Small reservoir reinforcement technology?

The reinforcement technology of small reservoirs is very important. Technology is formulated to solve a problem, and the handling of every detail is crucial. Zhong Da Consulting will explain the reinforcement technology for small reservoirs.

The slope of earth-rock dam moves downward and outward under the action of gravity and other forces. If the shear strength of rock and soil in the dam slope can resist this trend, the dam slope will be stable, otherwise it will be unstable and landslide will occur. The landslide of earth-rock dam is the result of many factors, and it is a complex instability and failure phenomenon. The basic factors of earth-rock dam landslide are essentially the increase of sliding force and the lack of sliding resistance.

Sliding force and sliding resistance depend on the pore water pressure in the dam or dam foundation and the properties of dam materials, including the shear strength related to pore water pressure caused by external conditions such as reservoir water and rainwater infiltration, construction method, construction speed and earthquake. Therefore, first of all, it is necessary to carry out landslide exploration, geotechnical test and observation to determine the nature and main causes of landslide and determine the design of landslide reinforcement, so as to carry out the construction and quality inspection of landslide reinforcement.

The earth dam body is made of artificial dam materials, and the dam foundation and bank slope are concealed works. According to the design standard of landslide reinforcement, the landslide reinforcement construction should be carried out according to SDJZ 13-83 Technical Specification for Construction of Roller Compacted Earth Dams. The construction methods of landslide reinforcement mainly include: cleaning dam foundation and bank slope, removing and treating roots, springs, caves, weathered rocks and landslides. Will cause hidden dangers to dam safety; Gravel that stabilizes the landslide; On the basis of stabilizing the landslide, deal with the landslide cracks in time; Fully cultivate the thickness and slow down the dam slope; The downstream dam slope is ballasted with rockfill, and a slope-attached filter layer is made.

Grouting reinforcement technology of secondary earth-rock dam body

At present, dam grouting methods can be divided into filling grouting and splitting grouting. The former refers to self-weight grouting (the orifice pressure is zero), and the latter refers to splitting the dam by grouting pressure to form a nearly vertical and continuous slurry curtain. In fact, both grouting methods are pressure grouting, but the pressure used is different.

These two grouting reinforcement technologies have achieved fruitful results with the efforts of water conservancy workers in China, and contributed to the reinforcement of dangerous earth-rock dams in China.

Dense reinforcement technology of dam body and dam foundation

The biggest hidden danger of the three earth-rock dams is that the filling quality of the dam body can not meet the design requirements and the soft dam foundation is not handled properly. Therefore, improving the compactness of dam and dam foundation is the primary task to eliminate dangerous reservoirs. Improving the compactness of dam body and dam foundation is one of the key technologies in the construction of earth-rock dam.

For new dams, the density of dam body and dam foundation must be strictly demonstrated, carefully designed, the optimal construction reinforcement scheme selected and carefully constructed. Dam density mainly controls the filling quality, including dam material selection, rolling test, rolling method and various parameters of rolling construction. In strict accordance with the relevant specifications, to ensure the quality of dam filling.

The filling density of the new dam body not only adopts rolling method, but also adopts vibration compaction method. There are many methods to strengthen the soft foundation of new dams, such as vibroflotation, staged drainage sand drain filling, deep mixing, dynamic compaction, replacement filling and chemical grouting.

The dam has been built and the dam body and dam foundation have formed a whole. If there is a problem with the compactness of the dam and dam foundation, try to choose the same method when choosing the reinforcement method. Among the above reinforcement methods, vibroflotation method has good applicability. Sand and gravel, earth materials and soft soil (cohesive soil or sandy soil) of dam foundation can be reinforced. Therefore, vibroflotation method is a better reinforcement scheme.

When the dam foundation is cohesive soil foundation, deep mixing method is also one of the alternative reinforcement schemes.

Four geosynthetics reinforcement technology

With the rapid development of polymer chemical industry, various synthetic fibers, such as polyvinyl alcohol fiber, polyvinyl alcohol fiber and polyphthalamide fiber, have appeared since the 20th century. Synthetic fiber is gradually accepted by people because of its superior performance to man-made fiber. Practice also shows that geosynthetics is an ideal new engineering material.

Geosynthetics, as a brand-new geotechnical building material, has a short history, but it has developed rapidly. At present, several series of products have appeared. The main products and their main application functions are as follows: ① Geotextile is a permeable fabric made of all synthetic fibers or natural fibers used in geotechnical and civil engineering, and its main functions are drainage, filtration, isolation, reinforcement, control and protection against erosion. (2) Geogrid is a regular network structure connected by tensile elements, and its opening area is much larger than that of tensile elements, so it is used for reinforcement; (3) Geotextile is a regular and compact network structure connected by overlapping ribs, which is used to transport liquids and gases; ④ Geomembrane is a relatively impermeable polymer sheet, which is used to transport liquids and gases in geotechnical and civil engineering; ⑤ Geotextile mat is a three-dimensional permeable polymer mat bonded by single fibers, which is used to protect soil particles, footings and tiny fabrics in erosion control; ⑥ Geocell is a three-dimensional structure which is cross-linked by fabric, mesh or membrane strip into honeycomb or spider mesh, and is used to control erosion and maintain soil; ⑦ Geosynthetics are composite materials made of two or more geosynthetics, which are used for drainage, water interception and reinforcement.

In a word, geomembrane has outstanding anti-seepage performance, which can be used in the following aspects in water conservancy anti-seepage engineering: ① dam anti-seepage inclined wall or vertical anti-seepage core wall; ② Horizontal impervious blanket and vertical impervious wall of dam on permeable foundation; ③ Impervious body of concrete dam, sewage dam and roller compacted concrete dam; ④ Seepage prevention of canal lining; ⑤ Horizontal bedding and seepage control of culvert gate; ⑥ Seepage prevention of buried pipes in tunnels and dams; ⑦ Seepage prevention of construction cofferdam; A large number of engineering records show that the anti-seepage effect is good, economical and practical, and the construction is convenient, which is worth popularizing. At present, the provisions on geomembrane seepage control of dams in SL/T225-98 and GB50290-98 Technical Specifications for the Application of Geosynthetics indicate that geomembrane seepage control technology is becoming more and more mature in dams in China, which will provide a good example for the popularization and application of this new technology and new material in dams.

In recent years, the most widely used geomembrane in seepage control is vertical plastic paving seepage control. This technology has become more and more mature, and is widely used in seepage prevention and reinforcement projects of reservoir dams and dikes in rivers and lakes. The basic principle is as follows: firstly, using water jet, chain bucket or reciprocating trenching machine to vertically drill slots in the soil that needs seepage prevention, and using mud to protect the wall; Then, the whole roll of geomembrane with the same depth as the groove is put into the groove, and the geomembrane is rolled back, so that the geomembrane is unfolded and two adjacent sheets are overlapped and connected; Finally, fill the soil on both sides of the membrane to form the impervious curtain. When backfilling, backfill clay at the bottom of the tank, with the thickness not less than 1m, in order to seal and prevent water from seeping from the lower part, and then backfill the same soil material as the original dam building material, and continue to fill and compact after the tank sinks and stabilizes; After the geomembrane is taken out of the tank, it shall be connected with the seepage control system of the building and shall not be exposed. At the joint with the building, the geomembrane should be rich enough to prevent the geomembrane from breaking when the building is deformed.

For more information about project/service/procurement bidding, and to improve the winning rate, please click on the bottom of official website Customer Service for free consultation:/#/? source=bdzd