1、 The development of geotextile profiles
Since the last century, China began to quote the late seventies geotextile fabric, all such new technologies and materials that in water, railway and transport industries, has attracted such wide attention geotechnical engineers. DuPont is the first one to apply the materials and technology into China of foreign enterprises, one that I presented the Ministry of Railways Institute of Science and 20 thousand square meters Spunbond geotextile fabric, was used to control railway subgrade mud-pumping test. Then, in East China Textile University, Shanghai Textile Academy of Sciences and other "non-woven" manufacturing technology, induced, in Jiangsu Province began to germinate a needle-free trial and production of textile machines, coupled with the party's reform and opening up the Third Plenum of the proposed Therefore, water conservancy and transportation in the railway industry, geotechnical engineers to absorb foreign advanced science and technology at the same time, quickly from production of paper-making chemical fiber carpet blankets and technology transfer to the needle geotextile up, formed a staple acupuncture earth fabric base. Coupled with a time when the national development of township enterprises, foreign enterprises have begun for the Chinese, they come with application technologies for market development initiatives, indeed also promoted progress in this area. At that time, however, although the United States, DuPont, Linz, Austria, France's Rhone-Poulenc companies have sights on the Chinese market is a pity that they emphasized the need to purchase U.S. dollars; on China's capacity to large-scale use is still no confidence; even more reluctant to take the risk of investment in China; Therefore, in a ~ 4 years of time, foreign companies have been wandering the. At that time, domestic engineering units, particularly in the design department of some policy-makers, the lack of new materials, new technologies, so as to be in the ideological realm and national conditions, and soon be applied on a large scale is very difficult to . This also became the companies abroad, from this area will soon make way causes. Of course, things are always changing, with advanced representation and full of vitality of the things that development will quickly become out of foreign-made staple fiber in China has long adopted the habit of needle geotextile become China's leading scientific research and higher education institutions promote the use of the origin. Our association (formerly Collaboration) in 86 years held a national of the first geotextile Applied Technology Exchange Conference, to attend the meeting of the representatives, beyond the three times the number originally planned, this is an unexpected and unprecedented. At that meeting, recalled a number of well-known foreign experts (France, Japan) report; five foreign exhibitions, as well as domestic use staple fiber needle geotextile (1m width double-width), or lifting 3 tons of multi-car, they all has played a sensational effect. Therefore, both the government leaders at the meeting or the experts and professors, have fully demonstrated a high degree of importance of the meeting and enthusiastic support; also fully demonstrated that the reform and opening up of the whole nation, is looking forward to how much science and technology. Our Principal Consultant, Chinese Academy of Sciences, Tsinghua University Professor Huang Wenxi In his opening statement earlier approval of the international community to say: geosynthetics geotechnical engineering is a revolution in this sentence. And pointed out that: The geotextile will be able to save much traffic (ie soil, sand, stone). In practice, this early 80s in the last century, he has already applied the elderly linked to the economic and social effects will come up, linked to the protection of the relationship between ecology and the environment will come up. So the following year at a meeting to see us with the instructions: to comprehensively promote the application of a variety of geosynthetics and not confined to the geotextile area. You can see his vision of how the elderly in line after my geosynthetics development process. Yes, according to our understanding of the time, after only one year (87 years) of China's annual consumption, or nearly 2 million m2, will be almost 86 years the total volume of 20 times before. Water sector, in particular, for the handling of Dangerous library, which amounts to nearly as many Office. Jinzhou highway for the non-paved road mud-pumping combat road bed, the effect particularly marked by on-site evaluation identified soon after that in the northeast, north cold area used widely; and quickly extended to cold regions of the railway system. All of these have fully demonstrated the vitality of geosynthetics.
Of course, primarily the party of reform and opening up policy and the national is in the spring of science, as a set of 2m ~ 4m wide staple acupuncture device is only 20 to 50 million per, nor water sewage and other environmental issues, so in township and village enterprises to develop quickly a twinkling of an eye as much as non-woven plant hundreds of the country, based solely on acupuncture geotextile and join our collaborative network reached more than 60. Just as Liu Zongyao net long said, the world's production of geotextiles companies together do not we have many factories in China geotextile. However, certain high-tech investment in larger and long-fiber (spunbond) acupuncture device, gripper and an increase is not so fast. Jiangsu, Shandong, Zhejiang, Beijing, woven geotextile fabrics for many years maintained for five state-owned enterprises, and no more competitors. So now seems like the system, also have their own advantages and disadvantages, one is a small rural business investment, flexible, and projects fast, strong sense of competition in product quality and price are highly comparable, in the the co-ordination with the user is also easier to coordinate. So, like plastic drainage belt (board) and some geotextile fabric bags, they are of this type, that is, the project express, factories Trinidad and Tobago. However, too many for the greater than demand, so operation is easy to do up Xiemenwaidao emerged; This is another drawback. The braiding of several state-run enterprises in that period, together with the Container exports and carpet with a cloth, supply tight in a good profit out of practice on the competition and not move forward. Until toward a market economy, township enterprises have accumulated a capital base in the national textile industry downturn, the opportunity to township and village enterprises are springing up in general increased, a shortage of state-owned enterprises, coupled with the state used to eat, significant lack of competitiveness. In fact, as the state-owned Wuxi plant has long geotextile bags provided to the weaving business lessons, but they did not pay attention only.
