In order to make clear the service life of the two composite geotextiles, their fatigue and dynamic creep properties were tested and compared. The experimental results show that the dynamic creep deformations of adhes...In order to make clear the service life of the two composite geotextiles, their fatigue and dynamic creep properties were tested and compared. The experimental results show that the dynamic creep deformations of adhesive bonded composite geotextiles are lower than those of needle -punched composite geotextiles and the former also have longer fatigue lifetime than the latter.As during the making process, the component parts of adhesive bonded composite geotextiles are not damaged by any factors which in case make their tensile strength higher than those of the needle- punched composite geotextiles. At the end of the paper, a proper explanation was given to this phenomenon.展开更多
The influence of the processing parameters on the properties of needle-punched composite geotextiles,compounded by polypropylene filament woven-fabrics and nonwoven fabrics is studied by using orthogonal design method...The influence of the processing parameters on the properties of needle-punched composite geotextiles,compounded by polypropylene filament woven-fabrics and nonwoven fabrics is studied by using orthogonal design method. The relationship between tensile strength and peeling strength is discussed. The experimental results are offered as reference.展开更多
Geosynthetics used as geotextiles/geomembranes lose their mechanical properties when exposed to outdoor solar radiation. The UV-component present in the solar radiation is main cause for such degradation of mechanical...Geosynthetics used as geotextiles/geomembranes lose their mechanical properties when exposed to outdoor solar radiation. The UV-component present in the solar radiation is main cause for such degradation of mechanical properties. The life of geosynthetics has to be predicted before the intended purpose by exposing the material under artificial UV-radiation in the laboratory. Simulation of UV-radiation has been set up for accelerated ageing condition of Mumbai climate.展开更多
This paper presents the results of triaxial tests conducted for the investigation of the influence of geotextiles on stress-strain and volumetric change behaviour of reinforced sandy soil. Tests were carried out on lo...This paper presents the results of triaxial tests conducted for the investigation of the influence of geotextiles on stress-strain and volumetric change behaviour of reinforced sandy soil. Tests were carried out on loose sandy soil. The experimental program includes drained compression tests on samples reinforced with different values of both geotextiles layers （Ng） and confining pressure （σ′c）. Two methods of preparation were used： air pluviation （AP） and moist tamping （MT）. Test results show that the geotextiles induce a quasi-linear increase in the stress deviator （q） and volume contraction in the reinforced sand. Method of preparation significantly affects the shear strength; samples prepared by the air pluviation method and mobilized deviator stresses are significantly higher than those prepared by moist tamping method. Geotextiles restrict the dilation of reinforced sandy soil and consequently the contraction increases. The mobilized friction angle increases with increasing number of layers and decreases with increasing initial confining pressure. Samples prepared by moist tamping present mobilized friction angles significantly lower than those prepared by air pluviation method. For samples prepared by the air pluviation method, the secant modulus at ε1=1% and 5% decreases with increasing geotextile layers; those prepared by the moist tamping method, secant modulus at ε1=1% and 5% increases with increasing number of geotextile layer sand confining pressure. From 10% axial strain, secant modulus increases with increasing inclusions of geotextile layers.展开更多
The pullout testing of geosynthetics is essential for studying interface interaction in the soil-reinforcement system. In this paper, a new method for testing interface properties of geotextiles is proposed. The inter...The pullout testing of geosynthetics is essential for studying interface interaction in the soil-reinforcement system. In this paper, a new method for testing interface properties of geotextiles is proposed. The interface frictional characters of two kinds of geotextiles (woven and needle-punched nonwoven) are investigated through pullout test. Nonwoven specimen has more wide variety of displacement along length than that of woven under the same pressure because of their different extensibility. The greater the elongation and deformation of specimens, the more evident the variations of displacement along reinforcement from front to pullout end. The greater the normal pressure, the smaller the displacement of every position along length with the same pullout load. The study focuses on the effects of the tensile modulus and the difference of pullout response between woven and nonwoven geotextiles.展开更多
