循环荷载波形变化对结构性软土变形及能量特性的影响

Effect of cyclic loading waveforms on deformation and energy characteristics of structural soft soil

针对循环荷载波形变化对结构性软土变形的影响,以天津滨海新区临港工业区海积软土为研究对象,对其土样施加不同波形、不同幅值的循环荷载,并对不同波形、不同幅值作用下软土的耗散能发展曲线进行研究,并提出两种发展模式下的结构性软土耗散能的演化方程。结果表明,在考虑荷载波形的情况下,循环荷载幅值较小(30 kPa)时,累积塑性应变发展缓慢,波形变化对塑性应变发展趋势的影响很小;循环荷载较大(40、60、80 kPa)时,累积塑性应变快速增加,方波荷载作用下的累积塑性应变发展最快,正弦波荷载次之,三角波荷载作用下的塑性应变发展最慢。

For investigating the effect of cyclic loading waveforms on deformation of structural soft soil,we take the marine soft soil of Lingang industrial area in Tianjin Binhai new area as the research object,carry out the cyclic loadings with varying waveforms and amplitudes to the samples,research the dissipated energy curves of structural soft soil are researched under cyclic loadings with varying waveforms and amplitudes,and propose the evolution equations in two cases.The results show that when the effect of the loading waveform is considered,the cumulative plastic strain develops slowly,and the change of the waveform has little effect on the development trend of plastic strain when the loading amplitude is below the threshold stress,for example,30 kPa.When the amplitude is much higher than the threshold,for example,40 kPa,60 kPa,and 80 kPa,the cumulative plastic strain increases rapidly,the rate of deformation for the square wave is fastest,and the sinusoidal wave comes the second,while the triangular wave is the last.