2, other geo-synthetic materials production and application of
Geomembrane product development in China is another process, at first because there is no heat welding machines, make more use of PVC as raw material, as suitable for adhesive bonding; and quickly add lead stabilizers from the transition to a health class. But the width is only l ~ 2m, and should not produce thin, and very easy to use. After that came the domestic hot-welding machine, then blow-molded PE geomembrane can be wide, so quickly occupied the market, and to users of PVC geomembrane diluted down. Although we emphasized the two have their own advantages and disadvantages, each with different fields of application, the final or in the different production costs Ershi PVC film being cold-shouldered. The past two years the MTR underground project be filed, and some companies also introduced EVA geomembrane, in fact, PE is still relatively large in a flexible, said formation of the tunnel wall lining, it is not easy to achieve a more fit, So, despite the higher prices, it also caused some of the user's attention. Another important feature of China's PE geomembrane is to use a cloth one film or two cloth one membrane are more complex products, it is mainly the designer that the composite membrane with the fabric, there is a protection, increased sense of security. Some even focus only compound the neglect of the thickness of the membrane. Our country is now reason why the significant increase in amount of needle geotextile, geomembrane composite usage among them: its composite geomembrane enterprises are many, most of the geotextile is a needle factory participation. Because acupuncture earth more and more wide-width fabrics (currently more than 6m width reached more than 10 production lines, the most wide up to 7.5m), so the composite geomembrane width also grows ever wider. This is a market positive. But also ignored the other side, that is, for the landfill, sewage treatment and a series of demands thicker geomembrane projects, which in turn is a negative. Until the past two years began to take on domestic environmental protection projects along the lines of the foreign designs use thick geomembrane wide when they feel upset for domestic products; some designers seem to think that the non-imported goods can not be. In general, the international application of Thick Film seepage of more, while domestic on the contrary, is a thin composite film-based. Personal opinions do not necessarily have to mechanically copying abroad, or in terms of conditions on the basis of seeking truth from facts. Such as environmental protection projects, especially the storage of poisonous substances, I am afraid not only to thick and starting a two-to three levels of impermeable layer; like a gold mine tailings seepage and so on, it is not so can not be. So why domestic production enterprise wide thick geomembrane relatively few do, because in one-time investment is too large, or high risk. On the contrary, a number of geotextile geotextile-grown plants using the advantages of several hundred thousand dollars to spend can buy a laminating machine, using someone else's film will start its operations, and if the past is now a soft plastic drain board water pipe, plastic blind ditch , three-dimensional mat and the current GCL and so on, a set of equipment investment generally 50 million or less, so items like this product much more investment soon. But the biggest problem is that these products are mostly clone belonging to improved products are few. So, too much is easy on the "deterioration" of. And some companies even the product description or promotional materials are also pictures and photographs of each copy, which put less serious manner of geosynthetics is too commercialized, and the loss of the development of new technologies, new materials, meaning. We remind all enterprises and to arouse the attention in this regard, or long-term effect on the country and has been harmful to both, should strive to create for creating change.
Since the 98-year Tai'an China Plastic Factory has been the first Chinese-made plastic geogrid production line since the short period of four years, the country that is more than 20 enterprises to invest in geogrid production, in which a single bi-directional grill can be produced on the there are 10 or so, the vast majority concentrated in the Shandong Province. This is a recipe from the raw materials do not pay attention to the beginning to the present refining machinery and equipment, emphasizing technology, focusing on the process of formulation optimization; make our product quality plastic stretched grid is, indeed, a certain increase. Some of them may be comparable with foreign brands; there in the stress-strain relations are appreciated by foreign investors and users; and some have continued to supply for sale abroad. The so-called preferred formula, that is, the raw material of different grades according to the strength, deformation, melting index and performance, as polypropylene, polyethylene copolymer of different dosage options; or separately for a few polyethylene or polypropylene blends of different grades in different dosage options ; so that after the full after the drawing process, both play with their weight per unit area corresponding to tensile strength, but also control the maximum fracture deformation within the scope of a smaller (about 10%); so as to achieve a smaller The purpose of the creep. This is a series of detailed and scientific research work, is to spend time-consuming. Fortunately, the majority of the current plastic stretched grid companies are constantly improving. Domestic grille has continued in its progress, because a. The product of the production equipment (including auxiliary, etc.) Investment in general were 160 to 200 million yuan, a large capital investment, thus a general increase in the enterprise a sense of responsibility for product quality. 2. User (design) in the country's products do not appear before the foreign investors, driven by the performance index on the grille a relatively clear understanding of and requirements, companies realize the importance of efforts to accommodate the way out. 3. There are a number of businesses, from the beginning, and strive to make the country's products meet or exceed the imports. Today, although did not rule out a small number of companies where there are low-priced sales obsession to the neglect of products including creep deformation, including problems, but most enterprises are the raw materials that affect product quality, formulation and device technology for change; one of the few companies is to work hard for the next level, this spirit is commendable. We believe that the ugly grille products will be eliminated! Chemical fiber and glass fiber warp grid production lines in China not only have a certain amount of imported equipment, there are some China-made equipment; the same time, the latter dealing with the development of composite processing fairly quickly. We have seen large-scale enterprises, through the combined treatment, the warp grille, than from the international exhibition of samples back even better. And they also engaged in the production line, component parts production, exported to abroad, and welcomed by the United States and other manufacturers. At the same time also made the application of co-ordination of efforts, such as cracks in order to control the construction of paved roads, production control and self-adhesive nail-type grille, so that was handy engineering applications. It is because of them from the application of a number of martial arts techniques from top to bottom, so the past two years, China's road pavement and part of the application of a number of roadbed warp grid; this, together with the singeing geotextile asphalt for our roads in the fight against reflective cracks in the forefront of the international approached. China's current high-grade highway construction to increase the scale and speed are still expected to climax soon will have a repair, when materials such as fiberglass grating is expected to have a greater supply, rather than a long period of oversupply of狀態(tài). Want to lose time trying to do a good job application technology and quality and improving co-ordination, rather than indulging in a price war among the. In the grille of the products, there is a order form that is reinforced with welded, which is reinforced with the use of some of our major (including the steel-plastic composite belt) production technology, a combination of grid-like material, has its own steel-degree of deformation (including creep small) small features of the node positions in its fastness and also the shortcomings of low shear capacity: combined with the thickness of the barrier is relatively thin parts, lattice large, on soil constraints and poor performance may be pulling some. Therefore, pay special attention to a single two-way stretch plastic grille, warp fiber grating, combined strip grating, one-way reinforced belts and five kinds of high-strength woven geotextile reinforced materials, have their own different kinds of projects properties and their respective applicable conditions, its design method and the amount is varied; so do not be confused, or abstract, what kind of negation. Even in the case are available, as well as economic comparison and construction, convenience and other issues.
