristics of structural soft soil have been widely studied. However, previous studies mainly focused on the dynamic characteristics of a structural soft soil under cyclic loading waveforms. In fact, soft soil foundations are actually subjected to different external cyclic loads such as earthquakes, high-speed traffic, wave loads, tanks and reservoirs Surface lift, etc., the equivalent of different circular waveforms. By stress-controlled dynamic triaxial tests, under the action of three kinds of cyclic loads, such as square wave, triangular wave and sine wave, considering the influence of loading frequency, vibration amplitude and vibration frequency, Characteristics and deformation characteristics of the soft soil, and simulate the soft soil stiffness softening behavior under different cyclic loading waveforms. By analyzing the softening index defined by the cyclic shear modulus, the variation law of softening index with the number of vibration The results show that the stiffness softening process of the soft soil under cyclic loading is obtained under three cyclic loadings.