用收缩试验资料间接估算压力板试验中的体积含水量   总被引：7，自引：1，他引：6  

张华 《岩土力学》1999,20(2):2-26

土水特征曲线是表征非饱和土基本性质的重要曲线之一,一般由压力板试验测定。膨胀土试样在压力板试验中体积变化很大,且其体积变化值又不得而知,故只能得到其重力含水量与基质吸力的关系。本文建议用收缩试验资料来间接估算压力板试验中试样的体积含水量,从而可得到用体积含水量与基质吸力关系表达的土水特征曲线。  相似文献   

Desiccation shrinkage of non‐clayey soils: a numerical study     

Liang Bo Hu  Hervé Péron  Tomasz Hueckel  Lyesse Laloui 《国际地质力学数值与分析法杂志》2013,37(12):1782-1800

A mesoscale model of desiccation of soil based on the evolution of the pore system idealized as bimodal is numerically examined. A simplified evolution of the model reveals a series of characteristics that qualitatively agree with the observed macroscopic experimental findings. The principal mechanism is deemed to be driven by the surface evaporation and water outflow generating a pore pressure gradient resulting in the shrinkage mainly of the largest pores. The amount of shrinkage is a function of (negative) pore pressure and is controlled by the compressibility of the solid matrix. The numerical model includes also the ensuing partial saturation stage initiated by the air entry simulated as a scenario with a moving phase interface inside the pore. The proposed model can be extended beyond the two‐mode porosity soils, to include the multi‐modal porosity, or its statistical representation.Copyright © 2012 John Wiley & Sons, Ltd.  相似文献   

颗粒破碎效应对堆石坝应力变形的影响     

沈婷  李国英  陈生水 《岩土力学》2006,27(Z2):469-474

颗粒破碎对堆石体的变形有重大影响,颗粒破碎除与母岩强度有关外,与应力状态密切相关,高堆石坝堆石体的大部分变形正是高应力场下颗粒破碎的反映。沈珠江院士提出的南水双屈服面模型虽可以较全面地反映堆石体的变形特性,但未充分考虑颗粒破碎引起的剪缩特性,因此坝体变形计算结果往往偏小,适用于中低堆石坝的分析中。本文的计算方法在南水双屈服面模型的基础上,考虑了堆石体在一定应力状态下颗粒破碎引起的应变,较真实地反映了堆石体的变形特性,可为堆石坝尤其是高堆石坝的应力变形研究提供更为合理的结果。  相似文献   

基于两种收缩试验的膨胀土地基变形预测方法的对比研究     

余飞  陈善雄  马佳 《岩土力学》2006,27(Z1):619-621

基于两种收缩试验的膨胀土地基变形预测方法进行了比较研究。分析表明,两种预测方法的计算结果存在较大差异,其原因在于其考虑的膨胀土地基的侧限状态不同,分别为无侧限状态和完全侧限状态下的预测结果。基于以上分析成果,并考虑膨胀土的裂隙性和实际地基的侧限状态,给出了膨胀土地基变形预测的经验公式,并将其应用于实际工程,为膨胀土地基变形的准确预测及合理处置方案的制定提供了可靠的依据。  相似文献   

A classification approach to reconstruct local daily drying dynamics at headwater streams     

Aurlien Beaufort  Julie Carreau  Eric Sauquet 《水文研究》2019,33(13):1896-1912

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嵩县大西沟矿区复杂地层钻探施工综合治理   总被引：2，自引：0，他引：2       下载免费PDF全文

翟东旭 《探矿工程》2012,39(10):32-35

河南省嵩县大西沟矿区地层复杂,构造多,岩层＂破、脆、碎＂,钻探施工非常困难,涌水、漏水、缩径、掉块现象频发,不少钻孔报废。针对该矿区地层特点及施工难点,从设备选择、钻孔结构、冲洗液以及水泥堵漏等方面采取有针对性的技术措施,取得了较好的效果。总结了钻探施工的经验和体会。  相似文献   

汶川地震断裂带科学钻探项目WFSD-4孔取心钻进技术   总被引：2，自引：0，他引：2       下载免费PDF全文

庄生明  吴金生  张伟  王稳石 《探矿工程》2014,41(9):126-129

介绍了汶川地震断裂带科学钻探项目4号孔（WFSD-4）取心钻进施工情况,对破碎和缩径地层的取心钻进工艺和技术措施及其应用效果进行了分析和总结。  相似文献   

泥质岩膨胀各向异性与循环胀缩特征     

柴肇云  张鹏  郭俊庆 《岩土力学》2014,299(2):346-350

采用自主开发研制的软岩膨胀试验装置,对新生代煤系地层中泥质岩进行膨胀试验研究,分析了泥质岩膨胀各向异性以及循环胀缩特性,并结合SEM试验结果,探讨了膨胀各向异性和循环胀缩特性的形成机制。结果表明:泥质岩膨胀性随岩样端面与层理面夹角的增大而减小,具有明显的各向异性;泥质岩所含黏土矿物颗粒排列的择优取向导致了泥质岩吸水膨胀的各向异性,可通过膨胀各向异性系数进行定量描述;随着干湿循环次数的增加,泥质岩绝对膨胀率增加,趋于某一稳定值;相对膨胀率和相对收缩率降低,亦趋于某一稳定值;泥质岩循环胀缩特性是干湿循环过程中矿物颗粒排列方式改变和微裂隙萌生扩展的能量耗散共同作用的结果。  相似文献   

Use of shredded tyre waste in improving the geotechnical properties of expansive black cotton soil     

Amit Srivastava  Shikha Pandey  Jeeshant Rana 《Geomechanics and Geoengineering》2014,9(4):303-311

In recent years, geotechnical engineers are using tyre waste to alter the properties of soil for providing sustainable solutions to complex engineering problems. It is noted that black cotton soil, which is expansive in nature, covers a major portion of the Indian sub-continent, such as the Deccan plateau, Malwa plateau and a portion of Gujarat and poses challenging problems to infrastructural development in the region. In the present study, authors have characterised the geotechnical properties of black cotton soil, which is partially replaced with 4.75 mm passing – 2 mm retained (coarse fraction) and 2.0 mm passing - 75 micron retained (fine fraction) shredded tyre waste. The results of the experimental studies clearly show that partial replacement of black cotton soil with shredded tyre waste alters the geotechnical properties favourable to engineering applications and greatly reduces the swelling potential of the black cotton soil. It is noted that instead of fine fraction (2.0–0.075 mm), replacement with coarse fraction (4.75–2.00 mm) of shredded tyre waste can better be used for light weight fill behind the retaining walls as well as for embankment construction as it helps in reducing swelling pressure as well as improving the strength properties.  相似文献   

路面土质底基层材料干缩试验方法研究     

蔡晓飞 《岩土工程技术》2010,24(3):139-141,146

路面土质底基层材料需具有良好的干缩性能,对土质干缩试件的尺寸、试模及测试仪器的设计、试件的制作与养生进行了探讨,论述了干燥收缩试验的机理、测试及计算方法,并列举了干缩试验的实例,提出了一种土质干缩试验方法。  相似文献