Nonwoven geotextiles have been widely used as drains orfilters in many civil engineerings.The hydraulic charac-teristics of geotextiles are the basic function in these ap-plications.The in-plane permeability of nonwov...Nonwoven geotextiles have been widely used as drains orfilters in many civil engineerings.The hydraulic charac-teristics of geotextiles are the basic function in these ap-plications.The in-plane permeability of nonwoven geo-textiles was discussed in this paper.The results of in-plane permeability coefficient of nonwoven geotextilesfrom measurement were analyzed.展开更多
In order to accelerate the consolidation of the dredged sludge and look for an effective material for mud-water separation,the study on the comparison of geotextiles is carried on. It is based on the laboratory model ...In order to accelerate the consolidation of the dredged sludge and look for an effective material for mud-water separation,the study on the comparison of geotextiles is carried on. It is based on the laboratory model test of aeration vacuum rapid mud- water separating( AVMWS) technique and evaluated by the cumulative weight of pumping water,the decrease of moisture content and the stable pumping speed. The results show that woven fabric is the best anti- clogging aeration vacuum material,followed by machine-woven fabric and non-woven fabric is the worst. The analysis has been proposed from two aspects of geotextile weaving technology and aeration vacuum condition.展开更多
In this paper,the failure features of strip tensile specimen were observed and analysed for need-le-punched non-woven geotextiles.A mechanical model which expresses the relation between thetensile modulus,the strip sp...In this paper,the failure features of strip tensile specimen were observed and analysed for need-le-punched non-woven geotextiles.A mechanical model which expresses the relation between thetensile modulus,the strip specimen size,contraction factor and the tensile strength of non-wovenfabric was derived.The theoretical prediction showed that the main factor influencing tensilestrength of non-woven geotextile specimens with different size is the contraction factor of specimenor the specimen aspect ratio(width/length).The larger the aspect ratio,the higher the tensilestrength test value of geotextiles,but the experiments showed that the specimen tensile strength isnot increased with increasing the width of specimen.The reason was discussed and it seemed thatthe deviation could be served as an indication of the degree of imperfectness of the non-wovenstructure.展开更多
In order to develope new composite geotextiles with good comprehensive properties,the needle-punched composite geotextiles and adhesive bonded composite geotextiles were made in the factory and laboratory separately.T...In order to develope new composite geotextiles with good comprehensive properties,the needle-punched composite geotextiles and adhesive bonded composite geotextiles were made in the factory and laboratory separately.The two processing methods were studied and the mechanical and hydraulic properties of the two kinds of products were tested and compared.The experimental resultsshow that the breaking strength of needle-punched composite geotextiles is much lower than that of adhesive bonded composite geotextiles and the latter also have better hydraulic properties than the former which used展开更多
Geotextiles and geotextile-related products Determination of water flowcapacity in their plane has just National standard. But has not a formal instrument at present. There are many kinds of geotextile and also lots o...Geotextiles and geotextile-related products Determination of water flowcapacity in their plane has just National standard. But has not a formal instrument at present. There are many kinds of geotextile and also lots of factors influential to the penetration coefficient thereof. The intelligent tester may be involved in testing penetration coefficient under different pressures/gradients resulted in fine repeatability controlled intelligently by microcomputer system.展开更多
It is well established that geotextiles/geomembranes polymers undergo degradation of their mechanical properties, electrical properties, theological properties when exposed to UV-radiation. The degradation of strength...It is well established that geotextiles/geomembranes polymers undergo degradation of their mechanical properties, electrical properties, theological properties when exposed to UV-radiation. The degradation of strength depends upon the physical properties viz. thickness vis-a-vis mass per unit area, exposure period and the condition under which the geotextiles/geomembranes polymers are exposed. The polymers： PET/PP/PVC/HDPE widely used as geotextiles/geomembranes were exposed to artificial UV-radiation with the accelerated rate under various exposure conditions and the degradation of their mechanical properties has been evaluated. The results for degradation of strength are presented elsewhere. The visual inspection of the process of degradation of UV degraded polymers is studied through SEM micrographs and the results are presented here.展开更多
