三峡工程永久船闸中隔墩岩体稳定性研究

STUDY ON THE DEFORMATION SIMULATION OF MIDDLE-ISOLATED PIER OF PERMANENT SHIPLOCK IN THE THREE GORGES PROJECT

运用离散单元法(DEM)与有限单元法(FEM)等数值模拟方法,全面地对长江三峡工程永久船闸二闸室至三闸首部分的中隔墩岩体分别在施工期和运行期的应力分布、变形规律进行了模拟研究。综合分析结果表明:垂直于闸室轴线的水平位移在开挖完成后基本处于稳定状态,而在运行期有所减少;平行于闸室轴线的水平位移总体向下游发展;而垂直方向的位移先表现为回弹,后发生沉降。在中隔墩中上部位出现拉应力区,拉应力值一般小于0.6MPa。

The middle-isolated pier (MIP) is one of the key structures of permanent shiplock of Three Gorges Project on Yangtze River, China. This paper deals with the study on rock mass deformation of middle-isolated pier of the second shiplock under various operation conditions. The numerical simulations using 2-D distinct element method and 3-D finite element method are applied to analyze the stresses distribution and deformation law of rock mass. The comprehensive results can be summarized as follows: (1) the horizontal displacement vertical to axial line of shiplock varies with process of excavation, and is in steady state after excavation; during operation of shiplock, the displacement is slightly decreased; (2) the horizontal displacement parallel to axial line of shiplock is of tendency of developing to downstream; (3) the vertical displacement has the property of which resilient deformation occurs during excavation, and then subsidence with slightly various values takes place in different part of the middle-isolated pier on different operation conditions; and (4) the tensile stresses less than 0.6Mpa are taken place on the upper part of MIP.