Numerical Simulation Analysis Of Earth-Rock Dam And Optimization Of Cut-off Wall Due To Secondary Development

As one of the oldest type of dam, the earth-rock dam has the advantages of esay to construction, making use of local materials and capability to fit for all the geologic and climatic conditions, and these make it to be the most important type of dam in the hydropower engineering. Study only on the seepage and stabilization has not met the requirements nowadays with the height increasing of dam, the stress and displacement compute become necessary in the design. The precision of compute depends on both the calculation method and the constitutive model. Along with the development of the technology and support of the computer, finite element method(FEM) is the most accurate and effective method to compute the stress and displacement of earth-rock dam; Duncan-Chang E-B model can simulate most of the soil characteristics, and the results meet the requirement, so it is widely used in the engineerings.This article based on the large FEM analysis software ABAQUS successfully realizing Duncan-Chang E-B model in it using its convenient and flexible secondary development connection, and used the active-kill method to simulate the construction process of the dam, and also established the result post-processing procedure to correct the displacement. Comparing the result of triaxial compression test simulation with the experiment data, we can see that they are in high degree of coincidence. In addition, through an example of 100 meter height dam, we can see that the maximum vertical displacement in construction period is 0.39 percent of dam height and it located in the middle height of the dam, and the stress distribution was obvious which corresponded to the ordinary rules of earth-rock dam.CAD/CAE integrated analysis was used in this article in a mixed dam engineering by the procedure and simulated the construction process of the concrete structure and earth-rock dam, and the result indicated that the nolinear and material partition of the dam, influence of dam subsidence by construction and storage were fully reflected.Concrete cut-off wall is an important measure in foundation anti-seepage in earth-rock dam, and its performance directly relates to the engineering safety. In this article optimization of construction plan was studied, and it showed that filling the dam before the cut-off wall could improve stress in the wall significantly. In addition optimization of the material was studied, it indicated that the soil-concrete could lower stress in the cut-off wall in the overburden which has weaker parameter, and then it could enhance the engineering security.