At present, many of our projects need geotextiles. They are used in landfills, in airport construction, in road construction, in isolation of tailings dams of concentrators, seepage prevention, etc., It is true in all aspects of life, but it is widely used in the field of construction.
1. Introduction of the Landfill Project Case
Project Name: Malaysia Landfill project
Project Site: Penang, Malaysia
Project Area: 50000square meters
Project Material: 400GSM PET Nonwoven Geotextile, 88000 square meters, 1.50mm HDPE Geomembrane
2. Introduction of Geotextile
There are two kinds of material of nonwoven Geotextile made by Shandong Dajin Geosynthetics are polyester(PET) and polypropylene(PP). Also, the production has two processes method, is the most used production process is filament spunbonded needle punched geotextile, and the raw material is polyester (PET). Another processed method is staple needle punched geotextile, and the material can be made of polyester and polypropylene. The weight of the specification covers 100g/m2~800g/m. Also, the nonwoven geotextile has excellent mechanical properties, good permeability, filtration, and adaptability to deformation. It meets the different functional requirements of customers, such as chemical corrosion resistance, isolation, drainage, protection, and enhancement.
1) high tensile strength, at the same gram weight, the longitudinal and horizontal tension are higher than other needled non-woven fabrics.
2) Good elongation property, the geotextile has a good elongation property under certain stress, which will make the geotextile adapt to an uneven base.
3) high-temperature adaption. The temperature of asphalt laying on geotextile is generally about 165~170 ℃, while the nonwoven geotextile begins to get soften at a temperature of about 210℃. Meanwhile. the geotextile can still maintain the structural integrity and keep physical properties unchanged.
4) Good drainage performance and vertical permeability. Because of the large thickness of the nonwoven Geotextile and its reinforcement by acupuncture, it has good plane drainage performance and vertical permeability.
5) Good UV-Resistance property, Non-woven PET Geotextile has the good property to resist high anti-ultraviolet radiation, which guarantees the long service time.
6) Good corrosion resistance property: the Nonwoven Geotextile is resistant to different chemical substances such as acid or alkali in the soil, gasoline, diesel, etc.
7) Good friction resistance property, the friction coefficient of the geotextile is higher than another conventional geotextile, not easy to fluff and damage.
8) Good creep resistance property. The non-woven Geotextile has good creep resistance and long-lasting function.
4. Geotextile Application and Roles
As a new type of construction material in civil engineering, geotextile has the functions of reinforcement, filtration, drainage, and reinforcement. It includes staple fiber needle-punched non-woven geotextiles and filament needle-punched geotextiles. The raw materials are synthetic fibers of high molecular polymers such as polyester and polypropylene.
Geotextile is used in the roadbed pavement construction and reinforcement project rule works:
(1) Pave and Lay according to the width and full section of the bottom of the embankment.
(2) Leave enough length space on each side of the embankment.
(3) To ensure the integrity of the project, when the continuous overlap method is adopted, the overlap length should be 0.3～0.5m. In the seaming method, the bonding width will not be less than 50mm.
(4) During on-site construction, the damaged material must be repaired immediately. The seams of the upper and lower layers should be staggered, and the staggering length should not be less than 0.5m.
(5) Try to avoid prolonged exposure and sun exposure.
Besides, geotextiles can also prevent many roadbed hazards such as frosting. This is a kind of foundation soil under the repeated action of dynamic load, the water pressure of the soil pores increases to the extent that the soil strength cannot be restrained, and then the soft soil can be squeezed into the coarse-grained soil layer under the action of the seepage force caused by the hydraulic slope, which is called coarse-grained soil. Soil pollution, when it is serious, it can be boiled in the coarse-grained layer.
The role of geotextile in the ecological environment: How does geotextile maintain the ecological environment? Geotextile is suitable for greening on planes, slopes and high slopes, so that moisture can flow between the bags and the soil in the bag, which is the loss of vegetation The moisture needed, and it will never cause fruit or soil erosion due to rain or watering. Moreover, geotextile is an ideal seeding block for plants. It is permeable and impervious to the soil. Grass can grow from the outside and grow in the name. , About the friendly vegetation, the root system of vegetation can grow between the bag and the bag, and the root system connects each non-woven geotextile into a whole, building a stable and permanent ecological slope.
The second role of geotextiles in the ecological environment: Greening the ecological environment has always been called for by society. Geotextiles have attracted public attention in this project. In the meanwhile, the ecological slope protection engineering system uses the original material to build flexible slopes and retaining walls. , And complete the planar greening of the reservoir and the sloping bank, which expresses the establishment of an ecological project that is preserved, energy-saving, lively, and breathable in the southern district. The project does not need high energy consumption, high pollution steel, lime, stone, and other hard materials, and can also be used for vertical or near-vertical Bitu rock slopes, Paihegou reservoir repairs, etc.
