西域砾岩砂砾料沥青混凝土心墙坝湿化变形数值分析  

Numerical analysis of wetting-induced deformation of Xiyu conglomerate gravel dam with asphalt concrete core

作　　者：邹德高[1,2] 杨小龙[2] 刘京茂[2] 孔宪京[1,2] 周扬[2] 

机构地区：[1]大连理工大学海岸和近海工程国家重点实验室,辽宁大连116024 [2]大连理工大学水利工程学院,辽宁大连116024

出　　处：《大连理工大学学报》2015年第6期605-611,共7页Journal of Dalian University of Technology

基　　金：国家自然科学基金资助项目(51279025;51379028);新世纪优秀人才支持计划资助项目(NCET-12-0083)

摘　　要：我国新疆地区广泛使用西域砾岩砂砾料作为筑坝材料,由于西域砾岩砂砾料浸水后易软化、崩解,大坝蓄水后的湿化变形分析成为工程界广泛关注的问题.联合广义塑性模型和西域砾岩砂砾料湿化模型,对某沥青混凝土心墙坝进行了湿化变形有限元分析.结果表明:广义塑性模型和西域砾岩砂砾料湿化模型能够很好地反映大坝湿化变形及应力分布规律;上游蓄水湿化使坝体向上游方向的水平位移和沉降都增大,最大水平位移由竣工时的1.5cm增至22cm左右,最大竖向沉降由竣工时的0.17%坝高增至0.53%坝高,筑坝料的湿陷使心墙的变形也增大;西域砾岩砂砾料的湿化变形明显大于花岗岩堆石料,最大竖向沉降是花岗岩堆石料的近3倍,其湿化造成坝顶上游侧出现局部拉应力区,有可能导致坝顶出现裂缝.因此,在新疆干旱地区采用西域砾岩砂砾料筑坝时考虑蓄水时的湿化影响是十分必要的.Gravel from Xiyu conglomerate, which is easily softened and disintegrated when inundated,is widely used as filling materials of dam in Xinjiang region of China.Therefore,the wetting deformation problem of earth dams during the reservoir filling is a serious concern in engineering field.The generalized plastic model and wetting model based on the wetting tests of Xiyu conglomerate gravel are incorporated into procedure,and numerical analyses of wetting-induced collapse of an asphalt concrete core dam are performed.Analytical results show that the generalized plastic model combined with the wetting model can well reflect the wetting deformation and stress distribution of the dam.Wetting collapse that happened in the upstream shell increases the horizontal displacement toward the upstream direction and settlement significantly,the maximum horizontal displacement increases from 1.5cm to as much as 22 cm and the maximum settlement increases from0.17%to 0.53% of the dam height,which leads to the significant deformation of the asphalt concrete core.Wetting deformation of Xiyu conglomerate gravel is apparently larger than the granite rockfill,for the maximum settlement is nearly 3times of that of the granite rockfill.Particularly,small tensile stress is observed around the dam crest,which may result in cracks nearby.Therefore,close attention should be paid to the wetting deformation during reservoir impoundment for dams filled with Xiyu conglomerate gravel in Xinjiang arid region.

关 键 词：广义塑性模型 湿化变形 西域砾岩砂砾料 数值分析 

分 类 号：TU411.3[建筑科学—岩土工程]