CAJ | 학술논문

通过砂土的一系列动三轴实验，研究不规则地震荷载作用下与定次数等幅荷载作用下土体变形间的关系，给出砂土相对密实度对二者间关系的影响规律。结果表明：真实地震荷载下土的变形发展与等幅正弦荷载明显不同，应变发展时程的形态主要受地震动的形态控制；应变比 C 与砂土相对密度间关系具有规律性，随相对密度增大而降低，若采用以20周作为标准作用次数、0.65倍地震波峰值为等幅荷载代替不规则的地震荷载，修正真实地震应力下的残余变形，其应变比 C 随砂土密实度的增大而减小。同时，冲击型荷载的应变比 C`要远大于振动型荷载。
통과사토적일계렬동삼축실험，연구불규칙지진하재작용하여정차수등폭하재작용하토체변형간적관계，급출사토상대밀실도대이자간관계적영향규률。결과표명：진실지진하재하토적변형발전여등폭정현하재명현불동，응변발전시정적형태주요수지진동적형태공제；응변비 C 여사토상대밀도간관계구유규률성，수상대밀도증대이강저，약채용이20주작위표준작용차수、0.65배지진파봉치위등폭하재대체불규칙적지진하재，수정진실지진응력하적잔여변형，기응변비 C 수사토밀실도적증대이감소。동시，충격형하재적응변비 C`요원대우진동형하재。
Conversion methods from seismic loads to uniform-amplitude loads are basic research topics in geotechnical earthquake engineering.Through a series of dynamic triaxial tests,the fea-ture of soil deformation under irregular seismic wave loading and the relationships of soil deform-ation under irregular seismic wave loading and fixed-number wave loading are analyzed.The ratio of residual strain under a constant-amplitude sinusoid wave with 20 cycles and an amplitude of 0.65 times the seismic wave peak value to residual strain under seismic loading is defined as the strain ratio C ,and the relationship between the strain ratio C and sand density is investigated.The results show that soil deformation development under irregular seismic loading obviously differs from that under sinusoidal loading,and the strain time history is mainly controlled by the per-formance of ground motion,rather than seismic loading amplitude and soil type.Under impact loading,the peak value (instead of other pulses)plays a significant role in control.Under a vibra-ting wave,besides the peak value,some other pulses with similar amplitudes and peak values have influences on the soil deformation.The strain ratio C will decrease with the increase of the relative density of the sand.When uniform sinusoidal loading,with 20 cycles and an amplitude of 0.65 times the seismic wave peak value,is employed instead of irregular seismic loading to modify residual deformation of soils under real seismic loading,the strain ratio C will decrease with the increase in the relative density of the sand.Meanwhile,the strain ratio C of impact-type loads is much larger than that of vibrating loads.