滩海吹填粉细砂地基长期承载力特性试验研究

Investigation into the enduring load-bearing traits of hydraulic fill with silty fine sand foundation on shallow sea artificial islands

对某运行10年以上出现沉陷冒水现象的滩海人工岛吹填粉细砂地基承载力进行分析,基于螺旋板载荷试验结果,研究了标贯击数、动探击数与地基承载力的关系,拟合了经验公式,在此基础上综合分析粉细砂地基承载力现状,探究地基长期承载力特性。研究结果表明,吹填粉细砂形成的滩海人工岛地基在长期反复的水力作用下可进一步密实,承载力有所提高,有利于场地的运行安全。但鉴于其松散特性,水力作用下易流失,防渗措施不到位可能导致沉陷脱空、冒水等工程问题,影响场地安全运行。因此,针对本工程沉陷冒水现象,需采取原位固化、帷幕封闭等防渗措施进行处理。

This article analyzes the bearing capacity of a shallow sea artificial island filled with silty fine sand foundation that has experienced subsidence and water seepage for more than 10 years of operation.Based on the results of spiral plate load tests,the relationship between the SPT’s blow count N’,DPT’s blow count N'120 and foundation bearing capacity is studied.Empirical formulas are fitted,and on this basis,the current bearing capacity of the silty fine sand foundation is comprehensively analyzed to explore the long-term bearing capacity characteristics of the foundation.The results indicate that the artificial island foundation formed by silty fine sand is further compacted under long-term repeated hydraulic action,and its bearing capacity is improved,which is conducive to the safe operation of the site.However,due to its loose nature,it is prone to loss under hydraulic action,and inadequate anti-seepage measures may lead to engineering problems such as subsidence,hollowing out,and water seepage,affecting the safe operation of the site.Therefore,in response to the phenomenon of subsidence and water leakage in this project,antiseepage measures such as in-situ solidification and curtain sealing need to be taken for treatment.