The effectiveness of geonet, geotextile and their composite as containment materials of landfill leachate has been examined in this paper through the use of system dynamics modeling method. The study area is Oriire Lo...The effectiveness of geonet, geotextile and their composite as containment materials of landfill leachate has been examined in this paper through the use of system dynamics modeling method. The study area is Oriire Local Government Area of Oyo State, Nigeria. Three materials were studied, which include： GN （geonet）, GT （geotextile） and GC （geocomposite）. The water absorption, hydraulic conductivity, porosity and thickness were the major properties studied in these liners. Governing equations coded in Visual Basic Computer Programming Language was employed in developing a model. Validation of the model was done with data on the study area. The interrelationship of the properties and the breakthrough times for each material was found through the STELLA 9.1.4 software application. This research showed that the effectiveness of the studied of the order GC 〈 GN 〈 GT. GT is, therefore, recommended for use as landfill liners in the study area.展开更多
This research shows the outcomes of laboratory-scale experiments to enhance the pull-out capacity of geosynthetic reinforced soil via an intelligent drainage system.The intelligent drainage system is designed inside a...This research shows the outcomes of laboratory-scale experiments to enhance the pull-out capacity of geosynthetic reinforced soil via an intelligent drainage system.The intelligent drainage system is designed inside a pull-out machine and is made of gravel and geotextiles.The drained water is collected in a container.The experiments were conducted following ASTM standard D 6706-01.Various test parameters,such as soil moisture levels and the magnitude of external loads,were considered during the experimental procedure.The experiments included temperatures of 20℃,35℃,and 50℃with an initial saturation of about 90%.The results showed that the temperature-aided intelligent drainage system increased the pull-out strength of the geosynthetic reinforced soil.Furthermore,there was also an increase in the interaction coefficient and the interface friction angle.Therefore,the detrimental effects of a saturated geosynthetic reinforced soil,especially during heavy rains which often cause failure,can be diminished by the proposed system.The research findings indicated that the intelligent drainage system enhanced the pull-out capacity and strength-related parameters of the geosynthetic reinforced soil by approximately 25%,thereby augmenting its internal stability.The practical implications of these results are thoroughly examined in the paper.展开更多
This paper aims to study the shear interaction mechanism of one of the critical geosynthetic interfaces,the geotextile/geomembrane, typically used for lined containment facilities such as landfills. A largedirect shea...This paper aims to study the shear interaction mechanism of one of the critical geosynthetic interfaces,the geotextile/geomembrane, typically used for lined containment facilities such as landfills. A largedirect shear machine is used to carry out 90 geosynthetic interface tests. The test results show a strainsoftening behavior with a very small dilatancy （〈0.5 mm） and nonlinear failure envelopes at a normalstress range of 25e450 kPa. The influences of the micro-level structure of these geosynthetics on themacro-level interface shear behavior are discussed in detail. This study has generated several practicalrecommendations to help professionals to choose what materials are more adequate. From the threegeotextiles tested, the thermally bonded monofilament exhibits the best interface shear strength underhigh normal stress. For low normal stress, however, needle-punched monofilaments are recommended.For the regular textured geomembranes tested, the space between the asperities is an important factor.The closer these asperities are, the better the result achieves. For the irregular textured geomembranestested, the nonwoven geotextiles made of monofilaments produce the largest interface shear strength.展开更多
