拉应变对土工织物孔径特征及反滤性能影响的研究

发布时间：2018-01-09 01:07

本文关键词：拉应变对土工织物孔径特征及反滤性能影响的研究　出处：《浙江大学》2014年博士论文　论文类型：学位论文

【摘要】：土工织物作为反滤材料广泛应用于水利、土木、港航等领域。土工织物要实现反滤功能,需满足保土、透水、防淤堵三个反滤准则。孔径是土工织物反滤准则的重要参数。由于土工织物纤维多、孔径小、工作状态应变大,其孔径受拉应变影响很大。而土工织物的孔径指标和测试均在未受拉状态下进行,导致实际应用中原本满足孔径指标的织物反滤失效。因此,本文通过理论分析与试验测试,研究拉应变T (Tensile)、土工织物孔径特征O (Opening)、及反滤性能F (Filtration)三者的关系。 1)建立单/双向拉应变与土工织物孔径特征关系的(T-O)理论模型。针对有纺织物平面二维结构,建立单/双向拉应变下有纺织物单孔模型,根据有纺织物基本物理力学参数和拉应变值,分别推导特征孔径(O)及开孔面积率(POA, Percent open area)随单/双向应变变化的理论解；针对无纺织物三维空间结构,基于单向应变下已有两种体系的孔径参数理论解,即佘巍(2011)等效孔径(095)理论解和Rawal(2011)孔径分布曲线(PSD, Pore size distributions)理论解,分别推导不等轴双向应变下无纺织物等效孔径O95bi理论解、及孔径分布曲线PSDbi理论解。 2)测试单/双向拉应变与土工织物孔径特征的(T-O)试验关系。通过数字图像法测试单丝条膜有纺织物孔径,在维持拉应变的同时采集图像,定量测试单/双向应变下,有纺织物孔径参数随拉应变的变化规律；通过干筛试验测试单/双向应变下,短纤针刺无纺织物孔径参数随拉应变的变化规律；用拉应变下的土工织物孔径参数理论解预测试验结果,理论值与试验值吻合较好,并得出土工织物孔径参数与拉应变的近似线性关系。 3)测试单向拉应变与土工织物反滤性能(T-F)的关系。运用梯度比渗透仪进行淤堵试验,对应反滤设计中透水、保土和防淤堵三个准则,分别测试单向拉应变对透过土工织物的水流速率、漏土量、梯度比的影响。拉应变下的反滤性能试验结果,佐证了孔径随拉应变的变化规律,由此建立了土工织物孔径特征与反滤性能(O-F)的定性关系。 4)探讨土工织物泊松比随拉应变的变化规律。通过图像法试验,测试8种有纺及无纺织物泊松比随单向拉应变的变化关系,并与Giroud(2004)提出的可压缩材料和不可压缩材料泊松比变化公式进行对比。
[Abstract]:Geotextiles as filter materials are widely used in water conservancy and civil engineering, shipping and other fields. The geotextile to realize the filter function, meet the needs of soil, water, anti clogging filter criterion. The three aperture is an important parameter of geotextile filter criterion. With geotextile fiber many small aperture, the working state of large strain, the large aperture tensile strain. The geotextile pore index and test were carried out without tension, leads to the actual application originally meet the index of aperture fabric filter failure. Therefore, through theoretical analysis and experimental test, study strain T (Tensile), geotextile pore characteristics of O (Opening), and the filter performance of F (Filtration) the relationship between the three.
1) a single / two-way tensile strain and geotextile pore characteristic relation (T-O) model for textile fabrics. The two-dimensional structure, the establishment of a textile fabric single hole model of single / two-way tensile strain, according to the basic physical and mechanical parameters of fabric and strain values are derived respectively characteristic pore size (O) and hole area ratio (POA, Percent open area) with single / two-way strain in the theoretical solution; for non woven fabric three-dimensional structure theory under unidirectional strain had two kind of system solutions based on aperture parameters, namely She Wei (2011) equivalent aperture (095) on the solution and Rawal (2011) the pore size distribution curve (PSD Pore, size distributions) theoretical solutions are derived from biaxial strain nonwoven fabric equivalent aperture theory O95bi solution, and the pore size distribution curve of the PSDbi theory.
2) test single / two-way tensile strain and geotextile pore characteristics (T-O) test. The digital image test monofilament with textile membrane aperture, while maintaining tensile strain and image acquisition, quantitative test and single / double way strain, textile fabrics aperture parameters changing with tensile strain; by dry sieving test single / biaxial strain, needledstaple fiber nonwoven fabric aperture parameters changing with tensile strain; theoretical solution to predict the test results by the geotextile tensile strain of the fabric aperture parameters, the theoretical value is in good agreement with the experimental data, and draw the geotextile aperture parameters and tensile strain of the linear approximation the relationship between.
3) test of unidirectional tensile strain and geotextile filtration property (T-F). The relationship between the use of gradient ratio test instrument clogging test, water filter design corresponding in soil and silt prevention three criteria were tested on the flow rate through the uniaxial tensile strain of geotextile and soil leakage the amount, effect of gradient ratio. The tensile strain of the anti filter performance test results, evidence of the aperture changes with tensile strain, the geotextile pore characteristics and filtration properties (O-F) relationship.
4) to investigate the geotextile Poisson ratio variation with tensile strain. Through image test, to test 8 types of woven and nonwoven fabrics with Poisson's ratio uniaxial tensile strain changes, and Giroud (2004) proposed a compressible material and incompressible material Poisson's ratio formula were compared.

【学位授予单位】：浙江大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：TU531.7;TU502

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