Vertical Earth Pressure And Load Reduction Study On The Positive-Buried Culverts

The culvert is a structure used widely in water conservancy and road construction, with the rapid development of China’s infrastructure, the use of the culvert is growing and increasingly complex terrain conditions faced by the construction of culverts. In this context, how to ensure the safe operation of the culvert become very important. In order to prevent the culverts from diseased, the vertical soil pressure at the top of the culvert need to correctly calculate in the design, and use the appropriate load reduction measures to reduce the value of the vertical soil pressure. Rational design is very important to ensure the culvert structural safety and prevent the cause of economic waste.This paper, based on the model experiment, for different boundary conditions of the culvert, analysis the culvert backfill displacement of the settlement and culverts surrounding soil pressure distribution. This paper use ANSYS finite element software to do numerical analysis, research the earth pressure distribution at the top of the culvert as well as the affection of vertical soil pressure through add reducing-load blocks at the top of the culverts, come to some guiding conclusions and recommendations of the culvert design and the reduction. The main research contents and results are as follows:(1) on the basis of model experiment, use the finite element software to analysis fill displacement settlement and earth pressure distribution of rigid culverts on rigid foundation for different filling height under a different section in the form of culverts, the relationship between the size of the coefficient of the vertical earth pressure and the factors for the trench bottom width B, the trench slope m, filling height H.(2) The procedures and precautions in the ANSYS software to analyze the culvert problem, before take load reduction measures, do some compare between the culverts simulation results and the model test results, the results are close, verify the feasibility of calculations using ANSYS finite element model the culvert by force.(3) on the basis of (2), analysis the effect of load reduction through add the reducing-load blocks on both sides of the culvert top, found that:it can indeed play a certain amount of load reduction effect by adding the reducing-load block, it has different load reduction effect for culverts with different height and width of the reducing-load block, the greater the width and the height of the block, the better the effect of load reduction, and found the curve of vertical earth pressure coefficient K at the top of the culverts with different filling height and block size. In addition, the paper also analyzes the affect by changing the elastic modulus of the soil between the two reducing-load block at the top of the culvert to the vertical earth pressure at the top of the culvert, and found that reducing the soil modulus of elasticity to some extent can be further reduced vertical earth pressure, play a better load reduction effect.The focus of this study is using finite element to analysis load reduction effect of reducing the culvert vertical soil pressure by adding reducing-load block, the load reduction way is a new culvert load reduction way, the study has some guiding significance for culvert load reduction. This study is about rigid culverts under the conditions of rigid foundation, corresponds to the complex and diverse culvert conditions, still need further improvement.