十三陵大坝弹性参数反演与稳定性评价

Back analysis of elastic parameters and stability evaluation of Ming Tombs Reservoir dam

为了掌握十三陵水库大坝在奥运铁人3项赛事期间受动态荷载和环境条件影响的力学效应和坝体的稳定性,基于奥运建筑荷载(建造看台和临时设施)响应的现场实测变形信息,利用正交设计反分析方法,对坝体黏土斜墙、砾质粗砂和砂质垫层3个主要土层的弹性模量进行了反演,采用反演得到的综合弹性模量对坝体受奥运建筑荷载及赛期动态加卸载过程进行了数值仿真分析。结果表明,大坝在赛期产生的最大沉降量在7.4 mm左右,最大水平位移不超过1 mm;大坝始终处于安全稳定状态,无剪切破坏和张拉破坏现象。现场坝坡测点变形监测值与数值模拟结果比较接近,表明基于实测位移反演参数的数值模拟能超前做出科学预测和定量评价。

In order to know the mechanical effect and the stability of the Ming Tombs Reservoir dam influenced by the dynamic loading and the environment condition during the Olympic game,the optimum elastic modulus scheme of the inclined clay wall,gravelly coarse sand and sandy cushion layer,which are the three main soil layers of the dam,is back analyzed by utilizing the orthogonal experiment design and based on in-situ measured deformation from the load response of the Olympic construction,including the spectator stand and the temporary facilities.The numerical simulations of the processes of initial Olympic construction and the dynamic loading-unloading cycles during the Olympic game are carried out by utilizing the obtained optimum parameters.The results show that the maximum settlement produced in the dam during the game is about 7.4 mm;and the maximum horizontal displacement is not over 1 mm;and the dam is safe and stable during the game and after the game;and the shear damage and tensile cracks do not appear.The monitored deformations during the game are close to the results of the numerical simulations,which indicates that the numerical simulations based on the parameters obtained by back analysis of in-situ measured displacements can make the scientific prediction and the quantitative evaluation for dams.