Currently claiming to be able to produce geocell products enterprises have as many as 6-7 at home, mainly due to Weihai, Shandong, Jiangsu Yancheng 2 production ultrasonic welding machines provide a convenient, all thought siding firmly welded the end of the story. But the key to whether the cell wall material to cross the border should be attention. Especially for a high degree of greater than 15cm of the cell room (prism) wall material, not only have a certain tensile strength, but also have a certain thickness of stiffness, so that the whole room in order to form a lattice structure of the real three-dimensional body force will not deformation due to such causes excessive loss of use value. In fact Geocell is still relatively small in domestic applications, in addition to roads, railways used as part of the desert areas outside the soft ground in dealing with temporary or for the beach used to enhance the bearing capacity of shallow oil development, it is also used some, this mainly by the corporate initiative designed to tie in with the achievements. Of course, take longer to resolve the vertical and horizontal issues such as widening, the construction of ways and means still owe the skilled, and often a lack of serious economic accounting; is dominated by the thinking of the higher price, it is difficult to become universal. Geocell can also be used for retaining structures, such as steep steps built with grid-shaped chamber, which is still used more in foreign countries, it can eliminate the re-slope; especially in the hilly city of using, but also to facilitate the steep slope with flowers and landscaping. Room on the grid for slope protection, may be due to the impact of high prices, is not yet (or rarely) used, but the foreign data, photographs, use (square, hexagonal and sometimes perforated) lattice rooms for slope protection of the It seems that a lot, should cause us to further reflection. Specific to our country, the need for 7 ~ 10cm high cell room and other slope protection material for further, more comprehensive comparison, which is not purely economic, but also works in which weather conditions, geological conditions, and other various factors, I believe there are always can play to their strengths lie. For example, a very dry areas, no gravel areas, water pouring concrete prism and slope also very expensive area, three-dimensional networks grass is difficult to conservation, there is no guarantee survival, and (despite the three-dimensional network Network kinds of grass than not to grass grow better, but still want to watering conservation) then the room with the grid slope, except for construction of simple addition, even if the legislation is also not afraid of heavy rains, with its long-term reliability.
It is true that the application of grid room, with our associations and enterprises make further efforts to be separated from, first, as soon as possible to help solve design method; Second, we must closely with business applications, development of series of varieties, in order to publicize and promote the use of technology to promote their own products. Must not follow suit in counterfeit products overstepped the bounds of the room.
Rachyan small, deformation of a large Geonet product had gone through a period of brisk sales in China, which is due to foreign materials, production technology in China reinforced containment due to forced and misleading. All of a sudden there are eight or so companies to spend at high prices from abroad Geonet more than 10 production lines, the product used in the slope protection, reinforcement and foundation reinforcement; Although the application project be successful, however, limited due to its performance, not only the relative amount of excess Great price, but limited to a smaller range of applications. Therefore, since the emergence of self-geogrid, which has been in a downward trend; and even a small number of companies have converted to other production or pulling out. At the same time, the association found that several leading members of the foreign is Geonet compatible with geotextile fabric and so on, mainly for drainage plane, that network is sandwiched between two layers of geotextile fabric and geomembrane, or between the overhead to facilitate drainage from role; or anyone else involved right geotextile serve to strengthen and protect the role. This is below the groundwater level in underground engineering and the cut-works great development potentials. However, due to this combination of domestic product has not yet mass production, in the design of application has not yet been recognized, it has not yet achieved its proper application. On the contrary, misled by the past influence Geonet the road sector, to prevent the bridge-jumping off the tram and slope protection, etc. are still used; of course, from an economic point of view, compared with the geogrid and other, such as Shouli Bu large, and are subject to deformation of the smaller projects, if it is still desirable, then, natural is reasonable. However, Geonet more material per square meter, is generally not cheaper than the two-way grid, it is worth noting that the other side.
In recent years, the soft water pipe and a variety of blind ditch drainage has developed very rapidly pity that most of the cloned products, very little has improved. In particular, plastic wire blind ditch drainage, or very rough, even recycled plastic are available, their use is also too much, the price is hard to be able to decline; and did not take long and widen the issues have been properly resolved, pending enterprises to further the practical application of phase and Engineering combined to improve as soon as possible. According to oral information, plastic wire by adding nano-ingredients can significantly increase product bending, compression capabilities, to see if I have the product structure, the size of the increase and decrease the density of the plastic wire improved.
Beginning of this year geotextile clay liner (GCL) has developed very rapidly in China, according to a preliminary understanding has been five or so went into operation, can be described as to keep up with the times. According to our contacts and observations, GCL products to remove stressed the need to have well-qualified bentonite addition, in the production technology and techniques to maintain uniform and stable layer of bentonite is no technical barriers. However, enterprises must be laid with the design application and construction of the close match, which is China's current understanding of this product just in terms of stage is very important. Otherwise, despite the production of many kinds, a result of the design, construction technology lags behind, causing foreign companies to seize the key, and then neglected the domestic enterprises. Therefore, enterprises should understand the situation, is always difficult, particularly in the application of all the meaning of the GCL and technology is not yet very familiar with the time, it even more difficult. We believe that both companies and associations have the responsibility to begin to help solve why should GCL seepage? How to use? How do construction and other difficult problems, and only thus open up the situation, GCL products have a future. First, of course, but also made sure that GCL product quality, product to show the advantages of going abroad, do not think that GCL can be produced, and can be a smooth sale; while still very difficult work to be done. Because GCL applications (design, construction) technology in China has not yet accumulated experience, especially when people have not fully aware of and understand the superiority of GCL to the application when the need for companies to go with the feeling our way forward. Only after obtaining some experience can be an area of the face of application development, a face of the product improvements; also include the product series. Although we geosynthetic material of any kind are so request, but for GCL products, so doing, it is more necessary, even more important. It is because of China at present is in this state, then the excessive production GCL, not too blind it?
