Review and Suggestions on CFRD Construction
Since 1985,starting from the Guanmenshan dam (50 m high) and the Xibeikou dam (100 m high),China has constructed more than 170 CFRDs with the height of more than 30 m,among which over 45 are above 100 m.It has also constructed a series of 200 m-level high dams such as Tianshengqiao I (178 m),Hongjiadu (179.5 m),Sanbanxi (185.5 m) and Shuibuya (233 m),etc.Moreover,250-300 m-level high dams such as Gushui,Rumei and Cihaxia are undergone the preparatory work of survey and design.Despite of lack corresponding project reference in the 1990s,the designers and constructors,through hard scientific research and development of a number of new technologies,have successfully constructed the 200 m high Tianshengqiao dam of huge scale and with complex technologies,for example,the material in the cushion and transitional layers met the demand of filter and seepage stability;cohesionless particles were used at the top of peripheral joints for filter (self-healing waterstop) ;complete monitoring projects were established and adequate data were available,full use of the excavated hard rock and soft rock for dam construction and overflowing on the dam surface during construction were achieved. The defects after operation such as large dam deformation,cracks in the slope surface of the cushion material,many cracks and dislocation in the slabs as well as the partial slab rupture of the vertical joints were properly handled. The dam was stable and in safe operation.It was concluded that the high CFRDs still had large deformation after its commissioning.Great importance should be attached to the creep deformation properties of the hard and soft rocks,deformation effects and dam deformation control,especially the uneven deformation of the dam body,which could provide crucial experience for high dam construction. The construction of a group of 200 m high dams and dams above 100 m has developed further the technology in terms of wide use of dam construction material;seepage stability and deformation control of the dam body;improvement of zoning scope of main and downstream rockfills;balance of the filling elevation of the dam body;gradual improvement of compaction standard;coordination of the placement time of the slab and control over the settlement period and its rate;crack prevent of the slabs and plinth;development of waterstop materials of peripheral joints and vertical joints as well as new structures;construction of the plinth on the deep sand-gravel overburdens;effective drainage of reverse seepage in the dam body;transformation of unfavorable terrain using high-toe walls;development of superlong observation equipment for study of high dam deformation;analysis on three-dimensional finite element method,the geotechnical centrifugal model test,earthquake resistance measures;reasonable setting of reservoir emptying structures;application of heavy vibrating roller and impact roller and further development in compaction quality control by the added mass method and GPS positioning technology.Constant accumulation of high dam technology and significant improvement in dam construction provide empirical,rational and regular technical information and reference results for the construction of super-high dams between 200-300 m with gratifying progress.It is suggested that the dam materials must be carefully investigated and tested and the strictly selected dam materials should be filled in the dam in accordance with the design specified zone;the compression modulus,as an important indicator of dam quality should be included in design standard;high dams should be constructed with reservoir emptying structures.It is expected that according to the requirements of good quality,significant efficiency and reasonable construction time,the engineering experience would be combined with the problems encountered to gain progress and development,making great contributions to the development of high CFRDs.
high CFRD hard rock soft rock deformation joint water stop compaction quality compression modulus
Zhao Zengkai
Water Resources & Hydro-power Planning & Design General Institute,Beijing 100011,China
国际会议
The 1st International Symposium on Rockfill Dams(第一届堆石坝国际研讨会)
成都
英文
3-14
2009-10-18（万方平台首次上网日期，不代表论文的发表时间）