高拱坝浇筑后河床坝基综合变形模量取值研究

Determining the Comprehensive Deformation Modulus of Foundation after High Dam Constructed

在高拱坝整个施工周期中,坝基岩体经历了开挖、卸荷、固结灌浆、大坝浇筑、加载等过程,其工程特性也必然发生相应变化.高拱坝浇筑完成后,坝基岩体综合变形模量是大坝安全评价、反馈分析等相关研究的重要参数,但该参数往往无法通过现场试验获得.针对这一问题,以溪洛渡水电站高拱坝为例,在坝基岩体地质条件、变形试验资料、钻孔弹模以及坝基岩体变形模量Eo和纵波波速Vp相关关系综合研究的基础上,提出了适用于高拱坝施工完成后坝基综合变形模量取值的思路与方法.采用该方法研究得出溪洛渡高拱坝施工完成后河床坝基综合变形模量为11 ～ 14 MPa.基于该参数进行三维数值模拟得到坝基岩体的变形值与监测成果基本一致,说明这种取值思路与方法是合适的.

The engineering properties of high arch dam＇s foundation rock change inevitably after excavation unloading,consolidation grouting and dam loading.The comprehensive deformation modulus of foundation rock mass is an important index for safety assessment and feedback analysis,but it cannot be obtained by field test.To solve this problem,we conducted researches on the geological condition,deformation test,borehole elastic modulus,and the relation between deformation modulus E0and longitudinal wave velocity Vp with Xiluodu hydropower station as an example.On this basis,we put forward a method of determining the comprehensive deformation modulus of foundation rock mass after the completion of high arch dam construction.The comprehensive deformation modulus of Xiluodu high arch dam foundation after construction completed is between 11-14 MPa.This parameter was used for 3-D numerical simulation,and the simulated deformation was in consistency with monitored deformation,which verified this method is appropriate.