三轴冲击荷载作用下淤泥力学响应研究

发布时间：2018-01-16 15:12

本文关键词：三轴冲击荷载作用下淤泥力学响应研究　出处：《岩土力学》2015年07期 　论文类型：期刊论文

【摘要】：利用SPAX-2000(改进型)静动真三轴系统,针对淤泥类超软土进行静动力排水固结试验,研究包括较高频率在内的各冲击荷载频率(1、8、16 Hz)与不同围压(200、250、300 k Pa)作用下淤泥的力学响应;此外,结合三轴剪切试验研究不同固结条件对淤泥不排水强度的影响。试验结果表明:(1)在相同冲击频率作用下,试样抗剪强度随着围压增大而提高;围压增大,使得球应力增大,体应变随着增大,有效地促进试样排水固结。(2)相同围压作用下,存在着一个冲击荷载频率阈值,当冲击频率低于这一阈值时,随着冲击荷载频率的提高,轴向应变量逐渐变小,反之逐渐变大。(3)冲击瞬间,体应变为负值,表现为体胀,这与原位试验夯击瞬间的孔隙水压力变化曲线一致,从而验证了高含水率淤泥在冲击作用下的孔压负增长现象。
[Abstract]:By using SPAX-2000 (modified) static and dynamic true triaxial system, static and dynamic drainage consolidation tests were carried out for super soft soil of silt type, and various impact load frequencies including higher frequency were studied. The mechanical response of the silt under the action of 16Hz) and different confining pressure (200,250,300kPa); In addition, the influence of different consolidation conditions on the undrained strength of silt is studied by triaxial shear test. The results show that the shear strength of the specimen increases with the increase of confining pressure under the same impact frequency. With the increase of confining pressure, the stress of the sphere increases, and the volume strain increases, which effectively promotes the drainage consolidation of the specimen under the same confining pressure, and there exists a frequency threshold of impact load. When the impact frequency is below this threshold, the axial strain becomes smaller with the increase of the frequency of impact load, whereas gradually becomes larger. 3) at the moment of impact, the body strain is negative, which is manifested as bulging. This is consistent with the pore water pressure change curve of in-situ test, which verifies the negative growth of pore pressure of high moisture content silt under impact.
【作者单位】：广东工业大学岩土工程研究所;
【基金】：国家自然科学基金资助项目(No.51178122)
【分类号】：TU447
【正文快照】： 1引言利用静动力排水固结法对高含水率饱和软黏土地基进行加固处理,已经有二十几年[1?2]。李彰明等[1?6]在深圳、广州、上海等地针对不同建构筑物的淤泥或淤泥质土体地基进行了大量的工程实践及监测测试,取得了成功。虽然静动力排水固结法得到广泛的工程应用,但该方法的理论研

【参考文献】