根据上海地区不同土层软土的一维和等向固结试验,得到一维固结下压缩指数Cc和回弹指数Cs与修正剑桥模型参数λ和κ之间的关系。鉴于室内试验耗时过长,而通过土样的基本物理指标(天然含水率wn、孔隙比e0、液限wL和塑性指数Ip)来推算压缩指数和回弹指数是一个快捷有效的方式,对比发现土的变形指标与基本物理指标间存在一定的相关性。结果表明:Cc/n0与Cc,C′s/n0与三轴试验各向同性固结下得到的C′s之间存在较好的线性关系,并给出了对应的关系式。由此,上海地区软土的变形指标可通过初始孔隙率来估算。在已有试验数据的基础上,总结分析我国沿海多个地区(广州、天津、深圳、温州、福州等)压缩指数试验数据,发现沿海地区软土压缩指数与初始孔隙率之间均存在较好的线性关系,并给出了对应的关系式。
Abstract
One-dimensional and isotropic consolidation tests were carried out on clay of varied depth in Shanghai to acquire the compression index Cc and the rebound index Cs and their relations with parameters parameters λ and κ in the modified Cambridge model. However, laboratory tests are time-consuming and expensive. Empirical relations need to be developed to predict compression index using physical indices (especially natural water content wn, initial void ratio e0, liquid limit wL and plastic index Ip) of soil which are relatively easier to obtain. Highly linear relations between Cc/n0 and Cc as well as C′s/n0 and C′s were found, and corresponding relational expressions were established. Hence, the deformation index of soft soil in Shanghai can be estimated by void ratio. In addition, according to test data of soft soil in coastal areas in China, including Guangzhou, Tianjin, Shenzhen, Wenzhou, and Fuzhou, an empirical function between Cc/n0 and Cc was constructed to predict compression index of soft soil in some coastal areas in China (Guangzhou, Tianjin, Shenzhen, Wenzhou, and Fuzhou) for preliminary engineering design.
关键词
软黏土 /
一维固结 /
等向固结 /
压缩指数 /
回弹指数 /
经验关系 /
沿海地区
Key words
soft clay /
one-dimensional consolidation /
isotropic consolidation /
compression index /
swelling index /
empirical correlations /
coastal areas
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基金
国家自然科学基金项目(41877236,41972275)
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