T型触探仪在南海北部深水软土中的应用分析

Application of T-bar penetrometer in soft clay under deep water in the north of South China Sea

原位测试在海洋岩土工程勘察中起着重要的作用。近年来,T型触探仪因其在软土中评价不排水抗剪强度的可靠性高于常规的孔压静力触探仪,而在深水油气开发中得到了应用。本文介绍了T型触探仪在南海北部深水软土区两个场址的应用,并和静力触探试验以及现场原位十字板试验和室内DSS试验结果相对比获得探头系数,结果显示T-bar系数NT-bar值变化范围要小于锥尖系数Nkt。根据计算结果,给出了南海北部深水软土区的T-bar系数NT-bar值和锥尖系数Nkt推荐值,可为南海深水工程勘察相关工程分析提供参考。

In situ tests play an important role in marine geotechnical investigation.Recently,the T-bar penetrometer has been introduced for deep water oil and gas field developments due to their reliability of interpreted undrained shear strength prior to CPTU for soft clays.The application of T-bar penetration test in two deep water soft clay sites were introduced in the north of South China Sea.The test results were compared to the results of CPTU,field vane tests and laboratory tests on samples at two soft clay sites.It indicates that T-bar factors are in narrower range compared to cone factors.Based on calculation,the recommendations of cone and T-bar factors are given.It could be referred for the engineering analysis of deep water geotechnical investigation.