What are the technical points of water conservancy dam reinforcement and slope protection engineering?

Recently, with the continuous promotion of water conservancy infrastructure construction in China, water conservancy dams, as the core project of flood control and disaster reduction and water resource allocation, are widely distributed in rivers, lakes, reservoirs and other regions, and their stability and disaster resistance capability are directly related to the safety of life and property of people along the coast, ecological environment security and regional economic development. Water conservancy embankments are subject to natural factors such as water flow erosion, wind and wave erosion, and geological settlement for a long time, which can easily lead to dam leakage, slope collapse, toe erosion, termite infestation, and other diseases. If the reinforcement and slope protection are not in place, it may cause major safety hazards such as dam collapse.
The reinforcement and slope protection engineering technology of water conservancy dams follows the core principles of "prevention first, combination of prevention and control, adaptation to local conditions, and long-term management and protection", which runs through the entire process of engineering survey, construction implementation, and later management and protection. The core goal is to improve the anti-seepage, anti impact, and anti sliding capabilities of dams, prevent various types of dam diseases, and ensure the long-term stable operation of dams. Industry experts say that the reinforcement and slope protection of water conservancy dams is a systematic project that requires targeted selection of technical measures based on the geological conditions, hydrological environment, and disease types of the dam, and precise control of every technical detail, in order to build a strong flood control safety barrier.

The technical key points of water conservancy dam reinforcement engineering mainly cover three core links: dam foundation reinforcement, dam body reinforcement, and hidden danger control. Each link must strictly follow industry standards, optimize construction technology based on actual engineering conditions, and fundamentally improve the bearing capacity and anti-seepage performance of dams.

Embankment foundation reinforcement is the foundation of dam reinforcement, with the core being to solve problems such as seepage and insufficient bearing capacity of the embankment foundation. Common techniques include anti-seepage wall reinforcement method, replacement and filling reinforcement method, etc. The anti-seepage wall reinforcement method is suitable for areas with severe leakage in the embankment foundation. Currently, the widely used technologies include plastic concrete anti-seepage walls, TRD method cement soil anti-seepage walls, etc. During construction, anti-seepage materials are injected underground through professional equipment to form a continuous and complete anti-seepage barrier. This can not only improve the anti-seepage capacity of the embankment, but also adapt to the deformation of the embankment body. In the key embankment reinforcement project of Dongting Lake, the construction team used a hydraulic grab bucket machine to excavate the embankment foundation, poured a plastic concrete anti-seepage wall with a width of 40 centimeters and a depth of about 30 meters, effectively blocked the underground seepage channel, and built a solid anti-seepage line for the embankment foundation. The TRD method involves inserting a cutting box with a cutting chain and blade into the ground, vertically cutting and injecting cement slurry, thoroughly mixing with the original foundation soil, and forming a cement impermeable wall of equal thickness in about 30 minutes. The construction efficiency and reinforcement effect are significant.

The replacement and reinforcement method is suitable for scenarios where the soil quality of the embankment foundation is poor and the bearing capacity is insufficient. By excavating the poor soil layer of the embankment foundation and replacing it with high-quality filling materials with high strength, strong permeability, and good stability, the bearing capacity of the embankment foundation is improved and settlement deformation is reduced after layered rolling and compaction. Before construction, it is necessary to clarify the depth and scope of the replacement through geological survey. During the replacement process, the quality of the filling material and rolling parameters should be strictly controlled to ensure that the replacement layer is dense and uniform. In addition, for permeable embankment foundations, a filter layer can be laid to prevent soil particle loss and further enhance the stability of the embankment foundation.

Embankment reinforcement mainly targets diseases such as leakage, cracks, and subsidence. Common techniques include grouting reinforcement method, thickening reinforcement method, etc. The grouting reinforcement method injects cement slurry, cement mortar and other grout into the cracks or pores of the embankment to fill the gaps and bond the soil, improving the overall integrity and impermeability of the embankment. It is suitable for the treatment of hidden dangers such as cracks and honeycomb defects in the embankment. During construction, it is necessary to control the grouting pressure and slurry concentration to avoid excessive pressure causing damage to the embankment body and ensure that the slurry evenly penetrates into all parts of the embankment body. The thickening and reinforcement method increases the thickness of the embankment body on the upstream or downstream side to enhance its anti sliding and anti impact capabilities. It is suitable for embankments with thin and unstable bodies. During the thickening process, layered filling and rolling are required to ensure a tight connection between the new and old embankments, avoiding problems such as layering and cracks.

Hidden danger control is an important supplement to dam reinforcement, focusing on common problems such as termite infestation and hidden dangers in structures crossing the dam. A thousand mile embankment collapses in an ant nest. Termite nests can damage the structure of the embankment and cause leakage hazards. During construction, a mesh survey method should be used to accurately locate termite nests with the help of detectors. Termites should be thoroughly killed through methods such as pesticide killing, grouting, and trapping, and the ant passages and cavities should be filled with pesticide slurry. After backfilling the soil, they should be compacted layer by layer to eliminate termite hazards. For structures such as embankments, culverts, and gates, due to the long history of some facilities, they are prone to damage, leakage, and other problems, and require renovation and reconstruction. During construction, it is necessary to seize the dry season, quickly complete dam excavation, structure renovation, and backfill reinforcement to ensure completion before the flood season and avoid potential leakage and collapse hazards.

