(1. Research Center of Coastal and Urban Geotechnical Engineering，Zhejiang University，Hangzhou，Zhejiang 310058，China；2. ZDOON Building Material Group，Ningbo，Zhejiang 315000，China)
Abstract：The static drill rooted nodular pile has lots of advantages such as high bearing capacity，high technology content and environment protection. In the application to some soft soil areas in the southeastern coast of China，the construction costs of the nodular piles was decreased by 10% compared to that of the bored piles，and the mud emission was largely reduced by using the static drill rooted method. Through the analysis of a test pile，it is found that the skin friction of the nodular pile is about 1.05–1.10 times that of the bored pile，while the standard of the precast pile is more appropriate with calculating the pile tip resistance of the nodular pile，and a reduction coefficient is applied. Combining the result of test pile and the literatures as well as standard in Japan，a simplified calculation formula was proposed. In order to verify the reliability of the proposed formula，test nodular piles in two projects were calculated using the formula. The calculated results fit the test results well. Therefore，the proposed formula could provide some reference for the actual engineering.
HORIGUCHI T，KARKEE M B. Load tests on bored PHC nodular piles in different ground conditions and the bearing capacity based on simple soil parameters[C]//Proceedings of Technical Report of Japanese Architectural Society. [S. l.]：[s. n.]，1995：89-94.
[2]
YABUUCHIS. Bearing mechanisms of muti-node piles[C]//Proceedings of the International Offshore and Polar Engineering Conference. [S. l.]：[s. n.]，1994：504-507.
[3]
MADAN B K，SHIGEO K，TAKASHI H. Quality assurance in bored PHC nodular piles through control of design capacity based on loading test data[C]//Proceedingsof the 7th International Conference and Exhibition，Piling and Deep Foundations. Vienna，Austria：[s. n.]，1998：1-9.
[4]
BORDAO，UNOM，TOWHATAI. Shaft capacity of nodular piles in loose sand[C]//Proceedings of the 49th National Conference，Japanese Geotechnical Society. [S. l.]：[s. n.]，2007，(2)：1175-1176.
[5]
KARKEE MB, HORIGUCHIT,KISHIDAH. Limit state formulation for the vertical resistance of bored PHC nodular piles based on field load test results[C]//Eleventh Asian Regional Conference on Soil Mechanics and Geotechnical Engineering. Seoul，Korea：[s. n.]，1999：237-240.
[6]
HONDA T，HIRAI Y，SATO E. Uplift capacity of belled and multi-belled piles in dense sand[J].Soils and Foundations，2011，51(3)：483-496.
[7]
KARKEE M B，HORIGUCHI T，KISHIDA H. Limit state formulation for the vertical resistance of bored PHC nodular piles based on field load test results[C]//Proceedings of 11thAsian Regional Conference on Soil Mechanics and Geotechnical Engineering. [S. l.]：[s. n.]，1999：16-20.
[8]
中华人民共和国行业标准编写组. JGJ 79－2012建筑地基处理技术规范[S]. 北京：中国建筑工业出版社，2012.(The Professional Standards Compilation Group of People¢s Republic of China.JGJ 79－2012Technical code forground treatment of buildings[S]. Beijing：China Architecture and Building Press，2012.(in Chinese))
[9]
刘汉龙，任连伟，郑 浩，等. 高喷插芯组合桩荷载传递机制足尺模型试验研究[J]. 岩土力学，2010，31(5)：1395-1401.(LIU Hanlong，REN Lianwei，ZHENG Hao，et al. Full-scale model test on load transfer mechanism for jet grouting soil-cement-pile strengthened pile[J]. Rock and Soil Mechanics，2010，31(5)：1395-1401.(in Chinese))
[10]
任连伟，刘汉龙，张华东，等. 高喷插芯组合桩承载力计算及影响因素分析[J]. 岩土力学，2010，31(7)：2219-2225.(REN Lianwei，LIU Hanlong，ZHANG Huadong，et al. Bearing capacity calculation and influence factors analysis of jet grouting soil-cement-pile strengthened pile[J]. Rock and Soil Mechanics，2010，31(7)：2219-2225.(in Chinese))
[11]
ZHOU JJ，WANG KH，GONG XN，et al. Bearing capacity and load transfer mechanism of a static drill rooted nodular pile in soft soil areas[J]. Journal of Zhejiang UniversitySCIENCE A：Applied Physics andEngineering，2013，14(10)：705-719.
[12]
中华人民共和国行业标准编写组. JGJ106－2003建筑基桩检测技术规范[S].北京：中国建筑工业出版社，2003.(The Professional Standards Compilation Group of People¢s Republic of China.JGJ106－2003Technical code for testing of building foundation piles[S]. Beijing：China Architecture and Building Press，2003.(in Chinese))
[13]
张忠苗. 桩基工程[M]. 北京：中国建筑工业出版社，2007：72-84.(ZHANG Zhongmiao. Pile foundation[M]. Beijing：China Architecture and Building Press，2007：72-84.(in Chinese))
2014, Vol. 33 
