Study On Mechanical Behavior And Design Calculation Of H-Type Retaining Structure In Ancient Landslide Area

As a kind of natural four major disasters, landslide geological disaster have caused great threat to human life and property, and it seriously hindered the good development of China’s economy. Therefore, the design of the safety and reliability of the slope reinforcement project is the key point of the railway construction when the railway crosses the ancient landslide area. There are many types of slope reinforcement project, the h-type retaining structure has just developed in recent years, it is an improved form of the portal anti slide pile, so there are many differences between portal anti slide pile and the h-type retaining structure. The theoretical research on the h-type retaining structure is far behind the engineering practice, so there is no code to follow in the actual design process. Many selected parameters are based on experience and can not completely meet the requirements of the engineering. The research focus of this paper is to use the h-type retaining structure to reinforce the landslide when the railway crosses the ancient landslide area. By means of theoretical analysis, numerical calculation and field monitoring combination, the force and deformation of h-type retaining structure and the influence of key parameters on the structure force and deformation are analyzed. The main conclusions are as follows:(1)The rationality of using rectangular distribution to simplify the thrust of landslide has been verified, and it is determined by the transfer coefficient method. The slope resistance is equal to one third of the passive earth pressure.(2)The h-type pile is simplified as a plane rigid frame, and the frame is divided into the three parts of the cantilever section, the middle section of door type and the anchorage section to consider. Finally, the method of structural mechanics is used to calculate it.(3)The dangerous section of the h-type pile is consist of two ends of the beam, the connection between pile and beam, the middle of the anchorage segment of the pile.(4)The numerical analysis shows that, the distribution and calculation method of the earth pressure during the theoretical calculations is reasonable, the distribution of numerical results and the theoretical results of the force and bending moment are very similar, and the theoretical value is generally greater than the numerical value.(5)The influence of the pile anchorage depth on the stress and deformation of the structure is very little. The increase of the beam stiffness can improve the structure stress and reduce the deformation of the structure. The reduction of the row spacing can improve the structure stress and reduce the deformation of the structure.(6)Through processing and analyzing the result of the field monitoring, the results show that the force of the structure is in good agreement with the numerical value, and it is smaller than the numerical value and the difference is not large, which shows that the numerical calculation is safe and reasonable, the measured force value of the structure is smaller than the theoretical value and the gap is larger, which shows that the theoretical calculation is conservative.