In this study, jute woven fabrics (1 × 1 plain, twill, zigzag and diamond weave) were manufactured from 100% raw jute yarn. The fabric specimens were treated by 5%, 10%, 15%, 20% and 25% unsaturated polyester res...In this study, jute woven fabrics (1 × 1 plain, twill, zigzag and diamond weave) were manufactured from 100% raw jute yarn. The fabric specimens were treated by 5%, 10%, 15%, 20% and 25% unsaturated polyester resin where styrene monomer used as a solvent and 1% methyl ethyl ketone peroxide (MEKP) was used as initiator. Two bar pressure was applied for complete wetting of the fabric by a Padder and curing was done at 130?C for 10 minutes. The physico-mechanical characteristics of untreated and treated samples were examined and evaluated. It was revealed that moisture content (MC) and water absorbency of the treated specimens were decreased with the increase of resin percentage (%) in the fabrics. MC and water absorbency were maximum decreased up to 50.23% and 60.14% respectively by 25% resin treatment. On the other hand, bending length (BL), flexural rigidity (FR), flexural modulus (FM) and tensile strength (TS) were enhanced with the increase of resin percentage in the fabrics which resulted higher fabric stiffness. The maximum improvement of BL, FR, FM and TS were found to be 6.67%, 56.04%, 10.57% and 18.75% respectively in comparison to untreated sample. Soil degradation tests exhibited that 33.59% TS loss occurred for untreated specimens where only 8.04% loss of TS found for 25% resin treated one. Furthermore, jute based twill, zigzag and diamond fabrics were also treated by 10%, 15%, 20% and 25% resin, then measured their TS and compared with plain fabrics. It was revealed that plain fabrics have superior TS over other fabrics. It was also evident that TS enhanced for all the fabrics after resin treatment and maximum increase found for all the fabrics up to 25% resin treatment.展开更多
Stress distribution of holed geotextile cross-section under uniaxial and double-axial tension is analyzed with the boundary element method (BEM). The calculation results indicate that stress distribution of holed geot...Stress distribution of holed geotextile cross-section under uniaxial and double-axial tension is analyzed with the boundary element method (BEM). The calculation results indicate that stress distribution of holed geotextile cross-section is greatly related to the dimension of the specimen, the size of the hole, the shape of the hole and the tensile condition, and the stress concentration area of holed geotextile from the side of the hole to 3-4 times of the hole diameter should be strengthened in order to improve quality of the projects. These results could provide guidance for engineering application of geotextiles.展开更多
The geotubes have been widely applied in the engineering of land reclamation from sea. At present three kinds of material can be used to make geotubes: splitting film, fibrillated splitting film and multifilament. The...The geotubes have been widely applied in the engineering of land reclamation from sea. At present three kinds of material can be used to make geotubes: splitting film, fibrillated splitting film and multifilament. The geotubes made of these materials have their advantages and disadvantages. In engineering application to know the rule of forces change is very important. Based on geometry way, limit-filling height of geotubes is determined. Experiment in Pudong International Airport reflects that packing soil height of small-size geotubes will be smaller than that of large-size geotubes.展开更多
Nowadays, geotextile tubes hydraulically filled with dredged materials have been used in the application of cofferdam, sea reclamation and deepwater channel regulation in China. The shape and mechanical behaviors duri...Nowadays, geotextile tubes hydraulically filled with dredged materials have been used in the application of cofferdam, sea reclamation and deepwater channel regulation in China. The shape and mechanical behaviors during the process of filling, consolidation and stacked are one of the main problems concemed by designers and researchers.This paper uses the method of elliptic integrals to study the behaviors of filling and deduces the regressive formulas of shape features and circumferential tension. The results show that the proposal regressive formulas are only the function of pressure at bottom; they are very convenient and suitable for the filling design. When the filling materials are sandy, the shape and mechanical behaviors nearly remain during the process of consolidation. The behaviors of stacked geotextile tubes are very complex, because they are involved in the properties of the filling material, geotextile and foundation.Using the commercial finite element analysis program ABAQUS, this paper establishes the entire 2- D finite element load model to investigate, which include the part of filling material, geotextile and foundation. The numerical results suggest that the maximun circumferential tension varies with the properties of filling materials and foundations, whereas the largest tensile force occurs during the filling process.展开更多