Plastic drainage belt (board) is located in China's use of geotextile after the second-largest species, harbor terminals of Reclamation land, highway, railway and water conservancy, construction of soft foundation treatment works for many years, peak usage of more than 70 million linear meters, which may be in the world. The product structure, raw materials (recycling) in the adoption and membrane localization of some of the features aspects. Although from the outside its appearance is not known, met with foreign direct shaking his head, but in practice proved to effect is good. Over the years, saved the state a lot of project investment has played a great role in knowledge-based economy. Of course, this aim with the entire application technology is inseparable from the art, such as the past 20 years, most especially the super-soft soft ground foundation treatment, using the vacuum preloading method, which is to Tianjin, China Harbor Engineering Research Institute, Tianjin University, common effort, its degree of vacuum up to 0.8 atmospheres, but also win over a high level of foreign chips. Today, some old plastic drainage belt business, is still the country's economic construction and continue to make contributions. One also has to open up overseas markets, from the appearance and raw materials to make improvements and get some foreign flew welcome. Of course, prices also climbed up; as foreigners welcome, is also a good thing. But this shows that our product to be able to long-term foothold in foreign countries, non-continuously strive to improve not. In order to export to cater to the taste of foreigners mouth membrane is a pass, do not look thin non-woven fabric of domestic manufacturers of equipment, there may still have to use the products of DuPont or Freudenberg. The sounding device attached to the product would not be necessary as the institutional construction in foreign countries so that the depth can not be set up to fight fraud and deceive itself. As for the quality and performance of membrane, over the years to study very little, which is due to specification requirements permeability coefficient ≥ 10-4cm / s relatively easy to achieve. The equivalent aperture set at ≤ 0.075mm is still some controversy; reason is that theory and practical operation due to the difference between. It is understood that over several years using an equivalent aperture membrane majority of large (slightly) in 0.075mm, but preloading works almost entirely successful. So from experience that the membrane pore size is equivalent to slightly greater than 0.075mm or applicable. Although it was brought after the digging drainage of view, with a core of material there are a few clay tablets, but in theory should be normal. Moreover, also failed to demonstrate ≤ 0.075mm clay when it does not necessarily occur, especially in the case of a high vacuum, it is actually more in line with the theory. However, do take note of the longitudinal and lateral membrane strength and deformation took place can not be lightly broken (open) fracture or embedded in grooves, thus affecting the application effect, foreigners could not understand why our home-made membrane, the key is to of these had no confidence.
3, product production and application needs to open up with each other
In short variety of geosynthetics in China's development is consistent with international trends, for example, the 7th International Conference on Geosynthetics papers focused on the specific separation of micro-reinforced articles, and our use of the split-film micro-reinforced wire fiber production enterprises have 2 ~ 3 as much as in the domestic has been increasingly used to prevent concrete cracking. Fiber reinforced soil studies are Tsinghua University, Tianjin University, etc. have been carried out: This is right there for, forge ahead and create a foundation for scientific research and policy. Membrane structure of production enterprises have settled down in Shanghai, which not only marks the expansion of the scope of application of geosynthetics, also showed that high-strength tubes impervious airtight bag in my country were available. Others like the large volume of foam (EPS), thermal insulation is, expansion strips, lining of, component pads, structural joints gaskets, adhesives, and grouting pipe joints and some other small amount, but rather special materials , also have a production enterprise. And they expressed their full co-operation with customers to jointly develop products in different specifications of the project. Therefore, as matter whether the new technology, new materials matter whether, "Geosynthetics" at home and abroad have long been a breakthrough compared with the original narrow definition. Such as Southeast Asia, jute, coconut fiber slope network in Western Europe with the polymer and metal products, China's municipal works for Concrete Curing (can be changed to black) as well as for non-rock (pure) engineering, have fully demonstrated the synthesis of materials, vitality and sustainability. Recently, Hainan Jihong too with India, after contacts and exchanges between related parties that: the formation of ultra-high molecular membrane (thick) material, can be widely used in civil engineering concrete pouring templates, especially in the complex structure form, can be greatly inflated way to facilitate the construction of circular and arc-shaped building, while deflation is also very easy to facilitate form removal; and even large-span can be done. The two sides of dual ultra-high molecular membrane material used in thermal power plant ash, sending ash, for travel liner, for a special isolation area, has its own steel, wood is not easy (should) do a good effect. Including its high degree of smoothness, water does not freeze with each other and strong thermal expansion and contraction of the difficulty. No doubt, this for us in geotechnical engineering applications also open a train of thought. To this end, we strongly advocate the production of this sector enterprises to the products and raw materials which should have a better understanding of characteristics, so as to press ahead.
Fourth, a few observations
The application of geosynthetics are in need of a professional construction team and specialized construction tools, specialized association of construction enterprises (members) have four, they are applications of geosynthetics professional contractor or a package in the end of the. The company works with a number of construction companies, but most are aimed at laying and welding geomembrane, the so-called with no real professional team can only be during construction in order to own a welding machine to help welding only. The good news is a small number of production companies Geocell, which could be the temporary works design or ask for help planning, construction, and construction. However, in roads and public works in the special commitment to the grid can be prestressed do not yet, which shows that this construction technology and equipment still lacks the necessary considerations, naturally also affects the application effect of improvement. Langfang City, Hebei Province earlier application of the road sector scissors principle of pre-tension applied to the geotextile: Last year, Central South University's civil engineering Professor Yang Youlin has also published articles stresses the pre-plus grid infrastructure can not keep up is no progress can be seen one of the reasons. It should be software and hardware go hand in hand. Wenzhou, Zhejiang has developed a Chinese-made automatic welding machine and an indoor crawling Geosynthetics tester; but the lack of on-site welding quality detector; works in-situ testing instrument and other necessary tools for the construction of supporting hope that through this meeting can be changed.
Many manufacturing enterprises in China at present has reached more than 200 member companies, mainly concentrated in Jiangsu, Shandong provinces, while Jiangsu's Changzhou, Wuxi, Yixing and Shandong Tai'an triangle around the product is very similar to each other to repeat. Country's current situation is that although the mechanism of competition, but not very wise to rely on the means, if the really quality, the level of victory, then it must rely on science and technology, to spend energy, time and capital to improve the, so that you can arbitrarily to low sales? After accounting for the cost of one is always limited. As for the small number of enterprises (including non-members) of the product, lacking substance, numbness in blindly, and even business people with factory product performance, features very little understanding of ... ... sooner or later, then was eliminated by lack of pity.
