土工合成材料垂直渗透性能规律及取值方法探讨

比较了国内外几种主要土工合成材料渗透性能测试标准成果的取值方法,通过理论分析及试验数据得出渗透性能中水头差及流速的关系式,并对测试标准取值方法提出建议。     

非织造土工织物垂直渗透检测技术浅析

为了给修订土工织物垂直渗透性能检测国家标准提供依据，以确定其中的两个检测方法的可行性，收集了“2012年土工合成材料产品质量国家监督抽查”中的非织造土工织物样品，采用不同的试验方法比较分析了检测结果，得出检测数量n=5时只有21．7％试验结果的CV值能够符合要求的结果，说明检测数量至少需要5个；在比较了检测5点求取结果和检测1点求取结果后认为，用于材料质量控制时可以只检测50mm水头差1点求取流速指数结果。     

织物渗透性能测试方法与测试仪器

着重介绍了几种常用的测试织物渗透性能的方法和测试仪器,如水压式织物透水性仪器、土工织物渗透仪、人造血管渗透性测试仪、卫生用薄型非织造布穿透性试验装置等,并通过红外线、数字摄影计算机图像这两种技术的运用对织物渗透性能测试仪器的发展作了展望。     

织物渗透件能测试方法与测试仪器

着重介绍了几种常用的测试织物渗透性能的方法和测试仪器,如水压式织物透水性仪器、土工织物渗透仪、人造血管渗透性测试仪.卫生用薄型非织造布穿透性试验装置等,并通过红外线、数字摄影计算机图像这两种技术的运用对织物渗透性能测试仪器的发展作了展望.     

土工织物渗透性能评价及其工程意义

本文通过对各类土工织物在不同垂直压力下的渗透实验,模拟织物在工程中的实际受压状态,提出反映实践的土工织物稳定受压强度及稳定渗透系数两个概念,从而量化了压力对土工织物渗透性能的影响,为工程设计提供准确可靠的依据。     

土工织物淤堵程度的量化方法探讨

通过对不同规格针刺土工织物连续24小时的反复实验,计算土工织物渗透性能的变化,根据数据与时间密切相关性采用时间序列分析方法,进行土工织布淤堵程度的量化分析和渗透性能的预测,从而为土工织物的工程提供准确可靠的设计依据。     

织物防紫外线性能的表征

本文概述了目前织物的防紫外线性能的评价指标、测试方法以及标准,并自行设计装置对织物进行检测。根据测试结果分析了各指标间的关系以及防紫外线性能的影响因素。     

用光杠杆法测试分析非织造土工布的蠕变性能

本文采用光杠杆法对非织造土工布蠕变量进行测试。根据实测曲线 ,对建立的线性三元件模型进行参数拟合。该模型可较好地描述非织造土工织物的蠕变性能。     

聚酯土工织物的热老化性能研究

土工织物被广泛应用于土木工程中,但其在大气环境中容易产生老化现象。介绍了在不同温度下对聚酯土工织物进行的老化性能测试,从而建立老化方程,并分析了其老化机理。     

土工合成材料应用机理及专项研究(Ⅰ)

本文报道了土工合成材料物理特性和力学特性的研究结果,包括土工织物的渗透、保砂、淤堵和老化的研究,以及土工织物的接缝强度和开孔的研究,为工程设计中土工织物的选择和工程方案的拟定提供了依据。     

土工织物拉伸性能测试与分析

本文对机织土工布、非织造布以及机织 /非织造复合土工布的拉伸性能进行测试分析 ,为复合土工布的进一步开发应用提供参考。     

Effect of Chemical Treatment on the Tensile Strength Behavior of Coir Geotextiles

ABSTRACT

The present study investigates the effects of chemical treatment on the tensile strength behavior of the two woven and two nonwoven coir geotextiles. The results reveal that tensile elongation at failure for the untreated and treated woven and nonwoven coir geotextiles was higher in the warp direction in comparison to the weft direction. The tensile elongation at failure for the untreated and treated woven coir geotextiles were influenced by the stiffness and the opening of kinks in the coir yarn whereas the tensile elongation at failure of the untreated/treated nonwoven coir geotextiles was influenced by the presence of the polyethylene (PE) yarn used in stitching along with PE netting and diameter of the yarn used in PE netting. The chemical treatment decreased and increased the tensile strength of both the woven and nonwoven coir geotextiles, respectively. The mass per unit area of woven coir geotextile decreased whereas it increased for both the nonwoven coir geotextiles after the chemical treatment. The chemical treatment modifies the surface characteristics of both the untreated woven and nonwoven coir geotextiles due the removal of impurities and filling up the voids present on the surface.     

