Study on Treatment of Sand Layers in Foundation of Changheba Gravel Soil Core Wall Rockfill Dam
The 240 m high rockfill dam with gravel soil core of Changheba hydropower station is located on thick alluvium deposit with the height of 60 m to 70 m.The basic earthquake intensity of the site is eight.The medium and silty-fine sand, which are 0.75 ~ 12.5 m thick, are widely distributed in the middle and top part of the alluvium deposit.And the sand layer covers the range of core wall and downstream dam shell.The differential deformation between the sand layer and alluvium deposit, as well as the liquefaction problem, will directly affect the safety of dam.Therefore it is necessary to study the treatment for the widely distributed sand layer.According to the judgments by the geological engineer, the sand layer could liquefy under the natural condition, and the dynamic response analysis result of the dam and foundation by three dimensional FEM proved that the sand layer may locally liquefy under the design earthquake condition.Whats more, the rigid body limit equilibrium analysis indicated the sand layer had bad effect on the seismic stability of the downstream dam slope.Considering the projects scale and importance, it is necessary to deal with the sand layer in dam foundation with special treatment.Seven kinds of treatment are studied, considering the methods of excavation, vibroflotation, jet grouting and static pressure grouting.The results show that the whole sand excavation method is recommended.
Changheba gravel soil core wall rockfill dam dam foundation sand layer
Zhang Dan Wu Xiaoyu Xiong Kun
HydroChina Chengdu Engineering Corporation, Chengdu, 610072, China Changjiang Survey, Planning, Design and Research Co.Wuhan,430010,China
国际会议
昆明
英文
214-222
2013-11-01（万方平台首次上网日期，不代表论文的发表时间）