Geosynthetic materials and technology, is a manifestation of advanced productive forces, belong to the scope of knowledge-based economy, but also a product of the times; the international community shows that comprehensive national strength is stronger, more advanced science and technology, the economy prospers, the greater amount. But first thing is that we rely on engineers to practice. After 1998, China increased variety of materials, design, construction practices and most of them have had, usage increased a lot; related materials aging and durability issues, mostly through the practice has also been gradually recognized and resolved; This is entirely consistent with the law of development of things. While we have made great achievements, but the booming economy and social construction, and the natural ecology and environmental protection is also the far distance, which must continue its efforts with the times, blaze new trails. Specifically, we need to re-emancipate the mind, respect the power of science to learn a little knowledge of polymer raw materials to further enhance the knowledge level of geotechnical engineering. I believe this new technology, new materials, space and the prospects of the application is still very wide. As long as we continue to practice - to improve - innovation - and then practice, we have the cause of geosynthetics in construction of the entire national economy play a more significant role in
Since the last century, China began to quote the late seventies geotextile fabric, all such new technologies and materials that in water, railway and transport industries, has attracted such wide attention geotechnical engineers. DuPont is the first one to apply the materials and technology into China of foreign enterprises, one that I presented the Ministry of Railways Institute of Science and 20 thousand square meters Spunbond geotextile fabric, was used to control railway subgrade mud-pumping test. Then, in East China Textile University, Shanghai Textile Academy of Sciences and other "non-woven" manufacturing technology, induced, in Jiangsu Province began to germinate a needle-free trial and production of textile machines, coupled with the party's reform and opening up the Third Plenum of the proposed Therefore, water conservancy and transportation in the railway industry, geotechnical engineers to absorb foreign advanced science and technology at the same time, quickly from production of paper-making chemical fiber carpet blankets and technology transfer to the needle geotextile up, formed a staple acupuncture earth fabric base. Coupled with a time when the national development of township enterprises, foreign enterprises have begun for the Chinese, they come with application technologies for market development initiatives, indeed also promoted progress in this area. At that time, however, although the United States, DuPont, Linz, Austria, France's Rhone-Poulenc companies have sights on the Chinese market is a pity that they emphasized the need to purchase U.S. dollars; on China's capacity to large-scale use is still no confidence; even more reluctant to take the risk of investment in China; Therefore, in a ~ 4 years of time, foreign companies have been wandering the. At that time, domestic engineering units, particularly in the design department of some policy-makers, the lack of new materials, new technologies, so as to be in the ideological realm and national conditions, and soon be applied on a large scale is very difficult to . This also became the companies abroad, from this area will soon make way causes. Of course, things are always changing, with advanced representation and full of vitality of the things that development will quickly become out of foreign-made staple fiber in China has long adopted the habit of needle geotextile become China's leading scientific research and higher education institutions promote the use of the origin. Our association (formerly Collaboration) in 86 years held a national of the first geotextile Applied Technology Exchange Conference, to attend the meeting of the representatives, beyond the three times the number originally planned, this is an unexpected and unprecedented. At that meeting, recalled a number of well-known foreign experts (France, Japan) report; five foreign exhibitions, as well as domestic use staple fiber needle geotextile (1m width double-width), or lifting 3 tons of multi-car, they all has played a sensational effect. Therefore, both the government leaders at the meeting or the experts and professors, have fully demonstrated a high degree of importance of the meeting and enthusiastic support; also fully demonstrated that the reform and opening up of the whole nation, is looking forward to how much science and technology. Our Principal Consultant, Chinese Academy of Sciences, Tsinghua University Professor Huang Wenxi In his opening statement earlier approval of the international community to say: geosynthetics geotechnical engineering is a revolution in this sentence. And pointed out that: The geotextile will be able to save much traffic (ie soil, sand, stone). In practice, this early 80s in the last century, he has already applied the elderly linked to the economic and social effects will come up, linked to the protection of the relationship between ecology and the environment will come up. So the following year at a meeting to see us with the instructions: to comprehensively promote the application of a variety of geosynthetics and not confined to the geotextile area. You can see his vision of how the elderly in line after my geosynthetics development process. Yes, according to our understanding of the time, after only one year (87 years) of China's annual consumption, or nearly 2 million m2, will be almost 86 years the total volume of 20 times before. Water sector, in particular, for the handling of Dangerous library, which amounts to nearly as many Office. Jinzhou highway for the non-paved road mud-pumping combat road bed, the effect particularly marked by on-site evaluation identified soon after that in the northeast, north cold area used widely; and quickly extended to cold regions of the railway system. All of these have fully demonstrated the vitality of geosynthetics.
Of course, primarily the party of reform and opening up policy and the national is in the spring of science, as a set of 2m ~ 4m wide staple acupuncture device is only 20 to 50 million per, nor water sewage and other environmental issues, so in township and village enterprises to develop quickly a twinkling of an eye as much as non-woven plant hundreds of the country, based solely on acupuncture geotextile and join our collaborative network reached more than 60. Just as Liu Zongyao net long said, the world's production of geotextiles companies together do not we have many factories in China geotextile. However, certain high-tech investment in larger and long-fiber (spunbond) acupuncture device, gripper and an increase is not so fast. Jiangsu, Shandong, Zhejiang, Beijing, woven geotextile fabrics for many years maintained for five state-owned enterprises, and no more competitors. So now seems like the system, also have their own advantages and disadvantages, one is a small rural business investment, flexible, and projects fast, strong sense of competition in product quality and price are highly comparable, in the the co-ordination with the user is also easier to coordinate. So, like plastic drainage belt (board) and some geotextile fabric bags, they are of this type, that is, the project express, factories Trinidad and Tobago. However, too many for the greater than demand, so operation is easy to do up Xiemenwaidao emerged; This is another drawback. The braiding of several state-run enterprises in that period, together with the Container exports and carpet with a cloth, supply tight in a good profit out of practice on the competition and not move forward. Until toward a market economy, township enterprises have accumulated a capital base in the national textile industry downturn, the opportunity to township and village enterprises are springing up in general increased, a shortage of state-owned enterprises, coupled with the state used to eat, significant lack of competitiveness. In fact, as the state-owned Wuxi plant has long geotextile bags provided to the weaving business lessons, but they did not pay attention only.