Wicking geotextile(WG)is considered as a possible countermeasure to reduce water content in unsaturated soil.In this research,rainfall tests were carried out to verify the drainage performance of WG.And capillary rise...Wicking geotextile(WG)is considered as a possible countermeasure to reduce water content in unsaturated soil.In this research,rainfall tests were carried out to verify the drainage performance of WG.And capillary rise tests were conducted to study the effect of WG on the prevention of capillary rise.Test results indicated that WG with good drainage performance could drain gravitational and capillary water out of kaolinite soil.For kaolinite soil column with water content of 12%and compaction degree of 90%,the whole process of capillary rise in soil column with a layer of WG was a typical two-stage mode,and the maximum capillary height was about 380 mm,which provided that the WG could work as a barrier to prevent capillary rise effectively.In addition,the total vertical influential regions of WG in kaolinite soil above and below the WG layer were 400 and 100 mm,respectively.展开更多
The technique of geotextile tubes used to construct dikes for land reclamation has been widely used. The tubes are usually filled with slun＇y of soil, such as sand, silt or clay. The tensile stress developed in the g...The technique of geotextile tubes used to construct dikes for land reclamation has been widely used. The tubes are usually filled with slun＇y of soil, such as sand, silt or clay. The tensile stress developed in the geotextile during filling the tube is the dominant factor for construction of a safe dike. The existing design methods are good for designing sausage shaped tubes and can not be directly applied for designing fiat tubes, which are commonly used in dike construction. This paper presents a procedure that can detenmine the relatiorrship among the tube size, the pumping pressure, the unit weight of the slurry, and the tensile stress developed in the geotextile during the tube filing. When the tubes are piling up to form the dike, the tubes in the bottom will sustain the load from the weight of the upper ones. A procedure is also developed to calculate the changes of the mechanical and geometrical behavior of the tubes under the load with a similar method. All these approaches have been programmed, which can help dike designers to select the suitable geotextile and determine the profile of the dike.展开更多
文摘In order to make clear the service life of the two composite geotextiles, their fatigue and dynamic creep properties were tested and compared. The experimental results show that the dynamic creep deformations of adhesive bonded composite geotextiles are lower than those of needle -punched composite geotextiles and the former also have longer fatigue lifetime than the latter.As during the making process, the component parts of adhesive bonded composite geotextiles are not damaged by any factors which in case make their tensile strength higher than those of the needle- punched composite geotextiles. At the end of the paper, a proper explanation was given to this phenomenon.
文摘The influence of the processing parameters on the properties of needle-punched composite geotextiles,compounded by polypropylene filament woven-fabrics and nonwoven fabrics is studied by using orthogonal design method. The relationship between tensile strength and peeling strength is discussed. The experimental results are offered as reference.
文摘Geosynthetics used as geotextiles/geomembranes lose their mechanical properties when exposed to outdoor solar radiation. The UV-component present in the solar radiation is main cause for such degradation of mechanical properties. The life of geosynthetics has to be predicted before the intended purpose by exposing the material under artificial UV-radiation in the laboratory. Simulation of UV-radiation has been set up for accelerated ageing condition of Mumbai climate.
文摘This paper presents the results of triaxial tests conducted for the investigation of the influence of geotextiles on stress-strain and volumetric change behaviour of reinforced sandy soil. Tests were carried out on loose sandy soil. The experimental program includes drained compression tests on samples reinforced with different values of both geotextiles layers （Ng） and confining pressure （σ′c）. Two methods of preparation were used： air pluviation （AP） and moist tamping （MT）. Test results show that the geotextiles induce a quasi-linear increase in the stress deviator （q） and volume contraction in the reinforced sand. Method of preparation significantly affects the shear strength; samples prepared by the air pluviation method and mobilized deviator stresses are significantly higher than those prepared by moist tamping method. Geotextiles restrict the dilation of reinforced sandy soil and consequently the contraction increases. The mobilized friction angle increases with increasing number of layers and decreases with increasing initial confining pressure. Samples prepared by moist tamping present mobilized friction angles significantly lower than those prepared by air pluviation method. For samples prepared by the air pluviation method, the secant modulus at ε1=1% and 5% decreases with increasing geotextile layers; those prepared by the moist tamping method, secant modulus at ε1=1% and 5% increases with increasing number of geotextile layer sand confining pressure. From 10% axial strain, secant modulus increases with increasing inclusions of geotextile layers.
