Based on the comprehensive collection and comprehensive study of the achievements and experience of landslide prevention and control engineering at home and abroad, this project systematically summarizes the effective landslide prevention and control engineering technologies and methods, and carries out experimental research on new technologies and methods of landslide prevention and control engineering such as anchoring technology, micro-composite anti-slide pile technology and slip zone grouting technology. On this basis, the "Demonstration and Guide of Landslide Prevention Technology and Method" is compiled to serve the prevention and control of geological disasters in China. The main research contents and achievements of this project are as follows:
1. Completed the summary and research of landslide prevention engineering methods at home and abroad.
This project has collected and analyzed a large number of domestic and foreign technical research achievements and prevention engineering cases, translated nearly 500,000 words of foreign landslide prevention technical manuals and technical regulations, and compiled a 85,000-word Comprehensive Investigation Report on Techniques and Methods of Landslide Prevention Engineering at Home and Abroad. On the basis of summarizing and studying the engineering methods of landslide prevention and control at home and abroad, according to China's national conditions, the technical system of landslide prevention and control in China is put forward, which mainly includes drainage, weight reduction, back pressure, retaining soil and improvement of sliding zone.
2. The key technical parameters and long-term effectiveness of landslide prestressed anchorage are studied.
Aiming at the problem that the design parameters of bonding force in current anchoring technology are mainly based on experience, the bonding force between anchor and mortar, and the bonding force between mortar and various rock and soil bodies are studied experimentally, and accurate bonding force data are given.
In view of the long-term effectiveness of the anchor cable, this project excavated a fully bonded prestressed anchor cable on the left bank slope of Manwan Hydropower Station, which has been undisturbed for 20 years, and carried out related research work, which is the first time in China. Through research, the situation of the outer anchor head, the locking part of the anchor clip and the free part of the cable body mortar that is not completely wrapped due to drilling bending is understood, and the physical, chemical and mechanical properties of the excavated anchor cable and surrounding rock body are tested. The research shows that the steel strand of fully bonded prestressed anchor cable has no obvious corrosion after 20 years of use. Although the elastic modulus of steel strand is weakened and the prestress is reduced, the tensile strength is basically unchanged, and the anchor cable works effectively and is safe.
3. The experimental research on micro composite anti-slide pile technology is carried out.
The working mechanism of micro-composite anti-slide pile is studied by indoor test and numerical simulation, and the interaction law between pile and soil is deeply analyzed. On this basis, the ideal length-diameter ratio of micro composite anti-slide pile is 50 ~ 120, and the distance-diameter ratio is 6 ~ 10, which provides an important basis for the design of micro composite anti-slide pile, especially for the rapid determination of emergency rescue scheme.
4. The slip zone grouting technology is studied experimentally.
Aiming at the typical landslide types suitable for grouting reinforcement, the slip zone grouting reinforcement test is carried out, the working mechanism is analyzed, the reinforcement effect is evaluated, and the key technical parameters of grouting reinforcement are obtained.
5. Completed the compilation of landslide prevention and control technical guidelines.
By collecting the technical standards and specifications of landslide prevention and control at home and abroad and the technical data of landslide exploration, design, treatment, monitoring and supervision at home and abroad, this paper systematically summarizes and analyzes the latest research results of landslide prevention and control methods at home and abroad and the successful experience and failure lessons of prevention and control projects, and formulates the technical guide for landslide prevention and control, so as to provide comprehensive and detailed technical data and scientific basis for engineers and technicians engaged in landslide prevention and control exploration, design and construction.
Technical Guide for Landslide Prevention consists of 8 chapters and 42 articles. The main contents include landslide identification and mechanism analysis, landslide survey, landslide stability analysis and risk assessment, determination and optimization of landslide prevention scheme, landslide prevention technology and design method, landslide prevention project construction, landslide monitoring and early warning and prediction, and typical cases of landslide prevention project.
Second, the scope of application and application examples
1. Application scope of results
The project systematically summarizes the engineering methods of landslide prevention and control at home and abroad, carries out research on new technologies and methods, and compiles the Technical Guide for Landslide Prevention and Control, which has achieved rich results and has important guiding significance for the prevention and control of landslide disasters.
Among them, the research results of key technical parameters and long-term effectiveness of prestressed anchorage have improved the cohesive force parameters of landslide anchorage, obtained the long-term working state of anchor cable for the first time, optimized the application of anchorage technology in landslide disaster prevention, and provided a basis for formulating more perfect landslide anchorage technical standards in the future.
The research results of micro composite anti-slide pile technology are suitable for the reinforcement of shallow-buried soil landslide or cataclastic rock landslide. For permanent treatment projects, it is suggested that the buried depth of sliding surface should not exceed 15m, and for landslide rescue projects or temporary reinforcement projects, the buried depth of sliding surface can be extended to 20m.
The Technical Guide for Landslide Prevention and Control is the first technical guide for landslide prevention and control in China, which is comprehensive, detailed, instructive, practical and authoritative, and can better meet the needs of landslide prevention and control technicians.
2. Application example
The research results of the micro composite anti-slide pile of this project have been applied in the K57 landslide control project in Neiyi expressway, the landslide rescue and reinforcement project of residential buildings in Qianwei County People's Hospital of Sichuan Province, the safety hazard control project of Longhui 3(5) well station and the landslide control project of Long 7 well successively, and good control effects have been achieved.
Third, promote the transformation form.
The promotion of specific technical achievements of this project can be carried out by means of meeting exchange, technical consultation and on-site service.
The technical guide for landslide prevention and control compiled by this project can be popularized through public publication, and after publication, it can further promote the transformation of achievements and promote the progress of landslide disaster prevention and control technology in China by holding training courses on landslide prevention and control technology.
Technical support unit: Institute of Prospecting Technology, Chinese Academy of Geological Sciences
Contact: Guo Qifeng
Mailing address: No.0/39, Hua Gang Road, Gangbei District, Chengdu Modern Industrial Zone, Pixian County, Chengdu.
Postal code: 6 1 1734
Tel: 028-66529383
E-mail: gqf28 @163.com.