上海地区软黏土的OCR及地质成因

发布时间：2018-06-12 16:30

本文选题：软黏土 + 原位十字板强度　；参考：《岩土工程学报》2017年S2期

【摘要】：通过覆盖上海地区两种沉积相(滨海平原和湖沼平原)19个工程的原位十字板强度Su FV,结合国内外研究成果,对上海3个软黏土层的超固结比OCR及其地质成因进行了分析。根据强度比S_(uFV)/σ'_(v0)(σ'_(v0)为有效上覆压力)计算OCR,给出了OCR随深度的变化规律。上海软土整体上处于超固结状态,浅部具有较大的OCR且较为离散(在1.3~5.0),随深度的增加OCR迅速减小,超过约13 m后维持在一稳定的数值(平均为1.6)。过去采用室内压缩试验给出的结果显著低估了上海软黏土的OCR。结合Hanzawa和Tanaka给出的模型对上海软黏土的强度及超固结地质成因进行了分析,认为基本符合浅部以胶结作用为主、深部以次压缩为主的特征。浅部的胶结作用变化范围较大而深部的次压缩作用则相对稳定,并初步给出了正常压缩、胶结作用和次压缩作用对总强度的贡献。
[Abstract]:Based on the in-situ cross plate strength Su FV of 19 projects covering two kinds of sedimentary facies (littoral plain and lake-marsh plain) in Shanghai area, combined with the domestic and foreign research results, the OCR and its geological origin of three soft clay layers in Shanghai were analyzed. The OCRs are calculated according to the strength ratio (S / S / S / V), and the variation law of OCR with depth is given. The soft soil in Shanghai is in an overconsolidated state as a whole, and the shallow part has a larger OCR and is relatively discrete (at 1.3 ~ 5.0g). With the increase of depth, the OCR decreases rapidly, and is maintained at a stable value (an average of 1.6m) when the depth is more than 13 m. In the past, the results of indoor compression tests have significantly underestimated the OCR of Shanghai soft clay. Based on the model given by Hanzawa and Tanaka, the strength and overconsolidation geological origin of soft clay in Shanghai are analyzed. It is considered that it basically accords with the characteristics of shallow cementation and secondary compression in depth. The change range of the cementation in shallow part is larger than that in the deep part, and the contribution of normal compression, cementation and secondary compression to the total strength is preliminarily given.
【作者单位】：同济大学地下建筑与工程系;绍兴文理学院土木工程学院;
【基金】：国家自然科学基金项目(40702051) 浙江省公益技术应用研究计划项目(2016C33052) 绍兴市公益技术应用研究计划项目(2015B70034)
【分类号】：TU44

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