摘要
为探究不同建基面形状对沥青混凝土心墙坝竣工期沉降的影响,采用邓肯-张非线性模型对轿子山沥青混凝土心墙坝的竣工期坝体沉降进行了计算。对比依据轿子山大坝实际剖面简化而来的理想算例以及不同坝高的其他典型工程计算结果,发现在数值模拟中计算大坝的最大沉降占比时,应该使用修正后的坝高,即总坝高减去心墙向下延伸的高度,且坝高90~140 m范围内最大沉降比与坝高之间为线性关系。为了进一步验证上述发现的普遍性,又对理想坝型研究了不同坝体建基面形状与心墙及过渡层(向下)延伸段对坝体沉降的影响。结果表明:在相同坝高下,坝体与基岩的交界面与水平方向的夹角越大,坝体最大沉降越小,从基岩受力变形角度初步解释了坝体沉降变化的原因,即是侧向分担了部分坝体自重;心墙及过渡层延伸段的存在会使坝体最大沉降略有减小,但延伸段高度及倾角的变化对坝体沉降的变化影响不明显。建议在坝基开挖的过程中,尽量使上下游建基面与水平面间保持一个尽可能大的夹角,同时将心墙及过渡层向坝基深处延伸一段距离。研究成果可供沥青混凝土心墙坝工程设计和施工参考。
In order to investigate the influence of dam foundation plane shape on dam settlement at the end of construction period of asphalt concrete core wall dams,Duncan-Chang nonlinear model was used to calculate the settlement of the Jiaozishan weathered asphalt concrete core wall dam based on ABAQUS platform.A benchmark model was designed according to practical profiles of Jiaozishan project.After comparing the calculation results of Jiaozishan dam with several similar projects with different dam heights,it was found that a modified dam height should be adopted when calculating the maximum settlement proportion of dams in numerical simulations,that is,the total dam height minus the height of the core wall extending downward,and the relationship between the maximum settlement ratio and the dam height is linear for dams heights of 90~140 m.Furthermore,the influence of foundation plane shape and the downward extension sections of core wall and the transition layer on the settlement of the dam body was studied.The results show that under the same dam height,the larger the angle between the interface of dam and foundation and the horizontal plane,the smaller the maximum settlement of a dam.This phenomenon is explained from the point of bedrock deformation,as part of the weight of dam body is laterally shared by bedrock.The downward extension sections of the core wall and the transition layer will reduce the maximum settlement of the dam slightly,but variation of height and inclination angle of the extension section has no obvious influence on the maximum settlement of the dam.It is suggested that in the excavation of dams foundation,the angle between upper and lower foundation planes and the horizontal plane should be as large as possible,while the extension sections of transition layer and core wall should extend downward for a certain distance,which can reduce the maximum settlement of the dam body.The results can be used as reference for engineering design and construction of asphalt concrete core wall dams.
作者
杜成斌
王作彤
黎亚生
曹庆明
江守燕
杜乐
DU Chengbin;WANG Zuotong;LI Yasheng;CAO Qingming;JIANG Shouyan;DU Le(Department of Engineering Mechanics,Hohai University,Nanjing 211100,China;Yunan Provincial Investigation,Design&Research Institute of Water Conservancy&Electric Power,Kunming 650021,China)
出处
《人民长江》
北大核心
2023年第7期128-133,共6页
Yangtze River
关键词
沥青混凝土心墙坝
建基面形状
坝体最大沉降
邓肯-张模型
asphalt concrete core wall dam
foundation plane shape
maximum settlement of a dam
Duncan-Chang model