文摘The pullout testing of geosynthetics is essential for studying interface interaction in the soil-reinforcement system. In this paper, a new method for testing interface properties of geotextiles is proposed. The interface frictional characters of two kinds of geotextiles (woven and needle-punched nonwoven) are investigated through pullout test. Nonwoven specimen has more wide variety of displacement along length than that of woven under the same pressure because of their different extensibility. The greater the elongation and deformation of specimens, the more evident the variations of displacement along reinforcement from front to pullout end. The greater the normal pressure, the smaller the displacement of every position along length with the same pullout load. The study focuses on the effects of the tensile modulus and the difference of pullout response between woven and nonwoven geotextiles.
文摘Nonwoven geotextiles have been widely used as drains orfilters in many civil engineerings.The hydraulic charac-teristics of geotextiles are the basic function in these ap-plications.The in-plane permeability of nonwoven geo-textiles was discussed in this paper.The results of in-plane permeability coefficient of nonwoven geotextilesfrom measurement were analyzed.
基金Sponsored by the National Natural Science Foundation of China(Grant No.51109071)
文摘In order to accelerate the consolidation of the dredged sludge and look for an effective material for mud-water separation,the study on the comparison of geotextiles is carried on. It is based on the laboratory model test of aeration vacuum rapid mud- water separating( AVMWS) technique and evaluated by the cumulative weight of pumping water,the decrease of moisture content and the stable pumping speed. The results show that woven fabric is the best anti- clogging aeration vacuum material,followed by machine-woven fabric and non-woven fabric is the worst. The analysis has been proposed from two aspects of geotextile weaving technology and aeration vacuum condition.
文摘In this paper,the failure features of strip tensile specimen were observed and analysed for need-le-punched non-woven geotextiles.A mechanical model which expresses the relation between thetensile modulus,the strip specimen size,contraction factor and the tensile strength of non-wovenfabric was derived.The theoretical prediction showed that the main factor influencing tensilestrength of non-woven geotextile specimens with different size is the contraction factor of specimenor the specimen aspect ratio(width/length).The larger the aspect ratio,the higher the tensilestrength test value of geotextiles,but the experiments showed that the specimen tensile strength isnot increased with increasing the width of specimen.The reason was discussed and it seemed thatthe deviation could be served as an indication of the degree of imperfectness of the non-wovenstructure.
文摘In order to develope new composite geotextiles with good comprehensive properties,the needle-punched composite geotextiles and adhesive bonded composite geotextiles were made in the factory and laboratory separately.The two processing methods were studied and the mechanical and hydraulic properties of the two kinds of products were tested and compared.The experimental resultsshow that the breaking strength of needle-punched composite geotextiles is much lower than that of adhesive bonded composite geotextiles and the latter also have better hydraulic properties than the former which used
文摘Geotextiles and geotextile-related products Determination of water flowcapacity in their plane has just National standard. But has not a formal instrument at present. There are many kinds of geotextile and also lots of factors influential to the penetration coefficient thereof. The intelligent tester may be involved in testing penetration coefficient under different pressures/gradients resulted in fine repeatability controlled intelligently by microcomputer system.
文摘It is well established that geotextiles/geomembranes polymers undergo degradation of their mechanical properties, electrical properties, theological properties when exposed to UV-radiation. The degradation of strength depends upon the physical properties viz. thickness vis-a-vis mass per unit area, exposure period and the condition under which the geotextiles/geomembranes polymers are exposed. The polymers： PET/PP/PVC/HDPE widely used as geotextiles/geomembranes were exposed to artificial UV-radiation with the accelerated rate under various exposure conditions and the degradation of their mechanical properties has been evaluated. The results for degradation of strength are presented elsewhere. The visual inspection of the process of degradation of UV degraded polymers is studied through SEM micrographs and the results are presented here.
文摘The effectiveness of geonet, geotextile and their composite as containment materials of landfill leachate has been examined in this paper through the use of system dynamics modeling method. The study area is Oriire Local Government Area of Oyo State, Nigeria. Three materials were studied, which include： GN （geonet）, GT （geotextile） and GC （geocomposite）. The water absorption, hydraulic conductivity, porosity and thickness were the major properties studied in these liners. Governing equations coded in Visual Basic Computer Programming Language was employed in developing a model. Validation of the model was done with data on the study area. The interrelationship of the properties and the breakthrough times for each material was found through the STELLA 9.1.4 software application. This research showed that the effectiveness of the studied of the order GC 〈 GN 〈 GT. GT is, therefore, recommended for use as landfill liners in the study area.