2, other geo-synthetic materials production and application of
Geomembrane product development in China is another process, at first because there is no heat welding machines, make more use of PVC as raw material, as suitable for adhesive bonding; and quickly add lead stabilizers from the transition to a health class. But the width is only l ~ 2m, and should not produce thin, and very easy to use. After that came the domestic hot-welding machine, then blow-molded PE geomembrane can be wide, so quickly occupied the market, and to users of PVC geomembrane diluted down. Although we emphasized the two have their own advantages and disadvantages, each with different fields of application, the final or in the different production costs Ershi PVC film being cold-shouldered. The past two years the MTR underground project be filed, and some companies also introduced EVA geomembrane, in fact, PE is still relatively large in a flexible, said formation of the tunnel wall lining, it is not easy to achieve a more fit, So, despite the higher prices, it also caused some of the user's attention. Another important feature of China's PE geomembrane is to use a cloth one film or two cloth one membrane are more complex products, it is mainly the designer that the composite membrane with the fabric, there is a protection, increased sense of security. Some even focus only compound the neglect of the thickness of the membrane. Our country is now reason why the significant increase in amount of needle geotextile, geomembrane composite usage among them: its composite geomembrane enterprises are many, most of the geotextile is a needle factory participation. Because acupuncture earth more and more wide-width fabrics (currently more than 6m width reached more than 10 production lines, the most wide up to 7.5m), so the composite geomembrane width also grows ever wider. This is a market positive. But also ignored the other side, that is, for the landfill, sewage treatment and a series of demands thicker geomembrane projects, which in turn is a negative. Until the past two years began to take on domestic environmental protection projects along the lines of the foreign designs use thick geomembrane wide when they feel upset for domestic products; some designers seem to think that the non-imported goods can not be. In general, the international application of Thick Film seepage of more, while domestic on the contrary, is a thin composite film-based. Personal opinions do not necessarily have to mechanically copying abroad, or in terms of conditions on the basis of seeking truth from facts. Such as environmental protection projects, especially the storage of poisonous substances, I am afraid not only to thick and starting a two-to three levels of impermeable layer; like a gold mine tailings seepage and so on, it is not so can not be. So why domestic production enterprise wide thick geomembrane relatively few do, because in one-time investment is too large, or high risk. On the contrary, a number of geotextile geotextile-grown plants using the advantages of several hundred thousand dollars to spend can buy a laminating machine, using someone else's film will start its operations, and if the past is now a soft plastic drain board water pipe, plastic blind ditch , three-dimensional mat and the current GCL and so on, a set of equipment investment generally 50 million or less, so items like this product much more investment soon. But the biggest problem is that these products are mostly clone belonging to improved products are few. So, too much is easy on the "deterioration" of. And some companies even the product description or promotional materials are also pictures and photographs of each copy, which put less serious manner of geosynthetics is too commercialized, and the loss of the development of new technologies, new materials, meaning. We remind all enterprises and to arouse the attention in this regard, or long-term effect on the country and has been harmful to both, should strive to create for creating change.
Since the 98-year Tai'an China Plastic Factory has been the first Chinese-made plastic geogrid production line since the short period of four years, the country that is more than 20 enterprises to invest in geogrid production, in which a single bi-directional grill can be produced on the there are 10 or so, the vast majority concentrated in the Shandong Province. This is a recipe from the raw materials do not pay attention to the beginning to the present refining machinery and equipment, emphasizing technology, focusing on the process of formulation optimization; make our product quality plastic stretched grid is, indeed, a certain increase. Some of them may be comparable with foreign brands; there in the stress-strain relations are appreciated by foreign investors and users; and some have continued to supply for sale abroad. The so-called preferred formula, that is, the raw material of different grades according to the strength, deformation, melting index and performance, as polypropylene, polyethylene copolymer of different dosage options; or separately for a few polyethylene or polypropylene blends of different grades in different dosage options ; so that after the full after the drawing process, both play with their weight per unit area corresponding to tensile strength, but also control the maximum fracture deformation within the scope of a smaller (about 10%); so as to achieve a smaller The purpose of the creep. This is a series of detailed and scientific research work, is to spend time-consuming. Fortunately, the majority of the current plastic stretched grid companies are constantly improving. Domestic grille has continued in its progress, because a. The product of the production equipment (including auxiliary, etc.) Investment in general were 160 to 200 million yuan, a large capital investment, thus a general increase in the enterprise a sense of responsibility for product quality. 2. User (design) in the country's products do not appear before the foreign investors, driven by the performance index on the grille a relatively clear understanding of and requirements, companies realize the importance of efforts to accommodate the way out. 3. There are a number of businesses, from the beginning, and strive to make the country's products meet or exceed the imports. Today, although did not rule out a small number of companies where there are low-priced sales obsession to the neglect of products including creep deformation, including problems, but most enterprises are the raw materials that affect product quality, formulation and device technology for change; one of the few companies is to work hard for the next level, this spirit is commendable. We believe that the ugly grille products will be eliminated! Chemical fiber and glass fiber warp grid production lines in China not only have a certain amount of imported equipment, there are some China-made equipment; the same time, the latter dealing with the development of composite processing fairly quickly. We have seen large-scale enterprises, through the combined treatment, the warp grille, than from the international exhibition of samples back even better. And they also engaged in the production line, component parts production, exported to abroad, and welcomed by the United States and other manufacturers. At the same time also made the application of co-ordination of efforts, such as cracks in order to control the construction of paved roads, production control and self-adhesive nail-type grille, so that was handy engineering applications. It is because of them from the application of a number of martial arts techniques from top to bottom, so the past two years, China's road pavement and part of the application of a number of roadbed warp grid; this, together with the singeing geotextile asphalt for our roads in the fight against reflective cracks in the forefront of the international approached. China's current high-grade highway construction to increase the scale and speed are still expected to climax soon will have a repair, when materials such as fiberglass grating is expected to have a greater supply, rather than a long period of oversupply of狀態(tài). Want to lose time trying to do a good job application technology and quality and improving co-ordination, rather than indulging in a price war among the. In the grille of the products, there is a order form that is reinforced with welded, which is reinforced with the use of some of our major (including the steel-plastic composite belt) production technology, a combination of grid-like material, has its own steel-degree of deformation (including creep small) small features of the node positions in its fastness and also the shortcomings of low shear capacity: combined with the thickness of the barrier is relatively thin parts, lattice large, on soil constraints and poor performance may be pulling some. Therefore, pay special attention to a single two-way stretch plastic grille, warp fiber grating, combined strip grating, one-way reinforced belts and five kinds of high-strength woven geotextile reinforced materials, have their own different kinds of projects properties and their respective applicable conditions, its design method and the amount is varied; so do not be confused, or abstract, what kind of negation. Even in the case are available, as well as economic comparison and construction, convenience and other issues.
