大连临空产业园淤泥固化现场试验段研究

Study on field test section of sludge solidification in Dalian Airport Industrial Park

针对目前淤泥固化土在自然养护条件下力学性质研究的不足,以大连临空产业园填海造地项目为依托工程,在现场开展用复合固化剂(水泥熟料、高炉矿渣粉、石膏粉)固化海相淤泥的试验段研究。通过原位钻探取样等进行力学测试,研究固化淤泥土强度变化规律、应力应变特性、冻融稳定性及承载力特征值的发展趋势。结果表明:在28 d龄期时固化剂掺量为16%的淤泥固化土的无侧限抗压强度(UCS)比同龄期的掺入比为10%、13%分别高出73.58%、40.45%。随着固化剂掺入比的增加,应力应变曲线由应变硬化转化为应变软化。经过200次的冻融循环之后的淤泥固化土的质量损失率与固化剂掺入比呈负相关。将试验结果应用于临空产业园地基处理中,通过数值模拟结果显示:经过固化土置换之后的地基稳定性满足规范要求。

In view of the shortage of the study on mechanical properties of sludge solidified soil under natural curing conditions at present,a study on the test section of solidifying marine sludge with composite solidifying agent(cement clinker,blast furnace slag powder,gypsum powder)was carried out on the spot based on the land reclamation project of Dalian Airport Industrial Park.The strength variation,stress-strain characteristics,freezing-thawing stability and the development trend of characteristic values of bearing capacity of solidified silt soil were studied by in-situ drilling and sampling.The test results show that the UCS of silt-solidified soil with 16%curing agent at 28 d age is 73.58%and 40.45%higher than that of 10%and 13%at the same age respectively.With the increase of the ratio of curing agent,the stress-strain curue changes from strain hardening to strain softening.The mass loss rate of sludge-solidified soil after 200 freeze-thaw cycles is negatively correlated with the mixing ratio of solidifier.The test results are applied to foundation treatment of the Airport Industrial Park.The numerical simulation results show that the foundation stability after replacement of solidified soil meets the requirements of specifications.