文摘This research shows the outcomes of laboratory-scale experiments to enhance the pull-out capacity of geosynthetic reinforced soil via an intelligent drainage system.The intelligent drainage system is designed inside a pull-out machine and is made of gravel and geotextiles.The drained water is collected in a container.The experiments were conducted following ASTM standard D 6706-01.Various test parameters,such as soil moisture levels and the magnitude of external loads,were considered during the experimental procedure.The experiments included temperatures of 20℃,35℃,and 50℃with an initial saturation of about 90%.The results showed that the temperature-aided intelligent drainage system increased the pull-out strength of the geosynthetic reinforced soil.Furthermore,there was also an increase in the interaction coefficient and the interface friction angle.Therefore,the detrimental effects of a saturated geosynthetic reinforced soil,especially during heavy rains which often cause failure,can be diminished by the proposed system.The research findings indicated that the intelligent drainage system enhanced the pull-out capacity and strength-related parameters of the geosynthetic reinforced soil by approximately 25%,thereby augmenting its internal stability.The practical implications of these results are thoroughly examined in the paper.
基金an extensive research project sponsored by the Company Ferrovial S.A.(Spain)conducted by the Geotechnical Group at the School of Civil Engineering,the University of Cantabria(Spain)
文摘This paper aims to study the shear interaction mechanism of one of the critical geosynthetic interfaces,the geotextile/geomembrane, typically used for lined containment facilities such as landfills. A largedirect shear machine is used to carry out 90 geosynthetic interface tests. The test results show a strainsoftening behavior with a very small dilatancy （〈0.5 mm） and nonlinear failure envelopes at a normalstress range of 25e450 kPa. The influences of the micro-level structure of these geosynthetics on themacro-level interface shear behavior are discussed in detail. This study has generated several practicalrecommendations to help professionals to choose what materials are more adequate. From the threegeotextiles tested, the thermally bonded monofilament exhibits the best interface shear strength underhigh normal stress. For low normal stress, however, needle-punched monofilaments are recommended.For the regular textured geomembranes tested, the space between the asperities is an important factor.The closer these asperities are, the better the result achieves. For the irregular textured geomembranestested, the nonwoven geotextiles made of monofilaments produce the largest interface shear strength.
文摘In this study, jute woven fabrics (1 × 1 plain, twill, zigzag and diamond weave) were manufactured from 100% raw jute yarn. The fabric specimens were treated by 5%, 10%, 15%, 20% and 25% unsaturated polyester resin where styrene monomer used as a solvent and 1% methyl ethyl ketone peroxide (MEKP) was used as initiator. Two bar pressure was applied for complete wetting of the fabric by a Padder and curing was done at 130?C for 10 minutes. The physico-mechanical characteristics of untreated and treated samples were examined and evaluated. It was revealed that moisture content (MC) and water absorbency of the treated specimens were decreased with the increase of resin percentage (%) in the fabrics. MC and water absorbency were maximum decreased up to 50.23% and 60.14% respectively by 25% resin treatment. On the other hand, bending length (BL), flexural rigidity (FR), flexural modulus (FM) and tensile strength (TS) were enhanced with the increase of resin percentage in the fabrics which resulted higher fabric stiffness. The maximum improvement of BL, FR, FM and TS were found to be 6.67%, 56.04%, 10.57% and 18.75% respectively in comparison to untreated sample. Soil degradation tests exhibited that 33.59% TS loss occurred for untreated specimens where only 8.04% loss of TS found for 25% resin treated one. Furthermore, jute based twill, zigzag and diamond fabrics were also treated by 10%, 15%, 20% and 25% resin, then measured their TS and compared with plain fabrics. It was revealed that plain fabrics have superior TS over other fabrics. It was also evident that TS enhanced for all the fabrics after resin treatment and maximum increase found for all the fabrics up to 25% resin treatment.
