苗家坝混凝土面板堆石坝三维应力变形分析

基于邓肯—张E-B模型,考虑坝体填筑施工和蓄水过程,并基于大型有限元软件ADINA平台,将三维子模型法应用于苗家坝面板堆石坝应力变形计算,并与监测资料和类似工程的计算结果作了对比分析。结果表明:子模型法能够大大减少网格数量,提高计算效率,面板及接缝的计算精度也有了提高;坝体最大沉降值约占坝高的1.1%,且沉降在竣工期已经基本完成;水库蓄水后,面板拉应力主要集中在面板与周边山体连接处,且最大拉应力均未超过2 MPa,建议通过增加面板的配筋,铺设粉煤灰或者细沙作为保护层来改善面板应力特性。周边缝变形最大值均未超过20 mm,止水结构不会因周边缝的变形过大而破坏。

3-D stress-deformation analysis on Miaojiaba Concrete Face Rockfill Dam

Based on Duncan-Chang E-B model and ADINA，the 3D sub-model method is applied to the calculation on the stress-deformation of the Miaojiaba Concrete Face Rockfill Dam under the consideration of the dam fill-construction and the process of the reservoir impoundment，and then the calculation results are compared with the monitoring data and the calculated results from the other similar projects. The result shows that the sub-model method can largely reduce the quantity of the calculation grids and enhance the calculation efficiency. Moreover，the calculation accuracies of both the face-slab and the joint are increased on a certain scale as well. The calculation indicates that the maximum settlement of the body of Miaojiaba Concrete Face Rockfill Dam is about 1.1% of the dam height and almost ends during the complete period. After the impoundment of the reservoir，the tensile stress of slab face is mainly concentrated at the joint between the face slab and the surrounding mountain with the maximum value less than 2 MPa. It is suggested that the stress characteristics of face slab can be improved by increasing reinforcements and placing fly ash or fine sand as a protection layer.