“铁板砂-黏土”中桩靴贯入峰值阻力的离心试验
|
摘要
东营埕岛海域广泛分布"铁板砂-黏土"地层,自升式平台的桩靴基础在这种复杂土层中安装时易发生穿刺失稳。为研究此类问题,进行了离心机模型试验,量测"铁板砂-黏土"中桩靴贯入阻力随深度的变化。针对铁板砂层中峰值阻力的幅值及出现深度,讨论了ISO规范和两种代表性预测方法的适用性,发现可以将铁板砂层视为不排水条件下的强黏土层,采用针对"强黏土-弱黏土"地层的预测方法估计峰值贯入阻力。
The"hard crust layer-clay"layered soil is spread widely in shallow waters near Chengdao,Dongying.When they are installed in such stratigraphy,the spudcan footings of jack-up rigs are vulnerable to punch-through failure.A number of centrifuge tests were conducted to explore the penetration resistance profile of spudcans in hard crust layer overlying clay.The approaches recommended in the ISO guidelines and other two representative approaches are compared,in terms of the magnitude of peak resistance and its corresponding depth.It is found that hard silty sand layer can be regarded as a strong clay layer under undrained conditions,then the peak resistance may be estimated through previous approaches for"stiff-over-soft"clays.
The"hard crust layer-clay"layered soil is spread widely in shallow waters near Chengdao,Dongying.When they are installed in such stratigraphy,the spudcan footings of jack-up rigs are vulnerable to punch-through failure.A number of centrifuge tests were conducted to explore the penetration resistance profile of spudcans in hard crust layer overlying clay.The approaches recommended in the ISO guidelines and other two representative approaches are compared,in terms of the magnitude of peak resistance and its corresponding depth.It is found that hard silty sand layer can be regarded as a strong clay layer under undrained conditions,then the peak resistance may be estimated through previous approaches for"stiff-over-soft"clays.
引文
[1]郑敬宾,胡畔,王栋.复杂土层中自升式平台桩靴安装穿刺预测[J].海洋工程,2018,36(3).
[2]Petroleum and Natural Gas Industries-Site-Specific Assessment of Mobile Offshore Units-Part 1:Jack-ups(ISO 19905-1)[S].Geneva,Switzerland:International Organization for Standardization,2012.
[3]Teh K L,Leung C F,Chow Y K,et al.Centrifuge model study of spudcan penetration in sand overlying clay[J].Geotechnique,2010,60(11):825-842.
[4]Lee K K,Randolph M F,Cassidy M J.Bearing capacity on sand overlying clay soils:A simplified conceptual model[J].Geotechnique,2013,63(15):1285-1297.
[5]Hu P,Wang D,Stanier S A,et al.Assessing the punchthrough hazard of a spudcan on sand overlying clay[J].Geotechnique,2015,65(11):883-896.
[6]Hossain M S,Randolph M F.Deep-penetrating spudcan foundations on layered clays:centrifuge tests[J].Geotechnique,2010,60(3):157-170.
[7]Zheng J,Hossain M S,Wang D.Prediction of spudcan penetration resistance profile in stiff-over-soft clays[J].Canadian Geotechnical Journal,2016,53(12):1978-1990.
[8]Kamata T,Tsukamoto Y,Ishihara K.Undrained shear strength of partially saturated sand in triaxial tests[J].Bulletin of the New Zealand Society for Earthquake Engineering,2009,42(1):57-62.
[9]Stewart D P,Randolph M F.T‐Bar Penetration Testing in Soft Clay[J].Journal of Geotechnical Engineering,1994,120(12):2230-2235.
[10]Finnie I M S,Randolph M F.Punch-through and liquefaction induced failure of shallow foundations on calcareous sediments[A].In:Proceedings of the 17th International Conference on the Behaviour of Offshore Structures[C].1994:217-230.
[11]White D J,Gaudin C,Boylan N,et al.Interpretation of T-bar penetrometer tests at shallow embedment and in very soft soils[J].Canadian Geotechnical Journal,2010,47(2):218-229.
[12]陈洋彬,孙永福,侯方,等.“铁板砂-黏土”地层中桩靴穿刺数值模拟研究[J].土工基础,2019,33(2).
[2]Petroleum and Natural Gas Industries-Site-Specific Assessment of Mobile Offshore Units-Part 1:Jack-ups(ISO 19905-1)[S].Geneva,Switzerland:International Organization for Standardization,2012.
[3]Teh K L,Leung C F,Chow Y K,et al.Centrifuge model study of spudcan penetration in sand overlying clay[J].Geotechnique,2010,60(11):825-842.
[4]Lee K K,Randolph M F,Cassidy M J.Bearing capacity on sand overlying clay soils:A simplified conceptual model[J].Geotechnique,2013,63(15):1285-1297.
[5]Hu P,Wang D,Stanier S A,et al.Assessing the punchthrough hazard of a spudcan on sand overlying clay[J].Geotechnique,2015,65(11):883-896.
[6]Hossain M S,Randolph M F.Deep-penetrating spudcan foundations on layered clays:centrifuge tests[J].Geotechnique,2010,60(3):157-170.
[7]Zheng J,Hossain M S,Wang D.Prediction of spudcan penetration resistance profile in stiff-over-soft clays[J].Canadian Geotechnical Journal,2016,53(12):1978-1990.
[8]Kamata T,Tsukamoto Y,Ishihara K.Undrained shear strength of partially saturated sand in triaxial tests[J].Bulletin of the New Zealand Society for Earthquake Engineering,2009,42(1):57-62.
[9]Stewart D P,Randolph M F.T‐Bar Penetration Testing in Soft Clay[J].Journal of Geotechnical Engineering,1994,120(12):2230-2235.
[10]Finnie I M S,Randolph M F.Punch-through and liquefaction induced failure of shallow foundations on calcareous sediments[A].In:Proceedings of the 17th International Conference on the Behaviour of Offshore Structures[C].1994:217-230.
[11]White D J,Gaudin C,Boylan N,et al.Interpretation of T-bar penetrometer tests at shallow embedment and in very soft soils[J].Canadian Geotechnical Journal,2010,47(2):218-229.
[12]陈洋彬,孙永福,侯方,等.“铁板砂-黏土”地层中桩靴穿刺数值模拟研究[J].土工基础,2019,33(2).