钱塘江冲海积粉土渗透破坏试验研究

发布时间：2018-04-18 01:21

本文选题：钱塘江冲海积粉土 + 渗透变形　；参考：《岩土力学》2016年S2期

【摘要】：钱塘江冲海积粉土以砂质粉土为主,呈"高粉性、低黏性"的地区特点,在地下水动水压力作用下极易产生渗透破坏。粉土是介于砂性土和黏性土之间的一种过渡类型土,工程性质既与砂性土不同又与黏性土有较大区别。采用自行研制的粉土抗渗强度测定设备,对钱塘江冲海积粉土5种典型样本和微层理原状样本进行了渗透稳定试验。结果表明,钱塘江冲海积粉土渗透稳定性差,抗渗强度低;砂质粉土临界水力比降i_(cr)为1.01~1.25,破坏形式为局部流土,从临界水力比降i_(cr)发展到破坏比降i_F的过程是瞬间的,基坑开挖遇到该类土层极易产生渗透破坏;黏质粉土临界水力比降i_(cr)随黏粒含量增加而增加,从临界水力比降i_(cr)发展到破坏比降i_F有个短暂的过程,是整体流土破坏;钱塘江冲海积粉土渗透稳定各向异性;渗流垂直微层理方向的临界水力比降i_(cr)最大,是渗流沿微层理方向i_(cr)的2.5倍左右。研究结果为粉土地基渗透破坏防治提供参考。
[Abstract]:The alluvial silt of Qiantang River is dominated by sandy silt, which is characterized by "high silty and low viscosity". It is easy to cause seepage damage under the action of groundwater hydrodynamic pressure.Silt is a transitional soil between sandy soil and clay soil. The engineering properties of silt are not only different from sandy soil but also different from clay soil.The permeation stability tests of five typical samples of silt and microstratified undisturbed samples of alluvial silt in Qiantang River were carried out by using the self-developed equipment for the determination of impermeability strength of silt.The results show that the infiltration stability of alluvial silt in Qiantang River is poor, and the seepage strength is low, the critical hydraulic ratio of sandy silt is 1.01 ~ 1.25, and the failure form is local flowing soil. The process of development from critical hydraulic ratio to reduced Icr-F is instantaneous.In excavation of foundation pit, it is easy to cause seepage failure in this kind of soil layer, and the critical hydraulic ratio of clay silt increases with the increase of clay content, and the development from critical hydraulic ratio to reduced IcrF is a transient process, which is the failure of whole fluid soil.The percolation stability anisotropy of alluvial silt in Qiantang River is stable, and the critical hydraulic ratio of percolation in the vertical direction of percolation is the largest, which is about 2.5 times that of the percolation along the direction of microstratification.The results provide a reference for the prevention and treatment of seepage failure of silty soil foundation.
【作者单位】：浙江树人大学城建学院;浙江大学滨海和城市岩土工程研究中心;浙江中材工程勘测设计有限公司;杭州市城市建设发展有限公司;
【基金】：国家自然科学基金(No.51338009) 国家大学生创新训练计划项目(No.201511842003) 浙江省科技计划项目(No.2008C33002) 浙江省大学生科技创新活动计划(新苗人才计划)(No.2013R420018)~~
【分类号】：TU41

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