【摘要】 为了获取石灰稳定土在极限状态下的动力学特性,在榆佳高速公路佳县某路段采取扰动土样,进行标准击实试验,制作标准重塑试件,利用DDS-70循环三轴试验系统,测试了动应力幅值为100、150、190、200kPa,围压为25、50、75kPa,含水量为26.0%、21%、18%,循环次数为2 000、5 000次,固结比为2.0、振动频率为3Hz、5Hz的条件下石灰土的动应力—应变关系。试验表明:在动荷载作用下,石灰土失稳破坏前的永久变形难以达到动强度判别标准所要求的应变值,采用临界动应力才能表征石灰土产生失稳变形的性状。石灰土的临界动应力范围值界定为190～200kPa。含水量与振动频率对所研究的石灰土临界动应力影响较小,但随着含水量的增大和振动频率的增加,石灰土的临界动应力总体上有减小的趋势,趋近于上述确定范围的下限值190kPa。这些值可以作为榆佳高速公路石灰稳定土的动力设计参考值。更多还原

【Abstract】 In order to obtain ultimate dynamic feature of roadbed lime stabilized soil under limit loading condition,standard reshaped specimens are done by standard compaction experiment using disturbed soil sample.Kinetic stress and strain relation curve of lime stabilized soil is tested using DDS-70 cycle triaxial test system under 100,150,190 and 200 kPa dynamic stress amplitude conditions,under 25,50 and 75 kPa confining pressure conditions,with 26.0%,21% and 18% water content,under 2 000 and 5000 cycle number or 3 Hz and 5Hz vibration frequency conditions with constant consolidation ratio.Test results show that permanent deformation of lime stabilized soil failure is hard to achieve value required by the dynamic strength standard,and ultimate dynamic stress is fit to judge dynamic failure of the soil.Critical dynamic stress is limited to 190-200 kPa.Water content and frequency have less effect on ultimate dynamic stress of the soil,but the stress generally tends to decrease with increasing of water content and frequency.And the range approaches lower limiting value of the range,190 kPa,which can be used as reference value of dynamic design on roadbed lime stabilized soil in Yujia highway.更多还原