Creep behaviour of geosynthetics

Empirical results dealing with rheological properties of some geosynthetics are presented. Creep tests performed on some Polish-made geotextiles are described and discussed within the framework of the standard linear solid (SLS) model. It is shown that the SLS model described by three parameters can serve as a useful low resolution approximation for a range of geosynthetics, for low stress levels which exclude secondary and tertiary creep. The parameters of the SLS model were determined by curve fitting for three types of Polish geotextiles as well as for some other geosynthetics. The problems of creep under increasing load and creep after partial unloading are discussed. Two modified rheological models of geotextiles, which take into account the plastic strains, are proposed.     

Geotextile filtration opening size under tension and confinement

Nonwoven geotextiles have been used as filters in geotechnical and geoenvironmental works for half a century. They are easy to install and can be specified to meet the requirements for proper filter performance. There are situations where a geotextile filter may be subjected to tensile loads, which may alter relevant filter properties, such as its filtration opening size. Examples of such situations are silty fence applications, geotextile separators, geotextile tubes and geotextiles under embankments on soft soils. This paper investigates the effects of tensile strains on geotextile pore dimensions. A special equipment and testing technique allowed tests to be carried out on geotextile specimens subjected to tension and confinement. The results obtained showed that the variation in filtration opening size depends on the type of strain state the geotextile is subjected, under which the geotextile pore diameter may remain rather constant or increase significantly. However, confinement reduces the geotextile filtration opening size independent on the strain mobilised. An upper bound for the filtration opening size of strained nonwoven geotextiles is introduced and was satisfactory for the geotextile products tested.     

土工合成材料在黄河三角洲地区水利工程上的应用

近年来,随着新技术、新材料的不断出现,地处黄河三角洲地区的胜利石油管理局在水利工程施工中使用了大量的土工合成材料,包括土工布、土工膜、复合土工膜等。通过在水利工程上的不断应用和探索,摸索出了一套适合黄河三角洲地区工程特点的土工合成材料施工方案,取得了较好的社会和经济效益。就土工合成材料在黄河三角洲地区水利工程上的应用作了较详细的介绍。     

针刺土工布Oe值影响因素探讨及特大Oe值厚型产品的研制与应用

在生产实践的基础上,对影响针刺土工布O_e值的主要因素作了一些尝试性的探讨,并对特大O_e值高规格产品的研制及应用范例作了介绍。     

土工织物的开发及应用

本文介绍了湘维厂近十年来所开发土工合成材料的品种。并结合工程应用实例,对土工布、复合土工膜、水井滤布的应用进行了阐述。     

黄洋麻针刺复合土工布在水土保持中的应用

在对比分析土工布类型的基础上,论述了黄洋麻针刺复合土工布的特点,指出其在治理水土流失、防止土壤沙化、改造沙漠、改善生态环境等方面发挥着重要作用,其性能优于其他土工布,可大力推广应用于水土保持工程中。     

土工织物垂直渗透系数测试技术研究

收集了国内外有关土工织物渗透性能的测试标准,并进行了比较。分析了土工织物的微观结构以及渗透原理,通过系列的试验数据探讨了土工织物渗透性能的规律,即水头差与流速的关系,比较三种拟合方式的拟合程度,提出最合适的拟合关系作为水头差和流速的理论关系式。分析比较几种检测标准取值的依据,提出检测结果取值的方案,为国家测试标准GB/T 15789-1995《土工布透水性测定方法》的修订提供依据。     

土工织物的蠕变性能和侧限蠕变试验研究

土工织物的蠕变现象十分明显，它的蠕变性质和许多因素有关。其中有无土侧限条件时，蠕变性能不一烊。提交了2种典型土工织物的侧限拉伸蠕变试验结果，分析在不同的荷载水平和上覆土压力限制下土工织物蠕变性能的变化，反映出土工织物在砂土中拉伸模量和抗拉强度随着上覆压力的增加而提高，蠕变应变和蠕变系数显著减小。     

土工布在运动场中的应用

运动场下铺设土工布对于提高运动场地的质量以及维护和保养运动场地有着十分重要的意义。本文针对运动场的排水 ,提出了运动场土工布铺设的结构模型 ,并对所用土工布的原料和生产方法进行了介绍。     

土工织物方兴未艾商机无限

土工织物因其良好的性能而具有过滤、排水、加筋、隔离、保护和防渗六大功能 ,用于工程建设中有造价低、效果好的优点 ,是继钢材、水泥、木材之后的第四种新型建筑材料。 1998年我国发生特大洪灾以后 ,加大了推广应用的力度 ,土工织物的开发与生产重点转向宽幅、系列化、合成型和复合型 ,具有极其广阔的发展前景。