超固结粘土不排水抗剪强度研究.pdfVIP

第50 卷 第6 期 港 工 技 术 Vol. 50 No.6 2013 年12月 总第215 期 Port Engineering Technology Dec.2013 Total 215 超固结粘土不排水抗剪强度的研究 刘剑涛 （中海油服物探事业部工程勘察中心，天津 300451） 摘要：本文通过5 个有代表性场地的室内试验和现场试验的结果，对不同条件下粉质粘土的不排水强度取值问题进行了 探讨。研究显示，对于超固结粉质粘土，采用常规的分析结果进行钻井船插深预测将可能产生比较大的计算误差；针对不 同的土质条件要采用不同的参数选择方法。因此，建议对于单一超固结粘土采取考虑超固结比OCR 影响的方法进行不排 水强度的确定。现场实测数据显示，采用上述方法进行钻井船插深预测取得了良好的效果。 关键词：超固结粘土；不排水强度；UU 试验；CPT ；超固结比 中图分类号：TU442 文献标志码：A 文章编号：1004-9592（2013 ）06-0047-04 TheStudyoftheUndrainedShearStrengthofOverconsolidatedClay Liu Jiantao （OilfieldServicesLimitedGeophysicalExplorationEngineeringSurveyCenter，Tianjin300451，China） Abstract：The undrained shear strength is one of the most important parameter used in spudcan penetration depth. With the development of offshore engineering in South China Sea ，it has been found by soil investigation that there is large distribution of overconsolidated clay in a certain area. In this paper ，the undrained shear strength of overconsolidated clay of three sites in South China Sea is studied based on tests in laboratory and in situ. It could be found that the undrained shear strength from UU tests brings a great error when they are used to predict the spudcan penetration depth. The undrained shear strength from seabed CPT with the most comonly used method also have a certain error. Therefore ，a method based on OCR is suggested for CPT data. The difference between this method and the most comonly used method becomes larger with the increment of OCR. The predicted spudcan penetration depth according to this method is very close to the measured data in practice. Keywords：overconsolidaed clay ，undrained shear