摘要
锦屏一级高拱坝最大坝高305 m,是目前在建的世界最高拱坝,其坝址区地质条件复杂,存在断层、蚀变岩脉、层间挤压带、节理裂隙及深部裂缝等各类软弱结构面,坝与地基的整体稳定问题突出。为使坝体达到良好的受力状态,满足拱座的抗滑稳定与变形稳定等要求,工程上采取了大量的加固措施,主要有左坝肩垫座、左右坝肩混凝土网格洞塞置换、刻槽置换、传力洞等。加固处理后,坝肩的整体稳定性以及坝肩坝基的加固效果如何是工程上关心的重要问题。采用两个三维地质力学模型,分别开展了锦屏一级高拱坝在地基未加固和加固两个方案下的坝肩稳定综合法破坏试验研究,对比分析了两个方案下坝与地基的变形分布特性、坝肩坝基失稳的破坏机制和整体稳定安全度。结果表明：坝肩坝基加固处理后,坝体及左、右两岸坝肩变位的对称性得到明显改善,变位量值减小;在相同的超载倍数下,加固方案下两坝肩开裂破坏的范围减小,破坏程度减轻,坝肩破坏失稳的超载系数增大,超载能力得到提高;未加固方案拱坝整体稳定综合法试验安全系数为4.7~5.0,加固方案下安全系数为5.2~6.0,安全度得到明显提高。综合分析认为,锦屏拱坝采用以坝肩垫座、混凝土网格置换洞塞、刻槽置换、传力洞等为主的加固方案对坝肩坝基起到了良好的加固效果。
The JinpingⅠ high arch dam with a height of 305 m is the highest under-construction dam of the world at present. The overall stability of the dam and foundation is a prominent problem due to the complex geological conditions in the dam site area. There are a variety of weak structural planes including faults, alteration veins, inner layer compressed zones, joint fissures and deep cracks. To make the dam be in much better stress state and meet anti-sliding stability and deformation stability of the skewback, a lot of reinforcement measures are adopted in the project. The main reinforcement measures include the left abutment concrete seating replacement, concrete grid and hole plug replacement, grooving replacement, and shearing resistant hole, etc. The overall stability of the dam abutment and the effects of dam abutment reinforcement are the important issues which must be concerned in practical engineering. The method of 3D geomechanical model test is adopted to carry out damage experiments. Two 3D models of JinpingⅠ high arch dam are established respectively. One model is for the unreinforced scheme, and the other one for the reinforced scheme. Deformation distribution characteristics of the dam and foundation, failure mechanism and the overall stability safety degree derived from the two models are comparatively analyzed. The results show that, after reinforced, the symmetry of displacement of the dam body and dam abutments are significantly improved and the displacements are greatly reduced; the crack range and the damage extent of dam abutments are reduced under the same overload ratio, the overload coefficients to failure of the dam abutments are increased and the overload capacity is raised. The safety factors of overall stability obtained with comprehensive method are 4.7-5.0 for unreinforced scheme, and 5.2-6.0 for reinforced scheme. The safety degree is obviously improved through reinforcement measures. Comprehensive analysis shows that the main reinforcement measures, including the left abutment con
出处
《岩土力学》
EI
CAS
CSCD
北大核心
2015年第3期819-826,共8页
Rock and Soil Mechanics
基金
国家自然科学基金资助项目(No.51379139
No.51109152
No.51409179)
四川大学青年教师科研启动基金(No.2012SCU11061)
关键词
锦屏一级高拱坝
地质力学模型
综合法试验
加固效果分析
整体稳定性研究
JinpingⅠhigh arch dam
geomechanical model
comprehensive method test
reinforcement effect analysis
overall stability study