文摘Stress distribution of holed geotextile cross-section under uniaxial and double-axial tension is analyzed with the boundary element method (BEM). The calculation results indicate that stress distribution of holed geotextile cross-section is greatly related to the dimension of the specimen, the size of the hole, the shape of the hole and the tensile condition, and the stress concentration area of holed geotextile from the side of the hole to 3-4 times of the hole diameter should be strengthened in order to improve quality of the projects. These results could provide guidance for engineering application of geotextiles.
文摘The geotubes have been widely applied in the engineering of land reclamation from sea. At present three kinds of material can be used to make geotubes: splitting film, fibrillated splitting film and multifilament. The geotubes made of these materials have their advantages and disadvantages. In engineering application to know the rule of forces change is very important. Based on geometry way, limit-filling height of geotubes is determined. Experiment in Pudong International Airport reflects that packing soil height of small-size geotubes will be smaller than that of large-size geotubes.
文摘Nowadays, geotextile tubes hydraulically filled with dredged materials have been used in the application of cofferdam, sea reclamation and deepwater channel regulation in China. The shape and mechanical behaviors during the process of filling, consolidation and stacked are one of the main problems concemed by designers and researchers.This paper uses the method of elliptic integrals to study the behaviors of filling and deduces the regressive formulas of shape features and circumferential tension. The results show that the proposal regressive formulas are only the function of pressure at bottom; they are very convenient and suitable for the filling design. When the filling materials are sandy, the shape and mechanical behaviors nearly remain during the process of consolidation. The behaviors of stacked geotextile tubes are very complex, because they are involved in the properties of the filling material, geotextile and foundation.Using the commercial finite element analysis program ABAQUS, this paper establishes the entire 2- D finite element load model to investigate, which include the part of filling material, geotextile and foundation. The numerical results suggest that the maximun circumferential tension varies with the properties of filling materials and foundations, whereas the largest tensile force occurs during the filling process.
基金Projects(41872240,41672280)supported by the National Natural Science Foundation of ChinaProject(2016-1-16-2)supported by Science and Technology Project of Jilin Province Transportation,ChinaProject(SJCX18-0052)supported by the Postgraduate Research&Practice Innovation Program of Jiangsu Province,China。
文摘Wicking geotextile(WG)is considered as a possible countermeasure to reduce water content in unsaturated soil.In this research,rainfall tests were carried out to verify the drainage performance of WG.And capillary rise tests were conducted to study the effect of WG on the prevention of capillary rise.Test results indicated that WG with good drainage performance could drain gravitational and capillary water out of kaolinite soil.For kaolinite soil column with water content of 12%and compaction degree of 90%,the whole process of capillary rise in soil column with a layer of WG was a typical two-stage mode,and the maximum capillary height was about 380 mm,which provided that the WG could work as a barrier to prevent capillary rise effectively.In addition,the total vertical influential regions of WG in kaolinite soil above and below the WG layer were 400 and 100 mm,respectively.
基金the Innovation Foundation of Tianjin Mayor (Grant No.07FDZDSF02100)
文摘The technique of geotextile tubes used to construct dikes for land reclamation has been widely used. The tubes are usually filled with slun＇y of soil, such as sand, silt or clay. The tensile stress developed in the geotextile during filling the tube is the dominant factor for construction of a safe dike. The existing design methods are good for designing sausage shaped tubes and can not be directly applied for designing fiat tubes, which are commonly used in dike construction. This paper presents a procedure that can detenmine the relatiorrship among the tube size, the pumping pressure, the unit weight of the slurry, and the tensile stress developed in the geotextile during the tube filing. When the tubes are piling up to form the dike, the tubes in the bottom will sustain the load from the weight of the upper ones. A procedure is also developed to calculate the changes of the mechanical and geometrical behavior of the tubes under the load with a similar method. All these approaches have been programmed, which can help dike designers to select the suitable geotextile and determine the profile of the dike.