The technical key points of water conservancy embankment slope protection engineering are to resist water flow erosion, wind and wave erosion, and protect the stability of the embankment slope. Common technologies are divided into two categories based on ecological needs and geological conditions: ecological slope protection and rigid slope protection. Suitable slope protection methods should be selected according to local conditions.

Rigid slope protection technology is suitable for embankment sections with steep slopes, fast water flow, and severe wind and wave erosion. Common methods include stone throwing slope protection, mortar rubble slope protection, concrete slope protection, etc. Throwing stones for slope protection is an important way to protect the embankment foot. By laying stones with a diameter of 30-50 centimeters and wearing "stone boots" on the embankment foot, the erosion of water flow on the embankment foot can be reduced. This is a concealed project, and the amount of throwing stones needs to be monitored through a smart management platform during construction to prevent cutting corners and ensure the effectiveness of protection. The mortar laid rubble slope protection is constructed by using cement mortar to build the rubble into a whole, with stable structure and good durability, which can effectively resist the erosion and weathering of water flow. During construction, it is necessary to ensure that the rubble is tightly filled and the surface is smooth to avoid problems such as looseness and voids.

Concrete slope protection is divided into two types: cast-in-place concrete and precast concrete block slope protection. Cast in place concrete slope protection has good overall integrity and is suitable for complex slopes. Prefabricated concrete block slope protection has a fast construction speed and can be prefabricated and spliced on site, making it suitable for large-scale slope protection projects. In the management of the Qingtongxia Dam flood control reservoir in Ningxia, the construction team used barriers and filled angular gravel to treat the front dam slope, and used lawn brick ecological slope protection on the back dam slope. At the same time, a reinforced concrete wave wall was built to effectively resist wind and wave erosion and safeguard the safety of the dam. In addition, geosynthetic material slope protection technology is widely used in temporary engineering or weak foundation embankment sections. By interlocking materials such as geogrids and geogrid chambers with the soil, the frictional force of the soil is increased to prevent soil sliding, making construction convenient and the construction period short.

Ecological slope protection technology is suitable for embankment sections with gentle slopes, good soil quality, and emphasis on ecological protection. Common methods include plant slope protection, lawn brick slope protection, etc. Plant slope protection is achieved by planting herbaceous plants such as dogweed roots and ryegrass, as well as shrubs such as purple locust. By utilizing the anchoring and reinforcing effects of plant roots, the soil's resistance to erosion is enhanced, and the environment is beautified and the ecology is improved. It is suitable for embankment slope protection in urban and landscape areas. During construction, it is necessary to choose plant species with strong adaptability and good soil consolidation ability, and to reasonably match herbs and shrubs to ensure even vegetation coverage and improve slope protection effect.

The construction quality control and later management of water conservancy dam reinforcement and slope protection engineering are equally crucial, and are important supports to ensure the long-term effectiveness of the project. During the construction process, it is necessary to strictly follow the SL51-93 "Construction Specification for Embankment Engineering", strengthen the control of material quality and construction technology, conduct strict acceptance of incoming materials, monitor key indicators such as grouting pressure, compaction parameters, and stone throwing volume in real time, keep construction records, and ensure traceability of the construction process. At the same time, it is necessary to seize favorable construction periods such as the dry season, arrange the construction schedule reasonably, ensure that the project is completed before the flood season, and avoid flooding during the construction process.

In the later stage of management and protection, it is necessary to establish a sound management and protection mechanism, regularly inspect the dam, and promptly discover and rectify hidden dangers such as cracks, leaks, and damaged slope protection; Strengthen termite monitoring and eradication, regularly clean up weeds and debris on the embankment slope to avoid affecting the stability of the embankment; Equip necessary emergency supplies and equipment, establish emergency teams, and enhance emergency response capabilities. In addition, intelligent means such as smart water conservancy platforms and digital monitoring stations can be used to achieve real-time monitoring of the operation status of dams and timely warning of various safety hazards.

The reporter learned that with the high-quality development of water conservancy engineering, the reinforcement and slope protection technology of water conservancy dams continue to be optimized, and the application of intelligent construction equipment and new environmentally friendly materials further improves construction efficiency and engineering quality. Industry experts remind that the reinforcement and slope protection projects of water conservancy dams are closely related to flood control safety. Construction units need to strictly implement the quality responsibility system, strengthen full process control, optimize technical solutions based on actual engineering conditions, strengthen professional training for construction personnel, and improve standardized operation levels. In the future, we will further promote the ecological, refined, and intelligent development of reinforcement and slope protection technology, improve technical standards and management mechanisms, provide strong guarantees for the safety of China's water conservancy infrastructure, and help build a solid defense line for flood control and disaster reduction.