Currently claiming to be able to produce geocell products enterprises have as many as 6-7 at home, mainly due to Weihai, Shandong, Jiangsu Yancheng 2 production ultrasonic welding machines provide a convenient, all thought siding firmly welded the end of the story. But the key to whether the cell wall material to cross the border should be attention. Especially for a high degree of greater than 15cm of the cell room (prism) wall material, not only have a certain tensile strength, but also have a certain thickness of stiffness, so that the whole room in order to form a lattice structure of the real three-dimensional body force will not deformation due to such causes excessive loss of use value. In fact Geocell is still relatively small in domestic applications, in addition to roads, railways used as part of the desert areas outside the soft ground in dealing with temporary or for the beach used to enhance the bearing capacity of shallow oil development, it is also used some, this mainly by the corporate initiative designed to tie in with the achievements. Of course, take longer to resolve the vertical and horizontal issues such as widening, the construction of ways and means still owe the skilled, and often a lack of serious economic accounting; is dominated by the thinking of the higher price, it is difficult to become universal. Geocell can also be used for retaining structures, such as steep steps built with grid-shaped chamber, which is still used more in foreign countries, it can eliminate the re-slope; especially in the hilly city of using, but also to facilitate the steep slope with flowers and landscaping. Room on the grid for slope protection, may be due to the impact of high prices, is not yet (or rarely) used, but the foreign data, photographs, use (square, hexagonal and sometimes perforated) lattice rooms for slope protection of the It seems that a lot, should cause us to further reflection. Specific to our country, the need for 7 ~ 10cm high cell room and other slope protection material for further, more comprehensive comparison, which is not purely economic, but also works in which weather conditions, geological conditions, and other various factors, I believe there are always can play to their strengths lie. For example, a very dry areas, no gravel areas, water pouring concrete prism and slope also very expensive area, three-dimensional networks grass is difficult to conservation, there is no guarantee survival, and (despite the three-dimensional network Network kinds of grass than not to grass grow better, but still want to watering conservation) then the room with the grid slope, except for construction of simple addition, even if the legislation is also not afraid of heavy rains, with its long-term reliability.
It is true that the application of grid room, with our associations and enterprises make further efforts to be separated from, first, as soon as possible to help solve design method; Second, we must closely with business applications, development of series of varieties, in order to publicize and promote the use of technology to promote their own products. Must not follow suit in counterfeit products overstepped the bounds of the room.
Rachyan small, deformation of a large Geonet product had gone through a period of brisk sales in China, which is due to foreign materials, production technology in China reinforced containment due to forced and misleading. All of a sudden there are eight or so companies to spend at high prices from abroad Geonet more than 10 production lines, the product used in the slope protection, reinforcement and foundation reinforcement; Although the application project be successful, however, limited due to its performance, not only the relative amount of excess Great price, but limited to a smaller range of applications. Therefore, since the emergence of self-geogrid, which has been in a downward trend; and even a small number of companies have converted to other production or pulling out. At the same time, the association found that several leading members of the foreign is Geonet compatible with geotextile fabric and so on, mainly for drainage plane, that network is sandwiched between two layers of geotextile fabric and geomembrane, or between the overhead to facilitate drainage from role; or anyone else involved right geotextile serve to strengthen and protect the role. This is below the groundwater level in underground engineering and the cut-works great development potentials. However, due to this combination of domestic product has not yet mass production, in the design of application has not yet been recognized, it has not yet achieved its proper application. On the contrary, misled by the past influence Geonet the road sector, to prevent the bridge-jumping off the tram and slope protection, etc. are still used; of course, from an economic point of view, compared with the geogrid and other, such as Shouli Bu large, and are subject to deformation of the smaller projects, if it is still desirable, then, natural is reasonable. However, Geonet more material per square meter, is generally not cheaper than the two-way grid, it is worth noting that the other side.
In recent years, the soft water pipe and a variety of blind ditch drainage has developed very rapidly pity that most of the cloned products, very little has improved. In particular, plastic wire blind ditch drainage, or very rough, even recycled plastic are available, their use is also too much, the price is hard to be able to decline; and did not take long and widen the issues have been properly resolved, pending enterprises to further the practical application of phase and Engineering combined to improve as soon as possible. According to oral information, plastic wire by adding nano-ingredients can significantly increase product bending, compression capabilities, to see if I have the product structure, the size of the increase and decrease the density of the plastic wire improved.
Beginning of this year geotextile clay liner (GCL) has developed very rapidly in China, according to a preliminary understanding has been five or so went into operation, can be described as to keep up with the times. According to our contacts and observations, GCL products to remove stressed the need to have well-qualified bentonite addition, in the production technology and techniques to maintain uniform and stable layer of bentonite is no technical barriers. However, enterprises must be laid with the design application and construction of the close match, which is China's current understanding of this product just in terms of stage is very important. Otherwise, despite the production of many kinds, a result of the design, construction technology lags behind, causing foreign companies to seize the key, and then neglected the domestic enterprises. Therefore, enterprises should understand the situation, is always difficult, particularly in the application of all the meaning of the GCL and technology is not yet very familiar with the time, it even more difficult. We believe that both companies and associations have the responsibility to begin to help solve why should GCL seepage? How to use? How do construction and other difficult problems, and only thus open up the situation, GCL products have a future. First, of course, but also made sure that GCL product quality, product to show the advantages of going abroad, do not think that GCL can be produced, and can be a smooth sale; while still very difficult work to be done. Because GCL applications (design, construction) technology in China has not yet accumulated experience, especially when people have not fully aware of and understand the superiority of GCL to the application when the need for companies to go with the feeling our way forward. Only after obtaining some experience can be an area of the face of application development, a face of the product improvements; also include the product series. Although we geosynthetic material of any kind are so request, but for GCL products, so doing, it is more necessary, even more important. It is because of China at present is in this state, then the excessive production GCL, not too blind it?
