摘要
严寒地区碾压混凝土坝越冬层面上、下游侧易出现水平裂缝。在越冬层面上、下游侧设置人工短缝,采用接触单元模拟人工短缝,考虑人工短缝切向接触摩擦力,并以扩展拉格朗日乘子法作为人工短缝的法向接触协调条件,采用三维有限元仿真计算程序对人工短缝的应力释放效果进行计算分析。计算结果表明,设置人工短缝对越冬层面坝轴线方向和顺水流方向温度应力影响较小,但越冬层面上、下游侧铅直向温度应力最大值大幅降低,应力释放效果显著;越冬层面中部铅直向温度应力虽有所增大,但仍未超过碾压混凝土的抗拉强度。在严寒地区碾压混凝土坝越冬层面上、下游侧设置人工短缝,配合缝内的止水及缝末端的槽钢,保证人工短缝的稳定性,能有效避免越冬层面附近上、下游侧出现无序的裂缝。
In severe cold area,horizontal crack easily appears in upstream and downstream of RCC dam overwintering face.Artificial short slit at the downstream side can be set on the overwintering face,and simulated with contact element in considering the tangential friction forces and extended Lagrange multiplier method as normal contact coordination conditions.The effect of stress release is calculated and analyzed with 3D finite element program.The results show that setting artificial slit has a little effect upon the temperature stress of the dam axis and flow direction,but on the vertical direction of overwintering face,the maximum of temperature stress is dramatically reduced,the effect of stress release is remarkable.On the other hand,the vertical temperature stress of central overwintering face has increased,but not still exceeded the tensile strength of roller compacted concrete.Therefore,in severe cold area,setting artificial short slit in the upstream and downstream of RCC dam overwintering face with water stop in the joint and channel steal at end of the joint can satisfy the stability,and effectively avoid the disordered crack appeared on the upstream and downstream of RCC dam overwintering face.
出处
《西安理工大学学报》
CAS
北大核心
2013年第1期38-44,共7页
Journal of Xi'an University of Technology
基金
国家自然科学基金项目(51009116)
中央财政支持地方高校发展专项基金资助项目(106-5X1205)
陕西省重点学科建设专项基金资助项目(106-00X903)
关键词
严寒地区
碾压混凝土坝
越冬层面
人工短缝
severe cold area
RCC dam
overwintering face
artificial short slit
