3-D FEM Analysis On Culvert Under Earth Dam

The culvert has been international accepted as lifeline engineering, its failure would cause the serious damage. In hydraulic engineering projects, the phenomena of cracking and seepage failure appeared usually in a considerable number of culverts under earth dam. This shows that the current calculation of the settlement and the earth pressure on culvert is still insufficient, it is necessary to make a further discussion on how to accurately calculate the earth pressure on culvert and how to reasonably control the uneven settlement.There are two main reasons for the culvert cracking. The article simulates the construction process of the culvert under earth dam in the form of three-dimensional finite element. The main works and achievements are as follows:1) To gather a mass of data on the earth pressure and the settlement of culvert, to collate and study the advantages and disadvantages of various earth pressure calculation method, compared with the measured data to find a more realistic calculation method;2) According to the disadvantage of the calculation of the settlement and the earth pressure on culvert, In order to better reflect the uneven settlement of the culvert, this paper consider the parting of culvert, set up frictional contact in contact surface in three-dimensional finite element model. The result shows that the parting of culvert is beneficial to the stress of the culvert, when it has no influence on the settlement of whole culvert;3) On the basis of balancing initial ground stress, the paper uses the software ABAQUS to analyze culvert under the dam in the way of three-dimensional finite element. The result shows that the force and the settlement of culvert are related to the dam body cross-section, and the values of the highest department of dam reach the maximum. In addition, the result also shows that the vertical earth pressure of the top of conduit distributes in the shape of "u", and the minimum value of earth pressure is the most close to the value of the place which locates in the center of top of culvert; 4) By change material parameters, to study the effect of these factors on earth pressure and settlement. The result shows that the coefficient of earth pressure decreased with the increase of filling height and elastic modulus of fill earth, while it increased with the increase of internal friction angle and elastic modulus of foundation soil, but it is unaffected with soil cohesion. In addition, the settlement of culvert increased with the increase of filling height, whereas it decreased with the increase of elastic modulus of fill earth and foundation soil, but it is unaffected with internal friction angle and soil cohesion.