The third role of geotextile in the ecological environment: Geotextile is used as a reinforcement material for asphalt pavement, which can prevent the pavement from cracking due to low-temperature shrinkage, change the structural stress distribution of the pavement, prevent the propagation of reflective cracks, and reduce rutting marks. After the surface chemical treatment of the glass fiber geotextile, the surface performance of the glass fiber is improved, and the adhesion between the glass fiber and the asphalt is strengthened so that it can be contacted with the asphalt mixture at a high temperature of 160 ℃ without cracking and warping. It has good construction performance, can prolong the service life of the road, and can also reduce the large thickness of the pavement structure layer, so about live up to the purpose of reducing road construction and transformation.
The fourth role of geotextile in the ecological environment: As a multifunctional product, geotextile can reduce or even avoid secondary pollution. Nonwoven Geotextile has good properties of water permeability and air permeability. It can be buried in the filling waste. improve the acceptance conditions for filling waste, enhance the tensile strength and deformation resistance of the filling, and improve the stability of the engineering project structure. The nonwoven geotextile is under the correct conditions of use. Needle-punched non-woven geotextiles and HDPE geomembranes are used as engineering materials for the anti-seepage layer. The design of the anti-seepage layer is to slow down the infiltration of polluting wastewater and the migration of pollutants and at the same time guide the drainage layer to discharge wastewater.
5. Service Time
Through the aging experiment on the geotextile fiber after different treatments, the influence of several main environmental factors on the life of the geotextile is discussed. The results show that the durability of geotextile fibers is most affected by metal ions, followed by water, and less affected by acids and alkalis; under pressure, the durability of geotextiles will also be reduced. Through experiments, the service life of polyester geotextile is longer than that of polypropylene geotextile, and the qualified geotextile is resistant to aging for more than 50 years.
After geological exploration, it was shown in the experiment that the dirt and sludge in the project had low shear resistance, strong permeability, poor stability, and prone to instability. After the study, the safety of the foundation pit was rated as Class II. The site is affected by the infiltration of seawater in the coastal zone, and its type is the upper stagnant water on the upper part of the site, and the basement is subject to different weathering in different years, pore-fissure water.
The raw materials used in the manufacture of geotextiles come from the downstream products of petroleum, which are processed into polypropylene, polyethylene, cotton, and other fibers through the method of factory weaving. In the construction of engineering projects, the composite geotextile is generally selected, which is reinforced by the geotextile. Drainage, isolation, and other effects are better. Generally used in coastal protection and soft soil foundation reinforcement. After analyzing the actual situation of the project, this kind of geotextile material is selected.
Omit to distribute the geotextile, unfold it from top to bottom along the slope to the end of the design, and also unfold the surrounding edges. During the laying process, it should not be stretched too. Omit to lay, the joints should be inspected in time to see if they meet the relevant requirements, so about avoid broken stones or stones from piercing the geotextile. If any problems are found, effective measures should be taken to remedy them on time, and the next construction task can only be carried out after the inspection is qualified.
6. Construction of the Geotextile
To do a good job in the construction quality control of nonwoven geotextiles, it needs to be grasped from two aspects: the quality control of raw materials and the control of the construction process. The quality control of materials is to ensure that the supplier of the product has a certificate of conformity, the performance of the material, and the instructions. In the control of the construction process, it is first necessary to ensure that the materials used in the construction process are consistent with the design and can function. For: breaking elongation greater than 30%, breaking tensile strength greater than or equal to 7.5k N/m, burst strength CBR greater than 1.5k N, tear-resistance greater than 250N, permeability coefficient less than 1*10cm/s, and then The monitoring center inspects the indicators until the inspection is qualified. Secondly, during the construction process, it is necessary to follow the laying measures designed by the engineer to carry out the construction, and it is necessary to put in place the follow-up, follow-up, and follow-up pressure. And it is necessary to check the joints and inspect the joints to see if there are wrinkles or scalding problems. Once any problems exist, they should be repaired in time. In the earthwork backfilling work, the appearance should be checked at any time, to check the flatness, leaking, and splitting of the geotextile.
The application of geotextile can enhance the stability of the roadbed and the safety and stability of the road. According to geotextile manufacturers’ experience in roadbed reinforcement construction, besides meeting the infiltration requirements, geotextiles should be covered with a thin layer of sand, generally 8-9cm thick, to get more satisfactory results. If used in road foundation reinforcement projects in cold areas, a new type of permeable layer can be formed, which serves to cut off the capillary so that the moisture in the lower soil cannot be supplied to the unsaturated soil layer above it.
The Advantages of Geotextile used in bed Reinforcement Projects:
Lightweight, good continuity, high tensile strength, corrosion resistance, anti-microbial erosion, and convenient construction. The pore diameter is small, the permeability is good, the texture is soft, and the soil is well combined.
In general, waterproof geotextiles have played a vital and irreplaceable role in sanitary landfills. Yet, anti-mechanical damage, anti-blocking, anti-sedimentation, anti-skid slope, and construction of special parts still need to be developed and updated with higher performance materials.