非织造土工布孔径分布与渗透性能关系的研究

在过滤和排水领域中 ,非织造土工布的孔径及其分布是一项非常重要的指标 ,与土工布的渗透性能密切相关。本文在前人研究的基础上利用PoissonPolyhedron理论对非织造土工布的理论孔径分布和最大孔径进行了研究 ,得出非织造土工布孔径分布与渗透性的关系。测试非织造土工布样品得到的垂直渗透系数与理论计算值相接近     

牵伸速度对PET纺粘纤维凝聚态结构的影响

在纺粘非织造布加工过程中,通过调整牵伸风的速度,制得不同结构的聚对苯二甲酸乙二醇酯(PET)纤维,研究了牵伸风速度对纺粘PET纤维外观形貌、直径、结晶度和取向度的影响。结果表明:牵伸风速度对纤维表观形貌没有影响;随着牵伸风速度的增加,PET纺粘纤维的直径逐渐减小,当牵伸风速度达到一定值后其对纤维直径的影响较小;PET纺粘纤维的结晶度低于15.0%,牵伸风速度对其影响不大;随着牵伸风速度的增加,PET纤维晶区的取向度逐渐增加,当牵伸风速度达到一定值后对其晶区取向度影响较小。     

Geotextiles: production,properties and performance

The monograph critically reviews most commonly used geotextile structures, their properties and performance characteristics. In general, both natural and synthetic fibres are used for the production of geotextiles, and the advantages and disadvantages of each type of fibre are discussed for various applications of geotextiles. The important functions of geotextiles, i.e. filtration, drainage, separation and reinforcement have been identified and have been related to several properties and major applications of geotextiles. Various geotextile properties, namely mechanical, hydraulic and chemical and their test methods have been critically discussed. A process–structure–property relationship for most commonly used geotextiles is also analysed. Furthermore, the design of a geotextile is of paramount importance for any civil engineering application. Thus, the design criteria for various functions of geotextiles have been addressed. Subsequently, the durability characteristics of geotextile have been introduced for analysing the performance over its lifetime.     

Coir Geotextiles for Paved Roads: A Laboratory and Field Study Using Non-Plastic Soil as Subgrade

ABSTRACT

In this paper, pavement proposed on soft subgrade (SG) that requires improvement is studied and reported. One of the methods of improvement is reinforcing SG with geotextile. Laboratory studies were conducted on both paved and unpaved sections, whereas field performance studies were conducted only on paved roads. Three types of woven and one type of nonwoven coir geotextiles were used as reinforcement in the laboratory study, out of which one woven geotextile was used in the field. Effects of reinforcements were studied by placing the geotextiles at different positions of the section in the lab model, and cyclic load tests were conducted and resistance to permanent deformation was reported. Field performances were evaluated by the Benkelman beam deflection (BBD) test, the dynamic cone penetration (DCP) test, and the field California bearing ratio (CBR) test. Test results indicate that the reinforced roads have less distress compared to the unreinforced one. Change in characteristic deflection, DCP indices, and about 50% improvement in field CBR values were obtained for the reinforced one.     

高强聚丙烯纺粘针刺土工布的耐久性能

为研究高强聚丙烯纺粘针刺土工布（HPP）的耐老化性能和耐化学腐蚀性能,采用热氧老化、酸与碱腐蚀液和纯水浸泡等实验,研究了不同温度和不同化学环境对其耐久性的影响,将其与普通聚丙烯土工布（PP）耐久性进行对比。结果表明：当样品在热氧化温度为110、120、130 ℃条件下处理25d 时,HPP 土工布质量保留率分别为 99.06%、98.85% 和 98.10%; PP 土工布质量保留率分别为98.89%、98.78% 和 97.78%;HPP 土工布纵向断裂强度保留率分别为75.00%、67.25% 和 64.71%,PP 土工布纵向断裂强度保留率分别为 72.15%、65.56% 和 54.00%。在 3 种不同液体处理下HPP 土工布的强度损失率均未超过5.00%,表明 HPP 土工布具有良好的耐腐蚀和耐水浸泡性。通过Arrhenius 定理拟合出 HPP 土工布热氧反应速率表达式,预测出 HPP 土工布使用 50a 后的强度保留率为27.30%。     

Retention of three heavy metals (Zn, Pb, and Cd) in a calcareous soil controlled by the modification of flow with geotextiles

Although geotextiles are increasingly employed in stormwater infiltration basins, their influence on the flow and transfer of contaminants, such as heavy metals, has not been fully investigated. Leaching column experiments were conducted to characterize the flow and transfer of three heavy metals (zinc, lead, and cadmium) in a calcareous soil with and without geotextiles under steady-state flow and close to saturation forthe soil. The influence of geotextiles was characterized for two types of geotextiles (needlepunched and thermosealed) and for two different initial saturation degrees for the needlepunched geotextile. The main results showed that, when placed wet, the needlepunched geotextile had no influence. When placed dry, it homogenized the flow in its surroundings and thus allowed better contact between heavy metals and the reactive soil, resulting in an increase of their retention. The thermosealed geotextile, placed dry, homogenized the flow and increased retention over a larger area, resulting in optimal global retention. In conclusion, geotextiles could be used in infiltration basins, provided that their effect on both flow and heavy metal retention is optimized by appropriate design--choice of geotextiles--and appropriate monitoring--control of hydric conditions.     

试样宽度对非织造土工布拉伸性能的影响

通过拉伸试验分析了非织造土工布断裂强度、一定伸长率时拉伸强度和试样宽度间的关系