砂土UH模型在土石坝有限元分析中的应用

Application of UH Model for Sands in Finite Element Analysis of Earth Rockfill Dam

利用砂土UH模型对两岔河水库工程心墙堆石坝进行了应力变形三维有限元计算,分析了坝体在竣工期和满蓄期的应力变形特性。结果显示:坝体在竣工期和满蓄期的最大沉降分别为73.8 cm和77.7 cm;坝体在竣工期和满蓄期的大主应力、小主应力均存在拱效应,大主应力的拱效应更显著,心墙内小主应力均为正,未出现拉应力;竣工期和满蓄期防渗墙左右两侧小主应力出现了拉应力区,防渗墙最大拉应力和压应力均在混凝土强度容许范围内。大坝应力变形的计算结果符合心墙堆石坝应力变形一般规律。有限元计算结果均在合理范围内,表明砂土UH模型在土石坝工程中有较好的适用性。

In this paper,the three-dimensional finite element analysis of stress and deformation for the core rockfill dam of Liangchahe Reservoir was performed by UH model for sands.The stress and deformation characteristics of the dam at the completion period and the full storage period are analyzed.The results are as follows.The maximum settlement at completion period and the full storage period was 73.8 cm and 77.7 cm,respectively.There are arching effects in the major principal stress and minor principal stresses of the dam during the completion and full storage period.The arch effect of the major principal stress is more significant.The minor principal stresses in the core wall were positive without any tensile stress.Tensile stress zones appear on the left and right sides of the cut-off wall on the contour lines of minor principal stress during the completion period and the full storage period.The maximum tensile stress of the cutoff wall is within the allowable range of concrete strength.The calculated results of dam stress and deformation basically accord with the general law of stress and deformation of core rockfill dam.The settlement ratio and displacement ratio of the dam measured by many existing earth-rock dams are collected.The finite element calculation results are all within a reasonable range,indicating that the UH model for sands has a good applicability in the earth-rock dam project.