Study On Stress Distribution In High Fill Culvert Foundation Soil

In order to adapt to the complex terrain of gullies in mountainous regions,high-filled and deep-digging roadbeds are also increasing.In order to meet the requirements of drainage,high-fill culverts are generally built in low-lying areas.While the number of high-filled culverts is increasing,the structural design and foundation treatment methods for high-fill culverts at home and abroad are still under development,and related theories are still not perfect,resulting in continuous occurrence of culvert diseases.Therefore,research on high-fill culverts has important engineering significance.In this paper,using indoor model tests,finite element numerical analysis and theoretical calculation methods to study the main factors affecting the stress in high-fill culvert foundation soil.The specific content is as follows:(1)Applying similarity theory,design and complete three groups of model tests,The upper culvert of the simulated culvert is loaded step by step with jacks.The culvert foundation is filled with layers of soil in the model box.The culvert side fill is simulated with a certain weight of sandbags and the earth pressure is buried to measure the stress in the ground soil.The results showed that,as the filling height increases,the stress in the ground soil gradually increases.When changing the fill height of the culvert,the ground stress growth rate at the same point first increases and then decreases.(2)Based on the ABAQUS finite element analysis software,a model was established based on the test soil parameters,and the stress in the ground soil was numerically simulated,and the simulation results were verified with the test results.Tweleve models were established for analysis by changing the structure of culverts,the basic forms of culverts,and the filling heights of culverts.The results show,culvert structural form has less influence on the stress in foundation soil;Because the separated foundation allows positive upward displacement of the foundation soil below the middle of the foundation,the stress concentration of the monolithic foundation is relieved,from the first floor at the base of the foundation,the foundation of the foundation is increased by approximately 20.9% from the foundation stress of the separated foundation;When the culvert filling is 0.3m,the stress growth rate in the foundation soil is maximum;When the culvert height at the top of the culvert is the same and the filling height at the culvert side is also the same,the stress growth rate is highest in the ground soil that is far from the base of the foundation in the first layer of the foundation.(3)Considering the stress concentration effect and the stress diffusion principle,the joint action of the Buchner's Nest method and the soil column method is used to solve the stress in the foundation soil under the action of culvert backfill.Through calculation,it can be seen that when the culvert backfill is below 0.4m,the method of this paper can be used to calculate the stress in the foundation soil of high fill culverts.