Plastic drainage belt (board) is located in China's use of geotextile after the second-largest species, harbor terminals of Reclamation land, highway, railway and water conservancy, construction of soft foundation treatment works for many years, peak usage of more than 70 million linear meters, which may be in the world. The product structure, raw materials (recycling) in the adoption and membrane localization of some of the features aspects. Although from the outside its appearance is not known, met with foreign direct shaking his head, but in practice proved to effect is good. Over the years, saved the state a lot of project investment has played a great role in knowledge-based economy. Of course, this aim with the entire application technology is inseparable from the art, such as the past 20 years, most especially the super-soft soft ground foundation treatment, using the vacuum preloading method, which is to Tianjin, China Harbor Engineering Research Institute, Tianjin University, common effort, its degree of vacuum up to 0.8 atmospheres, but also win over a high level of foreign chips. Today, some old plastic drainage belt business, is still the country's economic construction and continue to make contributions. One also has to open up overseas markets, from the appearance and raw materials to make improvements and get some foreign flew welcome. Of course, prices also climbed up; as foreigners welcome, is also a good thing. But this shows that our product to be able to long-term foothold in foreign countries, non-continuously strive to improve not. In order to export to cater to the taste of foreigners mouth membrane is a pass, do not look thin non-woven fabric of domestic manufacturers of equipment, there may still have to use the products of DuPont or Freudenberg. The sounding device attached to the product would not be necessary as the institutional construction in foreign countries so that the depth can not be set up to fight fraud and deceive itself. As for the quality and performance of membrane, over the years to study very little, which is due to specification requirements permeability coefficient ≥ 10-4cm / s relatively easy to achieve. The equivalent aperture set at ≤ 0.075mm is still some controversy; reason is that theory and practical operation due to the difference between. It is understood that over several years using an equivalent aperture membrane majority of large (slightly) in 0.075mm, but preloading works almost entirely successful. So from experience that the membrane pore size is equivalent to slightly greater than 0.075mm or applicable. Although it was brought after the digging drainage of view, with a core of material there are a few clay tablets, but in theory should be normal. Moreover, also failed to demonstrate ≤ 0.075mm clay when it does not necessarily occur, especially in the case of a high vacuum, it is actually more in line with the theory. However, do take note of the longitudinal and lateral membrane strength and deformation took place can not be lightly broken (open) fracture or embedded in grooves, thus affecting the application effect, foreigners could not understand why our home-made membrane, the key is to of these had no confidence.
3, product production and application needs to open up with each other
In short variety of geosynthetics in China's development is consistent with international trends, for example, the 7th International Conference on Geosynthetics papers focused on the specific separation of micro-reinforced articles, and our use of the split-film micro-reinforced wire fiber production enterprises have 2 ~ 3 as much as in the domestic has been increasingly used to prevent concrete cracking. Fiber reinforced soil studies are Tsinghua University, Tianjin University, etc. have been carried out: This is right there for, forge ahead and create a foundation for scientific research and policy. Membrane structure of production enterprises have settled down in Shanghai, which not only marks the expansion of the scope of application of geosynthetics, also showed that high-strength tubes impervious airtight bag in my country were available. Others like the large volume of foam (EPS), thermal insulation is, expansion strips, lining of, component pads, structural joints gaskets, adhesives, and grouting pipe joints and some other small amount, but rather special materials , also have a production enterprise. And they expressed their full co-operation with customers to jointly develop products in different specifications of the project. Therefore, as matter whether the new technology, new materials matter whether, "Geosynthetics" at home and abroad have long been a breakthrough compared with the original narrow definition. Such as Southeast Asia, jute, coconut fiber slope network in Western Europe with the polymer and metal products, China's municipal works for Concrete Curing (can be changed to black) as well as for non-rock (pure) engineering, have fully demonstrated the synthesis of materials, vitality and sustainability. Recently, Hainan Jihong too with India, after contacts and exchanges between related parties that: the formation of ultra-high molecular membrane (thick) material, can be widely used in civil engineering concrete pouring templates, especially in the complex structure form, can be greatly inflated way to facilitate the construction of circular and arc-shaped building, while deflation is also very easy to facilitate form removal; and even large-span can be done. The two sides of dual ultra-high molecular membrane material used in thermal power plant ash, sending ash, for travel liner, for a special isolation area, has its own steel, wood is not easy (should) do a good effect. Including its high degree of smoothness, water does not freeze with each other and strong thermal expansion and contraction of the difficulty. No doubt, this for us in geotechnical engineering applications also open a train of thought. To this end, we strongly advocate the production of this sector enterprises to the products and raw materials which should have a better understanding of characteristics, so as to press ahead.
Fourth, a few observations
The application of geosynthetics are in need of a professional construction team and specialized construction tools, specialized association of construction enterprises (members) have four, they are applications of geosynthetics professional contractor or a package in the end of the. The company works with a number of construction companies, but most are aimed at laying and welding geomembrane, the so-called with no real professional team can only be during construction in order to own a welding machine to help welding only. The good news is a small number of production companies Geocell, which could be the temporary works design or ask for help planning, construction, and construction. However, in roads and public works in the special commitment to the grid can be prestressed do not yet, which shows that this construction technology and equipment still lacks the necessary considerations, naturally also affects the application effect of improvement. Langfang City, Hebei Province earlier application of the road sector scissors principle of pre-tension applied to the geotextile: Last year, Central South University's civil engineering Professor Yang Youlin has also published articles stresses the pre-plus grid infrastructure can not keep up is no progress can be seen one of the reasons. It should be software and hardware go hand in hand. Wenzhou, Zhejiang has developed a Chinese-made automatic welding machine and an indoor crawling Geosynthetics tester; but the lack of on-site welding quality detector; works in-situ testing instrument and other necessary tools for the construction of supporting hope that through this meeting can be changed.
Many manufacturing enterprises in China at present has reached more than 200 member companies, mainly concentrated in Jiangsu, Shandong provinces, while Jiangsu's Changzhou, Wuxi, Yixing and Shandong Tai'an triangle around the product is very similar to each other to repeat. Country's current situation is that although the mechanism of competition, but not very wise to rely on the means, if the really quality, the level of victory, then it must rely on science and technology, to spend energy, time and capital to improve the, so that you can arbitrarily to low sales? After accounting for the cost of one is always limited. As for the small number of enterprises (including non-members) of the product, lacking substance, numbness in blindly, and even business people with factory product performance, features very little understanding of ... ... sooner or later, then was eliminated by lack of pity.
Geosynthetic materials and technology, is a manifestation of advanced productive forces, belong to the scope of knowledge-based economy, but also a product of the times; the international community shows that comprehensive national strength is stronger, more advanced science and technology, the economy prospers, the greater amount. But first thing is that we rely on engineers to practice. After 1998, China increased variety of materials, design, construction practices and most of them have had, usage increased a lot; related materials aging and durability issues, mostly through the practice has also been gradually recognized and resolved; This is entirely consistent with the law of development of things. While we have made great achievements, but the booming economy and social construction, and the natural ecology and environmental protection is also the far distance, which must continue its efforts with the times, blaze new trails. Specifically, we need to re-emancipate the mind, respect the power of science to learn a little knowledge of polymer raw materials to further enhance the knowledge level of geotechnical engineering. I believe this new technology, new materials, space and the prospects of the application is still very wide. As long as we continue to practice - to improve - innovation - and then practice, we have the cause of geosynthetics in construction of the entire national economy play a more significant role in