考虑振动碾压引起的颗粒破碎对堆石坝变形计算的影响  

Effects of particle breakage due to vibration compaction on the deformation behavior of rockfill dam

作　　者：刘京茂[1,2] 孔宪京[1,2] 邹德高[1,2] 

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：《水利学报》2015年第8期934-942,共9页Journal of Hydraulic Engineering

基　　金：国家自然科学基金资助项目(51279025;51379028;91215301);新世纪优秀人才支持计划资助(NCET-12-0083)

摘　　要：采用振动碾压填筑堆石坝的过程中,堆石料会发生大量的颗粒破碎,导致粗粒含量减小,细颗粒含量增加,碾压后的级配与设计级配已经不再相同。然而,目前在可研和初设阶段,开展现场碾压试验难度大,而有限元计算大坝变形时采用的堆石料计算参数往往都是设计级配(未考虑碾压)的三轴试验结果。实际上,设计级配的变形模量比碾压后级配(相同密度条件下)的试验结果高。本文参考已建大坝碾压时颗粒破碎的实测结果,采用考虑颗粒破碎的状态相关的堆石料弹塑性本构模型,开展了大坝施工和蓄水的有限元分析研究,计算结果表明:是否考虑碾压过程中的颗粒破碎对大坝变形计算结果有着较大的影响,如果在三轴试验或计算分析中不考虑这个因素,会明显地低估大坝的变形,对大坝的安全性评价是十分不利的,这可能是目前有限元计算的高坝沉降变形比实测偏小的主要原因之一。Taking the thin layer vibration compaction technology in construction of high rockfill dam, large particle breakage may happen with increasing small particles, leading to the difference of particle size distribution from the design. It is hard to conduct rolling compaction test in both feasibility research and design stages, and the design particle size distribution is often used to determine the model parameters. In fact, test results show the modulus of rockfill materials after particle breakage become smaller comparing with original roekfill materials with the same density. Based on the measured data of particle breakage caused by the vibration compaction from established rockfill dams, an advanced elasto-plastic model has been incorporated into nonlinear finite element procedure to study the effects of particle breakage due to vibration compaction on the deformation of rockfill dam during construction and impoundment. It is found that the deformation would he underestimated without considering the effect of particle breakage by vibration compaction, which has unfavorable influence on the safety evaluation of high rockfill dam. The effect of particle breakage should be attracted enough attention in the numerical analysis of high rockfill dam.

关 键 词：颗粒破碎 碾压 孔隙比 堆石坝 临界状态 

分 类 号：TV41[水利工程—水工结构工程]